FileRelay/internal/storage/s3.go

package storage

import (
	"context"
	"io"
	"strings"

	"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"
)

type S3Storage struct {
	client *s3.Client
	bucket string
}

func NewS3Storage(ctx context.Context, endpoint, region, accessKey, secretKey, bucket string, useSSL bool) (*S3Storage, error) {
	customResolver := aws.EndpointResolverWithOptionsFunc(func(service, region string, options ...interface{}) (aws.Endpoint, error) {
		if endpoint != "" {
			return aws.Endpoint{
				URL:               endpoint,
				SigningRegion:     region,
				HostnameImmutable: true,
			}, nil
		}
		return aws.Endpoint{}, &aws.EndpointNotFoundError{}
	})

	cfg, err := config.LoadDefaultConfig(ctx,
		config.WithRegion(region),
		config.WithCredentialsProvider(credentials.NewStaticCredentialsProvider(accessKey, secretKey, "")),
		config.WithEndpointResolverWithOptions(customResolver),
	)
	if err != nil {
		return nil, err
	}

	client := s3.NewFromConfig(cfg)
	return &S3Storage{
		client: client,
		bucket: bucket,
	}, nil
}

func (s *S3Storage) Save(ctx context.Context, path string, reader io.Reader) error {
	_, err := s.client.PutObject(ctx, &s3.PutObjectInput{
		Bucket: aws.String(s.bucket),
		Key:    aws.String(path),
		Body:   reader,
	})
	return err
}

func (s *S3Storage) Open(ctx context.Context, path string) (io.ReadCloser, error) {
	output, err := s.client.GetObject(ctx, &s3.GetObjectInput{
		Bucket: aws.String(s.bucket),
		Key:    aws.String(path),
	})
	if err != nil {
		return nil, err
	}
	return output.Body, nil
}

func (s *S3Storage) Delete(ctx context.Context, path string) error {
	_, err := s.client.DeleteObject(ctx, &s3.DeleteObjectInput{
		Bucket: aws.String(s.bucket),
		Key:    aws.String(path),
	})
	return err
}

func (s *S3Storage) Exists(ctx context.Context, path string) (bool, error) {
	_, err := s.client.HeadObject(ctx, &s3.HeadObjectInput{
		Bucket: aws.String(s.bucket),
		Key:    aws.String(path),
	})
	if err != nil {
		// In AWS SDK v2, we check if the error is 404
		if strings.Contains(err.Error(), "NotFound") || strings.Contains(err.Error(), "404") {
			return false, nil
		}
		return false, err
	}
	return true, nil
}