import 'dart:convert';

/// Represents a Nostr user profile (metadata from kind 0 events).
class NostrProfile {
  /// Public key (npub or hex).
  final String publicKey;

  /// Display name or username.
  final String? name;

  /// About/bio text.
  final String? about;

  /// Profile picture URL.
  final String? picture;

  /// Website URL.
  final String? website;

  /// NIP-05 identifier (e.g., user@domain.com).
  final String? nip05;

  /// Banner image URL.
  final String? banner;

  /// LUD16 (Lightning address).
  final String? lud16;

  /// Raw metadata JSON for additional fields.
  final Map<String, dynamic> rawMetadata;

  /// Timestamp when profile was last updated.
  final DateTime? updatedAt;

  /// Creates a [NostrProfile] instance.
  NostrProfile({
    required this.publicKey,
    this.name,
    this.about,
    this.picture,
    this.website,
    this.nip05,
    this.banner,
    this.lud16,
    Map<String, dynamic>? rawMetadata,
    this.updatedAt,
  }) : rawMetadata = rawMetadata ?? {};

  /// Creates a [NostrProfile] from Nostr metadata event content (JSON string).
  /// 
  /// [publicKey] - The public key of the profile owner.
  /// [content] - JSON string from kind 0 event content.
  /// [updatedAt] - Optional timestamp when profile was updated.
  factory NostrProfile.fromEventContent({
    required String publicKey,
    required String content,
    DateTime? updatedAt,
  }) {
    try {
      final metadata = jsonDecode(content) as Map<String, dynamic>;
      
      return NostrProfile(
        publicKey: publicKey,
        name: metadata['name'] as String?,
        about: metadata['about'] as String?,
        picture: metadata['picture'] as String?,
        website: metadata['website'] as String?,
        nip05: metadata['nip05'] as String?,
        banner: metadata['banner'] as String?,
        lud16: metadata['lud16'] as String?,
        rawMetadata: metadata,
        updatedAt: updatedAt ?? DateTime.now(),
      );
    } catch (e) {
      // Return minimal profile if parsing fails
      return NostrProfile(
        publicKey: publicKey,
        rawMetadata: {},
        updatedAt: updatedAt ?? DateTime.now(),
      );
    }
  }

  /// Creates a [NostrProfile] from a JSON map.
  factory NostrProfile.fromJson(Map<String, dynamic> json) {
    return NostrProfile(
      publicKey: json['publicKey'] as String,
      name: json['name'] as String?,
      about: json['about'] as String?,
      picture: json['picture'] as String?,
      website: json['website'] as String?,
      nip05: json['nip05'] as String?,
      banner: json['banner'] as String?,
      lud16: json['lud16'] as String?,
      rawMetadata: json['rawMetadata'] as Map<String, dynamic>? ?? {},
      updatedAt: json['updatedAt'] != null
          ? DateTime.parse(json['updatedAt'] as String)
          : null,
    );
  }

  /// Converts [NostrProfile] to JSON.
  Map<String, dynamic> toJson() {
    return {
      'publicKey': publicKey,
      'name': name,
      'about': about,
      'picture': picture,
      'website': website,
      'nip05': nip05,
      'banner': banner,
      'lud16': lud16,
      'rawMetadata': rawMetadata,
      'updatedAt': updatedAt?.toIso8601String(),
    };
  }

  /// Gets display name (name, nip05, or public key prefix).
  String get displayName {
    if (name != null && name!.isNotEmpty) return name!;
    if (nip05 != null && nip05!.isNotEmpty) return nip05!;
    return publicKey.length > 16 
        ? '${publicKey.substring(0, 8)}...${publicKey.substring(publicKey.length - 8)}'
        : publicKey;
  }

  @override
  String toString() {
    return 'NostrProfile(publicKey: ${publicKey.substring(0, 8)}..., name: $name)';
  }
}