import { NextResponse } from 'next/server';
import { recordEvent } from '@/lib/auditDb';
import { generateSeedanceVideo } from '@/lib/videoProviders';
import { loadSession, saveRemoteVideo, saveSession } from '@/lib/storage';
import { VIDEO_TEMPLATES } from '@/lib/templates';
import type { VideoGenerationRequest, VideoTask } from '@/lib/types';

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

export async function POST(req: Request) {
  const body = (await req.json()) as VideoGenerationRequest;
  try {
    recordEvent({ action: 'video.generate_started', sessionId: body.sessionId, targetType: 'video', targetId: body.templateId, status: 'started', provider: 'seedance', metadata: { ratio: body.ratio, duration: body.duration, hasImage: Boolean(body.imageUrl), refs: body.references?.length ?? 0 } });
    const response = await generateSeedanceVideo(body);
    let task: VideoTask | undefined;
    let videoUrl = response.videoUrl;

    if (body.sessionId && body.templateId) {
      const session = await loadSession(body.sessionId);
      if (!session) return NextResponse.json({ error: 'session not found' }, { status: 404 });
      const template = VIDEO_TEMPLATES.find(item => item.id === body.templateId);
      const now = Date.now();
      if (videoUrl) {
        videoUrl = await saveRemoteVideo(session.id, response.taskId || body.templateId, videoUrl);
      }
      task = {
        id: `vid_${session.id}_${body.templateId}`,
        templateId: body.templateId,
        title: body.templateTitle || template?.title || body.templateId,
        description: template?.description || '',
        prompt: body.prompt,
        anchorImageUrl: body.imageUrl,
        provider: response.provider,
        model: response.model,
        taskId: response.taskId,
        status: response.status,
        videoUrl,
        ratio: body.ratio || template?.ratio || '16:9',
        duration: body.duration || template?.duration || 6,
        submittedAt: now,
        updatedAt: now,
        raw: response.raw,
      };
      session.videoTasks = [
        ...(session.videoTasks ?? []).filter(item => item.templateId !== body.templateId),
        task,
      ];
      await saveSession(session);
    }

    recordEvent({ action: 'video.generate_submitted', sessionId: body.sessionId, targetType: 'video', targetId: response.taskId ?? body.templateId ?? response.status, status: 'queued', provider: 'seedance', metadata: { status: response.status, templateId: body.templateId } });
    return NextResponse.json({ ...response, videoUrl, task });
  } catch (error) {
    const message = String(error);
    recordEvent({ action: 'video.generate_failed', sessionId: body.sessionId, targetType: 'video', targetId: body.templateId, status: 'error', provider: 'seedance', message });
    return NextResponse.json({ error: message }, {
      status: message.includes('SEEDANCE_API_KEY missing') ? 503 : 500,
    });
  }
}