package storage

import (
	"fmt"
	"net/url"
	"strings"
)

// StorageURL represents a parsed storage URL.
type StorageURL struct {
	Scheme   string // "s3" or "file"
	Bucket   string // S3 bucket name (empty for file)
	Prefix   string // Path within bucket or filesystem base path
	Endpoint string // S3 endpoint (optional, default AWS)
	Region   string // S3 region (optional)
	UseSSL   bool   // Use HTTPS for S3 (default true)
}

// ParseStorageURL parses a storage URL string.
// Supported formats:
//   - s3://bucket/prefix?endpoint=host&region=us-east-1&ssl=true
//   - file:///absolute/path/to/backup
func ParseStorageURL(rawURL string) (*StorageURL, error) {
	if rawURL == "" {
		return nil, fmt.Errorf("storage URL is empty")
	}

	// Handle file:// URLs
	if strings.HasPrefix(rawURL, "file://") {
		path := strings.TrimPrefix(rawURL, "file://")
		if path == "" {
			return nil, fmt.Errorf("file URL path is empty")
		}
		return &StorageURL{
			Scheme: "file",
			Prefix: path,
		}, nil
	}

	// Handle s3:// URLs
	if strings.HasPrefix(rawURL, "s3://") {
		u, err := url.Parse(rawURL)
		if err != nil {
			return nil, fmt.Errorf("invalid URL: %w", err)
		}

		bucket := u.Host
		if bucket == "" {
			return nil, fmt.Errorf("s3 URL missing bucket name")
		}

		prefix := strings.TrimPrefix(u.Path, "/")

		query := u.Query()
		useSSL := true
		if query.Get("ssl") == "false" {
			useSSL = false
		}

		return &StorageURL{
			Scheme:   "s3",
			Bucket:   bucket,
			Prefix:   prefix,
			Endpoint: query.Get("endpoint"),
			Region:   query.Get("region"),
			UseSSL:   useSSL,
		}, nil
	}

	return nil, fmt.Errorf("unsupported URL scheme: must start with s3:// or file://")
}

// String returns a human-readable representation of the storage URL.
func (u *StorageURL) String() string {
	switch u.Scheme {
	case "file":
		return fmt.Sprintf("file://%s", u.Prefix)
	case "s3":
		endpoint := u.Endpoint
		if endpoint == "" {
			endpoint = "s3.amazonaws.com"
		}
		if u.Prefix != "" {
			return fmt.Sprintf("s3://%s/%s (endpoint: %s)", u.Bucket, u.Prefix, endpoint)
		}
		return fmt.Sprintf("s3://%s (endpoint: %s)", u.Bucket, endpoint)
	default:
		return fmt.Sprintf("%s://?", u.Scheme)
	}
}