/**
 * Hugging Face Hub API 封装类
 * 用于上传文件到 Hugging Face Dataset 仓库并获取文件
 * 
 * 参考文档：
 * - https://huggingface.co/docs/huggingface_hub/guides/upload
 * - https://huggingface.co/docs/huggingface.js/hub/README
 * 
 * 注意：为了避免 Cloudflare Workers 的 CPU 限制，
 * 本实现直接上传原始文件，不做任何编码转换。
 */
export class HuggingFaceAPI {
    constructor(token, repo, isPrivate = false) {
        this.token = token;
        this.repo = repo;  // 格式: username/repo-name
        this.isPrivate = isPrivate;
        this.baseURL = 'https://huggingface.co';
    }

    /**
     * 检查仓库是否存在
     * @returns {Promise<boolean>}
     */
    async repoExists() {
        try {
            const response = await fetch(`${this.baseURL}/api/datasets/${this.repo}`, {
                method: 'GET',
                headers: {
                    'Authorization': `Bearer ${this.token}`
                }
            });
            return response.ok;
        } catch (error) {
            console.error('Error checking repo existence:', error.message);
            return false;
        }
    }

    /**
     * 创建仓库（如果不存在）
     * @returns {Promise<boolean>}
     */
    async createRepoIfNotExists() {
        try {
            const exists = await this.repoExists();
            if (exists) {
                console.log('Repository already exists:', this.repo);
                return true;
            }

            console.log('Creating repository:', this.repo);
            const response = await fetch(`${this.baseURL}/api/repos/create`, {
                method: 'POST',
                headers: {
                    'Authorization': `Bearer ${this.token}`,
                    'Content-Type': 'application/json'
                },
                body: JSON.stringify({
                    name: this.repo.split('/')[1],
                    type: 'dataset',
                    private: this.isPrivate
                })
            });

            if (!response.ok) {
                if (response.status === 409) {
                    console.log('Repository already exists (409)');
                    return true;
                }
                const errorText = await response.text();
                console.error('Failed to create repo:', response.status, errorText);
                throw new Error(`Failed to create repo: ${response.status} - ${errorText}`);
            }

            console.log('Repository created successfully');
            return true;
        } catch (error) {
            console.error('Error creating repo:', error.message);
            return false;
        }
    }

    /**
     * 上传文件到仓库
     * 直接使用 PUT 请求上传文件，不做任何编码转换
     * 
     * @param {File|Blob} file - 要上传的文件
     * @param {string} filePath - 存储路径（如 images/xxx.jpg）
     * @param {string} commitMessage - 提交信息
     * @returns {Promise<Object>} 上传结果
     */
    async uploadFile(file, filePath, commitMessage = 'Upload file') {
        try {
            // 确保仓库存在
            const repoCreated = await this.createRepoIfNotExists();
            if (!repoCreated) {
                throw new Error('Failed to create or access repository');
            }

            console.log('=== HuggingFace Upload ===');
            console.log('Repo:', this.repo);
            console.log('File path:', filePath);
            console.log('File size:', file.size);
            console.log('File type:', file.type);

            // 使用 HuggingFace 的文件上传 API
            // PUT /api/datasets/{repo_id}/upload/main/{path_in_repo}
            const uploadUrl = `${this.baseURL}/api/datasets/${this.repo}/upload/main/${filePath}`;
            console.log('Upload URL:', uploadUrl);

            // 直接 PUT 文件内容，不做任何转换
            const response = await fetch(uploadUrl, {
                method: 'PUT',
                headers: {
                    'Authorization': `Bearer ${this.token}`,
                    'Content-Type': file.type || 'application/octet-stream'
                },
                body: file  // 直接传递 File/Blob 对象
            });

            console.log('Upload response status:', response.status);

            if (!response.ok) {
                const errorText = await response.text();
                console.error('Upload failed:', response.status, errorText);
                throw new Error(`Upload failed: ${response.status} - ${errorText}`);
            }

            const result = await response.json().catch(() => ({}));
            console.log('Upload result:', JSON.stringify(result));

            // 构建文件 URL
            const fileUrl = `${this.baseURL}/datasets/${this.repo}/resolve/main/${filePath}`;

            return {
                success: true,
                commitId: result.commitOid || result.oid || 'uploaded',
                filePath: filePath,
                fileUrl: fileUrl,
                fileSize: file.size
            };
        } catch (error) {
            console.error('HuggingFace upload error:', error.message);
            throw error;
        }
    }

    /**
     * 删除文件
     * @param {string} filePath - 文件路径
     * @param {string} commitMessage - 提交信息
     * @returns {Promise<boolean>}
     */
    async deleteFile(filePath, commitMessage = 'Delete file') {
        try {
            // 使用 DELETE 请求删除文件
            const deleteUrl = `${this.baseURL}/api/datasets/${this.repo}/delete/main/${filePath}`;
            
            const response = await fetch(deleteUrl, {
                method: 'DELETE',
                headers: {
                    'Authorization': `Bearer ${this.token}`
                }
            });

            if (!response.ok) {
                const errorText = await response.text();
                console.error('HuggingFace delete error:', response.status, errorText);
                return false;
            }

            return true;
        } catch (error) {
            console.error('Error deleting file from HuggingFace:', error.message);
            return false;
        }
    }

    /**
     * 获取文件内容（用于私有仓库）
     * @param {string} filePath - 文件路径
     * @returns {Promise<Response>}
     */
    async getFileContent(filePath) {
        const fileUrl = `${this.baseURL}/datasets/${this.repo}/resolve/main/${filePath}`;
        
        const response = await fetch(fileUrl, {
            headers: this.isPrivate ? { 'Authorization': `Bearer ${this.token}` } : {}
        });

        return response;
    }

    /**
     * 获取文件的公开访问 URL
     * @param {string} filePath - 文件路径
     * @returns {string}
     */
    getFileURL(filePath) {
        return `${this.baseURL}/datasets/${this.repo}/resolve/main/${filePath}`;
    }
}