package utils

import (
	"fmt"
	"io"
	"mime/multipart"
	"os"
	"path/filepath"
	"strings"
	"time"
)

// StorageType 存储类型
type StorageType string

const (
	StorageLocal  StorageType = "local"
	StorageQCloud StorageType = "qcloud"
	StorageAliyun StorageType = "aliyun"
	StorageQiniu  StorageType = "qiniu"
)

// OSSConfig OSS配置
type OSSConfig struct {
	StorageType string
	AccessKey   string
	SecretKey   string
	Bucket      string
	Region      string
	Domain      string
}

// OSSUploader OSS上传接口
type OSSUploader interface {
	Upload(file multipart.File, filename string, size int64) (string, string, error) // 返回 filePath, fileURL, error
	Delete(filePath string) error
}

// GetOSSUploader 根据存储类型获取上传器
func GetOSSUploader(config *OSSConfig) (OSSUploader, error) {
	switch StorageType(config.StorageType) {
	case StorageLocal:
		return &LocalUploader{
			BasePath: "./uploads",
			BaseURL:  "/uploads",
		}, nil
	case StorageQCloud:
		// TODO: 实现腾讯云COS上传
		return nil, fmt.Errorf("qcloud storage not implemented yet")
	case StorageAliyun:
		// TODO: 实现阿里云OSS上传
		return nil, fmt.Errorf("aliyun storage not implemented yet")
	case StorageQiniu:
		// TODO: 实现七牛云上传
		return nil, fmt.Errorf("qiniu storage not implemented yet")
	default:
		return nil, fmt.Errorf("unsupported storage type: %s", config.StorageType)
	}
}

// LocalUploader 本地存储上传器
type LocalUploader struct {
	BasePath string
	BaseURL  string
}

// Upload 上传文件到本地
func (l *LocalUploader) Upload(file multipart.File, filename string, size int64) (string, string, error) {
	// 生成唯一文件名
	ext := filepath.Ext(filename)
	timestamp := time.Now().Unix()
	randomStr := fmt.Sprintf("%d", timestamp)
	newFilename := fmt.Sprintf("%s_%s%s", strings.TrimSuffix(filename, ext), randomStr, ext)

	// 按日期创建目录
	dateDir := time.Now().Format("2006/01/02")
	uploadDir := filepath.Join(l.BasePath, dateDir)

	// 创建目录
	if err := os.MkdirAll(uploadDir, 0755); err != nil {
		return "", "", fmt.Errorf("failed to create upload directory: %v", err)
	}

	// 完整文件路径
	filePath := filepath.Join(uploadDir, newFilename)

	// 创建目标文件
	dst, err := os.Create(filePath)
	if err != nil {
		return "", "", fmt.Errorf("failed to create file: %v", err)
	}
	defer dst.Close()

	// 复制文件内容
	if _, err := io.Copy(dst, file); err != nil {
		return "", "", fmt.Errorf("failed to copy file: %v", err)
	}

	// 生成访问URL
	fileURL := fmt.Sprintf("%s/%s/%s", l.BaseURL, dateDir, newFilename)

	return filePath, fileURL, nil
}

// Delete 删除本地文件
func (l *LocalUploader) Delete(filePath string) error {
	// 确保文件路径在BasePath内（安全措施）
	absBasePath, err := filepath.Abs(l.BasePath)
	if err != nil {
		return err
	}

	absFilePath, err := filepath.Abs(filePath)
	if err != nil {
		return err
	}

	if !strings.HasPrefix(absFilePath, absBasePath) {
		return fmt.Errorf("invalid file path: outside base directory")
	}

	return os.Remove(filePath)
}

// GetFileType 根据MIME类型判断文件类型
func GetFileType(mimeType string) string {
	if strings.HasPrefix(mimeType, "image/") {
		return "image"
	} else if strings.HasPrefix(mimeType, "video/") {
		return "video"
	} else if strings.HasPrefix(mimeType, "application/pdf") ||
		strings.HasPrefix(mimeType, "application/msword") ||
		strings.HasPrefix(mimeType, "application/vnd.openxmlformats") ||
		strings.HasPrefix(mimeType, "text/") {
		return "document"
	}
	return "other"
}