// Copyright 2022 E99p1ant. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.

package storage

import (
	"fmt"
	"io"
	"mime/multipart"

	"github.com/pkg/errors"
	"github.com/wuhan005/gadget"

	"github.com/tamakyi/TamaBox/internal/conf"
)

// UploadPictureToOSS upload user's avatar or background image to OSS.
// It returns the uploaded asset URL.
func UploadPictureToOSS(file multipart.File, fileHeader *multipart.FileHeader) (string, error) {
	// 读取文件头，校验是否为图片
	header := make([]byte, 512)
	n, err := file.Read(header)
	if err != nil && err != io.EOF {
		return "", errors.Wrap(err, "read file header")
	}
	if n == 0 {
		return "", errors.New("empty file")
	}
	if !isSupportedImage(header[:n]) {
		return "", errors.New("不支持的文件格式，仅允许 JPEG、PNG、GIF、WebP 图片")
	}
	// 重置文件指针
	if _, err := file.Seek(0, io.SeekStart); err != nil {
		return "", errors.Wrap(err, "seek file")
	}

	// 获取共享 OSS bucket
	bucket, err := GetOSSBucket()
	if err != nil {
		return "", errors.Wrap(err, "get OSS bucket")
	}

	// OSS 通道原样上传原图（不转 WebP），扩展名沿用原始文件名。
	ext := ""
	if fileHeader != nil {
		ext = originalExt(fileHeader.Filename)
	}
	key := uploadKey(ext)

	if err := gadget.Retry(5, func() error {
		if err := bucket.PutObject(key, file); err != nil {
			return errors.Wrap(err, "put object")
		}
		return nil
	}); err != nil {
		return "", errors.Wrap(err, "retry 5 times")
	}

	if conf.Upload.AliyunBucketCDNHost != "" {
		return fmt.Sprintf("https://%s/%s", conf.Upload.AliyunBucketCDNHost, key), nil
	}
	return fmt.Sprintf("https://%s.%s/%s", conf.Upload.AliyunBucket, conf.Upload.AliyunEndpoint, key), nil
}