import { NextRequest } from 'next/server';
import { revalidatePath } from 'next/cache';
import { db } from '@/lib/db';
import { auth, checkProjectAccess } from '@/lib/auth';
import { rateLimit } from '@/lib/rate-limit';
import { collectVideoMediaUrls, deleteMediaFilesBestEffort } from '@/lib/r2-cleanup';
import { cleanupBunnyStreamVideosBestEffort } from '@/lib/bunny-stream-cleanup';
import { buildCleanupWarnings, logCleanupWarnings } from '@/lib/cleanup-warnings';
import { apiErrors, successResponse, withCacheControl } from '@/lib/api-response';
import { logError } from '@/lib/logger';
import { canDownloadProjectMedia } from '@/lib/project-download';

type RouteParams = { params: Promise<{ projectId: string; videoId: string }> };

// GET /api/projects/[projectId]/videos/[videoId]
export async function GET(request: NextRequest, { params }: RouteParams) {
  try {
    const session = await auth();
    const { projectId, videoId } = await params;

    // Parse query params for pagination and options
    const searchParams = request.nextUrl.searchParams;
    const includeComments = searchParams.get('includeComments') !== 'false';
    const commentLimit = Math.min(parseInt(searchParams.get('commentLimit') || '50'), 100);
    const commentOffset = Math.max(0, parseInt(searchParams.get('commentOffset') || '0'));
    const includeReplies = searchParams.get('includeReplies') === 'true';

    const video = await db.video.findFirst({
      where: { id: videoId, projectId },
      include: {
        project: true,
        versions: {
          orderBy: { versionNumber: 'desc' },
          ...(includeComments
            ? {
                include: {
                  comments: {
                    orderBy: { timestamp: 'asc' },
                    skip: commentOffset,
                    take: commentLimit,
                    select: {
                      id: true,
                      content: true,
                      timestamp: true,
                      timestampEnd: true,
                      createdAt: true,
                      updatedAt: true,
                      isResolved: true,
                      resolvedAt: true,
                      voiceUrl: true,
                      voiceDuration: true,
                      imageUrl: true,
                      images: { select: { id: true, url: true }, orderBy: { position: 'asc' } },
                      annotationData: true,
                      parentId: true,
                      authorId: true,
                      tagId: true,
                      versionId: true,
                      guestName: true,
                      // guestEmail excluded for privacy
                      author: { select: { id: true, name: true, image: true } },
                      tag: { select: { id: true, name: true, color: true } },
                      ...(includeReplies
                        ? {
                            replies: {
                              orderBy: { createdAt: 'asc' },
                              select: {
                                id: true,
                                content: true,
                                timestamp: true,
                                timestampEnd: true,
                                createdAt: true,
                                updatedAt: true,
                                isResolved: true,
                                resolvedAt: true,
                                voiceUrl: true,
                                voiceDuration: true,
                                imageUrl: true,
                                images: {
                                  select: { id: true, url: true },
                                  orderBy: { position: 'asc' },
                                },
                                annotationData: true,
                                parentId: true,
                                authorId: true,
                                tagId: true,
                                versionId: true,
                                guestName: true,
                                // guestEmail excluded for privacy
                                author: { select: { id: true, name: true, image: true } },
                                tag: { select: { id: true, name: true, color: true } },
                              },
                            },
                          }
                        : {}),
                    },
                    where: { parentId: null },
                  },
                  _count: { select: { comments: true } },
                },
              }
            : {
                select: {
                  id: true,
                  thumbnailUrl: true,
                  duration: true,
                  versionNumber: true,
                  versionLabel: true,
                  providerId: true,
                  videoId: true,
                  originalUrl: true,
                  title: true,
                  isActive: true,
                  _count: { select: { comments: true } },
                },
              }),
        },
      },
    });

    if (!video) {
      return apiErrors.notFound('Video');
    }

    // Check access including workspace membership
    const access = await checkProjectAccess(video.project, session?.user?.id);

    if (!access.hasAccess) {
      return apiErrors.forbidden('Access denied');
    }

    const canDownload = canDownloadProjectMedia(video.project, access);
    const response = successResponse({
      ...video,
      isAuthenticated: !!session?.user?.id,
      currentUserId: session?.user?.id || null,
      currentUserName: session?.user?.name || null,
      canDownload,
      canManageTags: access.canEdit,
      canResolveComments: access.canEdit,
      canRequestApproval: access.canEdit,
      canShareVideo: access.canEdit,
      canUploadAssets: access.hasAccess,
      canDownloadAssets: canDownload,
    });

    return withCacheControl(response, 'private, no-cache');
  } catch (error) {
    logError('Error fetching video:', error);
    return apiErrors.internalError('Failed to fetch video');
  }
}

// PATCH /api/projects/[projectId]/videos/[videoId]
export async function PATCH(request: NextRequest, { params }: RouteParams) {
  try {
    const limited = await rateLimit(request, 'mutate');
    if (limited) return limited;

    const session = await auth();
    const { projectId, videoId } = await params;

    if (!session?.user?.id) {
      return apiErrors.unauthorized();
    }

    const video = await db.video.findFirst({
      where: { id: videoId, projectId },
      include: {
        project: true,
      },
    });

    if (!video) {
      return apiErrors.notFound('Video');
    }

    const access = await checkProjectAccess(video.project, session.user.id);
    if (!access.canEdit) {
      return apiErrors.forbidden('Access denied');
    }

    const body = await request.json();
    const { title, description, position } = body;

    // Validate types before using string methods to prevent type confusion attacks
    if (
      position !== undefined &&
      (typeof position !== 'number' || !Number.isInteger(position) || position < 0)
    ) {
      return apiErrors.badRequest('position must be a non-negative integer');
    }

    const updateData: Record<string, unknown> = {};
    if (typeof title === 'string') updateData.title = title.trim();
    if (typeof description === 'string') updateData.description = description.trim() || null;
    if (position !== undefined) updateData.position = position;

    // Keep the response to scalar video fields: including versions would pull
    // in BigInt columns (sizeBytes) that JSON.stringify cannot serialize, and
    // no caller consumes the success payload beyond these fields.
    const updatedVideo = await db.video.update({
      where: { id: videoId },
      data: updateData,
      select: {
        id: true,
        title: true,
        description: true,
        position: true,
        projectId: true,
        updatedAt: true,
      },
    });

    const response = successResponse(updatedVideo);
    return withCacheControl(response, 'private, no-store');
  } catch (error) {
    logError('Error updating video:', error);
    return apiErrors.internalError('Failed to update video');
  }
}

// DELETE /api/projects/[projectId]/videos/[videoId]
export async function DELETE(request: NextRequest, { params }: RouteParams) {
  try {
    const limited = await rateLimit(request, 'mutate');
    if (limited) return limited;

    const session = await auth();
    const { projectId, videoId } = await params;

    if (!session?.user?.id) {
      return apiErrors.unauthorized();
    }

    const video = await db.video.findFirst({
      where: { id: videoId, projectId },
      include: {
        versions: {
          select: {
            providerId: true,
            videoId: true,
          },
        },
        assets: {
          select: {
            provider: true,
            providerVideoId: true,
          },
        },
        project: true,
      },
    });

    if (!video) {
      return apiErrors.notFound('Video');
    }

    const access = await checkProjectAccess(video.project, session.user.id);
    if (!access.canEdit) {
      return apiErrors.forbidden('Only project owner or admin can delete videos');
    }

    const bunnyRefs = [
      ...video.versions,
      ...video.assets
        .filter((asset) => asset.provider === 'BUNNY' && !!asset.providerVideoId)
        .map((asset) => ({
          providerId: 'bunny',
          videoId: asset.providerVideoId as string,
        })),
    ];

    const mediaUrls = await collectVideoMediaUrls(videoId);

    await db.video.delete({ where: { id: videoId } });

    revalidatePath(`/projects/${projectId}`);

    const [bunnyCleanupResult, r2CleanupResult] = await Promise.all([
      cleanupBunnyStreamVideosBestEffort(bunnyRefs),
      deleteMediaFilesBestEffort(mediaUrls),
    ]);
    const cleanupInput = {
      bunny: bunnyCleanupResult,
      r2: r2CleanupResult,
    };
    const cleanupWarnings = buildCleanupWarnings(cleanupInput);
    if (cleanupWarnings) {
      logCleanupWarnings({ entityType: 'video', entityId: videoId }, cleanupInput);
    }

    const response = successResponse({
      message: 'Video deleted',
      ...(cleanupWarnings ? { cleanupWarnings } : {}),
    });
    return withCacheControl(response, 'private, no-store');
  } catch (error) {
    logError('Error deleting video:', error);
    return apiErrors.internalError('Failed to delete video');
  }
}