use std::collections::HashMap;

use tauri::{AppHandle, Manager, State};
use tauri_plugin_opener::OpenerExt;

use super::engine::{CheckUrlResult, DownloadEngine};
use super::task::{DownloadTask, DownloaderSettings};
use super::torrent::TorrentInfo;

/// 获取所有任务
#[tauri::command]
#[specta::specta]
pub fn downloader_get_tasks(engine: State<'_, DownloadEngine>) -> Vec<DownloadTask> {
    engine.get_tasks()
}

/// 解析磁力链 / .torrent 文件，返回种子信息（名称 / infohash / 文件列表），供前端做文件勾选
#[tauri::command]
#[specta::specta]
pub async fn downloader_inspect(engine: State<'_, DownloadEngine>, input: String) -> Result<TorrentInfo, String> {
    engine.inspect(&input).await
}

/// 磁力任务：元数据解析成功后，用户勾选文件并确认开始下载
#[tauri::command]
#[specta::specta]
pub async fn downloader_select_bt_files(engine: State<'_, DownloadEngine>, id: String, only_files: Vec<u32>) -> Result<(), String> {
    engine.select_bt_files(&id, only_files).await
}

/// 检查 URL 重复性并探测文件信息（添加下载前调用）
#[tauri::command]
#[specta::specta]
pub async fn downloader_check_url(
    engine: State<'_, DownloadEngine>,
    url: String,
    dir: Option<String>,
    headers: Option<HashMap<String, String>>,
) -> Result<CheckUrlResult, String> {
    let headers = headers.unwrap_or_default();
    let (probe, duplicate, existing) = engine.check_url(&url, dir.as_deref(), &headers).await;
    let result = match probe {
        Ok(p) => CheckUrlResult {
            ok: true,
            error: None,
            filename: p.filename.clone(),
            total_size: p.total_size,
            supports_resume: p.supports_resume,
            duplicate,
            existing,
        },
        Err(e) => CheckUrlResult {
            ok: false,
            error: Some(e),
            filename: None,
            total_size: None,
            supports_resume: false,
            duplicate,
            existing,
        },
    };
    Ok(result)
}

/// 添加下载任务
#[tauri::command]
#[specta::specta]
pub async fn downloader_add_task(
    engine: State<'_, DownloadEngine>,
    url: String,
    filename: Option<String>,
    dir: Option<String>,
    headers: Option<HashMap<String, String>>,
    auto_rename: Option<bool>,
    only_files: Option<Vec<u32>>,
) -> Result<String, String> {
    engine.add_task(url, filename, dir, headers.unwrap_or_default(), auto_rename.unwrap_or(false), only_files).await
}

/// 暂停任务
#[tauri::command]
#[specta::specta]
pub fn downloader_pause_task(engine: State<'_, DownloadEngine>, id: String) -> Result<(), String> {
    engine.pause_task(&id)
}

/// 恢复任务
#[tauri::command]
#[specta::specta]
pub fn downloader_resume_task(engine: State<'_, DownloadEngine>, id: String) -> Result<(), String> {
    engine.resume_task(&id)
}

/// 取消任务（置为已取消，清空进度并删除下载文件，但保留记录）
#[tauri::command]
#[specta::specta]
pub fn downloader_cancel_task(engine: State<'_, DownloadEngine>, id: String) -> Result<(), String> {
    engine.cancel_task(&id)
}

/// 重新下载已取消/出错的任务
#[tauri::command]
#[specta::specta]
pub async fn downloader_redownload(engine: State<'_, DownloadEngine>, id: String) -> Result<(), String> {
    engine.redownload(&id).await
}

/// 移除任务
#[tauri::command]
#[specta::specta]
pub fn downloader_remove_task(
    engine: State<'_, DownloadEngine>,
    id: String,
    delete_files: Option<bool>,
) -> Result<(), String> {
    engine.remove_task(&id, delete_files.unwrap_or(false))
}

/// 获取设置
#[tauri::command]
#[specta::specta]
pub fn downloader_get_settings(engine: State<'_, DownloadEngine>) -> DownloaderSettings {
    engine.get_settings()
}

/// 保存设置
#[tauri::command]
#[specta::specta]
pub fn downloader_save_settings(
    engine: State<'_, DownloadEngine>,
    settings: DownloaderSettings,
) -> Result<(), String> {
    engine.save_settings(settings);
    Ok(())
}

/// 引擎状态（始终运行中）
#[tauri::command]
pub fn downloader_status(engine: State<'_, DownloadEngine>) -> serde_json::Value {
    serde_json::json!({
        "running": engine.is_started(),
    })
}

/// 获取扩展服务信息
#[tauri::command]
pub fn downloader_get_extension_info(engine: State<'_, DownloadEngine>) -> serde_json::Value {
    let settings = engine.get_settings();
    serde_json::json!({
        "url": format!("http://127.0.0.1:{}/", settings.extension_port),
        "port": settings.extension_port,
        "secret": settings.extension_secret,
        "hasSecret": !settings.extension_secret.is_empty(),
    })
}

/// 用系统资源管理器打开目录
#[tauri::command]
#[specta::specta]
pub fn downloader_open_dir(app: AppHandle, path: String) -> Result<(), String> {
    app.opener()
        .open_path(path, None::<&str>)
        .map_err(|e| format!("打开目录失败: {}", e))
}

/// 用系统默认浏览器打开 URL
#[tauri::command]
#[specta::specta]
pub fn downloader_open_url(app: AppHandle, url: String) -> Result<(), String> {
    app.opener()
        .open_url(url, None::<&str>)
        .map_err(|e| format!("打开链接失败: {}", e))
}

/// 将指定 label 的下载窗口显示并强制置为前台。
/// Tauri 的 set_focus 在 Windows 上受前台锁定限制（尤其下载窗口由后台进程创建、
/// 或创建到非主显示器时更明显），改用原生 SetForegroundWindow + BringWindowToTop
/// （模拟 Alt 键重置前台锁定），保证开始/完成下载时窗口能正确定位到前台。
#[tauri::command]
#[specta::specta]
pub fn downloader_focus_window(app: AppHandle, label: String) -> Result<(), String> {
    let Some(window) = app.get_webview_window(&label) else {
        return Ok(()); // 窗口已关闭则忽略
    };
    window.show().map_err(|e| e.to_string())?;
    window.unminimize().map_err(|e| e.to_string())?;
    match window.hwnd() {
        Ok(hwnd) => crate::win32_util::force_foreground(hwnd.0 as isize),
        Err(_) => {
            window.set_focus().ok();
        }
    }
    Ok(())
}