feat: s3 input & output clients

1 files changed, 156 insertions, 0 deletions

diff --git a/internal/client/input/s3.go b/internal/client/input/s3.go
new file mode 100644
index 0000000..4f84788
--- /dev/null
+++ b/internal/client/input/s3.go
@@ -0,0 +1,156 @@
+package input
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"slices"
+	"strings"
+
+	"github.com/aws/aws-sdk-go-v2/aws"
+	awsconfig "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/SayaAndy/saya-today-thumbnail-generator/config"
+)
+
+var _ InputClient = (*S3InputClient)(nil)
+
+type S3InputClient struct {
+	prefix          string
+	bucketName      string
+	s3cl            *s3.Client
+	knownExtensions []string
+}
+
+func NewS3InputClient(cfg *config.InputConfig) (InputClient, error) {
+	if cfg.Storage.Type != "s3" {
+		return nil, fmt.Errorf("invalid storage type for S3InputClient")
+	}
+	s3cfg := cfg.Storage.Config.(*config.S3Config)
+
+	s3cl, err := newS3Client(s3cfg)
+	if err != nil {
+		return nil, fmt.Errorf("create S3 client: %w", err)
+	}
+
+	return &S3InputClient{
+		s3cl:            s3cl,
+		bucketName:      s3cfg.BucketName,
+		prefix:          s3cfg.Prefix,
+		knownExtensions: cfg.KnownExtensions,
+	}, nil
+}
+
+func (c *S3InputClient) Scan() ([]string, error) {
+	var filePaths []string
+
+	paginator := s3.NewListObjectsV2Paginator(c.s3cl, &s3.ListObjectsV2Input{
+		Bucket: aws.String(c.bucketName),
+		Prefix: aws.String(c.prefix),
+	})
+
+	for paginator.HasMorePages() {
+		output, err := paginator.NextPage(context.Background())
+		if err != nil {
+			return nil, fmt.Errorf("list S3 objects: %w", err)
+		}
+
+		for _, obj := range output.Contents {
+			name := aws.ToString(obj.Key)
+
+			if len(c.knownExtensions) != 0 {
+				nameParts := strings.Split(name, ".")
+				if len(nameParts) < 2 {
+					continue
+				}
+				ext := strings.ToLower(nameParts[len(nameParts)-1])
+				if !slices.Contains(c.knownExtensions, ext) {
+					continue
+				}
+			}
+
+			filePaths = append(filePaths, strings.TrimPrefix(name, c.prefix))
+		}
+	}
+
+	return filePaths, nil
+}
+
+func (c *S3InputClient) ReadMetadata(path string) (*MetadataStruct, error) {
+	key := c.prefix + path
+
+	head, err := c.s3cl.HeadObject(context.Background(), &s3.HeadObjectInput{
+		Bucket: aws.String(c.bucketName),
+		Key:    aws.String(key),
+	})
+	if err != nil {
+		return nil, fmt.Errorf("head S3 object %s: %w", key, err)
+	}
+
+	metadata := MetadataStruct{
+		Name:        key,
+		StorageType: "s3",
+		Hash:        strings.Trim(aws.ToString(head.ETag), "\""),
+		ContentType: aws.ToString(head.ContentType),
+		Misc:        head.Metadata,
+	}
+
+	if head.ContentLength != nil {
+		metadata.Size = *head.ContentLength
+	}
+	if head.LastModified != nil {
+		metadata.LastModified = *head.LastModified
+		metadata.FirstCreated = *head.LastModified
+	}
+
+	return &metadata, nil
+}
+
+func (c *S3InputClient) ID(path string) string {
+	return fmt.Sprintf("s3://%s/%s%s", c.bucketName, c.prefix, path)
+}
+
+func (c *S3InputClient) GetReader(path string) (io.ReadCloser, error) {
+	key := c.prefix + path
+
+	output, err := c.s3cl.GetObject(context.Background(), &s3.GetObjectInput{
+		Bucket: aws.String(c.bucketName),
+		Key:    aws.String(key),
+	})
+	if err != nil {
+		return nil, fmt.Errorf("get S3 object %s: %w", key, err)
+	}
+
+	return output.Body, nil
+}
+
+func newS3Client(cfg *config.S3Config) (*s3.Client, error) {
+	opts := []func(*awsconfig.LoadOptions) error{
+		awsconfig.WithRegion(cfg.Region),
+	}
+
+	if cfg.AccessKeyID != "" && cfg.SecretAccessKey != "" {
+		opts = append(opts, awsconfig.WithCredentialsProvider(
+			credentials.NewStaticCredentialsProvider(cfg.AccessKeyID, cfg.SecretAccessKey, ""),
+		))
+	}
+
+	awsCfg, err := awsconfig.LoadDefaultConfig(context.Background(), opts...)
+	if err != nil {
+		return nil, fmt.Errorf("load AWS config: %w", err)
+	}
+
+	var s3Opts []func(*s3.Options)
+	if cfg.Endpoint != "" {
+		s3Opts = append(s3Opts, func(o *s3.Options) {
+			o.BaseEndpoint = aws.String(cfg.Endpoint)
+		})
+	}
+	s3Opts = append(s3Opts, func(o *s3.Options) {
+		o.UsePathStyle = cfg.UsePathStyle
+	})
+
+	return s3.NewFromConfig(awsCfg, s3Opts...), nil
+}