// Package storage abstracts photo object storage. Selection follows the
// backend's convention (backend/src/lib/storage.ts): S3 when S3_ENDPOINT
// and S3_BUCKET are both set, local disk otherwise. Keys are identical on
// both backends: galleries/<galleryID>/<variantDir>/<photoID>.<ext>.
package storage

import (
	"context"
	"errors"
	"io"
	"time"

	"git.azzamo.net/Michilis/Spanglish/photo-api/internal/config"
)

// ErrNoPresign is returned by backends that cannot presign (local disk);
// callers then stream the object through the API instead.
var ErrNoPresign = errors.New("presigned URLs not supported")

type Storage interface {
	Put(ctx context.Context, key string, r io.Reader, size int64, contentType string) error
	Open(ctx context.Context, key string) (io.ReadCloser, int64, error)
	Delete(ctx context.Context, key string) error
	PresignGet(ctx context.Context, key, downloadFilename, contentType string, expiry time.Duration) (string, error)
}

func New(cfg config.Config) (Storage, error) {
	if cfg.S3Enabled() {
		return newS3(cfg)
	}
	return newLocal(cfg.StoragePath)
}