1 files changed, 169 insertions, 0 deletions
diff --git a/internal/client/output/s3.go b/internal/client/output/s3.go
new file mode 100644
index 0000000..9d54a5e
--- /dev/null
+++ b/internal/client/output/s3.go
@@ -0,0 +1,169 @@
+package output
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"log/slog"
+	"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"
+	"github.com/SayaAndy/saya-today-thumbnail-generator/internal/client/input"
+)
+
+var _ OutputClient = (*S3OutputClient)(nil)
+
+type S3OutputClient struct {
+	prefix     string
+	bucketName string
+	s3cl       *s3.Client
+}
+
+func NewS3OutputClient(cfg *config.OutputConfig) (OutputClient, error) {
+	if cfg.Storage.Type != "s3" {
+		return nil, fmt.Errorf("invalid storage type for S3OutputClient")
+	}
+	s3cfg := cfg.Storage.Config.(*config.S3Config)
+
+	s3cl, err := newS3Client(s3cfg)
+	if err != nil {
+		return nil, fmt.Errorf("create S3 client: %w", err)
+	}
+
+	return &S3OutputClient{
+		s3cl:       s3cl,
+		bucketName: s3cfg.BucketName,
+		prefix:     s3cfg.Prefix,
+	}, nil
+}
+
+func (c *S3OutputClient) GetWriter(path string, inputMetadata *input.MetadataStruct, outputContentType string) (io.WriteCloser, error) {
+	key := c.prefix + path
+
+	return &s3WriteCloser{
+		key:               key,
+		bucketName:        c.bucketName,
+		s3cl:              c.s3cl,
+		contentType:       outputContentType,
+		hashOriginal:      inputMetadata.Hash,
+		buf:               &bytes.Buffer{},
+	}, nil
+}
+
+func (c *S3OutputClient) 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), "\""),
+		HashOriginal: head.Metadata["sha1-original"],
+		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 *S3OutputClient) IsMissing(path string) bool {
+	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 true
+	}
+
+	headJson, _ := json.Marshal(head)
+	slog.Debug("got object attrs", slog.String("path", path), slog.String("attrs", string(headJson)))
+
+	if head.ContentLength == nil || *head.ContentLength == 0 {
+		return true
+	}
+
+	return false
+}
+
+// s3WriteCloser buffers writes and uploads to S3 on Close.
+type s3WriteCloser struct {
+	key          string
+	bucketName   string
+	s3cl         *s3.Client
+	contentType  string
+	hashOriginal string
+	buf          *bytes.Buffer
+}
+
+func (w *s3WriteCloser) Write(p []byte) (int, error) {
+	return w.buf.Write(p)
+}
+
+func (w *s3WriteCloser) Close() error {
+	_, err := w.s3cl.PutObject(context.Background(), &s3.PutObjectInput{
+		Bucket:      aws.String(w.bucketName),
+		Key:         aws.String(w.key),
+		Body:        bytes.NewReader(w.buf.Bytes()),
+		ContentType: aws.String(w.contentType),
+		Metadata: map[string]string{
+			"sha1-original": w.hashOriginal,
+		},
+	})
+	if err != nil {
+		return fmt.Errorf("put S3 object %s: %w", w.key, err)
+	}
+	return 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
+}