// /api/videos/hls/[...path]/route.ts
// This endpoint serves HLS playlists and segments from the HLS directory

import { NextResponse } from 'next/server';
import * as fs from 'fs';
import * as path from 'path';
import { checkVideoAccess, getViewer } from '@/lib/video-access';

// Path to HLS directory (should match UPLOADS_DIR/hls)
const HLS_DIR = path.join(process.env.UPLOADS_DIR || '/uploads', 'hls');

export async function GET(
  request: Request,
  context: { params: Promise<{ path?: string[] }> }
) {
  try {
    const params = await context.params;
    const pathSegments = params?.path || [];

    if (pathSegments.length === 0) {
      return NextResponse.json(
        { error: 'Invalid HLS request' },
        { status: 400 }
      );
    }

    // Signed-in viewers only, and only for videos they may watch.
    // The first path segment is the video id.
    const viewer = await getViewer();
    if (!viewer) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }
    const access = await checkVideoAccess(viewer, pathSegments[0]);
    if (!access.ok) {
      return NextResponse.json({ error: access.error }, { status: access.status });
    }

    // Construct the file path and validate it
    const requestedPath = path.join(HLS_DIR, ...pathSegments);
    
    // Security: prevent directory traversal attacks
    if (!requestedPath.startsWith(HLS_DIR + path.sep)) {
      return NextResponse.json(
        { error: 'Invalid request' },
        { status: 403 }
      );
    }

    // Check if file exists
    if (!fs.existsSync(requestedPath)) {
      console.log(`[HLS] File not found: ${requestedPath}`);
      return NextResponse.json(
        { error: 'Not found' },
        { status: 404 }
      );
    }

    // Read the file
    const fileContent = await fs.promises.readFile(requestedPath);

    // Determine content type based on file extension
    let contentType = 'application/octet-stream';
    
    if (requestedPath.endsWith('.m3u8')) {
      contentType = 'application/vnd.apple.mpegurl';
    } else if (requestedPath.endsWith('.ts')) {
      contentType = 'video/mp2t';
    } else if (requestedPath.endsWith('.mp4')) {
      contentType = 'video/mp4';
    }

    // Return the file with appropriate headers
    return new NextResponse(fileContent, {
      status: 200,
      headers: {
        'Content-Type': contentType,
        'Cache-Control': 'private, max-age=3600', // Viewer's browser only, 1 hour
        'Accept-Ranges': 'bytes',
      },
    });
  } catch (error) {
    console.error('[HLS] Error serving HLS file:', error);
    return NextResponse.json(
      { error: 'Internal server error' },
      { status: 500 }
    );
  }
}

// HEAD request support for playlist validation
export async function HEAD(
  request: Request,
  context: { params: Promise<{ path?: string[] }> }
) {
  try {
    const params = await context.params;
    const pathSegments = params?.path || [];

    if (pathSegments.length === 0) {
      return new NextResponse(null, { status: 400 });
    }

    const viewer = await getViewer();
    if (!viewer) return new NextResponse(null, { status: 401 });
    const access = await checkVideoAccess(viewer, pathSegments[0]);
    if (!access.ok) return new NextResponse(null, { status: access.status });

    const requestedPath = path.join(HLS_DIR, ...pathSegments);
    
    // Security: prevent directory traversal attacks
    if (!requestedPath.startsWith(HLS_DIR + path.sep)) {
      return new NextResponse(null, { status: 403 });
    }

    // Check if file exists
    if (!fs.existsSync(requestedPath)) {
      return new NextResponse(null, { status: 404 });
    }

    return new NextResponse(null, { status: 200 });
  } catch (error) {
    console.error('[HLS] Error in HEAD request:', error);
    return new NextResponse(null, { status: 500 });
  }
}