use axum::{
    extract::Path,
    http::StatusCode,
    response::{IntoResponse, Response},
    routing::{get, post},
    Json, Router,
};
use serde::Deserialize;
use serde_json::{json, Value};
use std::net::SocketAddr;

use crate::{db, db::log_event};

/// 从 settings 表读取 MCP 端口，默认 27190
pub fn read_port() -> u16 {
    db::pool()
        .get()
        .ok()
        .and_then(|c| {
            c.query_row(
                "SELECT value FROM settings WHERE key = 'mcp_port'",
                [],
                |r| r.get::<_, String>(0),
            )
            .ok()
        })
        .and_then(|v| v.parse().ok())
        .unwrap_or(27190)
}

/// 启动 MCP HTTP 服务（Streamable HTTP transport）
pub async fn start(port: u16) {
    let app = Router::new()
        .route("/health", get(health))
        .route("/mcp/group/:group_id", post(handle_mcp));

    let addr = SocketAddr::from(([127, 0, 0, 1], port));
    match tokio::net::TcpListener::bind(addr).await {
        Ok(listener) => {
            log_event("mcp_server", "info", &format!("MCP Server 已启动，端口 {port}"), None);
            if let Err(e) = axum::serve(listener, app).await {
                log_event("mcp_server", "error", &format!("Server 异常退出: {e}"), None);
            }
        }
        Err(e) => log_event("mcp_server", "error", &format!("绑定端口 {port} 失败: {e}"), None),
    }
}

async fn health() -> &'static str {
    "炼境 MCP Server running"
}

// ── JSON-RPC 类型 ─────────────────────────────────────────────────────────────

#[derive(Deserialize)]
struct RpcRequest {
    #[allow(dead_code)]
    jsonrpc: String,
    method: String,
    id: Option<Value>,
    #[serde(default)]
    params: Option<Value>,
}

async fn handle_mcp(Path(group_id): Path<String>, Json(req): Json<RpcRequest>) -> Response {
    // MCP 通知（无 id）→ 202 Accepted，无需响应体
    if req.id.is_none() {
        return StatusCode::ACCEPTED.into_response();
    }

    let id = req.id.clone();

    let result = match req.method.as_str() {
        "initialize" => json!({
            "protocolVersion": "2024-11-05",
            "capabilities": { "tools": {} },
            "serverInfo": {
                "name": "炼境",
                "version": env!("CARGO_PKG_VERSION")
            }
        }),
        "tools/list" => tools_list_result(),
        "tools/call" => tools_call(&group_id, req.params.as_ref()).await,
        _ => {
            return Json(json!({
                "jsonrpc": "2.0",
                "id": id,
                "error": { "code": -32601, "message": "Method not found" }
            }))
            .into_response();
        }
    };

    Json(json!({ "jsonrpc": "2.0", "id": id, "result": result })).into_response()
}

// ── 工具定义 ──────────────────────────────────────────────────────────────────

fn tools_list_result() -> Value {
    json!({
        "tools": [
            {
                "name": "get_diagnostics",
                "description": "查询炼境运行时诊断信息：MCP Server 启动状态、各项目 MCP 配置注入结果、最近错误日志。排查功能是否正常时首先调用此工具。",
                "inputSchema": {
                    "type": "object",
                    "properties": {},
                    "required": []
                }
            },
            {
                "name": "list_group_projects",
                "description": "列出产品组内所有成员项目，包含名称、路径、平台、技术栈、角色等信息",
                "inputSchema": {
                    "type": "object",
                    "properties": {},
                    "required": []
                }
            },
            {
                "name": "get_project_blueprint",
                "description": "读取产品组内某个项目的蓝图文件（.blueprint/manifest.yaml），了解该项目的模块与任务状态",
                "inputSchema": {
                    "type": "object",
                    "properties": {
                        "project_id": {
                            "type": "string",
                            "description": "项目 workspace ID（来自 list_group_projects 的返回结果）"
                        }
                    },
                    "required": ["project_id"]
                }
            },
            {
                "name": "get_project_file",
                "description": "读取产品组内某个项目的任意文件内容，如 openapi.yaml、README.md、src/types.ts 等",
                "inputSchema": {
                    "type": "object",
                    "properties": {
                        "project_id": {
                            "type": "string",
                            "description": "项目 workspace ID"
                        },
                        "relative_path": {
                            "type": "string",
                            "description": "相对于项目根目录的文件路径，如 openapi.yaml 或 src/api/routes.ts"
                        }
                    },
                    "required": ["project_id", "relative_path"]
                }
            },
            {
                "name": "get_project_mentor_context",
                "description": "获取产品组内某个项目的完整导师上下文——包含健康状态、蓝图进度摘要、近期错误日志，以及格式化好的 Markdown 报告（可直接用于质量分析和成长建议）",
                "inputSchema": {
                    "type": "object",
                    "properties": {
                        "project_id": {
                            "type": "string",
                            "description": "项目 workspace ID（来自 list_group_projects 的返回结果）"
                        }
                    },
                    "required": ["project_id"]
                }
            },
            {
                "name": "append_project_note",
                "description": "将 Claude 的分析结论、建议或洞察写入项目笔记，供未来会话和用户在炼境中查阅。分析完项目后，将核心观点记录在此。",
                "inputSchema": {
                    "type": "object",
                    "properties": {
                        "project_id": {
                            "type": "string",
                            "description": "项目 workspace ID（来自 list_group_projects 的返回结果）"
                        },
                        "content": {
                            "type": "string",
                            "description": "笔记内容，支持 Markdown。建议包含：核心观点、发现的问题、下一步建议。"
                        }
                    },
                    "required": ["project_id", "content"]
                }
            },
            {
                "name": "get_project_snapshots",
                "description": "获取项目的历史健康快照（每日一条），包含 git 提交间隔、蓝图完成率、阻塞任务数、错误情况。用于分析趋势、识别高价值改进变量。",
                "inputSchema": {
                    "type": "object",
                    "properties": {
                        "project_id": {
                            "type": "string",
                            "description": "项目 workspace ID（来自 list_group_projects 的返回结果）"
                        },
                        "days": {
                            "type": "integer",
                            "description": "查询最近 N 天的快照，默认 30"
                        }
                    },
                    "required": ["project_id"]
                }
            }
        ]
    })
}

// ── 工具调用 ──────────────────────────────────────────────────────────────────

async fn tools_call(group_id: &str, params: Option<&Value>) -> Value {
    let tool_name = params
        .and_then(|p| p.get("name"))
        .and_then(|n| n.as_str())
        .unwrap_or("")
        .to_string();
    let args = params
        .and_then(|p| p.get("arguments"))
        .cloned()
        .unwrap_or(json!({}));
    let gid = group_id.to_string();

    let outcome = tokio::task::spawn_blocking(move || match tool_name.as_str() {
        "get_diagnostics" => get_diagnostics(),
        "list_group_projects" => list_group_projects(&gid),
        "get_project_blueprint" => {
            let pid = args.get("project_id").and_then(|v| v.as_str()).unwrap_or("");
            get_project_blueprint(&gid, pid)
        }
        "get_project_file" => {
            let pid = args.get("project_id").and_then(|v| v.as_str()).unwrap_or("");
            let rel = args
                .get("relative_path")
                .and_then(|v| v.as_str())
                .unwrap_or("");
            get_project_file(&gid, pid, rel)
        }
        "get_project_mentor_context" => {
            let pid = args.get("project_id").and_then(|v| v.as_str()).unwrap_or("");
            get_project_mentor_context(&gid, pid)
        }
        "append_project_note" => {
            let pid = args.get("project_id").and_then(|v| v.as_str()).unwrap_or("");
            let content = args.get("content").and_then(|v| v.as_str()).unwrap_or("");
            append_project_note(&gid, pid, content)
        }
        "get_project_snapshots" => {
            let pid = args.get("project_id").and_then(|v| v.as_str()).unwrap_or("");
            let days = args.get("days").and_then(|v| v.as_u64()).unwrap_or(30) as u32;
            get_project_snapshots(&gid, pid, days)
        }
        _ => Err(format!("未知工具: {}", tool_name)),
    })
    .await;

    match outcome {
        Ok(Ok(text)) => json!({ "content": [{ "type": "text", "text": text }] }),
        Ok(Err(e)) => json!({ "content": [{ "type": "text", "text": e }], "isError": true }),
        Err(e) => json!({ "content": [{ "type": "text", "text": e.to_string() }], "isError": true }),
    }
}

// ── 工具实现（同步，由 spawn_blocking 包裹）──────────────────────────────────

fn get_diagnostics() -> Result<String, String> {
    let conn = db::pool().get().map_err(|e| e.to_string())?;
    let port = read_port();

    // 服务启动时间（首条 mcp_server info 日志）
    let start_time: Option<String> = conn.query_row(
        "SELECT ts FROM runtime_logs WHERE category = 'mcp_server' AND level = 'info' ORDER BY id ASC LIMIT 1",
        [],
        |r| r.get(0),
    ).ok();

    let mut out = String::new();
    out.push_str("## 炼境 MCP 诊断报告\n\n");
    out.push_str(&format!("- **服务端口**: {}\n", port));
    out.push_str(&format!("- **启动时间**: {}\n\n", start_time.as_deref().unwrap_or("未知（可能在本次日志之前启动）")));

    // MCP 注入状态：每个 project_id 取最后一条
    out.push_str("### MCP 注入状态（每个项目最后一次结果）\n\n");
    let mut stmt = conn.prepare(
        "SELECT context, level, message, ts
         FROM runtime_logs
         WHERE category = 'mcp_inject'
           AND id IN (
               SELECT MAX(id) FROM runtime_logs
               WHERE category = 'mcp_inject'
               GROUP BY json_extract(context, '$.project_id')
           )
         ORDER BY ts DESC
         LIMIT 50",
    ).map_err(|e| e.to_string())?;

    let inject_rows: Vec<(Option<String>, String, String, String)> = stmt
        .query_map([], |row| Ok((row.get(0)?, row.get(1)?, row.get(2)?, row.get(3)?)))
        .map_err(|e| e.to_string())?
        .filter_map(|r| r.ok())
        .collect();

    if inject_rows.is_empty() {
        out.push_str("_暂无注入记录（成员加入产品组时会产生）_\n\n");
    } else {
        for (ctx, level, msg, ts) in &inject_rows {
            let project_id = ctx.as_deref()
                .and_then(|s| serde_json::from_str::<serde_json::Value>(s).ok())
                .and_then(|v| v.get("project_id").and_then(|x| x.as_str()).map(|s| s.to_string()))
                .unwrap_or_else(|| "unknown".to_string());
            let icon = if level == "info" { "✅" } else { "⚠️" };
            out.push_str(&format!("- {} `{}` — {} _({})\n", icon, project_id, msg, ts));
        }
        out.push('\n');
    }

    // 最近 20 条 error/warn
    out.push_str("### 最近错误日志（最多 20 条）\n\n");
    let mut stmt2 = conn.prepare(
        "SELECT ts, category, level, message FROM runtime_logs
         WHERE level IN ('error', 'warn')
         ORDER BY id DESC LIMIT 20",
    ).map_err(|e| e.to_string())?;

    let error_rows: Vec<(String, String, String, String)> = stmt2
        .query_map([], |row| Ok((row.get(0)?, row.get(1)?, row.get(2)?, row.get(3)?)))
        .map_err(|e| e.to_string())?
        .filter_map(|r| r.ok())
        .collect();

    if error_rows.is_empty() {
        out.push_str("_无错误记录_ ✅\n");
    } else {
        for (ts, cat, level, msg) in &error_rows {
            out.push_str(&format!("- `[{}]` **{}** `{}` — {}\n", ts, level, cat, msg));
        }
    }

    // ── 系统健康（复用 health check 逻辑）────────────────────────────────────
    out.push_str("\n### 系统健康\n\n");
    let report = crate::commands::settings::collect_health_report();
    out.push_str(&format!("检查时间：{}\n\n", report.checked_at));
    out.push_str("| 检查项 | 状态 | 详情 |\n|--------|------|------|\n");
    for item in &report.items {
        let icon = match item.status.as_str() {
            "ok"    => "✅",
            "warn"  => "⚠️",
            "error" => "❌",
            _       => "—",
        };
        out.push_str(&format!(
            "| {} | {} {} | {} |\n",
            item.name, icon, item.status,
            item.detail.as_deref().unwrap_or("-")
        ));
    }

    // ── 质量指标 ──────────────────────────────────────────────────────────────
    out.push_str("\n### 质量指标\n\n");
    let q = &report.quality;

    out.push_str(&format!("- **休眠项目**（>30天未 push）：{} 个\n", q.dormant_projects.len()));
    for p in &q.dormant_projects {
        out.push_str(&format!("  - {} （{} 天）\n", p.name, p.days_since_push));
    }

    out.push_str(&format!("- **孤立项目**（无分组 & 无 repo）：{} 个\n", q.orphaned_projects.len()));
    for p in &q.orphaned_projects {
        out.push_str(&format!("  - {}\n", p.name));
    }

    out.push_str(&format!(
        "- **MCP 注入异常产品组**（近 7 天）：{} 个\n",
        q.groups_with_inject_warn.len()
    ));
    for gid in &q.groups_with_inject_warn {
        out.push_str(&format!("  - `{}`\n", gid));
    }

    out.push_str(&format!("- **无本地路径项目**：{} 个\n", q.projects_without_path));

    Ok(out)
}

fn list_group_projects(group_id: &str) -> Result<String, String> {
    let conn = db::pool().get().map_err(|e| e.to_string())?;
    let mut stmt = conn
        .prepare(
            "SELECT pw.id, pp.name, pw.platform, pw.win_path, pw.wsl_path,
                    pp.tech_stack, pgm.role
             FROM project_group_map pgm
             JOIN project_workspaces pw ON pw.id = pgm.project_id
             JOIN project_profiles   pp ON pp.id = pw.profile_id
             WHERE pgm.group_id = ?1",
        )
        .map_err(|e| e.to_string())?;

    let rows: Vec<String> = stmt
        .query_map([group_id], |row| {
            let id: String = row.get(0)?;
            let name: String = row.get(1)?;
            let platform: Option<String> = row.get(2)?;
            let win_path: Option<String> = row.get(3)?;
            let wsl_path: Option<String> = row.get(4)?;
            let tech_stack: Option<String> = row.get(5)?;
            let role: Option<String> = row.get(6)?;
            Ok(format!(
                "- **{}** (id: `{}`)\n  平台: {} | 技术栈: {}{}\n  Windows 路径: {}\n  WSL 路径: {}",
                name,
                id,
                platform.as_deref().unwrap_or("unknown"),
                tech_stack.as_deref().unwrap_or("未配置"),
                role.map(|r| format!(" | 角色: {}", r)).unwrap_or_default(),
                win_path.as_deref().unwrap_or("未配置"),
                wsl_path.as_deref().unwrap_or("未配置"),
            ))
        })
        .map_err(|e| e.to_string())?
        .filter_map(|r| r.ok())
        .collect();

    if rows.is_empty() {
        return Ok("该产品组暂无成员项目。".to_string());
    }
    Ok(format!(
        "产品组成员（共 {} 个项目）：\n\n{}",
        rows.len(),
        rows.join("\n\n")
    ))
}

fn get_project_blueprint(group_id: &str, project_id: &str) -> Result<String, String> {
    let root = resolve_project_root(group_id, project_id)?;
    let path = root.join(".blueprint").join("manifest.yaml");
    std::fs::read_to_string(&path)
        .map_err(|e| format!("读取蓝图失败（{}）: {}", path.display(), e))
}

fn get_project_file(group_id: &str, project_id: &str, relative_path: &str) -> Result<String, String> {
    if relative_path.contains("..") {
        return Err("路径不允许包含 \"..\"".to_string());
    }
    let root = resolve_project_root(group_id, project_id)?;
    let path = root.join(relative_path);
    std::fs::read_to_string(&path)
        .map_err(|e| format!("读取文件失败（{}）: {}", path.display(), e))
}

/// 根据 group_id + project_id 解析项目根目录路径
/// WSL 项目自动转换为 Windows UNC 路径（\\wsl.localhost\<distro>\...）
fn resolve_project_root(group_id: &str, project_id: &str) -> Result<std::path::PathBuf, String> {
    let conn = db::pool().get().map_err(|e| e.to_string())?;

    let row: rusqlite::Result<(Option<String>, Option<String>, Option<String>)> = conn.query_row(
        "SELECT pw.win_path, pw.wsl_path, pw.platform
         FROM project_group_map pgm
         JOIN project_workspaces pw ON pw.id = pgm.project_id
         WHERE pgm.group_id = ?1 AND pgm.project_id = ?2",
        [group_id, project_id],
        |r| Ok((r.get(0)?, r.get(1)?, r.get(2)?)),
    );

    let (win_path, wsl_path, platform) = row.map_err(|_| {
        format!("项目 {} 不属于产品组 {}，或项目不存在", project_id, group_id)
    })?;

    if platform.as_deref() == Some("wsl") {
        let wsl = wsl_path.ok_or_else(|| "WSL 项目未配置 wsl_path".to_string())?;
        let distro: String = conn
            .query_row(
                "SELECT value FROM settings WHERE key = 'wsl_distro'",
                [],
                |r| r.get(0),
            )
            .unwrap_or_else(|_| "Ubuntu".to_string());
        // /home/user/project → \\wsl.localhost\Ubuntu\home\user\project
        let inner = wsl.trim_start_matches('/').replace('/', "\\");
        Ok(std::path::PathBuf::from(format!(
            "\\\\wsl.localhost\\{}\\{}",
            distro, inner
        )))
    } else {
        let win = win_path.ok_or_else(|| "Windows 项目未配置 win_path".to_string())?;
        Ok(std::path::PathBuf::from(win))
    }
}

fn get_project_mentor_context(group_id: &str, project_id: &str) -> Result<String, String> {
    // 验证项目属于该产品组（与其他 MCP 工具一致）
    let conn = db::pool().get().map_err(|e| e.to_string())?;
    let exists: bool = conn
        .query_row(
            "SELECT COUNT(*) FROM project_group_map WHERE group_id = ?1 AND project_id = ?2",
            [group_id, project_id],
            |r| r.get::<_, i64>(0),
        )
        .map(|n| n > 0)
        .unwrap_or(false);
    if !exists {
        return Err(format!("项目 {} 不属于产品组 {}，或项目不存在", project_id, group_id));
    }

    let ctx = crate::commands::mentor::get_mentor_context(project_id.to_string())
        .map_err(|e| format!("获取导师上下文失败: {e}"))?;
    Ok(ctx.mentor_markdown)
}

fn append_project_note(group_id: &str, project_id: &str, content: &str) -> Result<String, String> {
    if content.trim().is_empty() {
        return Err("笔记内容不能为空".to_string());
    }
    let conn = db::pool().get().map_err(|e| e.to_string())?;
    // 校验 project_id 属于该 group
    let exists: bool = conn
        .query_row(
            "SELECT COUNT(*) FROM project_group_map WHERE group_id = ?1 AND project_id = ?2",
            [group_id, project_id],
            |r| r.get::<_, i64>(0),
        )
        .map(|n| n > 0)
        .unwrap_or(false);
    if !exists {
        return Err(format!("项目 {} 不属于产品组 {}，或项目不存在", project_id, group_id));
    }
    conn.execute(
        "INSERT INTO project_notes (project_id, source, content) VALUES (?1, 'mcp', ?2)",
        rusqlite::params![project_id, content],
    )
    .map_err(|e| e.to_string())?;
    Ok("笔记已保存 ✅".to_string())
}

fn get_project_snapshots(group_id: &str, project_id: &str, days: u32) -> Result<String, String> {
    let conn = db::pool().get().map_err(|e| e.to_string())?;

    // 校验项目属于该产品组
    let exists: bool = conn
        .query_row(
            "SELECT COUNT(*) FROM project_group_map WHERE group_id = ?1 AND project_id = ?2",
            [group_id, project_id],
            |r| r.get::<_, i64>(0),
        )
        .map(|n| n > 0)
        .unwrap_or(false);
    if !exists {
        return Err(format!("项目 {} 不属于产品组 {}，或项目不存在", project_id, group_id));
    }

    let mut stmt = conn
        .prepare(
            "SELECT snapshot_date, days_since_commit, blueprint_done_rate,
                    blueprint_in_progress, blueprint_blocked, has_errors
             FROM project_snapshots
             WHERE project_id = ?1
               AND snapshot_date >= date('now', 'localtime', ?2)
             ORDER BY snapshot_date ASC",
        )
        .map_err(|e| e.to_string())?;

    let offset = format!("-{} days", days);
    let rows: Vec<(String, Option<i64>, Option<f64>, i64, i64, i64)> = stmt
        .query_map(rusqlite::params![project_id, offset], |r| {
            Ok((r.get(0)?, r.get(1)?, r.get(2)?, r.get(3)?, r.get(4)?, r.get(5)?))
        })
        .map_err(|e| e.to_string())?
        .filter_map(|r| r.ok())
        .collect();

    if rows.is_empty() {
        return Ok(format!(
            "项目 `{}` 暂无历史快照（快照在每次应用启动时写入，最多保留 {} 天）。",
            project_id, days
        ));
    }

    let mut md = format!(
        "# 项目历史快照：`{}`\n\n最近 {} 天，共 {} 条记录\n\n",
        project_id,
        days,
        rows.len()
    );
    md.push_str("| 日期 | 距上次提交(天) | 蓝图完成率 | 进行中模块 | 阻塞任务 | 有错误 |\n");
    md.push_str("|------|--------------|-----------|-----------|---------|------|\n");

    for (date, days_commit, done_rate, in_prog, blocked, has_err) in &rows {
        let commit_col = days_commit
            .map(|d| d.to_string())
            .unwrap_or_else(|| "—".to_string());
        let rate_col = done_rate
            .map(|r| format!("{:.0}%", r * 100.0))
            .unwrap_or_else(|| "—".to_string());
        let err_col = if *has_err == 1 { "⚠️" } else { "✅" };
        md.push_str(&format!(
            "| {} | {} | {} | {} | {} | {} |\n",
            date, commit_col, rate_col, in_prog, blocked, err_col
        ));
    }

    md.push_str("\n---\n\n请根据以上趋势数据，分析哪些变量与项目停滞或健康度下降最相关，并给出改进建议。\n");

    Ok(md)
}