package storage

import (
	"fmt"
	"io"
	"mime/multipart"
	"os"
	"path/filepath"

	"dianshang/internal/config"
)

// LocalStorage 本地存储服务
type LocalStorage struct {
	config *config.UploadConfig
}

// NewLocalStorage 创建本地存储服务实例
func NewLocalStorage(cfg *config.UploadConfig) *LocalStorage {
	return &LocalStorage{
		config: cfg,
	}
}

// UploadFile 上传文件到本地
func (s *LocalStorage) UploadFile(file multipart.File, filename string, objectPath string) (string, error) {
	// 创建保存路径
	savePath := filepath.Join(s.config.StaticPath, objectPath, filename)
	
	// 确保目录存在
	if err := os.MkdirAll(filepath.Dir(savePath), 0755); err != nil {
		return "", fmt.Errorf("创建目录失败: %w", err)
	}

	// 保存文件
	if err := saveFile(file, savePath); err != nil {
		return "", fmt.Errorf("保存文件失败: %w", err)
	}

	// 返回文件URL
	fileURL := fmt.Sprintf("%s/%s/%s", s.config.BaseURL, objectPath, filename)
	return fileURL, nil
}

// DeleteFile 删除本地文件
func (s *LocalStorage) DeleteFile(filePath string) error {
	err := os.Remove(filePath)
	if err != nil {
		return fmt.Errorf("删除本地文件失败: %w", err)
	}
	return nil
}

// IsFileExist 检查文件是否存在
func (s *LocalStorage) IsFileExist(filePath string) bool {
	_, err := os.Stat(filePath)
	return err == nil
}

// GetFileURL 获取文件访问URL
func (s *LocalStorage) GetFileURL(objectPath string, filename string) string {
	return fmt.Sprintf("%s/%s/%s", s.config.BaseURL, objectPath, filename)
}

// saveFile 保存上传的文件
func saveFile(file multipart.File, dst string) error {
	out, err := os.Create(dst)
	if err != nil {
		return err
	}
	defer out.Close()

	_, err = io.Copy(out, file)
	return err
}