//! Reference MCP connector presets shared across leading client ecosystems.
//!
//! These definitions intentionally avoid vendor-specific naming while capturing
//! the union of commonly shipped servers: local tooling, automation, retrieval,
//! observability, and productivity integrations.

use crate::config::McpServerConfig;
use crate::tools::tool_identifier_violation;
use anyhow::{Result, anyhow};
use std::collections::{HashMap, HashSet};
use std::str::FromStr;

/// High-level preset tiers exposed to CLI/TUI.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum PresetTier {
    Standard,
    Extended,
    Full,
}

impl PresetTier {
    pub fn as_str(self) -> &'static str {
        match self {
            PresetTier::Standard => "standard",
            PresetTier::Extended => "extended",
            PresetTier::Full => "full",
        }
    }

    pub fn all() -> &'static [PresetTier] {
        &[PresetTier::Standard, PresetTier::Extended, PresetTier::Full]
    }

    fn description(self) -> &'static str {
        match self {
            PresetTier::Standard => {
                "Core local tooling (filesystem, terminal, git, browser, fetch, python, notebook)."
            }
            PresetTier::Extended => {
                "Standard + retrieval/automation connectors (search, scraping, planning)."
            }
            PresetTier::Full => {
                "Extended + SaaS integrations (observability, productivity, data stores)."
            }
        }
    }
}

impl FromStr for PresetTier {
    type Err = anyhow::Error;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        let normalized = s.trim().to_ascii_lowercase();
        match normalized.as_str() {
            "standard" | "std" => Ok(PresetTier::Standard),
            "extended" | "ext" => Ok(PresetTier::Extended),
            "full" | "all" => Ok(PresetTier::Full),
            other => Err(anyhow!(format!(
                "Unknown preset tier '{other}'. Expected one of: standard, extended, full."
            ))),
        }
    }
}

/// Lightweight description of an MCP connector entry.
#[derive(Debug, Clone, Copy)]
pub struct PresetConnector {
    pub name: &'static str,
    pub command: &'static str,
    pub args: &'static [&'static str],
    pub env: &'static [(&'static str, &'static str)],
    pub description: &'static str,
    pub capabilities: &'static [&'static str],
}

impl PresetConnector {
    pub fn to_config(&self) -> McpServerConfig {
        if let Some(reason) = tool_identifier_violation(self.name) {
            panic!("Invalid preset connector '{}': {reason}", self.name);
        }

        McpServerConfig {
            name: self.name.to_string(),
            command: self.command.to_string(),
            args: self.args.iter().map(|arg| arg.to_string()).collect(),
            transport: "stdio".to_string(),
            env: self
                .env
                .iter()
                .map(|(k, v)| ((*k).to_string(), (*v).to_string()))
                .collect::<HashMap<_, _>>(),
            oauth: None,
            rpc_timeout_secs: None,
        }
    }
}

const STANDARD_CONNECTORS: &[PresetConnector] = &[
    PresetConnector {
        name: "filesystem",
        command: "npx",
        args: &["-y", "@modelcontextprotocol/server-filesystem"],
        env: &[],
        description: "Mount local project directories for read/write operations.",
        capabilities: &["filesystem", "local"],
    },
    PresetConnector {
        name: "terminal",
        command: "npx",
        args: &["-y", "@modelcontextprotocol/server-shell"],
        env: &[],
        description: "Execute shell commands within a sandboxed environment.",
        capabilities: &["shell", "local"],
    },
    PresetConnector {
        name: "git",
        command: "npx",
        args: &["-y", "@modelcontextprotocol/server-git"],
        env: &[],
        description: "Interact with Git repositories for status, diffs, commits.",
        capabilities: &["git", "local"],
    },
    PresetConnector {
        name: "browser",
        command: "npx",
        args: &["-y", "@modelcontextprotocol/server-browser"],
        env: &[],
        description: "Perform scripted browser automation via headless Chromium.",
        capabilities: &["browser", "automation"],
    },
    PresetConnector {
        name: "fetch",
        command: "npx",
        args: &["-y", "@modelcontextprotocol/server-fetch"],
        env: &[],
        description: "Issue structured HTTP requests for REST/JSON APIs.",
        capabilities: &["network"],
    },
    PresetConnector {
        name: "python",
        command: "npx",
        args: &["-y", "@modelcontextprotocol/server-python"],
        env: &[],
        description: "Run Python snippets in an isolated interpreter.",
        capabilities: &["compute", "python"],
    },
    PresetConnector {
        name: "notebook",
        command: "npx",
        args: &["-y", "@modelcontextprotocol/server-notebook"],
        env: &[],
        description: "Evaluate notebook cells and manage Jupyter sessions.",
        capabilities: &["compute", "notebook"],
    },
    PresetConnector {
        name: "sequential_thinking",
        command: "npx",
        args: &["-y", "@modelcontextprotocol/server-sequential-thinking"],
        env: &[],
        description: "Structured reasoning helper with planning support.",
        capabilities: &["planning"],
    },
    PresetConnector {
        name: "puppeteer",
        command: "npx",
        args: &["-y", "@modelcontextprotocol/server-puppeteer"],
        env: &[],
        description: "Full-browser automation via Puppeteer.",
        capabilities: &["browser", "automation"],
    },
];

const EXTENDED_CONNECTORS: &[PresetConnector] = &[
    PresetConnector {
        name: "brave_search",
        command: "npx",
        args: &["-y", "@modelcontextprotocol/server-brave-search"],
        env: &[("BRAVE_API_KEY", "")],
        description: "Search the web using Brave Search APIs.",
        capabilities: &["search", "network"],
    },
    PresetConnector {
        name: "tavily",
        command: "npx",
        args: &["-y", "@tavily/mcp-server"],
        env: &[("TAVILY_API_KEY", "")],
        description: "General-purpose research with Tavily's search/reasoning API.",
        capabilities: &["search", "network"],
    },
    PresetConnector {
        name: "perplexity",
        command: "npx",
        args: &["-y", "@perplexity-ai/mcp-server"],
        env: &[("PPLX_API_KEY", "")],
        description: "Ask questions against Perplexity's API.",
        capabilities: &["qa", "network"],
    },
    PresetConnector {
        name: "firecrawl",
        command: "npx",
        args: &["-y", "@firecrawl/mcp-server"],
        env: &[("FIRECRAWL_TOKEN", "")],
        description: "Crawl and scrape webpages for summarisation.",
        capabilities: &["scrape", "network"],
    },
    PresetConnector {
        name: "memory_bank",
        command: "npx",
        args: &["-y", "@modelcontextprotocol/server-memory"],
        env: &[],
        description: "Persist structured memories for long-lived tasks.",
        capabilities: &["memory"],
    },
];

const FULL_CONNECTORS: &[PresetConnector] = &[
    PresetConnector {
        name: "sentry",
        command: "npx",
        args: &["-y", "@sentry/mcp-server"],
        env: &[("SENTRY_AUTH_TOKEN", "")],
        description: "Query issues and alerts from Sentry.",
        capabilities: &["observability", "network"],
    },
    PresetConnector {
        name: "notion",
        command: "npx",
        args: &["-y", "@notionhq/mcp-server"],
        env: &[("NOTION_API_KEY", "")],
        description: "Access Notion databases and pages.",
        capabilities: &["productivity", "network"],
    },
    PresetConnector {
        name: "slack",
        command: "npx",
        args: &["-y", "@slack/mcp-server"],
        env: &[("SLACK_BOT_TOKEN", "")],
        description: "Send messages and search channels in Slack.",
        capabilities: &["communication", "network"],
    },
    PresetConnector {
        name: "stripe",
        command: "npx",
        args: &["-y", "@stripe/mcp-server"],
        env: &[("STRIPE_API_KEY", "")],
        description: "Inspect customers, invoices, and payment intents.",
        capabilities: &["payments", "network"],
    },
    PresetConnector {
        name: "google_drive",
        command: "npx",
        args: &["-y", "@modelcontextprotocol/server-google-drive"],
        env: &[("GOOGLE_DRIVE_CREDENTIALS", "")],
        description: "Browse and fetch Google Drive documents.",
        capabilities: &["storage", "network"],
    },
    PresetConnector {
        name: "zapier",
        command: "npx",
        args: &["-y", "@zapier/mcp-server"],
        env: &[("ZAPIER_NLA_API_KEY", "")],
        description: "Trigger Zapier actions and workflows.",
        capabilities: &["automation", "network"],
    },
    PresetConnector {
        name: "postgresql",
        command: "npx",
        args: &["-y", "@modelcontextprotocol/server-postgresql"],
        env: &[],
        description: "Run SQL against a PostgreSQL database.",
        capabilities: &["database"],
    },
    PresetConnector {
        name: "sqlite",
        command: "npx",
        args: &["-y", "@modelcontextprotocol/server-sqlite"],
        env: &[],
        description: "Run SQL against local SQLite databases.",
        capabilities: &["database"],
    },
    PresetConnector {
        name: "redis",
        command: "npx",
        args: &["-y", "@modelcontextprotocol/server-redis"],
        env: &[],
        description: "Inspect Redis keys and run commands.",
        capabilities: &["cache", "database"],
    },
    PresetConnector {
        name: "qdrant",
        command: "npx",
        args: &["-y", "@modelcontextprotocol/server-qdrant"],
        env: &[],
        description: "Interact with Qdrant vector collections.",
        capabilities: &["vector", "database"],
    },
];

fn connectors_for_tier_internal(tier: PresetTier) -> Vec<PresetConnector> {
    let mut result = Vec::new();
    result.extend_from_slice(STANDARD_CONNECTORS);
    if matches!(tier, PresetTier::Extended | PresetTier::Full) {
        result.extend_from_slice(EXTENDED_CONNECTORS);
    }
    if matches!(tier, PresetTier::Full) {
        result.extend_from_slice(FULL_CONNECTORS);
    }
    result
}

/// Return connectors for the given tier (including lower tiers).
pub fn connectors_for_tier(tier: PresetTier) -> Vec<PresetConnector> {
    connectors_for_tier_internal(tier)
}

/// Describe the preset tiers for help output.
pub fn tier_descriptions() -> Vec<(PresetTier, &'static str)> {
    PresetTier::all()
        .iter()
        .map(|tier| (*tier, tier.description()))
        .collect()
}

/// Details about changes performed when applying a preset.
#[derive(Debug)]
pub struct PresetApplyReport {
    pub tier: PresetTier,
    pub added: Vec<String>,
    pub updated: Vec<String>,
    pub removed: Vec<String>,
}

impl PresetApplyReport {
    fn new(tier: PresetTier) -> Self {
        Self {
            tier,
            added: Vec::new(),
            updated: Vec::new(),
            removed: Vec::new(),
        }
    }
}

/// Details discovered during audit.
#[derive(Debug)]
pub struct PresetAuditReport {
    pub tier: PresetTier,
    pub missing: Vec<PresetConnector>,
    pub mismatched: Vec<(PresetConnector, McpServerConfig)>,
    pub extra: Vec<McpServerConfig>,
}

impl PresetAuditReport {
    fn new(tier: PresetTier) -> Self {
        Self {
            tier,
            missing: Vec::new(),
            mismatched: Vec::new(),
            extra: Vec::new(),
        }
    }
}

/// Apply the requested preset to the given configuration.
pub fn apply_preset(
    config: &mut crate::config::Config,
    tier: PresetTier,
    prune: bool,
) -> Result<PresetApplyReport> {
    let mut report = PresetApplyReport::new(tier);

    let connectors = connectors_for_tier_internal(tier);
    let expected_names: HashSet<&str> = connectors.iter().map(|c| c.name).collect();

    if prune {
        config.mcp_servers.retain(|existing| {
            if expected_names.contains(existing.name.as_str()) {
                true
            } else {
                report.removed.push(existing.name.clone());
                false
            }
        });
    }

    for connector in connectors {
        match config
            .mcp_servers
            .iter_mut()
            .find(|srv| srv.name == connector.name)
        {
            Some(existing) => {
                let candidate = connector.to_config();
                if existing.command != candidate.command
                    || existing.args != candidate.args
                    || existing.env != candidate.env
                {
                    *existing = candidate;
                    report.updated.push(connector.name.to_string());
                }
            }
            None => {
                config.mcp_servers.push(connector.to_config());
                report.added.push(connector.name.to_string());
            }
        }
    }

    config.refresh_mcp_servers(None)?;
    Ok(report)
}

/// Audit the configuration against a preset without mutating it.
pub fn audit_preset(config: &crate::config::Config, tier: PresetTier) -> PresetAuditReport {
    let mut report = PresetAuditReport::new(tier);

    let connectors = connectors_for_tier_internal(tier);
    let expected: HashMap<&str, &PresetConnector> =
        connectors.iter().map(|c| (c.name, c)).collect();
    let mut seen = HashSet::new();

    for server in &config.mcp_servers {
        if let Some(expected_connector) = expected.get(server.name.as_str()) {
            seen.insert(server.name.as_str());
            let expected_config = expected_connector.to_config();
            if expected_config.command != server.command
                || expected_config.args != server.args
                || expected_config.env != server.env
            {
                report
                    .mismatched
                    .push((**expected_connector, server.clone()));
            }
        } else {
            report.extra.push(server.clone());
        }
    }

    for connector in connectors {
        if !seen.contains(connector.name) {
            report.missing.push(connector);
        }
    }

    report
}