import 'dart:typed_data';
import 'package:latlong2/latlong.dart';
import 'sar_marker.dart';

/// Message text types from MeshCore protocol
enum MessageTextType {
  plain(0),
  cliData(1),
  signedPlain(2);

  const MessageTextType(this.value);
  final int value;

  static MessageTextType fromValue(int value) {
    return MessageTextType.values.firstWhere(
      (e) => e.value == value,
      orElse: () => MessageTextType.plain,
    );
  }
}

/// Message type (contact or channel)
enum MessageType {
  contact,
  channel,
}

/// MeshCore message model
class Message {
  final String id;
  final MessageType messageType;
  final Uint8List? senderPublicKeyPrefix; // 6 bytes for contact messages
  final int? channelIdx; // For channel messages
  final int pathLen;
  final MessageTextType textType;
  final int senderTimestamp; // Unix timestamp
  final String text;

  // SAR marker data (if this is a SAR message)
  final bool isSarMarker;
  final SarMarkerType? sarMarkerType;
  final LatLng? sarGpsCoordinates;

  // Display metadata
  final DateTime receivedAt;
  final String? senderName;

  Message({
    required this.id,
    required this.messageType,
    this.senderPublicKeyPrefix,
    this.channelIdx,
    required this.pathLen,
    required this.textType,
    required this.senderTimestamp,
    required this.text,
    this.isSarMarker = false,
    this.sarMarkerType,
    this.sarGpsCoordinates,
    required this.receivedAt,
    this.senderName,
  });

  /// Get sender public key as hex string
  String? get senderKeyShort {
    if (senderPublicKeyPrefix == null) return null;
    return senderPublicKeyPrefix!
        .map((b) => b.toRadixString(16).padLeft(2, '0'))
        .join('');
  }

  /// Get sender timestamp as DateTime
  DateTime get sentAt {
    return DateTime.fromMillisecondsSinceEpoch(senderTimestamp * 1000);
  }

  /// Check if message is from a channel
  bool get isChannelMessage => messageType == MessageType.channel;

  /// Check if message is from a contact
  bool get isContactMessage => messageType == MessageType.contact;

  /// Get friendly time since message was sent
  String get timeAgo {
    final diff = DateTime.now().difference(sentAt);
    if (diff.inMinutes < 1) return 'Just now';
    if (diff.inMinutes < 60) return '${diff.inMinutes}m ago';
    if (diff.inHours < 24) return '${diff.inHours}h ago';
    return '${diff.inDays}d ago';
  }

  /// Get display name for sender
  String get displaySender {
    if (senderName != null && senderName!.isNotEmpty) {
      return senderName!;
    }
    if (senderKeyShort != null) {
      return senderKeyShort!.substring(0, 8);
    }
    if (isChannelMessage && channelIdx != null) {
      return 'Channel $channelIdx';
    }
    return 'Unknown';
  }

  /// Convert to SAR marker if applicable
  SarMarker? toSarMarker() {
    if (!isSarMarker || sarMarkerType == null || sarGpsCoordinates == null) {
      return null;
    }

    return SarMarker(
      id: id,
      type: sarMarkerType!,
      location: sarGpsCoordinates!,
      timestamp: sentAt,
      senderPublicKey: senderPublicKeyPrefix,
      senderName: senderName,
      notes: text,
    );
  }

  Message copyWith({
    String? id,
    MessageType? messageType,
    Uint8List? senderPublicKeyPrefix,
    int? channelIdx,
    int? pathLen,
    MessageTextType? textType,
    int? senderTimestamp,
    String? text,
    bool? isSarMarker,
    SarMarkerType? sarMarkerType,
    LatLng? sarGpsCoordinates,
    DateTime? receivedAt,
    String? senderName,
  }) {
    return Message(
      id: id ?? this.id,
      messageType: messageType ?? this.messageType,
      senderPublicKeyPrefix: senderPublicKeyPrefix ?? this.senderPublicKeyPrefix,
      channelIdx: channelIdx ?? this.channelIdx,
      pathLen: pathLen ?? this.pathLen,
      textType: textType ?? this.textType,
      senderTimestamp: senderTimestamp ?? this.senderTimestamp,
      text: text ?? this.text,
      isSarMarker: isSarMarker ?? this.isSarMarker,
      sarMarkerType: sarMarkerType ?? this.sarMarkerType,
      sarGpsCoordinates: sarGpsCoordinates ?? this.sarGpsCoordinates,
      receivedAt: receivedAt ?? this.receivedAt,
      senderName: senderName ?? this.senderName,
    );
  }

  @override
  String toString() {
    if (isSarMarker) {
      return 'Message(SAR: ${sarMarkerType?.displayName}, from: $displaySender)';
    }
    return 'Message(from: $displaySender, text: ${text.length > 30 ? '${text.substring(0, 30)}...' : text})';
  }

  @override
  bool operator ==(Object other) {
    if (identical(this, other)) return true;
    return other is Message && id == other.id;
  }

  @override
  int get hashCode => id.hashCode;
}