/// Transaction labels (built-in + user-created) and local annotations.
library;

import 'package:flutter/material.dart';

/// A spend/income label shown on transactions.
class TxLabel {
  const TxLabel({
    required this.id,
    required this.name,
    required this.color,
    this.icon = Icons.label_outline,
    this.custom = false,
  });

  final String id;
  final String name;
  final Color color;
  final IconData icon;
  final bool custom;

  Map<String, dynamic> toJson() => {
        'id': id,
        'name': name,
        // ignore: deprecated_member_use — wide compatibility across Flutter versions
        'color': color.value,
        'custom': custom,
      };

  factory TxLabel.fromJson(Map<String, dynamic> json) {
    return TxLabel(
      id: json['id'] as String? ?? 'custom',
      name: json['name'] as String? ?? 'Label',
      color: Color(json['color'] as int? ?? 0xFF64748B),
      custom: json['custom'] as bool? ?? true,
    );
  }
}

/// Built-in presets (no "uncategorized" / "other").
const List<TxLabel> kBuiltinLabels = [
  TxLabel(
    id: 'groceries',
    name: 'Groceries',
    color: Color(0xFF16A34A),
    icon: Icons.shopping_cart_outlined,
  ),
  TxLabel(
    id: 'energy',
    name: 'Energy',
    color: Color(0xFFEAB308),
    icon: Icons.bolt_outlined,
  ),
  TxLabel(
    id: 'salary',
    name: 'Salary',
    color: Color(0xFF0F766E),
    icon: Icons.payments_outlined,
  ),
  TxLabel(
    id: 'mortgage',
    name: 'Mortgage',
    color: Color(0xFF7C3AED),
    icon: Icons.home_work_outlined,
  ),
  TxLabel(
    id: 'transport',
    name: 'Transport',
    color: Color(0xFF2563EB),
    icon: Icons.directions_bus_outlined,
  ),
  TxLabel(
    id: 'dining',
    name: 'Dining',
    color: Color(0xFFEA580C),
    icon: Icons.restaurant_outlined,
  ),
  TxLabel(
    id: 'shopping',
    name: 'Shopping',
    color: Color(0xFFDB2777),
    icon: Icons.shopping_bag_outlined,
  ),
  TxLabel(
    id: 'health',
    name: 'Health',
    color: Color(0xFFDC2626),
    icon: Icons.local_hospital_outlined,
  ),
  TxLabel(
    id: 'transfer',
    name: 'Transfer',
    color: Color(0xFF0891B2),
    icon: Icons.swap_horiz,
  ),
];

/// Palette for newly created custom labels.
const List<Color> kCustomLabelColors = [
  Color(0xFF0F766E),
  Color(0xFF7C3AED),
  Color(0xFFEA580C),
  Color(0xFF2563EB),
  Color(0xFFDB2777),
  Color(0xFF16A34A),
  Color(0xFFDC2626),
  Color(0xFF57534E),
];

/// Local overlay for a bank transaction.
class TxMeta {
  const TxMeta({
    this.labelIds = const [],
    this.recurring = false,
    this.notes = '',
  });

  /// Zero or more label ids on this transaction.
  final List<String> labelIds;
  final bool recurring;
  final String notes;

  static const empty = TxMeta();

  bool get hasLabel => labelIds.isNotEmpty;
  bool get hasNotes => notes.trim().isNotEmpty;

  /// First label id, if any (for compact UI).
  String? get primaryLabelId => labelIds.isEmpty ? null : labelIds.first;

  bool hasLabelId(String id) => labelIds.contains(id);

  TxMeta copyWith({
    List<String>? labelIds,
    bool clearLabels = false,
    bool? recurring,
    String? notes,
  }) {
    return TxMeta(
      labelIds: clearLabels ? const [] : (labelIds ?? this.labelIds),
      recurring: recurring ?? this.recurring,
      notes: notes ?? this.notes,
    );
  }

  Map<String, dynamic> toJson() => {
        'labelIds': labelIds,
        // Legacy single-label keys for older builds.
        'labelId': primaryLabelId,
        'category': primaryLabelId,
        'recurring': recurring,
        'notes': notes,
      };

  factory TxMeta.fromJson(Map<String, dynamic> json) {
    return TxMeta(
      labelIds: _parseLabelIds(json),
      recurring: json['recurring'] as bool? ?? false,
      notes: json['notes'] as String? ?? '',
    );
  }
}

List<String> _parseLabelIds(Map<String, dynamic> json) {
  final raw = json['labelIds'];
  if (raw is List) {
    return [
      for (final item in raw)
        if (item is String &&
            item.isNotEmpty &&
            item != 'uncategorized' &&
            item != 'other')
          item,
    ];
  }
  final single = (json['labelId'] as String?) ??
      _migrateLegacyCategory(json['category'] as String?);
  if (single == null) return const [];
  return [single];
}

String? _migrateLegacyCategory(String? name) {
  if (name == null || name.isEmpty) return null;
  if (name == 'uncategorized' || name == 'other') return null;
  return name;
}

/// Notes / recurring template keyed by exact merchant+amount match.
class TxExactTemplate {
  const TxExactTemplate({this.notes = '', this.recurring = false});

  final String notes;
  final bool recurring;

  Map<String, dynamic> toJson() => {
        'notes': notes,
        'recurring': recurring,
      };

  factory TxExactTemplate.fromJson(Map<String, dynamic> json) {
    return TxExactTemplate(
      notes: json['notes'] as String? ?? '',
      recurring: json['recurring'] as bool? ?? false,
    );
  }
}

/// Strip bank noise so "AH Campus … Transactie:123" matches other AH Campus txs.
String merchantKeyFromDescription(String description) {
  var s = description.trim().toLowerCase().replaceAll(RegExp(r'\s+'), ' ');
  if (s.startsWith('naam:')) {
    s = s.substring(5).trim();
    final om = s.indexOf(' omschrijving:');
    if (om > 0) s = s.substring(0, om);
  }

  const markers = [
    ' pasvolgnr',
    ' kaartnr',
    ' datum:',
    ' tijd:',
    ' transactie:',
    ' term:',
    ' valutadatum',
    ' iban:',
    ' kenmerk:',
    ' machtiging',
    ' overige partij',
    ' retourpin',
  ];
  for (final marker in markers) {
    final index = s.indexOf(marker);
    if (index > 6) {
      s = s.substring(0, index);
    }
  }

  s = s
      .replaceAll(RegExp(r'\s+nld\s*$'), '')
      .replaceAll(RegExp(r'^bck\*'), '')
      .trim();
  return s;
}