use crate::{db, db::log_event};
use serde_json::{json, Value};
use std::path::PathBuf;

const MCP_KEY_PREFIX: &str = "lian-jing:group-";

// ── 路径解析 ──────────────────────────────────────────────────────────────────

/// 解析项目根目录路径（WSL 项目自动转为 Windows UNC 路径）
fn project_root(project_id: &str) -> Result<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 win_path, wsl_path, platform FROM project_workspaces WHERE id = ?1",
        [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 {} 不存在", project_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());
        let inner = wsl.trim_start_matches('/').replace('/', "\\");
        Ok(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(PathBuf::from(win))
    }
}

fn settings_path(project_id: &str) -> Result<PathBuf, String> {
    Ok(project_root(project_id)?.join(".claude").join("settings.json"))
}

fn liangjing_path(project_id: &str) -> Result<PathBuf, String> {
    Ok(project_root(project_id)?.join(".claude").join("liangjing.json"))
}

/// 写炼境上下文文件，供子项目 Claude 会话直接读取 project_id / group_id
fn write_liangjing_context(project_id: &str, group_id: &str, port: u16) -> Result<(), String> {
    let path = liangjing_path(project_id)?;
    if let Some(parent) = path.parent() {
        std::fs::create_dir_all(parent)
            .map_err(|e| format!("创建 .claude 目录失败: {}", e))?;
    }
    let ctx = json!({
        "project_id": project_id,
        "group_id": group_id,
        "mcp_port": port
    });
    let content = serde_json::to_string_pretty(&ctx).map_err(|e| e.to_string())?;
    std::fs::write(&path, content)
        .map_err(|e| format!("写入 liangjing.json 失败: {}", e))
}

/// 查找 claude CLI 路径（优先环境变量 CLAUDE_BIN，然后常用安装目录，最后 where 命令）
fn find_claude_bin() -> Option<String> {
    if let Ok(path) = std::env::var("CLAUDE_BIN") {
        if std::path::Path::new(&path).exists() {
            return Some(path);
        }
    }

    let home = std::env::var("USERPROFILE")
        .or_else(|_| std::env::var("HOME"))
        .unwrap_or_default();

    let candidates = [
        format!(r"{}\.local\bin\claude.exe", home),
        format!(r"{}\AppData\Local\AnthropicClaude\claude.exe", home),
        r"C:\Program Files\AnthropicClaude\claude.exe".to_string(),
    ];

    for c in &candidates {
        if std::path::Path::new(c).exists() {
            return Some(c.clone());
        }
    }

    // 最后尝试 where 命令（GUI 进程 PATH 可能不含用户 bin，but worth trying）
    if let Ok(out) = std::process::Command::new("where").arg("claude.exe").output() {
        if out.status.success() {
            if let Ok(stdout) = String::from_utf8(out.stdout) {
                if let Some(line) = stdout.lines().next() {
                    return Some(line.trim().to_string());
                }
            }
        }
    }

    None
}

/// 将产品组 MCP 注册到 Claude 全局配置（~/.claude.json），best-effort，失败仅记录日志
fn try_register_globally(group_id: &str, port: u16) {
    let server_name = format!("lian-jing-{}", group_id);
    let server_url = format!("http://127.0.0.1:{}/mcp/group/{}", port, group_id);

    let Some(claude_bin) = find_claude_bin() else {
        db::log_event(
            "mcp_inject",
            "warn",
            "claude CLI 未找到，跳过全局 Mcp 注册",
            None,
        );
        return;
    };

    let git_bash = std::env::var("CLAUDE_CODE_GIT_BASH_PATH").unwrap_or_else(|_| {
        r"C:\Program Files\Git\bin\bash.exe".to_string()
    });

    match std::process::Command::new(&claude_bin)
        .args([
            "mcp",
            "add",
            "--transport",
            "sse",
            "-s",
            "user",
            &server_name,
            &server_url,
        ])
        .env("CLAUDE_CODE_GIT_BASH_PATH", &git_bash)
        .output()
    {
        Ok(out) if out.status.success() => {
            db::log_event(
                "mcp_inject",
                "info",
                "全局 MCP 注册成功",
                Some(&server_name),
            );
        }
        Ok(out) => {
            let msg = format!(
                "claude mcp add 非零退出: {}",
                String::from_utf8_lossy(&out.stderr)
            );
            db::log_event("mcp_inject", "warn", &msg, Some(&server_name));
        }
        Err(e) => {
            db::log_event(
                "mcp_inject",
                "warn",
                &format!("执行 claude mcp add 失败: {}", e),
                Some(&server_name),
            );
        }
    }
}

// ── JSON 读写 ─────────────────────────────────────────────────────────────────

fn read_json(path: &PathBuf) -> Result<Value, String> {
    if !path.exists() {
        return Ok(json!({}));
    }
    let content = std::fs::read_to_string(path)
        .map_err(|e| format!("读取 settings.json 失败: {}", e))?;
    if content.trim().is_empty() {
        return Ok(json!({}));
    }
    serde_json::from_str(&content).map_err(|e| {
        format!(
            "settings.json 格式错误，请手动修复后重试（{}）: {}",
            path.display(),
            e
        )
    })
}

fn write_json(path: &PathBuf, value: &Value) -> Result<(), String> {
    if let Some(parent) = path.parent() {
        std::fs::create_dir_all(parent)
            .map_err(|e| format!("创建 .claude 目录失败: {}", e))?;
    }
    let content = serde_json::to_string_pretty(value).map_err(|e| e.to_string())?;
    std::fs::write(path, content).map_err(|e| format!("写入 settings.json 失败: {}", e))
}

// ── 公开接口 ──────────────────────────────────────────────────────────────────

/// 向项目的 .claude/settings.json 注入产品组 MCP 配置
pub fn inject_project_mcp(project_id: &str, group_id: &str) -> Result<(), String> {
    let port = crate::mcp_server::read_port();
    let path = settings_path(project_id)?;
    let mut settings = read_json(&path)?;

    let obj = settings
        .as_object_mut()
        .ok_or("settings.json 顶层必须是 JSON 对象")?;

    // 炼境管理的项目需要无人值守运行（/ship 等技能不应被 permission 弹窗打断）
    obj.entry("permissions")
        .or_insert(json!({"defaultMode": "bypassPermissions"}));

    let servers = obj.entry("mcpServers").or_insert(json!({}));

    let key = format!("{}{}", MCP_KEY_PREFIX, group_id);
    servers[&key] = json!({
        "type": "sse",
        "url": format!("http://127.0.0.1:{}/mcp/group/{}", port, group_id)
    });

    write_json(&path, &settings).inspect(|_| {
        let ctx = serde_json::json!({"project_id": project_id, "group_id": group_id}).to_string();
        log_event("mcp_inject", "info", "MCP 配置注入成功", Some(&ctx));
    })?;

    // 写炼境上下文（含 group_id），让子项目 Claude 会话无需遍历即可知道 project_id + group_id
    let _ = write_liangjing_context(project_id, group_id, port);

    // 同步注册到 ~/.claude.json，让 Claude Code 能加载 MCP 工具（best-effort）
    try_register_globally(group_id, port);
    Ok(())
}

/// 从项目的 .claude/settings.json 移除产品组 MCP 配置
pub fn remove_project_mcp(project_id: &str, group_id: &str) -> Result<(), String> {
    let path = settings_path(project_id)?;
    if !path.exists() {
        return Ok(());
    }
    let mut settings = read_json(&path)?;

    let key = format!("{}{}", MCP_KEY_PREFIX, group_id);
    if let Some(servers) = settings
        .get_mut("mcpServers")
        .and_then(|v| v.as_object_mut())
    {
        servers.remove(&key);
    }

    write_json(&path, &settings)
}

/// 端口变更后重新注入所有产品组成员的 MCP 配置
/// 返回注入失败的错误列表（部分失败不影响其他项目）
pub fn reinject_all_mcp() -> Vec<String> {
    let conn = match db::pool().get() {
        Ok(c) => c,
        Err(e) => return vec![e.to_string()],
    };

    let mappings: Vec<(String, String)> = {
        let mut stmt = match conn.prepare("SELECT project_id, group_id FROM project_group_map") {
            Ok(s) => s,
            Err(e) => return vec![e.to_string()],
        };
        stmt.query_map([], |row| Ok((row.get(0)?, row.get(1)?)))
            .map(|iter| iter.filter_map(|r| r.ok()).collect())
            .unwrap_or_default()
    };

    let mut errors = Vec::new();
    for (project_id, group_id) in mappings {
        if let Err(e) = inject_project_mcp(&project_id, &group_id) {
            errors.push(format!("项目 {}: {}", project_id, e));
        }
    }
    errors
}