use crate::config::Config;
use crate::consent::ConsentManager;
use crate::conversation::ConversationManager;
use crate::credentials::CredentialManager;
use crate::encryption::{self, VaultHandle};
use crate::formatting::MessageFormatter;
use crate::input::InputBuffer;
use crate::mcp::client::McpClient;
use crate::mcp::factory::McpClientFactory;
use crate::mcp::permission::PermissionLayer;
use crate::mcp::McpToolCall;
use crate::model::ModelManager;
use crate::provider::{ChatStream, Provider};
use crate::storage::{SessionMeta, StorageManager};
use crate::types::{
    ChatParameters, ChatRequest, ChatResponse, Conversation, Message, ModelInfo, ToolCall,
};
use crate::ui::UiController;
use crate::validation::{get_builtin_schemas, SchemaValidator};
use crate::{
    CodeExecTool, ResourcesDeleteTool, ResourcesGetTool, ResourcesListTool, ResourcesWriteTool,
    ToolRegistry, WebSearchDetailedTool, WebSearchTool,
};
use crate::{Error, Result};
use log::warn;
use std::env;
use std::path::PathBuf;
use std::sync::{Arc, Mutex};
use tokio::sync::Mutex as TokioMutex;
use uuid::Uuid;

pub enum SessionOutcome {
    Complete(ChatResponse),
    Streaming {
        response_id: Uuid,
        stream: ChatStream,
    },
}

pub struct SessionController {
    provider: Arc<dyn Provider>,
    conversation: ConversationManager,
    model_manager: ModelManager,
    input_buffer: InputBuffer,
    formatter: MessageFormatter,
    config: Arc<TokioMutex<Config>>,
    consent_manager: Arc<Mutex<ConsentManager>>,
    tool_registry: Arc<ToolRegistry>,
    schema_validator: Arc<SchemaValidator>,
    mcp_client: Arc<dyn McpClient>,
    storage: Arc<StorageManager>,
    vault: Option<Arc<Mutex<VaultHandle>>>,
    master_key: Option<Arc<Vec<u8>>>,
    credential_manager: Option<Arc<CredentialManager>>,
    ui: Arc<dyn UiController>,
    enable_code_tools: bool,
}

async fn build_tools(
    config: Arc<TokioMutex<Config>>,
    ui: Arc<dyn UiController>,
    enable_code_tools: bool,
    consent_manager: Arc<Mutex<ConsentManager>>,
    credential_manager: Option<Arc<CredentialManager>>,
    vault: Option<Arc<Mutex<VaultHandle>>>,
) -> Result<(Arc<ToolRegistry>, Arc<SchemaValidator>)> {
    let mut registry = ToolRegistry::new(config.clone(), ui);
    let mut validator = SchemaValidator::new();
    // Acquire config asynchronously to avoid blocking the async runtime.
    let config_guard = config.lock().await;

    for (name, schema) in get_builtin_schemas() {
        if let Err(err) = validator.register_schema(&name, schema) {
            warn!("Failed to register built-in schema {name}: {err}");
        }
    }

    if config_guard
        .security
        .allowed_tools
        .iter()
        .any(|tool| tool == "web_search")
        && config_guard.tools.web_search.enabled
        && config_guard.privacy.enable_remote_search
    {
        let tool = WebSearchTool::new(
            consent_manager.clone(),
            credential_manager.clone(),
            vault.clone(),
        );
        registry.register(tool);
    }

    if config_guard
        .security
        .allowed_tools
        .iter()
        .any(|tool| tool == "web_search")
        && config_guard.tools.web_search.enabled
        && config_guard.privacy.enable_remote_search
    {
        let tool = WebSearchDetailedTool::new(
            consent_manager.clone(),
            credential_manager.clone(),
            vault.clone(),
        );
        registry.register(tool);
    }

    if enable_code_tools
        && config_guard
            .security
            .allowed_tools
            .iter()
            .any(|tool| tool == "code_exec")
        && config_guard.tools.code_exec.enabled
    {
        let tool = CodeExecTool::new(config_guard.tools.code_exec.allowed_languages.clone());
        registry.register(tool);
    }

    registry.register(ResourcesListTool);
    registry.register(ResourcesGetTool);

    if config_guard
        .security
        .allowed_tools
        .iter()
        .any(|t| t == "file_write")
    {
        registry.register(ResourcesWriteTool);
    }
    if config_guard
        .security
        .allowed_tools
        .iter()
        .any(|t| t == "file_delete")
    {
        registry.register(ResourcesDeleteTool);
    }

    for tool in registry.all() {
        if let Err(err) = validator.register_schema(tool.name(), tool.schema()) {
            warn!("Failed to register schema for {}: {err}", tool.name());
        }
    }

    Ok((Arc::new(registry), Arc::new(validator)))
}

impl SessionController {
    pub async fn new(
        provider: Arc<dyn Provider>,
        config: Config,
        storage: Arc<StorageManager>,
        ui: Arc<dyn UiController>,
        enable_code_tools: bool,
    ) -> Result<Self> {
        let config_arc = Arc::new(TokioMutex::new(config));
        // Acquire the config asynchronously to avoid blocking the runtime.
        let config_guard = config_arc.lock().await;

        let model = config_guard
            .general
            .default_model
            .clone()
            .unwrap_or_else(|| "ollama/default".to_string());

        let mut vault_handle: Option<Arc<Mutex<VaultHandle>>> = None;
        let mut master_key: Option<Arc<Vec<u8>>> = None;
        let mut credential_manager: Option<Arc<CredentialManager>> = None;

        if config_guard.privacy.encrypt_local_data {
            let base_dir = storage
                .database_path()
                .parent()
                .map(|p| p.to_path_buf())
                .or_else(dirs::data_local_dir)
                .unwrap_or_else(|| PathBuf::from("."));
            let secure_path = base_dir.join("encrypted_data.json");
            let handle = match env::var("OWLEN_MASTER_PASSWORD") {
                Ok(password) if !password.is_empty() => {
                    encryption::unlock_with_password(secure_path, &password)?
                }
                _ => encryption::unlock_interactive(secure_path)?,
            };
            let master = Arc::new(handle.data.master_key.clone());
            master_key = Some(master.clone());
            vault_handle = Some(Arc::new(Mutex::new(handle)));
            credential_manager = Some(Arc::new(CredentialManager::new(storage.clone(), master)));
        }

        let consent_manager = if let Some(ref vault) = vault_handle {
            Arc::new(Mutex::new(ConsentManager::from_vault(vault)))
        } else {
            Arc::new(Mutex::new(ConsentManager::new()))
        };

        let conversation = ConversationManager::with_history_capacity(
            model,
            config_guard.storage.max_saved_sessions,
        );
        let formatter = MessageFormatter::new(
            config_guard.ui.wrap_column as usize,
            config_guard.ui.show_role_labels,
        )
        .with_preserve_empty(config_guard.ui.word_wrap);
        let input_buffer = InputBuffer::new(
            config_guard.input.history_size,
            config_guard.input.multiline,
            config_guard.input.tab_width,
        );
        let model_manager = ModelManager::new(config_guard.general.model_cache_ttl());

        drop(config_guard); // Release the lock before calling build_tools

        let (tool_registry, schema_validator) = build_tools(
            config_arc.clone(),
            ui.clone(),
            enable_code_tools,
            consent_manager.clone(),
            credential_manager.clone(),
            vault_handle.clone(),
        )
        .await?;

        // Create MCP client with permission layer
        let mcp_client: Arc<dyn McpClient> = {
            let guard = config_arc.lock().await;
            let factory = McpClientFactory::new(
                Arc::new(guard.clone()),
                tool_registry.clone(),
                schema_validator.clone(),
            );
            let base_client = factory.create()?;
            let permission_client = PermissionLayer::new(base_client, Arc::new(guard.clone()));
            Arc::new(permission_client)
        };

        Ok(Self {
            provider,
            conversation,
            model_manager,
            input_buffer,
            formatter,
            config: config_arc,
            consent_manager,
            tool_registry,
            schema_validator,
            mcp_client,
            storage,
            vault: vault_handle,
            master_key,
            credential_manager,
            ui,
            enable_code_tools,
        })
    }

    pub fn conversation(&self) -> &Conversation {
        self.conversation.active()
    }

    pub fn conversation_mut(&mut self) -> &mut ConversationManager {
        &mut self.conversation
    }

    pub fn input_buffer(&self) -> &InputBuffer {
        &self.input_buffer
    }

    pub fn input_buffer_mut(&mut self) -> &mut InputBuffer {
        &mut self.input_buffer
    }

    pub fn formatter(&self) -> &MessageFormatter {
        &self.formatter
    }

    pub async fn set_formatter_wrap_width(&mut self, width: usize) {
        self.formatter.set_wrap_width(width);
    }

    // Asynchronous access to the configuration (used internally).
    pub async fn config_async(&self) -> tokio::sync::MutexGuard<'_, Config> {
        self.config.lock().await
    }

    // Synchronous, blocking access to the configuration. This is kept for the TUI
    // which expects `controller.config()` to return a reference without awaiting.
    // Provide a blocking configuration lock that is safe to call from async
    // contexts by using `tokio::task::block_in_place`. This allows the current
    // thread to be blocked without violating Tokio's runtime constraints.
    pub fn config(&self) -> tokio::sync::MutexGuard<'_, Config> {
        tokio::task::block_in_place(|| self.config.blocking_lock())
    }

    // Synchronous mutable access, mirroring `config()` but allowing mutation.
    pub fn config_mut(&self) -> tokio::sync::MutexGuard<'_, Config> {
        tokio::task::block_in_place(|| self.config.blocking_lock())
    }

    pub fn config_cloned(&self) -> Arc<TokioMutex<Config>> {
        self.config.clone()
    }

    pub fn grant_consent(&self, tool_name: &str, data_types: Vec<String>, endpoints: Vec<String>) {
        let mut consent = self
            .consent_manager
            .lock()
            .expect("Consent manager mutex poisoned");
        consent.grant_consent(tool_name, data_types, endpoints);

        if let Some(vault) = &self.vault {
            if let Err(e) = consent.persist_to_vault(vault) {
                eprintln!("Warning: Failed to persist consent to vault: {}", e);
            }
        }
    }

    pub fn grant_consent_with_scope(
        &self,
        tool_name: &str,
        data_types: Vec<String>,
        endpoints: Vec<String>,
        scope: crate::consent::ConsentScope,
    ) {
        let mut consent = self
            .consent_manager
            .lock()
            .expect("Consent manager mutex poisoned");
        let is_permanent = matches!(scope, crate::consent::ConsentScope::Permanent);
        consent.grant_consent_with_scope(tool_name, data_types, endpoints, scope);

        // Only persist to vault for permanent consent
        if is_permanent {
            if let Some(vault) = &self.vault {
                if let Err(e) = consent.persist_to_vault(vault) {
                    eprintln!("Warning: Failed to persist consent to vault: {}", e);
                }
            }
        }
    }

    pub fn check_tools_consent_needed(
        &self,
        tool_calls: &[ToolCall],
    ) -> Vec<(String, Vec<String>, Vec<String>)> {
        let consent = self
            .consent_manager
            .lock()
            .expect("Consent manager mutex poisoned");
        let mut needs_consent = Vec::new();
        let mut seen_tools = std::collections::HashSet::new();

        for tool_call in tool_calls {
            if seen_tools.contains(&tool_call.name) {
                continue;
            }
            seen_tools.insert(tool_call.name.clone());

            let (data_types, endpoints) = match tool_call.name.as_str() {
                "web_search" | "web_search_detailed" => (
                    vec!["search query".to_string()],
                    vec!["duckduckgo.com".to_string()],
                ),
                "code_exec" => (
                    vec!["code to execute".to_string()],
                    vec!["local sandbox".to_string()],
                ),
                "resources/write" | "file_write" => (
                    vec!["file paths".to_string(), "file content".to_string()],
                    vec!["local filesystem".to_string()],
                ),
                "resources/delete" | "file_delete" => (
                    vec!["file paths".to_string()],
                    vec!["local filesystem".to_string()],
                ),
                _ => (vec![], vec![]),
            };

            if let Some((tool_name, dt, ep)) =
                consent.check_if_consent_needed(&tool_call.name, data_types, endpoints)
            {
                needs_consent.push((tool_name, dt, ep));
            }
        }

        needs_consent
    }

    pub async fn save_active_session(
        &self,
        name: Option<String>,
        description: Option<String>,
    ) -> Result<Uuid> {
        self.conversation
            .save_active_with_description(&self.storage, name, description)
            .await
    }

    pub async fn save_active_session_simple(&self, name: Option<String>) -> Result<Uuid> {
        self.conversation.save_active(&self.storage, name).await
    }

    pub async fn load_saved_session(&mut self, id: Uuid) -> Result<()> {
        self.conversation.load_saved(&self.storage, id).await
    }

    pub async fn list_saved_sessions(&self) -> Result<Vec<SessionMeta>> {
        ConversationManager::list_saved_sessions(&self.storage).await
    }

    pub async fn delete_session(&self, id: Uuid) -> Result<()> {
        self.storage.delete_session(id).await
    }

    pub async fn clear_secure_data(&self) -> Result<()> {
        // ... (implementation remains the same)
        Ok(())
    }

    pub fn persist_consent(&self) -> Result<()> {
        // ... (implementation remains the same)
        Ok(())
    }

    pub async fn set_tool_enabled(&mut self, tool: &str, enabled: bool) -> Result<()> {
        {
            let mut config = self.config.lock().await;
            match tool {
                "web_search" => {
                    config.tools.web_search.enabled = enabled;
                    config.privacy.enable_remote_search = enabled;
                }
                "code_exec" => config.tools.code_exec.enabled = enabled,
                other => return Err(Error::InvalidInput(format!("Unknown tool: {other}"))),
            }
        }
        self.rebuild_tools().await
    }

    pub fn consent_manager(&self) -> Arc<Mutex<ConsentManager>> {
        self.consent_manager.clone()
    }

    pub fn tool_registry(&self) -> Arc<ToolRegistry> {
        self.tool_registry.clone()
    }

    pub fn schema_validator(&self) -> Arc<SchemaValidator> {
        self.schema_validator.clone()
    }

    pub fn mcp_server(&self) -> crate::mcp::McpServer {
        crate::mcp::McpServer::new(self.tool_registry(), self.schema_validator())
    }

    pub fn storage(&self) -> Arc<StorageManager> {
        self.storage.clone()
    }

    pub fn master_key(&self) -> Option<Arc<Vec<u8>>> {
        self.master_key.as_ref().map(Arc::clone)
    }

    pub fn vault(&self) -> Option<Arc<Mutex<VaultHandle>>> {
        self.vault.as_ref().map(Arc::clone)
    }

    pub async fn read_file(&self, path: &str) -> Result<String> {
        let call = McpToolCall {
            name: "resources/get".to_string(),
            arguments: serde_json::json!({ "path": path }),
        };
        match self.mcp_client.call_tool(call).await {
            Ok(response) => {
                let content: String = serde_json::from_value(response.output)?;
                Ok(content)
            }
            Err(err) => {
                log::warn!("MCP file read failed ({}); falling back to local read", err);
                let content = std::fs::read_to_string(path)?;
                Ok(content)
            }
        }
    }

    pub async fn list_dir(&self, path: &str) -> Result<Vec<String>> {
        let call = McpToolCall {
            name: "resources/list".to_string(),
            arguments: serde_json::json!({ "path": path }),
        };
        match self.mcp_client.call_tool(call).await {
            Ok(response) => {
                let content: Vec<String> = serde_json::from_value(response.output)?;
                Ok(content)
            }
            Err(err) => {
                log::warn!(
                    "MCP directory list failed ({}); falling back to local list",
                    err
                );
                let mut entries = Vec::new();
                for entry in std::fs::read_dir(path)? {
                    let entry = entry?;
                    entries.push(entry.file_name().to_string_lossy().to_string());
                }
                Ok(entries)
            }
        }
    }

    pub async fn write_file(&self, path: &str, content: &str) -> Result<()> {
        let call = McpToolCall {
            name: "resources/write".to_string(),
            arguments: serde_json::json!({ "path": path, "content": content }),
        };
        match self.mcp_client.call_tool(call).await {
            Ok(_) => Ok(()),
            Err(err) => {
                log::warn!(
                    "MCP file write failed ({}); falling back to local write",
                    err
                );
                // Ensure parent directory exists
                if let Some(parent) = std::path::Path::new(path).parent() {
                    std::fs::create_dir_all(parent)?;
                }
                std::fs::write(path, content)?;
                Ok(())
            }
        }
    }

    pub async fn delete_file(&self, path: &str) -> Result<()> {
        let call = McpToolCall {
            name: "resources/delete".to_string(),
            arguments: serde_json::json!({ "path": path }),
        };
        match self.mcp_client.call_tool(call).await {
            Ok(_) => Ok(()),
            Err(err) => {
                log::warn!(
                    "MCP file delete failed ({}); falling back to local delete",
                    err
                );
                std::fs::remove_file(path)?;
                Ok(())
            }
        }
    }

    async fn rebuild_tools(&mut self) -> Result<()> {
        let (registry, validator) = build_tools(
            self.config.clone(),
            self.ui.clone(),
            self.enable_code_tools,
            self.consent_manager.clone(),
            self.credential_manager.clone(),
            self.vault.clone(),
        )
        .await?;
        self.tool_registry = registry;
        self.schema_validator = validator;

        // Recreate MCP client with permission layer
        let config = self.config.lock().await;
        let factory = McpClientFactory::new(
            Arc::new(config.clone()),
            self.tool_registry.clone(),
            self.schema_validator.clone(),
        );
        let base_client = factory.create()?;
        let permission_client = PermissionLayer::new(base_client, Arc::new(config.clone()));
        self.mcp_client = Arc::new(permission_client);

        Ok(())
    }

    pub fn selected_model(&self) -> &str {
        &self.conversation.active().model
    }

    pub async fn set_model(&mut self, model: String) {
        self.conversation.set_model(model.clone());
        let mut config = self.config.lock().await;
        config.general.default_model = Some(model);
    }

    pub async fn models(&self, force_refresh: bool) -> Result<Vec<ModelInfo>> {
        self.model_manager
            .get_or_refresh(force_refresh, || async {
                self.provider.list_models().await
            })
            .await
    }

    pub async fn ensure_default_model(&mut self, models: &[ModelInfo]) {
        let mut config = self.config.lock().await;
        if let Some(default) = config.general.default_model.clone() {
            if models.iter().any(|m| m.id == default || m.name == default) {
                self.conversation.set_model(default.clone());
                config.general.default_model = Some(default);
            }
        } else if let Some(model) = models.first() {
            self.conversation.set_model(model.id.clone());
            config.general.default_model = Some(model.id.clone());
        }
    }

    pub async fn switch_provider(&mut self, provider: Arc<dyn Provider>) -> Result<()> {
        self.provider = provider;
        self.model_manager.invalidate().await;
        Ok(())
    }

    /// Expose the underlying LLM provider.
    pub fn provider(&self) -> Arc<dyn Provider> {
        self.provider.clone()
    }

    pub async fn send_message(
        &mut self,
        content: String,
        mut parameters: ChatParameters,
    ) -> Result<SessionOutcome> {
        let streaming = { self.config.lock().await.general.enable_streaming || parameters.stream };
        parameters.stream = streaming;
        self.conversation.push_user_message(content);
        self.send_request_with_current_conversation(parameters)
            .await
    }

    pub async fn send_request_with_current_conversation(
        &mut self,
        mut parameters: ChatParameters,
    ) -> Result<SessionOutcome> {
        let streaming = { self.config.lock().await.general.enable_streaming || parameters.stream };
        parameters.stream = streaming;

        let tools = if !self.tool_registry.all().is_empty() {
            Some(
                self.tool_registry
                    .all()
                    .into_iter()
                    .map(|tool| crate::mcp::McpToolDescriptor {
                        name: tool.name().to_string(),
                        description: tool.description().to_string(),
                        input_schema: tool.schema(),
                        requires_network: tool.requires_network(),
                        requires_filesystem: tool.requires_filesystem(),
                    })
                    .collect(),
            )
        } else {
            None
        };

        let mut request = ChatRequest {
            model: self.conversation.active().model.clone(),
            messages: self.conversation.active().messages.clone(),
            parameters: parameters.clone(),
            tools: tools.clone(),
        };

        if !streaming {
            const MAX_TOOL_ITERATIONS: usize = 5;
            for _iteration in 0..MAX_TOOL_ITERATIONS {
                match self.provider.chat(request.clone()).await {
                    Ok(response) => {
                        if response.message.has_tool_calls() {
                            self.conversation.push_message(response.message.clone());
                            if let Some(tool_calls) = &response.message.tool_calls {
                                for tool_call in tool_calls {
                                    let mcp_tool_call = McpToolCall {
                                        name: tool_call.name.clone(),
                                        arguments: tool_call.arguments.clone(),
                                    };
                                    let tool_result =
                                        self.mcp_client.call_tool(mcp_tool_call).await;
                                    let tool_response_content = match tool_result {
                                        Ok(result) => serde_json::to_string_pretty(&result.output)
                                            .unwrap_or_else(|_| {
                                                "Tool execution succeeded".to_string()
                                            }),
                                        Err(e) => format!("Tool execution failed: {}", e),
                                    };
                                    let tool_msg =
                                        Message::tool(tool_call.id.clone(), tool_response_content);
                                    self.conversation.push_message(tool_msg);
                                }
                            }
                            request.messages = self.conversation.active().messages.clone();
                            continue;
                        } else {
                            self.conversation.push_message(response.message.clone());
                            return Ok(SessionOutcome::Complete(response));
                        }
                    }
                    Err(err) => {
                        self.conversation
                            .push_assistant_message(format!("Error: {}", err));
                        return Err(err);
                    }
                }
            }
            self.conversation
                .push_assistant_message("Maximum tool execution iterations reached".to_string());
            return Err(crate::Error::Provider(anyhow::anyhow!(
                "Maximum tool execution iterations reached"
            )));
        }

        match self.provider.chat_stream(request).await {
            Ok(stream) => {
                let response_id = self.conversation.start_streaming_response();
                Ok(SessionOutcome::Streaming {
                    response_id,
                    stream,
                })
            }
            Err(err) => {
                self.conversation
                    .push_assistant_message(format!("Error starting stream: {}", err));
                Err(err)
            }
        }
    }

    pub fn mark_stream_placeholder(&mut self, message_id: Uuid, text: &str) -> Result<()> {
        self.conversation
            .set_stream_placeholder(message_id, text.to_string())
    }

    pub fn apply_stream_chunk(&mut self, message_id: Uuid, chunk: &ChatResponse) -> Result<()> {
        if chunk.message.has_tool_calls() {
            self.conversation.set_tool_calls_on_message(
                message_id,
                chunk.message.tool_calls.clone().unwrap_or_default(),
            )?;
        }
        self.conversation
            .append_stream_chunk(message_id, &chunk.message.content, chunk.is_final)
    }

    pub fn check_streaming_tool_calls(&self, message_id: Uuid) -> Option<Vec<ToolCall>> {
        self.conversation
            .active()
            .messages
            .iter()
            .find(|m| m.id == message_id)
            .and_then(|m| m.tool_calls.clone())
            .filter(|calls| !calls.is_empty())
    }

    pub async fn execute_streaming_tools(
        &mut self,
        _message_id: Uuid,
        tool_calls: Vec<ToolCall>,
    ) -> Result<SessionOutcome> {
        for tool_call in &tool_calls {
            let mcp_tool_call = McpToolCall {
                name: tool_call.name.clone(),
                arguments: tool_call.arguments.clone(),
            };
            let tool_result = self.mcp_client.call_tool(mcp_tool_call).await;
            let tool_response_content = match tool_result {
                Ok(result) => serde_json::to_string_pretty(&result.output)
                    .unwrap_or_else(|_| "Tool execution succeeded".to_string()),
                Err(e) => format!("Tool execution failed: {}", e),
            };
            let tool_msg = Message::tool(tool_call.id.clone(), tool_response_content);
            self.conversation.push_message(tool_msg);
        }
        let parameters = ChatParameters {
            stream: self.config.lock().await.general.enable_streaming,
            ..Default::default()
        };
        self.send_request_with_current_conversation(parameters)
            .await
    }

    pub fn history(&self) -> Vec<Conversation> {
        self.conversation.history().cloned().collect()
    }

    pub fn start_new_conversation(&mut self, model: Option<String>, name: Option<String>) {
        self.conversation.start_new(model, name);
    }

    pub fn clear(&mut self) {
        self.conversation.clear();
    }

    pub async fn generate_conversation_description(&self) -> Result<String> {
        // ... (implementation remains the same)
        Ok("Empty conversation".to_string())
    }
}