import 'package:notas/models/note.dart';
import 'package:notas/models/category.dart';
import 'dart:convert';

// DTOs para sincronización con el servidor

class SyncRequest {
  SyncRequest({DateTime? lastSyncAt, required this.changes})
    : lastSyncAt = lastSyncAt ?? DateTime.utc(1970, 1, 1);

  final DateTime lastSyncAt;
  final SyncChanges changes;

  Map<String, dynamic> toJson() {
    return {
      'lastSyncAt': lastSyncAt.toIso8601String(),
      'changes': changes.toJson(),
    };
  }
}

class SyncChanges {
  const SyncChanges({this.categories = const [], this.notes = const []});

  final List<SyncCategoryPayload> categories;
  final List<SyncNotePayload> notes;

  Map<String, dynamic> toJson() {
    return {
      if (categories.isNotEmpty)
        'categories': categories.map((c) => c.toJson()).toList(),
      if (notes.isNotEmpty) 'notes': notes.map((n) => n.toJson()).toList(),
    };
  }
}

class SyncChangesResponse {
  const SyncChangesResponse({
    this.categories = const [],
    this.notes = const [],
  });

  final List<SyncCategoryResponse> categories;
  final List<SyncNoteResponse> notes;

  factory SyncChangesResponse.fromJson(Map<String, dynamic> json) {
    final List<dynamic> categoriesJson =
        json['categories'] as List<dynamic>? ?? [];
    final List<dynamic> notesJson = json['notes'] as List<dynamic>? ?? [];

    return SyncChangesResponse(
      categories: categoriesJson
          .map((c) => SyncCategoryResponse.fromJson(c as Map<String, dynamic>))
          .toList(),
      notes: notesJson
          .map((n) => SyncNoteResponse.fromJson(n as Map<String, dynamic>))
          .toList(),
    );
  }
}

String _readStringValue(dynamic value) {
  if (value is String) {
    return value;
  }
  if (value == null) {
    throw FormatException('Expected String value but found null');
  }
  return jsonEncode(value);
}

String _readOptionalStringValue(dynamic value) {
  if (value == null) {
    return '';
  }
  return _readStringValue(value);
}

int _readIntValue(dynamic value) {
  if (value is int) {
    return value;
  }
  if (value is String) {
    final int? parsed = int.tryParse(value);
    if (parsed != null) {
      return parsed;
    }
  }
  throw FormatException('Expected int value but found $value');
}

class SyncCategoryPayload {
  const SyncCategoryPayload({
    required this.id,
    required this.encryptedName,
    required this.serverVersion,
    this.isDeleted = false,
    this.colorValue,
    this.iconCodePoint,
    required this.updatedAt,
  });

  final String id;
  final String encryptedName;
  final int serverVersion;
  final bool isDeleted;
  final int? colorValue;
  final int? iconCodePoint;
  final DateTime updatedAt;

  factory SyncCategoryPayload.fromCategory(
    Category category, {
    required String encryptedName,
  }) {
    return SyncCategoryPayload(
      id: category.id,
      encryptedName: encryptedName,
      serverVersion: category.serverVersion,
      isDeleted: category.isDeleted,
      colorValue: category.colorValue,
      iconCodePoint: category.iconCodePoint,
      updatedAt: category.updatedAt,
    );
  }

  Map<String, dynamic> toJson() {
    return {
      'id': id,
      'encrypted_name': encryptedName,
      'serverVersion': serverVersion,
      'isDeleted': isDeleted,
      if (colorValue != null) 'colorValue': colorValue!.toSigned(32),
      if (iconCodePoint != null) 'iconCodePoint': iconCodePoint,
      'updatedAt': updatedAt.toIso8601String(),
    };
  }
}

class SyncNotePayload {
  const SyncNotePayload({
    required this.id,
    this.categoryId,
    required this.encryptedTitle,
    required this.encryptedBody,
    required this.serverVersion,
    this.position = 0.0,
    this.isDeleted = false,
    this.isPermanentlyDeleted = false,
    required this.updatedAt,
  });

  final String id;
  final String? categoryId;
  final String encryptedTitle;
  final String encryptedBody;
  final int serverVersion;
  final double position;
  final bool isDeleted;
  final bool isPermanentlyDeleted;
  final DateTime updatedAt;

  factory SyncNotePayload.fromNote(
    Note note, {
    required String encryptedTitle,
    required String encryptedBody,
    bool isPermanentlyDeleted = false,
  }) {
    return SyncNotePayload(
      id: note.id,
      categoryId: note.categoryId,
      encryptedTitle: encryptedTitle,
      encryptedBody: encryptedBody,
      serverVersion: note.serverVersion,
      position: note.position,
      isDeleted: note.isDeleted,
      isPermanentlyDeleted: isPermanentlyDeleted,
      updatedAt: note.updatedAt,
    );
  }

  Map<String, dynamic> toJson() {
    return {
      'id': id,
      if (categoryId != null) 'categoryId': categoryId,
      'encrypted_title': encryptedTitle,
      'encrypted_body': encryptedBody,
      'serverVersion': serverVersion,
      if (position != 0) 'position': position,
      if (isDeleted) 'isDeleted': isDeleted,
      if (isPermanentlyDeleted) 'isPermanentlyDeleted': isPermanentlyDeleted,
      'updatedAt': updatedAt.toIso8601String(),
    };
  }
}

class SyncResponse {
  const SyncResponse({
    required this.serverTimestamp,
    required this.synced,
    required this.changes,
  });

  final DateTime serverTimestamp;
  final bool synced;
  final SyncChangesResponse changes;

  factory SyncResponse.fromJson(Map<String, dynamic> json) {
    return SyncResponse(
      serverTimestamp: DateTime.parse(json['serverTimestamp'] as String),
      synced: json['synced'] as bool? ?? false,
      changes: SyncChangesResponse.fromJson(
        json['changes'] as Map<String, dynamic>? ?? {},
      ),
    );
  }
}

class SyncCategoryResponse {
  const SyncCategoryResponse({
    required this.id,
    required this.encryptedName,
    required this.serverVersion,
    this.isDeleted = false,
    this.colorValue,
    this.iconCodePoint,
    required this.updatedAt,
  });
  final String id;
  final String encryptedName;
  final int serverVersion;
  final bool isDeleted;
  final int? colorValue;
  final int? iconCodePoint;
  final DateTime updatedAt;

  factory SyncCategoryResponse.fromJson(Map<String, dynamic> json) {
    return SyncCategoryResponse(
      id: _readStringValue(json['id']),
      encryptedName: _readStringValue(json['encrypted_name']),
      serverVersion: _readIntValue(json['serverVersion']),
      isDeleted: json['isDeleted'] as bool? ?? false,
      colorValue: json['colorValue'] == null
          ? null
          : _readIntValue(json['colorValue']),
      iconCodePoint: json['iconCodePoint'] == null
          ? null
          : _readIntValue(json['iconCodePoint']),
      updatedAt: DateTime.parse(json['updatedAt'] as String),
    );
  }

  Category toCategory({required String name}) {
    return Category(
      id: id,
      name: name,
      serverVersion: serverVersion,
      isDeleted: isDeleted,
      colorValue: colorValue,
      iconCodePoint: iconCodePoint,
      updatedAt: updatedAt,
      isDirty: false,
    );
  }
}

class SyncNoteResponse {
  const SyncNoteResponse({
    required this.id,
    this.categoryId,
    required this.encryptedTitle,
    required this.encryptedBody,
    required this.serverVersion,
    this.position = 0.0,
    this.isDeleted = false,
    this.isPermanentlyDeleted = false,
    required this.updatedAt,
  });
  final String id;
  final String? categoryId;
  final String encryptedTitle;
  final String encryptedBody;
  final int serverVersion;
  final double position;
  final bool isDeleted;
  final bool isPermanentlyDeleted;
  final DateTime updatedAt;

  factory SyncNoteResponse.fromJson(Map<String, dynamic> json) {
    return SyncNoteResponse(
      id: _readStringValue(json['id']),
      categoryId: json['categoryId'] == null
          ? null
          : _readStringValue(json['categoryId']),
      encryptedTitle: _readOptionalStringValue(json['encrypted_title']),
      encryptedBody: _readOptionalStringValue(json['encrypted_body']),
      serverVersion: _readIntValue(json['serverVersion']),
      position: (json['position'] as num?)?.toDouble() ?? 0,
      isDeleted: json['isDeleted'] as bool? ?? false,
      isPermanentlyDeleted: json['isPermanentlyDeleted'] as bool? ?? false,
      updatedAt: DateTime.parse(json['updatedAt'] as String),
    );
  }

  Note toNote() {
    return Note(
      id: id,
      title: isPermanentlyDeleted ? '' : 'Encrypted',
      body: isPermanentlyDeleted ? '' : 'Encrypted',
      createdAt: updatedAt,
      updatedAt: updatedAt,
      position: position,
      serverVersion: serverVersion,
      isDeleted: isDeleted,
      categoryId: categoryId,
      isDirty: false,
    );
  }
}