/**
 * HuggingFace 大文件直传 API
 * 
 * 流程：
 * 1. 前端计算 SHA256 和文件样本
 * 2. 前端调用此 API 获取 LFS 上传 URL
 * 3. 前端直接上传到 HuggingFace S3
 * 4. 前端调用 commitUpload API 提交文件引用
 * 
 * 这样可以绕过 CF Workers 的 100MB 请求体限制和 CPU 时间限制
 */

import { HuggingFaceAPI } from '../../utils/huggingfaceAPI.js';
import { getUploadConfig } from '../../utils/sysConfig.js';

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

    try {
        // 验证认证码
        const authCode = request.headers.get('authcode');
        if (env.AUTH_CODE && authCode !== env.AUTH_CODE) {
            return new Response(JSON.stringify({ error: 'Unauthorized' }), {
                status: 401,
                headers: { 'Content-Type': 'application/json' }
            });
        }

        const body = await request.json();
        const { fileSize, fileName, sha256, fileSample, channelName } = body;

        if (!fileSize || !fileName || !sha256 || !fileSample) {
            return new Response(JSON.stringify({ 
                error: 'Missing required fields: fileSize, fileName, sha256, fileSample' 
            }), {
                status: 400,
                headers: { 'Content-Type': 'application/json' }
            });
        }

        // 获取 HuggingFace 配置
        const uploadConfig = await getUploadConfig(env);
        const hfSettings = uploadConfig.huggingface;

        if (!hfSettings || !hfSettings.channels || hfSettings.channels.length === 0) {
            return new Response(JSON.stringify({ error: 'No HuggingFace channel configured' }), {
                status: 400,
                headers: { 'Content-Type': 'application/json' }
            });
        }

        // 选择渠道
        let hfChannel;
        if (channelName) {
            hfChannel = hfSettings.channels.find(c => c.name === channelName);
        }
        if (!hfChannel) {
            hfChannel = hfSettings.loadBalance?.enabled
                ? hfSettings.channels[Math.floor(Math.random() * hfSettings.channels.length)]
                : hfSettings.channels[0];
        }

        if (!hfChannel || !hfChannel.token || !hfChannel.repo) {
            return new Response(JSON.stringify({ error: 'HuggingFace channel not properly configured' }), {
                status: 400,
                headers: { 'Content-Type': 'application/json' }
            });
        }

        // 构建文件路径
        const now = new Date();
        const yearMonth = `${now.getFullYear()}${String(now.getMonth() + 1).padStart(2, '0')}`;
        
        // 生成唯一文件名
        const ext = fileName.includes('.') ? fileName.substring(fileName.lastIndexOf('.')) : '';
        const uniqueId = crypto.randomUUID().replace(/-/g, '');
        const fullId = uniqueId + ext;
        const filePath = `images/${yearMonth}/${fullId}`;

        // 获取 LFS 上传信息
        const huggingfaceAPI = new HuggingFaceAPI(hfChannel.token, hfChannel.repo, hfChannel.isPrivate || false);
        const uploadInfo = await huggingfaceAPI.getLfsUploadInfo(fileSize, filePath, sha256, fileSample);

        // 返回上传信息
        return new Response(JSON.stringify({
            success: true,
            fullId,
            filePath,
            channelName: hfChannel.name,
            repo: hfChannel.repo,
            isPrivate: hfChannel.isPrivate || false,
            ...uploadInfo
        }), {
            status: 200,
            headers: { 'Content-Type': 'application/json' }
        });

    } catch (error) {
        console.error('getUploadUrl error:', error.message);
        return new Response(JSON.stringify({ error: error.message }), {
            status: 500,
            headers: { 'Content-Type': 'application/json' }
        });
    }
}