package storage

import (
	"context"
	"fmt"
	"io"
	"time"

	"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"

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

// s3Store targets AWS S3 or path-style compatibles (Garage/MinIO), same as
// the backend's S3 backend. The bucket is never public: downloads use
// short-lived presigned GETs so visibility rules keep holding on S3.
type s3Store struct {
	client  *s3.Client
	presign *s3.PresignClient
	bucket  string
}

func newS3(cfg config.Config) (*s3Store, error) {
	awsCfg, err := awsconfig.LoadDefaultConfig(context.Background(),
		awsconfig.WithRegion(cfg.S3Region),
		awsconfig.WithCredentialsProvider(
			credentials.NewStaticCredentialsProvider(cfg.S3AccessKeyID, cfg.S3SecretKey, "")),
	)
	if err != nil {
		return nil, fmt.Errorf("s3 config: %w", err)
	}
	client := s3.NewFromConfig(awsCfg, func(o *s3.Options) {
		o.BaseEndpoint = aws.String(cfg.S3Endpoint)
		o.UsePathStyle = cfg.S3ForcePathStyle
	})
	return &s3Store{
		client:  client,
		presign: s3.NewPresignClient(client),
		bucket:  cfg.S3Bucket,
	}, nil
}

func (s *s3Store) Put(ctx context.Context, key string, r io.Reader, size int64, contentType string) error {
	_, err := s.client.PutObject(ctx, &s3.PutObjectInput{
		Bucket:        aws.String(s.bucket),
		Key:           aws.String(key),
		Body:          r,
		ContentLength: aws.Int64(size),
		ContentType:   aws.String(contentType),
	})
	return err
}

func (s *s3Store) Open(ctx context.Context, key string) (io.ReadCloser, int64, error) {
	out, err := s.client.GetObject(ctx, &s3.GetObjectInput{
		Bucket: aws.String(s.bucket),
		Key:    aws.String(key),
	})
	if err != nil {
		return nil, 0, err
	}
	return out.Body, aws.ToInt64(out.ContentLength), nil
}

func (s *s3Store) Delete(ctx context.Context, key string) error {
	_, err := s.client.DeleteObject(ctx, &s3.DeleteObjectInput{
		Bucket: aws.String(s.bucket),
		Key:    aws.String(key),
	})
	return err
}

func (s *s3Store) PresignGet(ctx context.Context, key, downloadFilename, contentType string, expiry time.Duration) (string, error) {
	in := &s3.GetObjectInput{
		Bucket: aws.String(s.bucket),
		Key:    aws.String(key),
	}
	if contentType != "" {
		in.ResponseContentType = aws.String(contentType)
	}
	if downloadFilename != "" {
		in.ResponseContentDisposition = aws.String(fmt.Sprintf("attachment; filename=%q", downloadFilename))
	}
	req, err := s.presign.PresignGetObject(ctx, in, s3.WithPresignExpires(expiry))
	if err != nil {
		return "", err
	}
	return req.URL, nil
}