package storage

import (
	"context"
	"fmt"
	"io"
	"log"
	"path/filepath"
	"strings"

	"github.com/google/uuid"
	"github.com/minio/minio-go/v7"
	"github.com/minio/minio-go/v7/pkg/credentials"
)

type MinIOStorage struct {
	client *minio.Client
	bucket string
}

type MinIOConfig struct {
	Endpoint  string
	AccessKey string
	SecretKey string
	Bucket    string
	UseSSL    bool
}

func NewMinIOStorage(cfg MinIOConfig) (*MinIOStorage, error) {
	client, err := minio.New(cfg.Endpoint, &minio.Options{
		Creds:  credentials.NewStaticV4(cfg.AccessKey, cfg.SecretKey, ""),
		Secure: cfg.UseSSL,
	})
	if err != nil {
		return nil, fmt.Errorf("create minio client: %w", err)
	}

	ctx := context.Background()
	exists, err := client.BucketExists(ctx, cfg.Bucket)
	if err != nil {
		return nil, fmt.Errorf("check bucket: %w", err)
	}
	if !exists {
		if err := client.MakeBucket(ctx, cfg.Bucket, minio.MakeBucketOptions{}); err != nil {
			return nil, fmt.Errorf("create bucket: %w", err)
		}
		log.Printf("created minio bucket: %s", cfg.Bucket)

		// Set bucket policy to allow public read
		policy := fmt.Sprintf(`{
			"Version": "2012-10-17",
			"Statement": [{
				"Effect": "Allow",
				"Principal": {"AWS": ["*"]},
				"Action": ["s3:GetObject"],
				"Resource": ["arn:aws:s3:::%s/*"]
			}]
		}`, cfg.Bucket)
		if err := client.SetBucketPolicy(ctx, cfg.Bucket, policy); err != nil {
			log.Printf("warning: set bucket policy: %v", err)
		}
	}

	return &MinIOStorage{client: client, bucket: cfg.Bucket}, nil
}

// Upload stores a file in MinIO and returns the object path (without bucket prefix).
// The returned path can be used to construct the public URL: /uploads/{path}
func (s *MinIOStorage) Upload(ctx context.Context, pathPrefix string, filename string, reader io.Reader, size int64, contentType string) (string, error) {
	ext := filepath.Ext(filename)
	if ext == "" {
		ext = guessExt(contentType)
	}
	objectName := fmt.Sprintf("%s/%s%s", pathPrefix, uuid.New().String(), ext)

	_, err := s.client.PutObject(ctx, s.bucket, objectName, reader, size, minio.PutObjectOptions{
		ContentType: contentType,
	})
	if err != nil {
		return "", fmt.Errorf("put object: %w", err)
	}

	return objectName, nil
}

func guessExt(contentType string) string {
	switch {
	case strings.HasPrefix(contentType, "image/jpeg"):
		return ".jpg"
	case strings.HasPrefix(contentType, "image/png"):
		return ".png"
	case strings.HasPrefix(contentType, "image/gif"):
		return ".gif"
	case strings.HasPrefix(contentType, "image/webp"):
		return ".webp"
	case strings.HasPrefix(contentType, "image/svg"):
		return ".svg"
	default:
		return ".bin"
	}
}