//! Ollama provider built on top of the `ollama-rs` crate.
use std::{
    collections::{HashMap, HashSet},
    convert::TryFrom,
    env,
    net::{SocketAddr, TcpStream},
    pin::Pin,
    process::Command,
    sync::{Arc, OnceLock},
    time::{Duration, Instant, SystemTime},
};

use anyhow::anyhow;
use futures::{Stream, StreamExt, future::BoxFuture, future::join_all};
use log::{debug, warn};
use ollama_rs::{
    Ollama,
    error::OllamaError,
    generation::chat::{
        ChatMessage as OllamaMessage, ChatMessageResponse as OllamaChatResponse,
        MessageRole as OllamaRole, request::ChatMessageRequest as OllamaChatRequest,
    },
    generation::tools::{ToolCall as OllamaToolCall, ToolCallFunction as OllamaToolCallFunction},
    headers::{AUTHORIZATION, HeaderMap, HeaderValue},
    models::{LocalModel, ModelInfo as OllamaModelInfo, ModelOptions},
};
use reqwest::{Client, StatusCode, Url};
use serde::Deserialize;
use serde_json::{Map as JsonMap, Value, json};
use tokio::{sync::RwLock, time::sleep};

#[cfg(test)]
use std::sync::{Mutex, MutexGuard};
#[cfg(test)]
use tokio_test::block_on;
use uuid::Uuid;

use crate::{
    Error, Result,
    config::{
        GeneralSettings, LEGACY_OLLAMA_CLOUD_API_KEY_ENV, LEGACY_OWLEN_OLLAMA_CLOUD_API_KEY_ENV,
        OLLAMA_API_KEY_ENV, OLLAMA_CLOUD_BASE_URL, OLLAMA_CLOUD_ENDPOINT_KEY, OLLAMA_MODE_KEY,
    },
    llm::{LlmProvider, ProviderConfig},
    mcp::McpToolDescriptor,
    model::{DetailedModelInfo, ModelDetailsCache, ModelManager},
    types::{
        ChatParameters, ChatRequest, ChatResponse, Message, ModelInfo, Role, TokenUsage, ToolCall,
    },
};

const DEFAULT_TIMEOUT_SECS: u64 = 120;
const DEFAULT_MODEL_CACHE_TTL_SECS: u64 = 60;
pub(crate) const CLOUD_BASE_URL: &str = OLLAMA_CLOUD_BASE_URL;
const LOCAL_PROBE_TIMEOUT_MS: u64 = 200;
const LOCAL_PROBE_TARGETS: &[&str] = &["127.0.0.1:11434", "[::1]:11434"];
const LOCAL_TAGS_TIMEOUT_STEPS_MS: [u64; 3] = [400, 800, 1_600];
const LOCAL_TAGS_RETRY_DELAYS_MS: [u64; 2] = [150, 300];
const HEALTHCHECK_TIMEOUT_MS: u64 = 1_000;

static LEGACY_CLOUD_ENV_WARNING: OnceLock<()> = OnceLock::new();

fn warn_legacy_cloud_env(var_name: &str) {
    if LEGACY_CLOUD_ENV_WARNING.set(()).is_ok() {
        warn!(
            "Using legacy Ollama Cloud API key environment variable `{var_name}`. \
             Prefer configuring OLLAMA_API_KEY; legacy names remain supported but may be removed."
        );
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
enum OllamaMode {
    Local,
    Cloud,
}

impl OllamaMode {
    fn default_base_url(self) -> &'static str {
        match self {
            Self::Local => "http://localhost:11434",
            Self::Cloud => CLOUD_BASE_URL,
        }
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum ScopeAvailability {
    Unknown,
    Available,
    Unavailable,
}

impl ScopeAvailability {
    fn as_str(self) -> &'static str {
        match self {
            ScopeAvailability::Unknown => "unknown",
            ScopeAvailability::Available => "available",
            ScopeAvailability::Unavailable => "unavailable",
        }
    }
}

#[derive(Debug, Clone)]
struct ScopeSnapshot {
    models: Vec<ModelInfo>,
    fetched_at: Option<Instant>,
    availability: ScopeAvailability,
    last_error: Option<String>,
    last_checked: Option<Instant>,
    last_success_at: Option<Instant>,
}

impl Default for ScopeSnapshot {
    fn default() -> Self {
        Self {
            models: Vec::new(),
            fetched_at: None,
            availability: ScopeAvailability::Unknown,
            last_error: None,
            last_checked: None,
            last_success_at: None,
        }
    }
}

impl ScopeSnapshot {
    fn is_stale(&self, ttl: Duration) -> bool {
        match self.fetched_at {
            Some(ts) => ts.elapsed() >= ttl,
            None => !self.models.is_empty(),
        }
    }

    fn last_checked_age_secs(&self) -> Option<u64> {
        self.last_checked.map(|instant| instant.elapsed().as_secs())
    }

    fn last_success_age_secs(&self) -> Option<u64> {
        self.last_success_at
            .map(|instant| instant.elapsed().as_secs())
    }
}

#[derive(Clone)]
struct ScopeHandle {
    client: Ollama,
    http_client: Client,
    base_url: String,
}

impl ScopeHandle {
    fn new(client: Ollama, http_client: Client, base_url: impl Into<String>) -> Self {
        Self {
            client,
            http_client,
            base_url: base_url.into(),
        }
    }

    fn api_url(&self, endpoint: &str) -> String {
        build_api_endpoint(&self.base_url, endpoint)
    }
}

#[derive(Debug, Deserialize)]
struct TagsResponse {
    #[serde(default)]
    models: Vec<LocalModel>,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum ProviderVariant {
    Local,
    Cloud,
}

impl ProviderVariant {
    fn supports_local(self) -> bool {
        matches!(self, ProviderVariant::Local)
    }

    fn supports_cloud(self) -> bool {
        matches!(self, ProviderVariant::Cloud)
    }
}

#[derive(Debug)]
struct OllamaOptions {
    provider_name: String,
    variant: ProviderVariant,
    mode: OllamaMode,
    base_url: String,
    request_timeout: Duration,
    model_cache_ttl: Duration,
    api_key: Option<String>,
    cloud_endpoint: Option<String>,
}

impl OllamaOptions {
    fn new(
        provider_name: impl Into<String>,
        variant: ProviderVariant,
        mode: OllamaMode,
        base_url: impl Into<String>,
    ) -> Self {
        Self {
            provider_name: provider_name.into(),
            variant,
            mode,
            base_url: base_url.into(),
            request_timeout: Duration::from_secs(DEFAULT_TIMEOUT_SECS),
            model_cache_ttl: Duration::from_secs(DEFAULT_MODEL_CACHE_TTL_SECS),
            api_key: None,
            cloud_endpoint: None,
        }
    }

    fn with_general(mut self, general: &GeneralSettings) -> Self {
        self.model_cache_ttl = general.model_cache_ttl();
        self
    }
}

/// Ollama provider implementation backed by `ollama-rs`.
#[derive(Debug)]
pub struct OllamaProvider {
    provider_name: String,
    variant: ProviderVariant,
    mode: OllamaMode,
    client: Ollama,
    http_client: Client,
    base_url: String,
    request_timeout: Duration,
    api_key: Option<String>,
    cloud_endpoint: Option<String>,
    model_manager: ModelManager,
    model_details_cache: ModelDetailsCache,
    model_cache_ttl: Duration,
    scope_cache: Arc<RwLock<HashMap<OllamaMode, ScopeSnapshot>>>,
}

fn configured_mode_from_extra(config: &ProviderConfig) -> Option<OllamaMode> {
    config
        .extra
        .get(OLLAMA_MODE_KEY)
        .and_then(|value| value.as_str())
        .and_then(|value| match value.trim().to_ascii_lowercase().as_str() {
            "local" => Some(OllamaMode::Local),
            "cloud" => Some(OllamaMode::Cloud),
            _ => None,
        })
}

fn is_explicit_local_base(base_url: Option<&str>) -> bool {
    base_url
        .and_then(|raw| Url::parse(raw).ok())
        .and_then(|parsed| parsed.host_str().map(|host| host.to_ascii_lowercase()))
        .map(|host| host == "localhost" || host == "127.0.0.1" || host == "::1")
        .unwrap_or(false)
}

fn is_explicit_cloud_base(base_url: Option<&str>) -> bool {
    base_url
        .map(|raw| {
            let trimmed = raw.trim_end_matches('/');
            trimmed == CLOUD_BASE_URL || trimmed.starts_with("https://ollama.com/")
        })
        .unwrap_or(false)
}

#[cfg(test)]
static PROBE_OVERRIDE: OnceLock<Mutex<Option<bool>>> = OnceLock::new();

#[cfg(test)]
static TAGS_OVERRIDE: OnceLock<Mutex<Vec<std::result::Result<Vec<LocalModel>, Error>>>> =
    OnceLock::new();

#[cfg(test)]
static TAGS_OVERRIDE_GATE: OnceLock<Mutex<()>> = OnceLock::new();

#[cfg(test)]
static PROBE_OVERRIDE_GATE: OnceLock<Mutex<()>> = OnceLock::new();

#[cfg(test)]
fn set_probe_override(value: Option<bool>) {
    let guard = PROBE_OVERRIDE.get_or_init(|| Mutex::new(None));
    *guard.lock().expect("probe override mutex poisoned") = value;
}

#[cfg(test)]
fn probe_override_value() -> Option<bool> {
    PROBE_OVERRIDE
        .get_or_init(|| Mutex::new(None))
        .lock()
        .expect("probe override mutex poisoned")
        .to_owned()
}

#[cfg(test)]
fn set_tags_override(
    sequence: Vec<std::result::Result<Vec<LocalModel>, Error>>,
) -> TagsOverrideGuard {
    let gate = TAGS_OVERRIDE_GATE
        .get_or_init(|| Mutex::new(()))
        .lock()
        .expect("tags override gate mutex poisoned");

    let store = TAGS_OVERRIDE.get_or_init(|| Mutex::new(Vec::new()));
    {
        let mut guard = store.lock().expect("tags override mutex poisoned");
        guard.clear();
        for item in sequence.into_iter().rev() {
            guard.push(item);
        }
    }
    TagsOverrideGuard { gate: Some(gate) }
}

#[cfg(test)]
fn pop_tags_override() -> Option<std::result::Result<Vec<LocalModel>, Error>> {
    TAGS_OVERRIDE
        .get_or_init(|| Mutex::new(Vec::new()))
        .lock()
        .expect("tags override mutex poisoned")
        .pop()
}

#[cfg(test)]
struct TagsOverrideGuard {
    gate: Option<MutexGuard<'static, ()>>,
}

#[cfg(test)]
impl Drop for TagsOverrideGuard {
    fn drop(&mut self) {
        if let Some(store) = TAGS_OVERRIDE.get() {
            let mut guard = store.lock().expect("tags override mutex poisoned");
            guard.clear();
        }
        self.gate.take();
    }
}

fn probe_default_local_daemon(timeout: Duration) -> bool {
    #[cfg(test)]
    {
        if let Some(value) = probe_override_value() {
            return value;
        }
    }

    for target in LOCAL_PROBE_TARGETS {
        if let Ok(address) = target.parse::<SocketAddr>() {
            if TcpStream::connect_timeout(&address, timeout).is_ok() {
                return true;
            }
        }
    }
    false
}

impl OllamaProvider {
    /// Create a provider targeting an explicit base URL (local usage).
    pub fn new(base_url: impl Into<String>) -> Result<Self> {
        let input = base_url.into();
        let normalized =
            normalize_base_url(Some(&input), OllamaMode::Local).map_err(Error::Config)?;
        Self::with_options(OllamaOptions::new(
            "ollama_local",
            ProviderVariant::Local,
            OllamaMode::Local,
            normalized,
        ))
    }

    /// Construct a provider from configuration settings.
    pub fn from_config(
        provider_id: &str,
        config: &ProviderConfig,
        general: Option<&GeneralSettings>,
    ) -> Result<Self> {
        let provider_type = config.provider_type.trim().to_ascii_lowercase();
        let register_name = {
            let candidate = provider_id.trim();
            if candidate.is_empty() {
                if provider_type.is_empty() {
                    "ollama".to_string()
                } else {
                    provider_type.clone()
                }
            } else {
                candidate.replace('-', "_")
            }
        };

        let variant = if register_name == "ollama_cloud" || provider_type == "ollama_cloud" {
            ProviderVariant::Cloud
        } else {
            ProviderVariant::Local
        };

        let mut api_key = resolve_api_key(config.api_key.clone())
            .or_else(|| resolve_api_key_env_hint(config.api_key_env.as_deref()))
            .or_else(|| env_var_non_empty(OLLAMA_API_KEY_ENV))
            .or_else(|| {
                warn_legacy_cloud_env(LEGACY_OLLAMA_CLOUD_API_KEY_ENV);
                env_var_non_empty(LEGACY_OLLAMA_CLOUD_API_KEY_ENV)
            })
            .or_else(|| {
                warn_legacy_cloud_env(LEGACY_OWLEN_OLLAMA_CLOUD_API_KEY_ENV);
                env_var_non_empty(LEGACY_OWLEN_OLLAMA_CLOUD_API_KEY_ENV)
            });
        let api_key_present = api_key.is_some();

        let configured_mode = configured_mode_from_extra(config);
        let configured_mode_label = config
            .extra
            .get(OLLAMA_MODE_KEY)
            .and_then(|value| value.as_str())
            .unwrap_or("auto");
        let base_url = config.base_url.as_deref();
        let base_is_local = is_explicit_local_base(base_url);
        let base_is_cloud = is_explicit_cloud_base(base_url);
        let _base_is_other = base_url.is_some() && !base_is_local && !base_is_cloud;

        let mut local_probe_result = None;
        let cloud_endpoint = config
            .extra
            .get(OLLAMA_CLOUD_ENDPOINT_KEY)
            .and_then(Value::as_str)
            .map(normalize_cloud_endpoint)
            .transpose()
            .map_err(Error::Config)?;

        if matches!(variant, ProviderVariant::Local) && configured_mode.is_none() {
            let probe = probe_default_local_daemon(Duration::from_millis(LOCAL_PROBE_TIMEOUT_MS));
            local_probe_result = Some(probe);
        }

        let mode = match variant {
            ProviderVariant::Local => OllamaMode::Local,
            ProviderVariant::Cloud => OllamaMode::Cloud,
        };

        if matches!(variant, ProviderVariant::Cloud) {
            if !api_key_present {
                return Err(Error::Config(
                    "Ollama Cloud API key not configured. Set providers.ollama_cloud.api_key or export OLLAMA_API_KEY (legacy: OLLAMA_CLOUD_API_KEY / OWLEN_OLLAMA_CLOUD_API_KEY)."
                        .into(),
                ));
            }
        }

        let base_candidate = match mode {
            OllamaMode::Local => base_url,
            OllamaMode::Cloud => {
                if base_is_cloud {
                    base_url
                } else {
                    Some(CLOUD_BASE_URL)
                }
            }
        };

        let normalized_base_url =
            normalize_base_url(base_candidate, mode).map_err(Error::Config)?;

        let mut options = OllamaOptions::new(
            register_name.clone(),
            variant,
            mode,
            normalized_base_url.clone(),
        );
        options.cloud_endpoint = cloud_endpoint.clone();

        if let Some(timeout) = config
            .extra
            .get("timeout_secs")
            .and_then(|value| value.as_u64())
        {
            options.request_timeout = Duration::from_secs(timeout.max(5));
        }

        if let Some(cache_ttl) = config
            .extra
            .get("model_cache_ttl_secs")
            .and_then(|value| value.as_u64())
        {
            options.model_cache_ttl = Duration::from_secs(cache_ttl.max(5));
        }

        options.api_key = api_key.take();

        if let Some(general) = general {
            options = options.with_general(general);
        }

        debug!(
            "Resolved Ollama provider '{}': mode={:?}, base_url={}, configured_mode={}, api_key_present={}, local_probe={}",
            register_name,
            mode,
            normalized_base_url,
            configured_mode_label,
            if options.api_key.is_some() {
                "yes"
            } else {
                "no"
            },
            match local_probe_result {
                Some(true) => "success",
                Some(false) => "failed",
                None => "skipped",
            }
        );

        Self::with_options(options)
    }

    fn with_options(options: OllamaOptions) -> Result<Self> {
        let OllamaOptions {
            provider_name,
            variant,
            mode,
            base_url,
            request_timeout,
            model_cache_ttl,
            api_key,
            cloud_endpoint,
        } = options;

        let api_key_ref = api_key.as_deref();
        let (ollama_client, http_client) =
            build_client_for_base(&base_url, request_timeout, api_key_ref)?;

        let scope_cache = {
            let mut initial = HashMap::new();
            initial.insert(OllamaMode::Local, ScopeSnapshot::default());
            initial.insert(OllamaMode::Cloud, ScopeSnapshot::default());
            Arc::new(RwLock::new(initial))
        };

        Ok(Self {
            provider_name: provider_name.trim().to_ascii_lowercase(),
            variant,
            mode,
            client: ollama_client,
            http_client,
            base_url: base_url.trim_end_matches('/').to_string(),
            request_timeout,
            api_key,
            cloud_endpoint,
            model_manager: ModelManager::new(model_cache_ttl),
            model_details_cache: ModelDetailsCache::new(model_cache_ttl),
            model_cache_ttl,
            scope_cache,
        })
    }

    fn api_url(&self, endpoint: &str) -> String {
        build_api_endpoint(&self.base_url, endpoint)
    }

    fn local_base_url() -> &'static str {
        OllamaMode::Local.default_base_url()
    }

    fn scope_key(scope: OllamaMode) -> &'static str {
        match scope {
            OllamaMode::Local => "local",
            OllamaMode::Cloud => "cloud",
        }
    }

    fn supports_local_scope(&self) -> bool {
        self.variant.supports_local()
    }

    fn supports_cloud_scope(&self) -> bool {
        self.variant.supports_cloud()
    }

    fn build_local_client(&self) -> Result<Option<ScopeHandle>> {
        if !self.supports_local_scope() {
            return Ok(None);
        }

        if matches!(self.mode, OllamaMode::Local) {
            return Ok(Some(ScopeHandle::new(
                self.client.clone(),
                self.http_client.clone(),
                self.base_url.clone(),
            )));
        }

        let (client, http_client) =
            build_client_for_base(Self::local_base_url(), self.request_timeout, None)?;
        Ok(Some(ScopeHandle::new(
            client,
            http_client,
            Self::local_base_url(),
        )))
    }

    fn build_cloud_client(&self) -> Result<Option<ScopeHandle>> {
        if !self.supports_cloud_scope() {
            return Ok(None);
        }

        if matches!(self.mode, OllamaMode::Cloud) {
            return Ok(Some(ScopeHandle::new(
                self.client.clone(),
                self.http_client.clone(),
                self.base_url.clone(),
            )));
        }

        let api_key = match self.api_key.as_deref() {
            Some(key) if !key.trim().is_empty() => key,
            _ => return Ok(None),
        };

        let endpoint = self.cloud_endpoint.as_deref().unwrap_or(CLOUD_BASE_URL);

        let (client, http_client) =
            build_client_for_base(endpoint, self.request_timeout, Some(api_key))?;
        Ok(Some(ScopeHandle::new(client, http_client, endpoint)))
    }

    async fn cached_scope_models(&self, scope: OllamaMode) -> Option<Vec<ModelInfo>> {
        let cache = self.scope_cache.read().await;
        cache.get(&scope).and_then(|entry| {
            if entry.availability == ScopeAvailability::Unknown {
                return None;
            }

            if entry.models.is_empty() {
                return None;
            }

            if let Some(ts) = entry.fetched_at {
                if ts.elapsed() < self.model_cache_ttl {
                    return Some(entry.models.clone());
                }
            }

            // Fallback to last good models even if stale; UI will mark as degraded
            Some(entry.models.clone())
        })
    }

    async fn update_scope_success(&self, scope: OllamaMode, models: &[ModelInfo]) {
        let mut cache = self.scope_cache.write().await;
        let entry = cache.entry(scope).or_default();
        let now = Instant::now();
        entry.models = models.to_vec();
        entry.fetched_at = Some(now);
        entry.last_checked = Some(now);
        entry.last_success_at = Some(now);
        entry.availability = ScopeAvailability::Available;
        entry.last_error = None;
    }

    async fn mark_scope_failure(&self, scope: OllamaMode, message: String) {
        let mut cache = self.scope_cache.write().await;
        let entry = cache.entry(scope).or_default();
        entry.availability = ScopeAvailability::Unavailable;
        entry.last_error = Some(message);
        entry.last_checked = Some(Instant::now());
    }

    async fn annotate_scope_status(&self, models: &mut [ModelInfo]) {
        if models.is_empty() {
            return;
        }

        let cache = self.scope_cache.read().await;
        for (scope, snapshot) in cache.iter() {
            if snapshot.availability == ScopeAvailability::Unknown {
                continue;
            }
            let scope_key = Self::scope_key(*scope);
            let capability = format!(
                "scope-status:{}:{}",
                scope_key,
                snapshot.availability.as_str()
            );

            for model in models.iter_mut() {
                if !model.capabilities.iter().any(|cap| cap == &capability) {
                    model.capabilities.push(capability.clone());
                }
            }

            let stale = snapshot.is_stale(self.model_cache_ttl);
            let stale_capability = format!(
                "scope-status-stale:{}:{}",
                scope_key,
                if stale { "1" } else { "0" }
            );
            for model in models.iter_mut() {
                if !model
                    .capabilities
                    .iter()
                    .any(|cap| cap == &stale_capability)
                {
                    model.capabilities.push(stale_capability.clone());
                }
            }

            if let Some(age) = snapshot.last_checked_age_secs() {
                let age_capability = format!("scope-status-age:{}:{}", scope_key, age);
                for model in models.iter_mut() {
                    if !model.capabilities.iter().any(|cap| cap == &age_capability) {
                        model.capabilities.push(age_capability.clone());
                    }
                }
            }

            if let Some(success_age) = snapshot.last_success_age_secs() {
                let success_capability =
                    format!("scope-status-success-age:{}:{}", scope_key, success_age);
                for model in models.iter_mut() {
                    if !model
                        .capabilities
                        .iter()
                        .any(|cap| cap == &success_capability)
                    {
                        model.capabilities.push(success_capability.clone());
                    }
                }
            }

            if let Some(raw_reason) = snapshot.last_error.as_ref() {
                let cleaned = raw_reason.replace('\n', " ").trim().to_string();
                if !cleaned.is_empty() {
                    let truncated: String = cleaned.chars().take(160).collect();
                    let message_capability =
                        format!("scope-status-message:{}:{}", scope_key, truncated);
                    for model in models.iter_mut() {
                        if !model
                            .capabilities
                            .iter()
                            .any(|cap| cap == &message_capability)
                        {
                            model.capabilities.push(message_capability.clone());
                        }
                    }
                }
            }
        }
    }

    /// Attempt to resolve detailed model information for the given model, using the local cache when possible.
    pub async fn get_model_info(&self, model_name: &str) -> Result<DetailedModelInfo> {
        if let Some(info) = self.model_details_cache.get(model_name).await {
            return Ok(info);
        }
        self.fetch_and_cache_model_info(model_name, None).await
    }

    /// Force-refresh model information for the specified model.
    pub async fn refresh_model_info(&self, model_name: &str) -> Result<DetailedModelInfo> {
        self.model_details_cache.invalidate(model_name).await;
        self.fetch_and_cache_model_info(model_name, None).await
    }

    /// Retrieve detailed information for all locally available models.
    pub async fn get_all_models_info(&self) -> Result<Vec<DetailedModelInfo>> {
        let models = self
            .client
            .list_local_models()
            .await
            .map_err(|err| self.map_ollama_error("list models", err, None))?;

        let mut details = Vec::with_capacity(models.len());
        for local in &models {
            match self
                .fetch_and_cache_model_info(&local.name, Some(local))
                .await
            {
                Ok(info) => details.push(info),
                Err(err) => warn!("Failed to gather model info for '{}': {}", local.name, err),
            }
        }
        Ok(details)
    }

    /// Return any cached model information without touching the Ollama daemon.
    pub async fn cached_model_info(&self) -> Vec<DetailedModelInfo> {
        self.model_details_cache.cached().await
    }

    /// Remove a single model's cached information.
    pub async fn invalidate_model_info(&self, model_name: &str) {
        self.model_details_cache.invalidate(model_name).await;
    }

    /// Clear the entire model information cache.
    pub async fn clear_model_info_cache(&self) {
        self.model_details_cache.invalidate_all().await;
    }

    async fn fetch_and_cache_model_info(
        &self,
        model_name: &str,
        local: Option<&LocalModel>,
    ) -> Result<DetailedModelInfo> {
        let detail = self
            .client
            .show_model_info(model_name.to_string())
            .await
            .map_err(|err| self.map_ollama_error("show_model_info", err, Some(model_name)))?;

        let local_owned = if let Some(local) = local {
            Some(local.clone())
        } else {
            let models = self
                .client
                .list_local_models()
                .await
                .map_err(|err| self.map_ollama_error("list models", err, None))?;
            models.into_iter().find(|m| m.name == model_name)
        };

        let detailed =
            Self::convert_detailed_model_info(self.mode, model_name, local_owned.as_ref(), &detail);
        self.model_details_cache.insert(detailed.clone()).await;
        Ok(detailed)
    }

    fn prepare_chat_request(
        &self,
        model: String,
        messages: Vec<Message>,
        parameters: ChatParameters,
        tools: Option<Vec<McpToolDescriptor>>,
    ) -> Result<(String, OllamaChatRequest)> {
        if self.mode == OllamaMode::Cloud && !model.contains("-cloud") {
            warn!(
                "Model '{}' does not use the '-cloud' suffix. Cloud-only models may fail to load.",
                model
            );
        }

        if let Some(descriptors) = &tools
            && !descriptors.is_empty()
        {
            debug!(
                "Ignoring {} MCP tool descriptors for Ollama request (tool calling unsupported)",
                descriptors.len()
            );
        }

        let converted_messages = messages.into_iter().map(convert_message).collect();
        let mut request = OllamaChatRequest::new(model.clone(), converted_messages);

        if let Some(options) = build_model_options(&parameters)? {
            request.options = Some(options);
        }

        Ok((model, request))
    }

    async fn fetch_models(&self) -> Result<Vec<ModelInfo>> {
        let mut combined = Vec::new();
        let mut seen: HashSet<String> = HashSet::new();
        let mut errors: Vec<Error> = Vec::new();

        if let Some(local_handle) = self.build_local_client()? {
            match self
                .fetch_models_for_scope(OllamaMode::Local, local_handle)
                .await
            {
                Ok(models) => {
                    for model in models {
                        let key = format!("local::{}", model.id);
                        if seen.insert(key) {
                            combined.push(model);
                        }
                    }
                }
                Err(err) => errors.push(err),
            }
        }

        if let Some(cloud_handle) = self.build_cloud_client()? {
            match self
                .fetch_models_for_scope(OllamaMode::Cloud, cloud_handle)
                .await
            {
                Ok(models) => {
                    for model in models {
                        let key = format!("cloud::{}", model.id);
                        if seen.insert(key) {
                            combined.push(model);
                        }
                    }
                }
                Err(err) => errors.push(err),
            }
        }

        if combined.is_empty() {
            if let Some(err) = errors.pop() {
                return Err(err);
            }
        }

        self.annotate_scope_status(&mut combined).await;
        combined.sort_by(|a, b| a.name.to_lowercase().cmp(&b.name.to_lowercase()));
        Ok(combined)
    }

    async fn fetch_models_for_scope(
        &self,
        scope: OllamaMode,
        handle: ScopeHandle,
    ) -> Result<Vec<ModelInfo>> {
        let tags_result = self.fetch_scope_tags_with_retry(scope, &handle).await;

        let models = match tags_result {
            Ok(models) => models,
            Err(err) => {
                let original_detail = err.to_string();
                let (error, banner) = self.decorate_scope_error(scope, &handle.base_url, err);
                if banner != original_detail {
                    debug!(
                        "Model list for {:?} at {} failed: {}",
                        scope, handle.base_url, original_detail
                    );
                }
                self.mark_scope_failure(scope, banner.clone()).await;
                if let Some(cached) = self.cached_scope_models(scope).await {
                    return Ok(cached);
                }
                return Err(error);
            }
        };

        let cache = self.model_details_cache.clone();
        let client = handle.client.clone();
        let fetched = join_all(models.into_iter().map(|local| {
            let client = client.clone();
            let cache = cache.clone();
            async move {
                let name = local.name.clone();
                let detail = match client.show_model_info(name.clone()).await {
                    Ok(info) => {
                        let detailed = OllamaProvider::convert_detailed_model_info(
                            scope,
                            &name,
                            Some(&local),
                            &info,
                        );
                        cache.insert(detailed).await;
                        Some(info)
                    }
                    Err(err) => {
                        debug!("Failed to fetch Ollama model info for '{name}': {err}");
                        None
                    }
                };
                (local, detail)
            }
        }))
        .await;

        let converted: Vec<ModelInfo> = fetched
            .into_iter()
            .map(|(local, detail)| self.convert_model(scope, local, detail))
            .collect();

        self.update_scope_success(scope, &converted).await;
        Ok(converted)
    }

    async fn fetch_scope_tags_with_retry(
        &self,
        scope: OllamaMode,
        handle: &ScopeHandle,
    ) -> Result<Vec<LocalModel>> {
        let attempts = if matches!(scope, OllamaMode::Local) {
            LOCAL_TAGS_TIMEOUT_STEPS_MS.len()
        } else {
            1
        };

        let mut last_error: Option<Error> = None;

        for attempt in 0..attempts {
            match self.fetch_scope_tags_once(scope, handle, attempt).await {
                Ok(models) => return Ok(models),
                Err(err) => {
                    let should_retry = matches!(scope, OllamaMode::Local)
                        && attempt + 1 < attempts
                        && matches!(err, Error::Timeout(_) | Error::Network(_));

                    if should_retry {
                        debug!(
                            "Retrying Ollama model list for {:?} (attempt {}): {}",
                            scope,
                            attempt + 1,
                            err
                        );
                        last_error = Some(err);
                        sleep(self.tags_retry_delay(attempt)).await;
                        continue;
                    }
                    return Err(err);
                }
            }
        }

        Err(last_error
            .unwrap_or_else(|| Error::Unknown("Ollama model list retries exhausted".to_string())))
    }

    async fn fetch_scope_tags_once(
        &self,
        scope: OllamaMode,
        handle: &ScopeHandle,
        attempt: usize,
    ) -> Result<Vec<LocalModel>> {
        #[cfg(test)]
        if let Some(result) = pop_tags_override() {
            return result;
        }

        if matches!(scope, OllamaMode::Local) {
            match self.list_local_models_via_cli() {
                Ok(models) => return Ok(models),
                Err(err) => {
                    debug!("`ollama ls` failed ({}); falling back to HTTP listing", err);
                }
            }
        }

        let url = handle.api_url("tags");
        let response = handle
            .http_client
            .get(&url)
            .timeout(self.tags_request_timeout(scope, attempt))
            .send()
            .await
            .map_err(|err| map_reqwest_error("list models", err))?;

        if !response.status().is_success() {
            let status = response.status();
            let detail = response.text().await.unwrap_or_else(|err| err.to_string());
            return Err(self.map_http_failure("list models", status, detail, None));
        }

        let bytes = response
            .bytes()
            .await
            .map_err(|err| map_reqwest_error("list models", err))?;
        let parsed: TagsResponse = serde_json::from_slice(&bytes)?;
        Ok(parsed.models)
    }

    fn tags_request_timeout(&self, scope: OllamaMode, attempt: usize) -> Duration {
        if matches!(scope, OllamaMode::Local) {
            let idx = attempt.min(LOCAL_TAGS_TIMEOUT_STEPS_MS.len() - 1);
            Duration::from_millis(LOCAL_TAGS_TIMEOUT_STEPS_MS[idx])
        } else {
            self.request_timeout
        }
    }

    fn tags_retry_delay(&self, attempt: usize) -> Duration {
        let idx = attempt.min(LOCAL_TAGS_RETRY_DELAYS_MS.len() - 1);
        Duration::from_millis(LOCAL_TAGS_RETRY_DELAYS_MS[idx])
    }

    fn list_local_models_via_cli(&self) -> Result<Vec<LocalModel>> {
        let output = Command::new("ollama")
            .arg("ls")
            .output()
            .map_err(|err| {
                Error::Provider(anyhow!(
                    "Failed to execute `ollama ls`: {err}. Ensure the Ollama CLI is installed and accessible in PATH."
                ))
            })?;

        if !output.status.success() {
            let stderr = String::from_utf8_lossy(&output.stderr);
            return Err(Error::Provider(anyhow!(
                "`ollama ls` exited with status {}: {}",
                output.status,
                stderr.trim()
            )));
        }

        let stdout = String::from_utf8(output.stdout).map_err(|err| {
            Error::Provider(anyhow!("`ollama ls` returned non-UTF8 output: {err}"))
        })?;

        let mut models = Vec::new();
        for line in stdout.lines() {
            let trimmed = line.trim();
            if trimmed.is_empty() {
                continue;
            }
            let lowercase = trimmed.to_ascii_lowercase();
            if lowercase.starts_with("name") {
                continue;
            }

            let mut parts = trimmed.split_whitespace();
            let Some(name) = parts.next() else {
                continue;
            };
            let metadata_start = trimmed[name.len()..].trim();

            models.push(LocalModel {
                name: name.to_string(),
                modified_at: metadata_start.to_string(),
                size: 0,
            });
        }

        Ok(models)
    }

    fn decorate_scope_error(
        &self,
        scope: OllamaMode,
        base_url: &str,
        err: Error,
    ) -> (Error, String) {
        if matches!(scope, OllamaMode::Local) {
            match err {
                Error::Timeout(_) => {
                    let message = format_local_unreachable_message(base_url);
                    (Error::Timeout(message.clone()), message)
                }
                Error::Network(original) => {
                    if is_connectivity_error(&original) {
                        let message = format_local_unreachable_message(base_url);
                        (Error::Network(message.clone()), message)
                    } else {
                        let message = original.clone();
                        (Error::Network(original), message)
                    }
                }
                other => {
                    let message = other.to_string();
                    (other, message)
                }
            }
        } else {
            let message = err.to_string();
            (err, message)
        }
    }

    fn convert_detailed_model_info(
        mode: OllamaMode,
        model_name: &str,
        local: Option<&LocalModel>,
        detail: &OllamaModelInfo,
    ) -> DetailedModelInfo {
        let map = &detail.model_info;

        let architecture =
            pick_first_string(map, &["architecture", "model_format", "model_type", "arch"]);

        let parameters = non_empty(detail.parameters.clone())
            .or_else(|| pick_first_string(map, &["parameters"]));

        let parameter_size = pick_first_string(map, &["parameter_size"]);

        let context_length = pick_first_u64(map, &["context_length", "num_ctx", "max_context"]);
        let embedding_length = pick_first_u64(map, &["embedding_length"]);

        let quantization =
            pick_first_string(map, &["quantization_level", "quantization", "quantize"]);

        let family = pick_first_string(map, &["family", "model_family"]);
        let mut families = pick_string_list(map, &["families", "model_families"]);

        if families.is_empty() {
            families.extend(family.clone());
        }

        let system = pick_first_string(map, &["system"]);

        let mut modified_at = local
            .and_then(|entry| non_empty(entry.modified_at.clone()))
            .or_else(|| pick_first_string(map, &["modified_at", "created_at"]));

        if modified_at.is_none() && mode == OllamaMode::Cloud {
            modified_at = pick_first_string(map, &["updated_at"]);
        }

        let size = local
            .and_then(|entry| {
                if entry.size > 0 {
                    Some(entry.size)
                } else {
                    None
                }
            })
            .or_else(|| pick_first_u64(map, &["size", "model_size", "download_size"]));

        let digest = pick_first_string(map, &["digest", "sha256", "checksum"]);

        let mut info = DetailedModelInfo {
            name: model_name.to_string(),
            architecture,
            parameters,
            context_length,
            embedding_length,
            quantization,
            family,
            families,
            parameter_size,
            template: non_empty(detail.template.clone()),
            system,
            license: non_empty(detail.license.clone()),
            modelfile: non_empty(detail.modelfile.clone()),
            modified_at,
            size,
            digest,
        };

        if info.parameter_size.is_none() {
            info.parameter_size = info.parameters.clone();
        }

        info.with_normalised_strings()
    }

    fn convert_model(
        &self,
        scope: OllamaMode,
        model: LocalModel,
        detail: Option<OllamaModelInfo>,
    ) -> ModelInfo {
        let scope_tag = match scope {
            OllamaMode::Local => "local",
            OllamaMode::Cloud => "cloud",
        };

        let name = model.name;
        let mut capabilities: Vec<String> = detail
            .as_ref()
            .map(|info| {
                info.capabilities
                    .iter()
                    .map(|cap| cap.to_ascii_lowercase())
                    .collect()
            })
            .unwrap_or_default();

        push_capability(&mut capabilities, "chat");

        for heuristic in heuristic_capabilities(&name) {
            push_capability(&mut capabilities, &heuristic);
        }

        push_capability(&mut capabilities, &format!("scope:{scope_tag}"));

        let description = build_model_description(scope_tag, detail.as_ref());

        let context_window = detail.as_ref().and_then(|info| {
            pick_first_u64(
                &info.model_info,
                &["context_length", "num_ctx", "max_context"],
            )
            .and_then(|raw| u32::try_from(raw).ok())
        });

        ModelInfo {
            id: name.clone(),
            name,
            description: Some(description),
            provider: self.provider_name.clone(),
            context_window,
            capabilities,
            supports_tools: false,
        }
    }

    fn convert_ollama_response(response: OllamaChatResponse, streaming: bool) -> ChatResponse {
        let usage = response.final_data.as_ref().map(|data| {
            let prompt = clamp_to_u32(data.prompt_eval_count);
            let completion = clamp_to_u32(data.eval_count);
            TokenUsage {
                prompt_tokens: prompt,
                completion_tokens: completion,
                total_tokens: prompt.saturating_add(completion),
            }
        });

        ChatResponse {
            message: convert_ollama_message(response.message),
            usage,
            is_streaming: streaming,
            is_final: if streaming { response.done } else { true },
        }
    }

    fn map_ollama_error(&self, action: &str, err: OllamaError, model: Option<&str>) -> Error {
        match err {
            OllamaError::ReqwestError(request_err) => {
                if let Some(status) = request_err.status() {
                    self.map_http_failure(action, status, request_err.to_string(), model)
                } else if request_err.is_timeout() {
                    Error::Timeout(format!("Ollama {action} timed out: {request_err}"))
                } else {
                    Error::Network(format!("Ollama {action} request failed: {request_err}"))
                }
            }
            OllamaError::InternalError(internal) => Error::Provider(anyhow!(internal.message)),
            OllamaError::Other(message) => Error::Provider(anyhow!(message)),
            OllamaError::JsonError(err) => Error::Serialization(err),
            OllamaError::ToolCallError(err) => Error::Provider(anyhow!(err)),
        }
    }

    fn map_http_failure(
        &self,
        action: &str,
        status: StatusCode,
        detail: String,
        model: Option<&str>,
    ) -> Error {
        match status {
            StatusCode::NOT_FOUND => {
                if let Some(model) = model {
                    Error::InvalidInput(format!(
                        "Model '{model}' was not found at {}. Verify the name or pull it with `ollama pull {model}`.",
                        self.base_url
                    ))
                } else {
                    Error::InvalidInput(format!(
                        "{action} returned 404 from {}: {detail}",
                        self.base_url
                    ))
                }
            }
            StatusCode::UNAUTHORIZED | StatusCode::FORBIDDEN => Error::Auth(format!(
                "Ollama rejected the request ({status}): {detail}. Check your API key and account permissions."
            )),
            StatusCode::BAD_REQUEST => {
                Error::InvalidInput(format!("{action} rejected by Ollama ({status}): {detail}"))
            }
            StatusCode::SERVICE_UNAVAILABLE | StatusCode::GATEWAY_TIMEOUT => Error::Timeout(
                format!("Ollama {action} timed out ({status}). The model may still be loading."),
            ),
            _ => Error::Network(format!("Ollama {action} failed ({status}): {detail}")),
        }
    }
}

impl LlmProvider for OllamaProvider {
    type Stream = Pin<Box<dyn Stream<Item = Result<ChatResponse>> + Send>>;
    type ListModelsFuture<'a>
        = BoxFuture<'a, Result<Vec<ModelInfo>>>
    where
        Self: 'a;
    type SendPromptFuture<'a>
        = BoxFuture<'a, Result<ChatResponse>>
    where
        Self: 'a;
    type StreamPromptFuture<'a>
        = BoxFuture<'a, Result<Self::Stream>>
    where
        Self: 'a;
    type HealthCheckFuture<'a>
        = BoxFuture<'a, Result<()>>
    where
        Self: 'a;

    fn name(&self) -> &str {
        &self.provider_name
    }

    fn list_models(&self) -> Self::ListModelsFuture<'_> {
        Box::pin(async move {
            self.model_manager
                .get_or_refresh(false, || async { self.fetch_models().await })
                .await
        })
    }

    fn send_prompt(&self, request: ChatRequest) -> Self::SendPromptFuture<'_> {
        Box::pin(async move {
            let ChatRequest {
                model,
                messages,
                parameters,
                tools,
            } = request;

            let (model_id, ollama_request) =
                self.prepare_chat_request(model, messages, parameters, tools)?;

            let response = self
                .client
                .send_chat_messages(ollama_request)
                .await
                .map_err(|err| self.map_ollama_error("chat", err, Some(&model_id)))?;

            Ok(Self::convert_ollama_response(response, false))
        })
    }

    fn stream_prompt(&self, request: ChatRequest) -> Self::StreamPromptFuture<'_> {
        Box::pin(async move {
            let ChatRequest {
                model,
                messages,
                parameters,
                tools,
            } = request;

            let (model_id, ollama_request) =
                self.prepare_chat_request(model, messages, parameters, tools)?;

            let stream = self
                .client
                .send_chat_messages_stream(ollama_request)
                .await
                .map_err(|err| self.map_ollama_error("chat_stream", err, Some(&model_id)))?;

            let mapped = stream.map(|item| match item {
                Ok(chunk) => Ok(Self::convert_ollama_response(chunk, true)),
                Err(_) => Err(Error::Provider(anyhow!(
                    "Ollama returned a malformed streaming chunk"
                ))),
            });

            Ok(Box::pin(mapped) as Self::Stream)
        })
    }

    fn health_check(&self) -> Self::HealthCheckFuture<'_> {
        Box::pin(async move {
            let url = self.api_url("tags?limit=1");
            let response = self
                .http_client
                .get(&url)
                .timeout(Duration::from_millis(HEALTHCHECK_TIMEOUT_MS))
                .send()
                .await
                .map_err(|err| map_reqwest_error("health check", err))?;

            if response.status().is_success() {
                return Ok(());
            }

            let status = response.status();
            let detail = response.text().await.unwrap_or_else(|err| err.to_string());
            Err(self.map_http_failure("health check", status, detail, None))
        })
    }

    fn config_schema(&self) -> serde_json::Value {
        serde_json::json!({
            "type": "object",
            "properties": {
                "base_url": {
                    "type": "string",
                    "description": "Base URL for the Ollama API (ignored when api_key is provided)",
                    "default": self.mode.default_base_url()
                },
                "timeout_secs": {
                    "type": "integer",
                    "description": "HTTP request timeout in seconds",
                    "minimum": 5,
                    "default": DEFAULT_TIMEOUT_SECS
                },
                "model_cache_ttl_secs": {
                    "type": "integer",
                    "description": "Seconds to cache model listings",
                    "minimum": 5,
                    "default": DEFAULT_MODEL_CACHE_TTL_SECS
                }
            }
        })
    }
}

fn build_model_options(parameters: &ChatParameters) -> Result<Option<ModelOptions>> {
    let mut options = JsonMap::new();

    for (key, value) in &parameters.extra {
        options.insert(key.clone(), value.clone());
    }

    if let Some(temperature) = parameters.temperature {
        options.insert("temperature".to_string(), json!(temperature));
    }

    if let Some(max_tokens) = parameters.max_tokens {
        let capped = i32::try_from(max_tokens).unwrap_or(i32::MAX);
        options.insert("num_predict".to_string(), json!(capped));
    }

    if options.is_empty() {
        return Ok(None);
    }

    serde_json::from_value(Value::Object(options))
        .map(Some)
        .map_err(|err| Error::Config(format!("Invalid Ollama options: {err}")))
}

fn convert_message(message: Message) -> OllamaMessage {
    let Message {
        role,
        content,
        metadata,
        tool_calls,
        ..
    } = message;

    let role = match role {
        Role::User => OllamaRole::User,
        Role::Assistant => OllamaRole::Assistant,
        Role::System => OllamaRole::System,
        Role::Tool => OllamaRole::Tool,
    };

    let tool_calls = tool_calls
        .unwrap_or_default()
        .into_iter()
        .map(|tool_call| OllamaToolCall {
            function: OllamaToolCallFunction {
                name: tool_call.name,
                arguments: tool_call.arguments,
            },
        })
        .collect();

    let thinking = metadata
        .get("thinking")
        .and_then(|value| value.as_str().map(|s| s.to_owned()));

    OllamaMessage {
        role,
        content,
        tool_calls,
        images: None,
        thinking,
    }
}

fn convert_ollama_message(message: OllamaMessage) -> Message {
    let role = match message.role {
        OllamaRole::Assistant => Role::Assistant,
        OllamaRole::System => Role::System,
        OllamaRole::Tool => Role::Tool,
        OllamaRole::User => Role::User,
    };

    let tool_calls = if message.tool_calls.is_empty() {
        None
    } else {
        Some(
            message
                .tool_calls
                .into_iter()
                .enumerate()
                .map(|(idx, tool_call)| ToolCall {
                    id: format!("tool-call-{idx}"),
                    name: tool_call.function.name,
                    arguments: tool_call.function.arguments,
                })
                .collect::<Vec<_>>(),
        )
    };

    let mut metadata = HashMap::new();
    if let Some(thinking) = message.thinking {
        metadata.insert("thinking".to_string(), Value::String(thinking));
    }

    Message {
        id: Uuid::new_v4(),
        role,
        content: message.content,
        metadata,
        timestamp: SystemTime::now(),
        tool_calls,
    }
}

fn clamp_to_u32(value: u64) -> u32 {
    u32::try_from(value).unwrap_or(u32::MAX)
}

fn push_capability(capabilities: &mut Vec<String>, capability: &str) {
    let candidate = capability.to_ascii_lowercase();
    if !capabilities
        .iter()
        .any(|existing| existing.eq_ignore_ascii_case(&candidate))
    {
        capabilities.push(candidate);
    }
}

fn heuristic_capabilities(name: &str) -> Vec<String> {
    let lowercase = name.to_ascii_lowercase();
    let mut detected = Vec::new();

    if lowercase.contains("vision")
        || lowercase.contains("multimodal")
        || lowercase.contains("image")
    {
        detected.push("vision".to_string());
    }

    if lowercase.contains("think")
        || lowercase.contains("reason")
        || lowercase.contains("deepseek-r1")
        || lowercase.contains("r1")
    {
        detected.push("thinking".to_string());
    }

    if lowercase.contains("audio") || lowercase.contains("speech") || lowercase.contains("voice") {
        detected.push("audio".to_string());
    }

    detected
}

fn build_model_description(scope: &str, detail: Option<&OllamaModelInfo>) -> String {
    if let Some(info) = detail {
        let mut parts = Vec::new();

        if let Some(family) = info
            .model_info
            .get("family")
            .and_then(|value| value.as_str())
        {
            parts.push(family.to_string());
        }

        if let Some(parameter_size) = info
            .model_info
            .get("parameter_size")
            .and_then(|value| value.as_str())
        {
            parts.push(parameter_size.to_string());
        }

        if let Some(variant) = info
            .model_info
            .get("variant")
            .and_then(|value| value.as_str())
        {
            parts.push(variant.to_string());
        }

        if !parts.is_empty() {
            return format!("Ollama ({scope}) – {}", parts.join(" · "));
        }
    }

    format!("Ollama ({scope}) model")
}

fn non_empty(value: String) -> Option<String> {
    let trimmed = value.trim();
    if trimmed.is_empty() {
        None
    } else {
        Some(value)
    }
}

fn pick_first_string(map: &JsonMap<String, Value>, keys: &[&str]) -> Option<String> {
    keys.iter()
        .filter_map(|key| map.get(*key))
        .find_map(value_to_string)
        .map(|s| s.trim().to_string())
        .filter(|s| !s.is_empty())
}

fn pick_first_u64(map: &JsonMap<String, Value>, keys: &[&str]) -> Option<u64> {
    keys.iter()
        .filter_map(|key| map.get(*key))
        .find_map(value_to_u64)
}

fn pick_string_list(map: &JsonMap<String, Value>, keys: &[&str]) -> Vec<String> {
    for key in keys {
        if let Some(value) = map.get(*key) {
            match value {
                Value::Array(items) => {
                    let collected: Vec<String> = items
                        .iter()
                        .filter_map(value_to_string)
                        .map(|s| s.trim().to_string())
                        .filter(|s| !s.is_empty())
                        .collect();
                    if !collected.is_empty() {
                        return collected;
                    }
                }
                Value::String(text) => {
                    let collected: Vec<String> = text
                        .split(',')
                        .map(|part| part.trim())
                        .filter(|part| !part.is_empty())
                        .map(|part| part.to_string())
                        .collect();
                    if !collected.is_empty() {
                        return collected;
                    }
                }
                _ => {}
            }
        }
    }
    Vec::new()
}

fn value_to_string(value: &Value) -> Option<String> {
    match value {
        Value::String(text) => Some(text.clone()),
        Value::Number(num) => Some(num.to_string()),
        Value::Bool(flag) => Some(flag.to_string()),
        _ => None,
    }
}

fn value_to_u64(value: &Value) -> Option<u64> {
    match value {
        Value::Number(num) => {
            if let Some(v) = num.as_u64() {
                Some(v)
            } else if let Some(v) = num.as_i64() {
                v.try_into().ok()
            } else if let Some(v) = num.as_f64() {
                if v >= 0.0 { Some(v as u64) } else { None }
            } else {
                None
            }
        }
        Value::String(text) => text.trim().parse::<u64>().ok(),
        _ => None,
    }
}

fn format_local_unreachable_message(base_url: &str) -> String {
    let display = display_host_port(base_url);
    format!(
        "Ollama not reachable on {display}. Start the Ollama daemon (`ollama serve`) and try again."
    )
}

fn display_host_port(base_url: &str) -> String {
    Url::parse(base_url)
        .ok()
        .and_then(|url| {
            url.host_str().map(|host| {
                if let Some(port) = url.port() {
                    format!("{host}:{port}")
                } else {
                    host.to_string()
                }
            })
        })
        .unwrap_or_else(|| base_url.to_string())
}

fn is_connectivity_error(message: &str) -> bool {
    let lower = message.to_ascii_lowercase();
    const CONNECTIVITY_MARKERS: &[&str] = &[
        "connection refused",
        "failed to connect",
        "connect timeout",
        "timed out while contacting",
        "dns error",
        "failed to lookup address",
        "no route to host",
        "host unreachable",
    ];

    CONNECTIVITY_MARKERS
        .iter()
        .any(|marker| lower.contains(marker))
}

fn env_var_non_empty(name: &str) -> Option<String> {
    env::var(name)
        .ok()
        .map(|value| value.trim().to_string())
        .filter(|value| !value.is_empty())
}

fn resolve_api_key_env_hint(env_var: Option<&str>) -> Option<String> {
    let var = env_var?.trim();
    if var.is_empty() {
        return None;
    }

    if var.eq_ignore_ascii_case(LEGACY_OLLAMA_CLOUD_API_KEY_ENV)
        || var.eq_ignore_ascii_case(LEGACY_OWLEN_OLLAMA_CLOUD_API_KEY_ENV)
    {
        warn_legacy_cloud_env(var);
    }

    env_var_non_empty(var)
}

fn resolve_api_key(configured: Option<String>) -> Option<String> {
    let raw = configured?.trim().to_string();
    if raw.is_empty() {
        return None;
    }

    if let Some(variable) = raw
        .strip_prefix("${")
        .and_then(|value| value.strip_suffix('}'))
        .or_else(|| raw.strip_prefix('$'))
    {
        let var_name = variable.trim();
        if var_name.is_empty() {
            return None;
        }
        return env_var_non_empty(var_name);
    }

    Some(raw)
}

fn map_reqwest_error(action: &str, err: reqwest::Error) -> Error {
    if err.is_timeout() {
        Error::Timeout(format!("Ollama {action} request timed out: {err}"))
    } else {
        Error::Network(format!("Ollama {action} request failed: {err}"))
    }
}

fn normalize_base_url(
    input: Option<&str>,
    mode_hint: OllamaMode,
) -> std::result::Result<String, String> {
    let mut candidate = input
        .map(str::trim)
        .filter(|value| !value.is_empty())
        .map(|value| value.to_string())
        .unwrap_or_else(|| mode_hint.default_base_url().to_string());

    if !candidate.starts_with("http://") && !candidate.starts_with("https://") {
        candidate = format!("https://{candidate}");
    }

    let mut url =
        Url::parse(&candidate).map_err(|err| format!("Invalid Ollama URL '{candidate}': {err}"))?;

    if url.cannot_be_a_base() {
        return Err(format!("URL '{candidate}' cannot be used as a base URL"));
    }

    if mode_hint == OllamaMode::Cloud && url.scheme() != "https" {
        return Err("Ollama Cloud requires https:// base URLs".to_string());
    }

    let path = url.path().trim_end_matches('/');
    if path == "/api" {
        url.set_path("/");
    } else if !path.is_empty() && path != "/" {
        return Err("Ollama base URLs must not include additional path segments".to_string());
    }

    if mode_hint == OllamaMode::Cloud {
        if let Some(host) = url.host_str() {
            if host.eq_ignore_ascii_case("api.ollama.com") {
                url.set_host(Some("ollama.com"))
                    .map_err(|err| format!("Failed to normalise Ollama Cloud host: {err}"))?;
            }
        }
    }

    url.set_query(None);
    url.set_fragment(None);

    Ok(url.to_string().trim_end_matches('/').to_string())
}

fn normalize_cloud_endpoint(input: &str) -> std::result::Result<String, String> {
    normalize_base_url(Some(input), OllamaMode::Cloud)
}

fn build_api_endpoint(base_url: &str, endpoint: &str) -> String {
    let trimmed_base = base_url.trim_end_matches('/');
    let trimmed_endpoint = endpoint.trim_start_matches('/');

    if trimmed_base.ends_with("/api") {
        format!("{trimmed_base}/{trimmed_endpoint}")
    } else {
        format!("{trimmed_base}/api/{trimmed_endpoint}")
    }
}

fn build_client_for_base(
    base_url: &str,
    timeout: Duration,
    api_key: Option<&str>,
) -> Result<(Ollama, Client)> {
    let url = Url::parse(base_url)
        .map_err(|err| Error::Config(format!("Invalid Ollama base URL '{base_url}': {err}")))?;

    let mut headers = HeaderMap::new();
    if let Some(key) = api_key {
        let value = HeaderValue::from_str(&format!("Bearer {key}"))
            .map_err(|_| Error::Config("OLLAMA API key contains invalid characters".to_string()))?;
        headers.insert(AUTHORIZATION, value);
    }

    let mut client_builder = Client::builder().timeout(timeout);
    if !headers.is_empty() {
        client_builder = client_builder.default_headers(headers.clone());
    }

    let http_client = client_builder.build().map_err(|err| {
        Error::Config(format!(
            "Failed to build HTTP client for '{base_url}': {err}"
        ))
    })?;

    let port = url.port_or_known_default().ok_or_else(|| {
        Error::Config(format!("Unable to determine port for Ollama URL '{}'", url))
    })?;

    let mut ollama_client = Ollama::new_with_client(url.clone(), port, http_client.clone());
    if !headers.is_empty() {
        ollama_client.set_headers(Some(headers));
    }

    Ok((ollama_client, http_client))
}

#[cfg(test)]
mod tests {
    use super::*;
    use serde_json::{Map as JsonMap, Value};
    use std::collections::HashMap;

    #[test]
    fn resolve_api_key_prefers_literal_value() {
        assert_eq!(
            resolve_api_key(Some("direct-key".into())),
            Some("direct-key".into())
        );
    }

    #[test]
    fn resolve_api_key_expands_env_var() {
        unsafe {
            std::env::set_var("OLLAMA_TEST_KEY", "secret");
        }
        assert_eq!(
            resolve_api_key(Some("${OLLAMA_TEST_KEY}".into())),
            Some("secret".into())
        );
        unsafe {
            std::env::remove_var("OLLAMA_TEST_KEY");
        }
    }

    #[test]
    fn normalize_base_url_removes_api_path() {
        let url = normalize_base_url(Some("https://ollama.com/api"), OllamaMode::Cloud).unwrap();
        assert_eq!(url, "https://ollama.com");
    }

    #[test]
    fn normalize_base_url_canonicalises_api_hostname() {
        let url = normalize_base_url(Some("https://api.ollama.com"), OllamaMode::Cloud).unwrap();
        assert_eq!(url, "https://ollama.com");
    }

    #[test]
    fn normalize_base_url_rejects_cloud_without_https() {
        let err = normalize_base_url(Some("http://ollama.com"), OllamaMode::Cloud).unwrap_err();
        assert!(err.contains("https"));
    }

    #[test]
    fn explicit_local_mode_overrides_api_key() {
        let mut config = ProviderConfig {
            enabled: true,
            provider_type: "ollama".to_string(),
            base_url: Some("http://localhost:11434".to_string()),
            api_key: Some("secret-key".to_string()),
            api_key_env: None,
            extra: HashMap::new(),
        };
        config.extra.insert(
            OLLAMA_MODE_KEY.to_string(),
            Value::String("local".to_string()),
        );

        let provider = OllamaProvider::from_config("ollama_local", &config, None)
            .expect("provider constructed");

        assert_eq!(provider.mode, OllamaMode::Local);
        assert_eq!(provider.base_url, "http://localhost:11434");
    }

    #[test]
    fn auto_mode_prefers_explicit_local_base() {
        let config = ProviderConfig {
            enabled: true,
            provider_type: "ollama".to_string(),
            base_url: Some("http://localhost:11434".to_string()),
            api_key: Some("secret-key".to_string()),
            api_key_env: None,
            extra: HashMap::new(),
        };
        // simulate missing explicit mode; defaults to auto

        let provider = OllamaProvider::from_config("ollama_local", &config, None)
            .expect("provider constructed");

        assert_eq!(provider.mode, OllamaMode::Local);
        assert_eq!(provider.base_url, "http://localhost:11434");
    }

    #[test]
    fn auto_mode_with_api_key_and_no_local_probe_switches_to_cloud() {
        let mut config = ProviderConfig {
            enabled: true,
            provider_type: "ollama".to_string(),
            base_url: None,
            api_key: Some("secret-key".to_string()),
            api_key_env: None,
            extra: HashMap::new(),
        };
        config.extra.insert(
            OLLAMA_MODE_KEY.to_string(),
            Value::String("auto".to_string()),
        );

        let provider = OllamaProvider::from_config("ollama_cloud", &config, None)
            .expect("provider constructed");

        assert_eq!(provider.mode, OllamaMode::Cloud);
        assert_eq!(provider.base_url, CLOUD_BASE_URL);
    }

    #[test]
    fn cloud_provider_requires_api_key() {
        let config = ProviderConfig {
            enabled: true,
            provider_type: "ollama_cloud".to_string(),
            base_url: None,
            api_key: None,
            api_key_env: None,
            extra: HashMap::new(),
        };

        let err = OllamaProvider::from_config("ollama_cloud", &config, None)
            .expect_err("expected config error");
        match err {
            Error::Config(message) => {
                assert!(message.contains("API key"));
            }
            other => panic!("unexpected error variant: {other:?}"),
        }
    }

    #[test]
    fn cloud_provider_uses_explicit_api_key() {
        let config = ProviderConfig {
            enabled: true,
            provider_type: "ollama_cloud".to_string(),
            base_url: None,
            api_key: Some("secret-cloud-key".to_string()),
            api_key_env: None,
            extra: HashMap::new(),
        };

        let provider = OllamaProvider::from_config("ollama_cloud", &config, None)
            .expect("provider constructed");
        assert_eq!(provider.name(), "ollama_cloud");
        assert_eq!(provider.mode, OllamaMode::Cloud);
        assert_eq!(provider.base_url, CLOUD_BASE_URL);
    }

    #[test]
    fn cloud_provider_reads_api_key_from_env_hint() {
        let config = ProviderConfig {
            enabled: true,
            provider_type: "ollama_cloud".to_string(),
            base_url: None,
            api_key: None,
            api_key_env: Some("OLLAMA_TEST_CLOUD_KEY".to_string()),
            extra: HashMap::new(),
        };

        unsafe {
            std::env::set_var("OLLAMA_TEST_CLOUD_KEY", "env-secret");
        }

        assert!(std::env::var("OLLAMA_TEST_CLOUD_KEY").is_ok());
        assert!(resolve_api_key_env_hint(config.api_key_env.as_deref()).is_some());
        assert_eq!(config.api_key_env.as_deref(), Some("OLLAMA_TEST_CLOUD_KEY"));

        let provider = OllamaProvider::from_config("ollama_cloud", &config, None)
            .expect("provider constructed");
        assert_eq!(provider.name(), "ollama_cloud");
        assert_eq!(provider.mode, OllamaMode::Cloud);

        unsafe {
            std::env::remove_var("OLLAMA_TEST_CLOUD_KEY");
        }
    }

    #[test]
    fn fetch_scope_tags_with_retry_success_uses_override() {
        let provider = OllamaProvider::new("http://localhost:11434").expect("provider constructed");
        let handle = ScopeHandle::new(
            provider.client.clone(),
            provider.http_client.clone(),
            provider.base_url.clone(),
        );

        let _guard = set_tags_override(vec![Ok(vec![LocalModel {
            name: "llama3".into(),
            modified_at: "2024-01-01T00:00:00Z".into(),
            size: 42,
        }])]);

        let models = block_on(provider.fetch_scope_tags_with_retry(OllamaMode::Local, &handle))
            .expect("models returned");
        assert_eq!(models.len(), 1);
        assert_eq!(models[0].name, "llama3");
    }

    #[test]
    fn convert_model_propagates_context_window_from_details() {
        let provider = OllamaProvider::new("http://localhost:11434").expect("provider constructed");
        let local = LocalModel {
            name: "gemma3n:e4b".into(),
            modified_at: "2024-01-01T00:00:00Z".into(),
            size: 0,
        };

        let mut meta = JsonMap::new();
        meta.insert(
            "context_length".into(),
            Value::Number(serde_json::Number::from(32_768)),
        );

        let detail = OllamaModelInfo {
            license: String::new(),
            modelfile: String::new(),
            parameters: String::new(),
            template: String::new(),
            model_info: meta,
            capabilities: vec![],
        };

        let info = provider.convert_model(OllamaMode::Local, local, Some(detail));
        assert_eq!(info.context_window, Some(32_768));
    }

    #[test]
    fn fetch_scope_tags_with_retry_retries_on_timeout_then_succeeds() {
        let provider = OllamaProvider::new("http://localhost:11434").expect("provider constructed");
        let handle = ScopeHandle::new(
            provider.client.clone(),
            provider.http_client.clone(),
            provider.base_url.clone(),
        );

        let _guard = set_tags_override(vec![
            Err(Error::Timeout("first attempt".into())),
            Ok(vec![LocalModel {
                name: "llama3".into(),
                modified_at: "2024-01-01T00:00:00Z".into(),
                size: 42,
            }]),
        ]);

        let models = block_on(provider.fetch_scope_tags_with_retry(OllamaMode::Local, &handle))
            .expect("models returned after retry");
        assert_eq!(models.len(), 1);
        assert_eq!(models[0].name, "llama3");
    }

    #[test]
    fn decorate_scope_error_returns_friendly_message_for_connectivity() {
        let provider = OllamaProvider::new("http://localhost:11434").expect("provider constructed");
        let (error, message) = provider.decorate_scope_error(
            OllamaMode::Local,
            "http://localhost:11434",
            Error::Network("failed to connect to host".into()),
        );

        assert!(matches!(
            error,
            Error::Network(ref text) if text.contains("Ollama not reachable")
        ));
        assert!(message.contains("Ollama not reachable"));
        assert!(message.contains("localhost:11434"));
    }

    #[test]
    fn decorate_scope_error_preserves_http_failure_message() {
        let provider = OllamaProvider::new("http://localhost:11434").expect("provider constructed");
        let original = "Ollama list models failed (500): boom".to_string();
        let (error, message) = provider.decorate_scope_error(
            OllamaMode::Local,
            "http://localhost:11434",
            Error::Network(original.clone()),
        );

        assert!(matches!(error, Error::Network(ref text) if text.contains("500")));
        assert_eq!(message, original);
    }

    #[test]
    fn decorate_scope_error_translates_timeout() {
        let provider = OllamaProvider::new("http://localhost:11434").expect("provider constructed");
        let (error, message) = provider.decorate_scope_error(
            OllamaMode::Local,
            "http://localhost:11434",
            Error::Timeout("deadline exceeded".into()),
        );

        assert!(matches!(
            error,
            Error::Timeout(ref text) if text.contains("Ollama not reachable")
        ));
        assert!(message.contains("Ollama not reachable"));
    }

    #[test]
    fn map_http_failure_model_not_found_suggests_pull_hint() {
        let provider = OllamaProvider::new("http://localhost:11434").expect("provider constructed");
        let err = provider.map_http_failure(
            "chat",
            StatusCode::NOT_FOUND,
            "missing model".to_string(),
            Some("llama3"),
        );

        let message = match err {
            Error::InvalidInput(message) => message,
            other => panic!("unexpected error variant: {other:?}"),
        };

        assert!(message.contains("ollama pull llama3"));
    }

    #[test]
    fn build_model_options_merges_parameters() {
        let mut parameters = ChatParameters::default();
        parameters.temperature = Some(0.3);
        parameters.max_tokens = Some(128);
        parameters
            .extra
            .insert("num_ctx".into(), Value::from(4096_u64));

        let options = build_model_options(&parameters)
            .expect("options built")
            .expect("options present");
        let serialized = serde_json::to_value(&options).expect("serialize options");
        let temperature = serialized["temperature"]
            .as_f64()
            .expect("temperature present");
        assert!((temperature - 0.3).abs() < 1e-6);
        assert_eq!(serialized["num_predict"], json!(128));
        assert_eq!(serialized["num_ctx"], json!(4096));
    }

    #[test]
    fn heuristic_capabilities_detects_thinking_models() {
        let caps = heuristic_capabilities("deepseek-r1");
        assert!(caps.iter().any(|cap| cap == "thinking"));
    }

    #[test]
    fn push_capability_avoids_duplicates() {
        let mut caps = vec!["chat".to_string()];
        push_capability(&mut caps, "Chat");
        push_capability(&mut caps, "Vision");
        push_capability(&mut caps, "vision");

        assert_eq!(caps.len(), 2);
        assert!(caps.iter().any(|cap| cap == "vision"));
    }
}

#[cfg(test)]
struct ProbeOverrideGuard {
    gate: Option<MutexGuard<'static, ()>>,
}

#[cfg(test)]
impl ProbeOverrideGuard {
    fn set(value: Option<bool>) -> Self {
        let gate = PROBE_OVERRIDE_GATE
            .get_or_init(|| Mutex::new(()))
            .lock()
            .expect("probe override gate mutex poisoned");
        set_probe_override(value);
        ProbeOverrideGuard { gate: Some(gate) }
    }
}

#[cfg(test)]
impl Drop for ProbeOverrideGuard {
    fn drop(&mut self) {
        set_probe_override(None);
        self.gate.take();
    }
}

#[test]
fn auto_mode_with_api_key_and_successful_probe_prefers_local() {
    let _guard = ProbeOverrideGuard::set(Some(true));

    let mut config = ProviderConfig {
        enabled: true,
        provider_type: "ollama".to_string(),
        base_url: None,
        api_key: Some("secret-key".to_string()),
        api_key_env: None,
        extra: HashMap::new(),
    };
    config.extra.insert(
        OLLAMA_MODE_KEY.to_string(),
        Value::String("auto".to_string()),
    );

    assert!(probe_default_local_daemon(Duration::from_millis(1)));

    let provider =
        OllamaProvider::from_config("ollama_local", &config, None).expect("provider constructed");

    assert_eq!(provider.mode, OllamaMode::Local);
    assert_eq!(provider.base_url, "http://localhost:11434");
}

#[test]
fn auto_mode_with_api_key_and_failed_probe_prefers_cloud() {
    let _guard = ProbeOverrideGuard::set(Some(false));

    let mut config = ProviderConfig {
        enabled: true,
        provider_type: "ollama".to_string(),
        base_url: None,
        api_key: Some("secret-key".to_string()),
        api_key_env: None,
        extra: HashMap::new(),
    };
    config.extra.insert(
        OLLAMA_MODE_KEY.to_string(),
        Value::String("auto".to_string()),
    );

    let provider =
        OllamaProvider::from_config("ollama_cloud", &config, None).expect("provider constructed");

    assert_eq!(provider.mode, OllamaMode::Cloud);
    assert_eq!(provider.base_url, CLOUD_BASE_URL);
}

#[test]
fn annotate_scope_status_adds_capabilities_for_unavailable_scopes() {
    let config = ProviderConfig {
        enabled: true,
        provider_type: "ollama".to_string(),
        base_url: Some("http://localhost:11434".to_string()),
        api_key: None,
        api_key_env: None,
        extra: HashMap::new(),
    };

    let provider =
        OllamaProvider::from_config("ollama_local", &config, None).expect("provider constructed");

    let mut models = vec![ModelInfo {
        id: "llama3".to_string(),
        name: "Llama 3".to_string(),
        description: None,
        provider: "ollama".to_string(),
        context_window: None,
        capabilities: vec!["scope:local".to_string()],
        supports_tools: false,
    }];

    block_on(async {
        {
            let mut cache = provider.scope_cache.write().await;
            let entry = cache.entry(OllamaMode::Cloud).or_default();
            entry.availability = ScopeAvailability::Unavailable;
            entry.last_error = Some("Cloud endpoint unreachable".to_string());
            entry.last_checked = Some(Instant::now());
        }

        provider.annotate_scope_status(&mut models).await;
    });

    let capabilities = &models[0].capabilities;
    assert!(
        capabilities
            .iter()
            .any(|cap| cap == "scope-status:cloud:unavailable")
    );
    assert!(
        capabilities
            .iter()
            .any(|cap| cap.starts_with("scope-status-message:cloud:"))
    );
    assert!(
        capabilities
            .iter()
            .any(|cap| cap.starts_with("scope-status-age:cloud:"))
    );
    assert!(
        capabilities
            .iter()
            .any(|cap| cap == "scope-status-stale:cloud:0")
    );
}