package storage

import (
	"context"
	"sync"

	"github.com/aliyun/aliyun-oss-go-sdk/oss"
	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/config"
	"github.com/aws/aws-sdk-go-v2/credentials"
	"github.com/aws/aws-sdk-go-v2/service/s3"
	"github.com/pkg/errors"

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

var (
	s3ClientOnce sync.Once
	s3Client     *s3.Client
	s3ClientErr  error

	ossClientOnce sync.Once
	ossBucket     *oss.Bucket
	ossClientErr  error
)

// GetS3Client 返回共享的 S3 客户端（单例），避免每次上传重复创建。
func GetS3Client() (*s3.Client, error) {
	s3ClientOnce.Do(func() {
		if conf.Upload.ImageEndpoint == "" {
			s3ClientErr = errors.New("S3 endpoint not configured")
			return
		}

		r2Resolver := aws.EndpointResolverWithOptionsFunc(func(service, region string, options ...interface{}) (aws.Endpoint, error) {
			return aws.Endpoint{
				URL:               conf.Upload.ImageEndpoint,
				HostnameImmutable: true,
				Source:            aws.EndpointSourceCustom,
			}, nil
		})

		cfg, err := config.LoadDefaultConfig(context.Background(),
			config.WithEndpointResolverWithOptions(r2Resolver),
			config.WithCredentialsProvider(credentials.NewStaticCredentialsProvider(
				conf.Upload.ImageAccessID,
				conf.Upload.ImageAccessSecret,
				"",
			)),
			config.WithRegion("auto"),
		)
		if err != nil {
			s3ClientErr = errors.Wrap(err, "load S3 config")
			return
		}
		s3Client = s3.NewFromConfig(cfg)
	})
	return s3Client, s3ClientErr
}

// GetOSSBucket 返回共享的 OSS Bucket（单例）。
func GetOSSBucket() (*oss.Bucket, error) {
	ossClientOnce.Do(func() {
		if conf.Upload.AliyunEndpoint == "" {
			ossClientErr = errors.New("OSS endpoint not configured")
			return
		}
		client, err := oss.New(conf.Upload.AliyunEndpoint, conf.Upload.AliyunAccessID, conf.Upload.AliyunAccessSecret)
		if err != nil {
			ossClientErr = errors.Wrap(err, "new OSS client")
			return
		}
		bucket, err := client.Bucket(conf.Upload.AliyunBucket)
		if err != nil {
			ossClientErr = errors.Wrap(err, "get OSS bucket")
			return
		}
		ossBucket = bucket
	})
	return ossBucket, ossClientErr
}