import { exec } from "child_process";

/**
 * 构建梯子参数
 * @param isOversea
 * @param proxy
 * @returns {string|string}
 */
function constructProxyParam(isOversea, proxy) {
    return isOversea ? "" : `--proxy ${proxy}`;
}

/**
 * 构造cookie参数
 * 目前只支持YouTube构造cookie，否则就必须修改`url.includes("youtu")`
 * @param url
 * @param cookiePath
 * @returns {string}
 */
function constructCookiePath(url, cookiePath) {
    return (cookiePath !== "" && url.includes("youtu")) ? `--cookies ${ cookiePath }` : "";
}

/**
 * yt-dlp获取标题的时候可能需要的一个编码参数，也在一定程度上解决部分window系统乱码问题
 * @param url
 * @returns {string}
 */
function constructEncodingParam(url) {
    return "--encoding UTF-8"; // 始终为标题获取使用 UTF-8 编码
}


/**
 * 获取时长
 * @param url
 * @param isOversea
 * @param proxy
 * @param cookiePath
 * @returns string
 */
export function ytDlpGetDuration(url, isOversea, proxy, cookiePath = "") {
    return new Promise((resolve, reject) => {
        // 构造 cookie 参数
        const cookieParam = constructCookiePath(url, cookiePath);
        const command = `yt-dlp --get-duration --skip-download ${cookieParam} ${constructProxyParam(isOversea, proxy)} "${url}"`;
        exec(command, (error, stdout, stderr) => {
            if (error) {
                logger.error(`[R插件][yt-dlp审计] Error executing ytDlpGetDuration: ${error}. Stderr: ${stderr}`);
                reject(error);
            } else {
                resolve(stdout.trim());
            }
        });
    });
}

/**
 * 获取标题
 * @param url
 * @param isOversea
 * @param proxy
 * @param cookiePath
 * @returns string
 */
export function ytDlpGetTilt(url, isOversea, proxy, cookiePath = "") {
    return new Promise((resolve, reject) => {
        // 构造 cookie 参数
        const cookieParam = constructCookiePath(url, cookiePath);
        // 构造 编码 参数
        const encodingParam = constructEncodingParam(url);
        const command = `yt-dlp --get-title --skip-download ${cookieParam} ${ constructProxyParam(isOversea, proxy) } "${url}" ${encodingParam}`;
        exec(command, (error, stdout, stderr) => {
            if (error) {
                logger.error(`[R插件][yt-dlp审计] Error executing ytDlpGetTilt: ${error}. Stderr: ${stderr}`);
                reject(error);
            } else {
                resolve(stdout.trim());
            }
        });
    });
}

/**
 * 获取封面
 * @param path
 * @param url
 * @param isOversea
 * @param proxy
 * @param cookiePath
 * @param thumbnailFilenamePrefix 缩略图文件名前缀 (不含扩展名)
 */
export function ytDlpGetThumbnail(path, url, isOversea, proxy, cookiePath = "", thumbnailFilenamePrefix = "thumbnail") {
    return new Promise((resolve, reject) => {
        const cookieParam = constructCookiePath(url, cookiePath);
        const finalThumbnailName = thumbnailFilenamePrefix || "thumbnail";
        const command = `yt-dlp --write-thumbnail --convert-thumbnails png --skip-download ${cookieParam} ${constructProxyParam(isOversea, proxy)} "${url}" -P "${path}" -o "${finalThumbnailName}.%(ext)s"`;

        exec(command, (error, stdout, stderr) => {
            if (error) {
                logger.error(`[R插件][yt-dlp审计] Error executing ytDlpGetThumbnail: ${error}. Stderr: ${stderr}`);
                return reject(error);
            }
            // 从yt-dlp的输出中提取文件名
            const match = stdout.match(/Writing thumbnail to: (.*)/);
            if (match && match[1]) {
                const thumbnailPath = match[1].trim();
                // 只返回文件名部分
                const thumbnailFilename = thumbnailPath.split(/[\\/]/).pop();
                logger.info(`[R插件][yt-dlp审计] Thumbnail downloaded: ${thumbnailFilename}`);
                resolve(thumbnailFilename);
            } else {
                // 兜底方案：如果无法从输出中解析，则按原逻辑拼接
                logger.warn("[R插件][yt-dlp审计] Could not parse thumbnail filename from stdout. Falling back to default.");
                // 尝试查找文件，因为yt-dlp可能没有输出我们期望的格式
                const expectedPngPath = `${finalThumbnailName}.png`;
                resolve(expectedPngPath);
            }
        });
    });
}

/**
 * yt-dlp 工具类
 * @returns {Promise<void>}
 * @param path       下载路径
 * @param url        下载链接
 * @param isOversea  是否是海外用户
 * @param proxy      代理地址
 * @param merge      是否合并输出为 mp4 格式 (仅适用于视频合并需求)
 * @param graphics   YouTube画质参数
 * @param timeRange  截取时间段
 * @param maxThreads 最大并发
 * @param outputFilename 输出文件名 (不含扩展名)
 * @param cookiePath Cookie所在位置
 */
export async function ytDlpHelper(path, url, isOversea, proxy, maxThreads, outputFilename, merge = false, graphics, timeRange, cookiePath = "") {
    return new Promise((resolve, reject) => {
        let command = "";
        // 构造 cookie 参数
        const cookieParam = constructCookiePath(url, cookiePath);
        // 确保 outputFilename 不为空，提供一个默认值以防万一
        const finalOutputFilename = outputFilename || "temp_download";

        if (url.includes("music")) {
            // 这里是 YouTube Music的处理逻辑
            // e.g yt-dlp -x --audio-format mp3 https://youtu.be/5wEtefq9VzM -o test.mp3
            command = `yt-dlp -x --audio-format flac -f ba ${cookieParam} ${constructProxyParam(isOversea, proxy)} -P "${path}" -o "${finalOutputFilename}.flac" "${url}"`;
        } else {
            // 正常情况下的处理逻辑
            const fParam = url.includes("youtu") ? `--download-sections "*${timeRange}" -f "bv${graphics}[ext=mp4]+ba[ext=m4a]" ` : "";

            command = `yt-dlp -N ${maxThreads} ${fParam} --concurrent-fragments ${maxThreads} ${cookieParam} ${constructProxyParam(isOversea, proxy)} -P "${path}" -o "${finalOutputFilename}.%(ext)s" "${url}"`;
        }

        logger.info(`[R插件][yt-dlp审计] ${command}`);

        exec(command, (error, stdout) => {
            if (error) {
                logger.error(`[R插件][yt-dlp审计] 执行命令时出错: ${error}`);
                reject(error);
            } else {
                resolve(stdout);
            }
        });
    });
}