import { NextRequest } from 'next/server';
import { db } from '@/lib/db';
import { auth, checkProjectAccess } from '@/lib/auth';
import { apiErrors, successResponse, withCacheControl } from '@/lib/api-response';
import { rateLimit } from '@/lib/rate-limit';
import crypto from 'crypto';
import { cleanupBunnyStreamVideos } from '@/lib/bunny-stream-cleanup';
import { createBunnyUploadToken, verifyBunnyUploadToken } from '@/lib/bunny-upload-token';
import { isBunnyUploadsFeatureEnabled } from '@/lib/feature-flags';

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

async function getProjectWithEditAccess(projectId: string, userId: string) {
    const project = await db.project.findUnique({
        where: { id: projectId },
        select: { id: true, name: true, ownerId: true, workspaceId: true, visibility: true },
    });

    if (!project) return null;

    const access = await checkProjectAccess(project, userId, { intent: 'manage' });
    const canEdit = access.canEdit;

    if (!canEdit) return null;

    return project;
}

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

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

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

        const project = await getProjectWithEditAccess(projectId, session.user.id);
        if (!project) {
            return apiErrors.forbidden('Access denied');
        }

        const body = await request.json().catch(() => null);
        const title = typeof body?.title === 'string' ? body.title.trim() : '';

        if (!title) {
            return apiErrors.badRequest('Title is required');
        }

        if (!isBunnyUploadsFeatureEnabled()) {
            return apiErrors.badRequest('Direct uploads are disabled by this host');
        }

        const apiKey = process.env.BUNNY_STREAM_API_KEY;
        const libraryId = process.env.BUNNY_STREAM_LIBRARY_ID || process.env.NEXT_PUBLIC_BUNNY_STREAM_LIBRARY_ID;

        if (!apiKey || !libraryId) {
            return apiErrors.internalError('Bunny Stream is not configured correctly');
        }

        // 1. Create video object in Bunny Stream
        const bunnyRes = await fetch(`https://video.bunnycdn.com/library/${libraryId}/videos`, {
            method: 'POST',
            headers: {
                'AccessKey': apiKey,
                'Content-Type': 'application/json',
                'Accept': 'application/json'
            },
            body: JSON.stringify({ title })
        });

        if (!bunnyRes.ok) {
            console.error('Failed to create Bunny Stream video', await bunnyRes.text());
            return apiErrors.internalError('Failed to initialize video upload with provider');
        }

        const bunnyVideo = await bunnyRes.json();
        const videoId = bunnyVideo.guid;
        if (typeof videoId !== 'string' || videoId.length === 0) {
            return apiErrors.internalError('Upload provider did not return a valid video identifier');
        }

        // 2. Generate TUS upload signature
        const expirationTime = Math.floor(Date.now() / 1000) + 3600; // 1 hour validity

        // SHA256(library_id + api_key + expiration_time + video_id)
        const hash = crypto.createHash('sha256');
        hash.update(libraryId + apiKey + expirationTime + videoId);
        const signature = hash.digest('hex');
        const uploadToken = createBunnyUploadToken({
            userId: session.user.id,
            projectId,
            videoId,
        }, 3600);

        const response = successResponse({
            videoId,
            libraryId,
            signature,
            expirationTime,
            uploadToken,
        });

        return withCacheControl(response, 'private, no-store');
    } catch (error) {
        console.error('Error initializing Bunny upload:', error);
        return apiErrors.internalError('Failed to initialize upload');
    }
}

// DELETE /api/projects/[projectId]/videos/bunny-init
// Best-effort cleanup for interrupted uploads before a DB row is created.
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 } = await params;

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

        const project = await getProjectWithEditAccess(projectId, session.user.id);
        if (!project) {
            return apiErrors.forbidden('Access denied');
        }

        const body = await request.json().catch(() => null);
        const videoId = typeof body?.videoId === 'string' ? body.videoId.trim() : '';
        const uploadToken = typeof body?.uploadToken === 'string' ? body.uploadToken.trim() : '';

        if (!videoId || !uploadToken) {
            return apiErrors.badRequest('videoId and uploadToken are required');
        }

        const isValidUploadToken = verifyBunnyUploadToken(uploadToken, {
            userId: session.user.id,
            projectId,
            videoId,
        });
        if (!isValidUploadToken) {
            return apiErrors.forbidden('Invalid Bunny upload token');
        }

        await cleanupBunnyStreamVideos([{ providerId: 'bunny', videoId }]);

        const response = successResponse({ message: 'Pending upload cleaned up' });
        return withCacheControl(response, 'private, no-store');
    } catch (error) {
        console.error('Error cleaning up pending Bunny upload:', error);
        return apiErrors.internalError('Failed to cleanup pending upload');
    }
}