/* eslint-disable no-console,@typescript-eslint/no-explicit-any */

import { NextResponse } from "next/server";

import { getConfig } from "@/lib/config";
import { getBaseUrl, resolveUrl } from "@/lib/live";
import { validateProxyUrlServerSide } from '@/lib/server/ssrf';
import { buildProxyM3u8Headers, buildProxyStreamHeaders } from '@/lib/server/proxy-headers';

export const runtime = 'nodejs';

export async function GET(request: Request) {
  const { searchParams } = new URL(request.url);
  const url = searchParams.get('url');
  const source = searchParams.get('source'); // 视频源key

  if (!url) {
    return NextResponse.json({ error: 'Missing url' }, { status: 400 });
  }

  if (!source) {
    return NextResponse.json({ error: 'Missing source' }, { status: 400 });
  }

  // 检查该视频源是否启用了代理模式
  const config = await getConfig();
  const videoSource = config.SourceConfig?.find((s: any) => s.key === source);

  if (!videoSource) {
    return NextResponse.json({ error: 'Source not found' }, { status: 404 });
  }

  if (!videoSource.proxyMode) {
    return NextResponse.json({ error: 'Proxy mode not enabled for this source' }, { status: 403 });
  }

  let response: Response | null = null;
  let responseUsed = false;

  try {
    const decodedUrl = decodeURIComponent(url);

    // 安全校验：防 SSRF 拦截请求内网或非法 URL
    const isSafeUrl = await validateProxyUrlServerSide(decodedUrl);
    if (!isSafeUrl) {
      return NextResponse.json({ error: 'Proxy request to local or invalid network is forbidden' }, { status: 403 });
    }

    response = await fetch(decodedUrl, {
      cache: 'no-cache',
      redirect: 'follow',
      credentials: 'same-origin',
      headers: {
        'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36',
        'Referer': decodedUrl,
      },
    });

    if (!response.ok) {
      return NextResponse.json({ error: 'Failed to fetch m3u8' }, { status: 500 });
    }

    const contentType = response.headers.get('Content-Type') || '';
    // rewrite m3u8
    if (contentType.toLowerCase().includes('mpegurl') || contentType.toLowerCase().includes('octet-stream') || decodedUrl.includes('.m3u8')) {
      // 获取最终的响应URL（处理重定向后的URL）
      const finalUrl = response.url;
      const m3u8Content = await response.text();
      responseUsed = true; // 标记 response 已被使用

      // 使用最终的响应URL作为baseUrl，而不是原始的请求URL
      const baseUrl = getBaseUrl(finalUrl);

      // 重写 M3U8 内容
      const modifiedContent = rewriteM3U8Content(m3u8Content, baseUrl, request, source);

      const headers = buildProxyM3u8Headers(contentType || undefined);
      return new Response(modifiedContent, { headers });
    }
    // just proxy
    const headers = buildProxyStreamHeaders(
      response.headers.get('Content-Type') || 'application/vnd.apple.mpegurl'
    );
    headers.set('Cache-Control', 'no-cache');

    // 直接返回视频流
    return new Response(response.body, {
      status: 200,
      headers,
    });
  } catch (error) {
    return NextResponse.json({ error: 'Failed to fetch m3u8' }, { status: 500 });
  } finally {
    // 确保 response 被正确关闭以释放资源
    if (response && !responseUsed) {
      try {
        response.body?.cancel();
      } catch (error) {
        // 忽略关闭时的错误
        console.warn('Failed to close response body:', error);
      }
    }
  }
}

function rewriteM3U8Content(content: string, baseUrl: string, req: Request, source: string) {
  // 从 referer 头提取协议信息
  const referer = req.headers.get('referer');
  let protocol = 'http';
  if (referer) {
    try {
      const refererUrl = new URL(referer);
      protocol = refererUrl.protocol.replace(':', '');
    } catch (error) {
      // ignore
    }
  }

  const host = req.headers.get('host');
  const proxyBase = `${protocol}://${host}/api/proxy/vod`;

  const lines = content.split('\n');
  const rewrittenLines: string[] = [];

  for (let i = 0; i < lines.length; i++) {
    let line = lines[i].trim();

    // 处理 TS 片段 URL 和其他媒体文件
    if (line && !line.startsWith('#')) {
      const resolvedUrl = resolveUrl(baseUrl, line);
      const proxyUrl = `${proxyBase}/segment?url=${encodeURIComponent(resolvedUrl)}&source=${source}`;
      rewrittenLines.push(proxyUrl);
      continue;
    }

    // 处理 EXT-X-MAP 标签中的 URI
    if (line.startsWith('#EXT-X-MAP:')) {
      line = rewriteMapUri(line, baseUrl, proxyBase, source);
    }

    // 处理 EXT-X-KEY 标签中的 URI
    if (line.startsWith('#EXT-X-KEY:')) {
      line = rewriteKeyUri(line, baseUrl, proxyBase, source);
    }

    // 处理嵌套的 M3U8 文件 (EXT-X-STREAM-INF)
    if (line.startsWith('#EXT-X-STREAM-INF:')) {
      rewrittenLines.push(line);
      // 下一行通常是 M3U8 URL
      if (i + 1 < lines.length) {
        i++;
        const nextLine = lines[i].trim();
        if (nextLine && !nextLine.startsWith('#')) {
          const resolvedUrl = resolveUrl(baseUrl, nextLine);
          const proxyUrl = `${proxyBase}/m3u8?url=${encodeURIComponent(resolvedUrl)}&source=${source}`;
          rewrittenLines.push(proxyUrl);
        } else {
          rewrittenLines.push(nextLine);
        }
      }
      continue;
    }

    rewrittenLines.push(line);
  }

  return rewrittenLines.join('\n');
}

function rewriteMapUri(line: string, baseUrl: string, proxyBase: string, source: string) {
  const uriMatch = line.match(/URI="([^"]+)"/);
  if (uriMatch) {
    const originalUri = uriMatch[1];
    const resolvedUrl = resolveUrl(baseUrl, originalUri);
    const proxyUrl = `${proxyBase}/segment?url=${encodeURIComponent(resolvedUrl)}&source=${source}`;
    return line.replace(uriMatch[0], `URI="${proxyUrl}"`);
  }
  return line;
}

function rewriteKeyUri(line: string, baseUrl: string, proxyBase: string, source: string) {
  const uriMatch = line.match(/URI="([^"]+)"/);
  if (uriMatch) {
    const originalUri = uriMatch[1];
    const resolvedUrl = resolveUrl(baseUrl, originalUri);
    const proxyUrl = `${proxyBase}/key?url=${encodeURIComponent(resolvedUrl)}&source=${source}`;
    return line.replace(uriMatch[0], `URI="${proxyUrl}"`);
  }
  return line;
}