import { NextRequest, NextResponse } from 'next/server';
import { ConcurrencyLimitError, transcodeOrchestrator, TranscodeDisabledError } from '@/lib/transcode/orchestrator';

export const runtime = 'nodejs';
export const dynamic = 'force-dynamic';

export async function POST(request: NextRequest) {
  try {
    const body = await request.json();
    const mediaId = Number(body.mediaId);
    const startTime = Number(body.startTime || 0);
    const profile = typeof body.profile === 'string' ? body.profile : undefined;

    if (!Number.isInteger(mediaId) || mediaId <= 0) {
      return NextResponse.json({ error: 'Invalid mediaId' }, { status: 400 });
    }

    if (!Number.isFinite(startTime) || startTime < 0) {
      return NextResponse.json({ error: 'Invalid startTime' }, { status: 400 });
    }

    const job = await transcodeOrchestrator.start(mediaId, profile, startTime);
    return NextResponse.json({
      jobId: job.id,
      playlistUrl: `/api/transcode/${job.id}/master.m3u8`,
      etaSeconds: 1,
      profile: job.profile,
      decision: job.decision.kind,
      duration: job.knownDuration,
      startTime: job.startTime,
    });
  } catch (error) {
    if (error instanceof TranscodeDisabledError) {
      return NextResponse.json({ error: error.message, code: 'TRANSCODE_DISABLED' }, { status: 403 });
    }

    if (error instanceof ConcurrencyLimitError) {
      return NextResponse.json(
        { error: error.message, code: 'TRANSCODE_BUSY', retryAfterSeconds: error.retryAfterSeconds },
        { status: 503, headers: { 'Retry-After': error.retryAfterSeconds.toString() } },
      );
    }

    console.error('[TranscodeAPI] start failed:', error);
    return NextResponse.json({ error: error instanceof Error ? error.message : 'Failed to start transcode' }, { status: 500 });
  }
}