import { randomUUID } from 'crypto';
import { eq } from 'drizzle-orm';
import { Router } from 'express';

import { db } from '../../db/client';
import { streamSessions } from '../../db/schema';
import { createLiveMediaSession } from '../../media/service';
import { sfuService } from '../../media/sfu/service';
import { requireDeviceAuth } from '../../middleware/device-auth';
import { sendRealtimeToDevice } from '../../realtime/gateway';
import { createRecordingForStream } from '../../services/recordings';
import { writeAuditLog } from '../../services/audit';
import { enqueuePushNotification } from '../../services/push';
import { createStreamStartedPayload, toSimpleStreamSessionResponse } from '../../streaming/simple';
import { acceptStreamSchema, streamParamSchema } from './schemas';
import { ensureStreamDeviceAuth, shouldCreateRecordingPlaceholder } from './shared';

const router = Router();

router.post('/:streamSessionId/accept', requireDeviceAuth, async (req, res) => {
  const parsedParams = streamParamSchema.safeParse(req.params);

  if (!parsedParams.success) {
    res.status(400).json({ message: 'Invalid streamSessionId', errors: parsedParams.error.flatten() });
    return;
  }

  const parsed = acceptStreamSchema.safeParse(req.body ?? {});

  if (!parsed.success) {
    res.status(400).json({ message: 'Invalid request body', errors: parsed.error.flatten() });
    return;
  }

  const deviceAuth = ensureStreamDeviceAuth(req, res);
  if (!deviceAuth) return;

  const session = await db.query.streamSessions.findFirst({
    where: eq(streamSessions.id, parsedParams.data.streamSessionId),
  });

  if (!session || session.ownerUserId !== deviceAuth.userId || session.cameraDeviceId !== deviceAuth.deviceId) {
    res.status(404).json({ message: 'Stream session not found for this camera device' });
    return;
  }

  if (session.status !== 'requested' && session.status !== 'starting') {
    res.status(409).json({ message: `Stream session cannot be accepted from status ${session.status}` });
    return;
  }

  const now = new Date();
  const streamKey = parsed.data.streamKey ?? `stream_${session.id}_${randomUUID()}`;
  const mediaSession = await createLiveMediaSession({
    streamSessionId: session.id,
    ownerUserId: session.ownerUserId,
    cameraDeviceId: session.cameraDeviceId,
    requesterDeviceId: session.requesterDeviceId,
  });

  const [updated] = await db
    .update(streamSessions)
    .set({
      status: 'streaming',
      streamKey: mediaSession ? streamKey : null,
      mediaProvider: mediaSession?.provider ?? 'simple',
      mediaSessionId: mediaSession?.mediaSessionId ?? null,
      publishEndpoint: mediaSession?.publishUrl ?? null,
      subscribeEndpoint: mediaSession?.subscribeUrl ?? null,
      metadata: parsed.data.metadata ?? session.metadata,
      startedAt: now,
      updatedAt: now,
    })
    .where(eq(streamSessions.id, session.id))
    .returning();

  if (!updated) {
    res.status(500).json({ message: 'Failed to update stream session' });
    return;
  }

  if (shouldCreateRecordingPlaceholder()) {
    await createRecordingForStream(updated.id);
  }

  if (sfuService) {
    try {
      await sfuService.startSession({
        streamSessionId: updated.id,
        ownerUserId: updated.ownerUserId,
        cameraDeviceId: updated.cameraDeviceId,
        requesterDeviceId: updated.requesterDeviceId,
      });
      await sfuService.setSessionState(updated.id, 'live');
    } catch (error) {
      console.error('Failed starting SFU session', error);
      res.status(500).json({ message: 'Failed to initialize SFU session' });
      return;
    }
  }

  const startedPayload = createStreamStartedPayload(updated);
  console.info('[stream.accept]', {
    streamSessionId: updated.id,
    requesterDeviceId: updated.requesterDeviceId,
    cameraDeviceId: updated.cameraDeviceId,
    mode: mediaSession ? 'legacy' : 'simple',
  });
  const deliveredToRequester = sendRealtimeToDevice(session.requesterDeviceId, 'stream:started', startedPayload);

  if (!deliveredToRequester) {
    await enqueuePushNotification({
      ownerUserId: session.ownerUserId,
      recipientDeviceId: session.requesterDeviceId,
      type: 'stream_started',
      payload: startedPayload,
    });
  }

  res.json({ message: 'Stream accepted', streamSession: toSimpleStreamSessionResponse(updated) });

  await writeAuditLog({
    ownerUserId: session.ownerUserId,
    actorDeviceId: session.cameraDeviceId,
    action: 'stream.accepted',
    targetType: 'stream_session',
    targetId: session.id,
    metadata: mediaSession
      ? { mediaSessionId: updated.mediaSessionId, mediaProvider: updated.mediaProvider }
      : { transport: 'webrtc' },
    ipAddress: req.ip,
  });
});

export default router;