package utils

import (
	"context"
	"github.com/minio/minio-go/v7"
	"github.com/minio/minio-go/v7/pkg/credentials"
	"sync"
	"time"
)

const (
	DefaultExpiredTime = 30 * time.Minute
)

var (
	once        sync.Once
	minioClient *MinioOss
)

type MinioOss struct {
	bucketName  string
	ObjectName  string
	minioClient *minio.Client
	ExpiredTime time.Duration
}

func (mo *MinioOss) oss() *minio.Client {
	return mo.minioClient
}
func (mo *MinioOss) GetObject(objectName string, filePath string) (err error) {
	err = minioClient.oss().FGetObject(context.Background(), mo.GetBucketName(), objectName, filePath, minio.GetObjectOptions{})
	return
}
func (mo *MinioOss) SaveObject(objectName string, filePath string) (err error) {
	_, err = minioClient.oss().FPutObject(context.Background(), mo.GetBucketName(), objectName, filePath, minio.PutObjectOptions{})
	return
}
func (mo *MinioOss) GetState(objectName string) (state minio.ObjectInfo, err error) {
	state, err = minioClient.oss().StatObject(context.Background(), mo.GetBucketName(), objectName, minio.GetObjectOptions{})
	return
}
func (mo *MinioOss) GetObjectExt(contentType string) (ext string) {
	return getFileExtensionFromContentType(contentType)
}
func getFileExtensionFromContentType(contentType string) string {
	switch contentType {
	case "image/jpeg":
		return ".jpg"
	case "image/png":
		return ".png"
	case "application/pdf":
		return ".pdf"
	case "application/msword":
		return ".doc"
	case "application/vnd.openxmlformats-officedocument.wordprocessingml.document":
		return ".docx"
	case "application/vnd.ms-excel":
		return ".xls"
	case "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet":
		return ".xlsx"
	case "text/plain":
		return ".txt"
	case "application/json":
		return ".json"
	case "application/octet-stream":
		return ".bin"
	default:
		return ""
	}
}

func DefaultClient() *MinioOss {
	once.Do(func() {
		if minioClient == nil {
			// 此处兼容一下前后端endpoint不一致的情况, 前端用minio_endpoint后端用minio_back_endpoint, minio_back_endpoint为空则都取前者
			endpoint := MinIoEndpoint
			if MinIoBackEndpoint != "" {
				endpoint = MinIoBackEndpoint
			}
			accessKeyID := MinIoAccessKeyId
			secretAccessKey := MinIoAccessKeySecret
			useSSL := false
			if MinIoUseSSL == "true" {
				useSSL = true
			}
			client, err := minio.New(endpoint, &minio.Options{
				Creds:  credentials.NewStaticV4(accessKeyID, secretAccessKey, ""),
				Secure: useSSL,
			})
			if err != nil {
				FileLog.Error("初始化minio客户端失败: %s", err)
			}
			bucketName := MinIoBucketname
			exists, errBucketExists := client.BucketExists(context.Background(), bucketName)
			if errBucketExists != nil || !exists {
				FileLog.Error("BucketExists: %v; err: %v", exists, errBucketExists)
			}
			minioClient = &MinioOss{
				minioClient: client,
				bucketName:  bucketName,
				ExpiredTime: DefaultExpiredTime,
			}
		}
	})
	return minioClient
}

func (mo *MinioOss) GetBucketName() string {
	return mo.bucketName
}
func (mo *MinioOss) GetExpiredTime() time.Duration {
	return mo.ExpiredTime
}

// 生成预签名的PUT URL
func (mo *MinioOss) GeneratePreSignedPutURLHandler(objectName string) (url string, err error) {
	// 生成预签名的PUT URL
	PreSignedURL, err := minioClient.oss().PresignedPutObject(context.Background(), minioClient.GetBucketName(), objectName, minioClient.GetExpiredTime())
	if err != nil {
		FileLog.Error("生成预签名的PUT URL失败: %s", err)
		return
	}
	url = PreSignedURL.String()
	return
}