const API_URL = 'https://catbox.moe/user/api.php';
const R2_PUBLIC_URL = 'https://cucks.qzz.io';

export async function onRequest(context) {
    const { request, env } = context;

    if (request.method === 'OPTIONS') {
        return new Response(null, { status: 204, headers: corsHeaders() });
    }

    if (request.method !== 'POST') {
        return jsonError('Method not allowed', 405);
    }

    const useR2 = env.R2_BUCKET;

    try {
        const contentType = request.headers.get('content-type') || '';
        let file;
        let fileName;
        let fileType;

        if (contentType.includes('application/json')) {
            const body = await request.json();
            if (!body.fileUrl) return jsonError('No fileUrl provided', 400);

            const res = await fetch(body.fileUrl);
            if (!res.ok) throw new Error('Failed to fetch remote file');

            file = await res.arrayBuffer();
            fileName = body.fileName || body.fileUrl.split('/').pop();
            fileType = res.headers.get('content-type') || 'application/octet-stream';
        } else {
            const form = await request.formData();
            const uploaded = form.get('file');
            if (!uploaded) return jsonError('No file provided', 400);

            if (uploaded.size > 10 * 1024 * 1024) {
                return jsonError('File exceeds 10MB', 400);
            }

            file = await uploaded.arrayBuffer();
            fileName = uploaded.name;
            fileType = uploaded.type || 'application/octet-stream';
        }

        let url;

        if (useR2) {
            const key = `${Date.now()}-${fileName}`;
            await env.R2_BUCKET.put(key, file, { httpMetadata: { contentType: fileType } });
            url = `${R2_PUBLIC_URL}/${key}`;
        } else {
            const formData = new FormData();
            formData.append('reqtype', 'fileupload');
            formData.append('fileToUpload', new Blob([file], { type: fileType }), fileName);

            const response = await fetch(API_URL, {
                method: 'POST',
                body: formData,
            });

            const responseText = await response.text();

            if (!response.ok) {
                throw new Error(`Upload failed: ${responseText}`);
            }

            url = responseText.trim();
        }

        return jsonResponse({
            success: true,
            url: url,
        });
    } catch (err) {
        return jsonError(err.message, 500);
    }
}

function jsonResponse(obj, status = 200) {
    return new Response(JSON.stringify(obj), {
        status,
        headers: {
            'Content-Type': 'application/json',
            ...corsHeaders(),
        },
    });
}

function jsonError(message, status) {
    return jsonResponse({ success: false, error: message }, status);
}

function corsHeaders() {
    return {
        'Access-Control-Allow-Origin': '*',
        'Access-Control-Allow-Methods': 'POST, OPTIONS',
        'Access-Control-Allow-Headers': '*',
    };
}