// 上传文件到cloudflare R2
package handler
import (
	"bytes"
	"fmt"
	"net/http"
	"github.com/gin-gonic/gin"
	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/credentials"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/s3"
)

type UploadHandler struct {
	accessKey string
	secretKey string
	bucket string
	endpoint string
	customDomain string
}

type UploadRequest struct {
	File string `json:"file" binding:"required"`
	APIKey string `json:"apikey" binding:"required"`
}

type UploadResponse struct {
	ImageURL string `json:"image_url"`
	Success bool `json:"success"`
}

func NewUploadHandler(accessKey, secretKey, bucket, endpoint, customDomain string) *UploadHandler {
	return &UploadHandler{
		accessKey: accessKey,
		secretKey: secretKey,
		bucket: bucket,
		endpoint: endpoint,
		customDomain: customDomain,
	}
}
// 上传文件到cloudflare R2。判断文件是否是图片，如果是图片，则上传到R2，并返回图片的url，如果不是图片，则返回错误。
// 图片大小限制为10M，图片格式为jpg, jpeg, png, gif, bmp, tiff, webp
// HandleUpload 上传文件到Cloudflare R2
func (h *UploadHandler) HandleUpload(c *gin.Context) {
	// 解析请求体
	file, header, err := c.Request.FormFile("file")
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Failed to read file from request"})
		return
	}
	defer file.Close()

	// 读取文件内容
	fileBuffer := make([]byte, header.Size)
	_, err = file.Read(fileBuffer)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to read file content"})
		return
	}

	// 验证文件类型
	contentType := http.DetectContentType(fileBuffer)
	if !isImage(contentType) {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid file type. Only images are allowed"})
		return
	}

	// 验证文件大小
	if header.Size > 10<<20 { // 10MB
		c.JSON(http.StatusBadRequest, gin.H{"error": "File size exceeds the limit of 10MB"})
		return
	}

	// 上传文件到R2
	imageURL, err := h.uploadToR2(fileBuffer, header.Filename, contentType)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": fmt.Sprintf("Failed to upload file to R2: %v", err)})
		return
	}

	// 返回结果
	response := UploadResponse{
		ImageURL: imageURL,
		Success:  true,
	}
	c.JSON(http.StatusOK, response)
}

// uploadToR2 上传文件到Cloudflare R2
func (h *UploadHandler) uploadToR2(file []byte, fileName, contentType string) (string, error) {
	// 创建S3会话
	sess, err := session.NewSession(&aws.Config{
		Endpoint:    aws.String(h.endpoint),
		Region:      aws.String("auto"),
		Credentials: credentials.NewStaticCredentials(h.accessKey, h.secretKey, ""),
	})
	if err != nil {
		return "", fmt.Errorf("failed to create S3 session: %v", err)
	}

	// 创建S3服务客户端
	svc := s3.New(sess)

	// 上传文件到R2
	_, err = svc.PutObject(&s3.PutObjectInput{
		Bucket:      aws.String(h.bucket),
		Key:         aws.String(fileName),
		Body:        bytes.NewReader(file),
		ContentType: aws.String(contentType),
		ACL:         aws.String("public-read"), // 设置文件为公开可读
	})
	if err != nil {
		return "", fmt.Errorf("failed to upload file to R2: %v", err)
	}

	// 生成文件的URL
	imageURL := fmt.Sprintf("https://%s/%s", h.customDomain, fileName)
	return imageURL, nil
}

// isImage 检查文件是否是图片
func isImage(contentType string) bool {
	allowedTypes := []string{"image/jpeg", "image/png", "image/gif", "image/bmp", "image/tiff", "image/webp"}
	for _, t := range allowedTypes {
		if contentType == t {
			return true
		}
	}
	return false
}