import 'dart:convert';
import 'package:flutter_test/flutter_test.dart';
import 'package:motorcycle_dash/models/maintenance_models.dart';

void main() {
  group('Motorcycle Maintenance Due Tracking (MOB-16)', () {
    test('MaintenanceData parses from specificationJson safely', () {
      final initialSpec = json.encode({
        'year': 2024,
        'manufacturer': 'Yamaha',
        'model': 'YZF-R7',
        'baseOdometer': 1200.0,
        'serviceRecords': [
          {
            'id': 'srv_1',
            'date': '2026-08-15T10:00:00Z',
            'odometer': 600.0,
            'serviceType': 'Break-in Oil & Filter',
            'notes': 'Yamalube 10W-40, OEM filter',
            'cost': 45.00,
          },
        ],
      });

      final data = MaintenanceData.fromSpecificationJson(initialSpec);
      expect(data.baseOdometer, 1200.0);
      expect(data.serviceRecords.length, 1);
      expect(data.serviceRecords.first.serviceType, 'Break-in Oil & Filter');
      expect(data.serviceRecords.first.cost, 45.00);
    });

    test('MaintenanceData handles null or empty specificationJson gracefully', () {
      final dataNull = MaintenanceData.fromSpecificationJson(null);
      expect(dataNull.baseOdometer, 0.0);
      expect(dataNull.serviceRecords, isEmpty);

      final dataEmpty = MaintenanceData.fromSpecificationJson('');
      expect(dataEmpty.baseOdometer, 0.0);
      expect(dataEmpty.serviceRecords, isEmpty);

      final dataCorrupt = MaintenanceData.fromSpecificationJson('{corrupted json}');
      expect(dataCorrupt.baseOdometer, 0.0);
      expect(dataCorrupt.serviceRecords, isEmpty);
    });

    test('calculatePills accurately counts down miles and determines urgency', () {
      final data = MaintenanceData(
        baseOdometer: 1000.0,
        serviceRecords: [
          ServiceRecord(
            id: 'srv_1',
            date: DateTime(2026, 8, 1),
            odometer: 1000.0,
            serviceType: 'Engine Oil Change',
          ),
          ServiceRecord(
            id: 'srv_2',
            date: DateTime(2026, 8, 10),
            odometer: 1400.0,
            serviceType: 'Chain Clean & Lube',
          ),
        ],
      );

      // Ride 500 miles
      final pills = data.calculatePills(500.0);
      // Total odometer = 1000 + 500 = 1500 mi.
      // Oil last serviced at 1000 mi -> miles since service = 500 mi.
      // Oil interval is 3000 mi -> miles remaining = 2500 mi (Urgency: ok).
      final oilPill = pills.firstWhere((p) => p.key == 'oil');
      expect(oilPill.milesRemaining, 2500.0);
      expect(oilPill.urgency, MaintenanceUrgency.ok);
      expect(oilPill.label, '2500 mi remaining');

      // Chain last serviced at 1400 mi -> miles since service = 100 mi.
      // Chain interval is 600 mi -> miles remaining = 500 mi (Urgency: ok).
      final chainPill = pills.firstWhere((p) => p.key == 'chain');
      expect(chainPill.milesRemaining, 500.0);
      expect(chainPill.urgency, MaintenanceUrgency.ok);

      // Tire wear: no service logged yet -> defaults to baseOdometer (1000 mi).
      // Miles since service = 500 mi. Interval = 4000 mi -> remaining = 3500 mi.
      final tirePill = pills.firstWhere((p) => p.key == 'tire');
      expect(tirePill.milesRemaining, 3500.0);
      expect(tirePill.urgency, MaintenanceUrgency.ok);
    });

    test('calculatePills flags dueSoon and overdue accurately', () {
      final data = MaintenanceData(
        baseOdometer: 2800.0,
        serviceRecords: [
          ServiceRecord(
            id: 'srv_1',
            date: DateTime(2026, 1, 1),
            odometer: 0.0,
            serviceType: 'Initial Oil',
          ),
          ServiceRecord(
            id: 'srv_2',
            date: DateTime(2026, 1, 1),
            odometer: 2250.0,
            serviceType: 'Chain Service',
          ),
        ],
      );

      // Ride 50 miles -> total odometer = 2850 mi.
      // Oil: last serviced 0 mi -> miles since service = 2850 mi.
      // Interval = 3000 mi -> remaining = 150 mi (dueSoonThreshold is 350 mi) -> dueSoon!
      final pills = data.calculatePills(50.0);
      final oilPill = pills.firstWhere((p) => p.key == 'oil');
      expect(oilPill.milesRemaining, 150.0);
      expect(oilPill.urgency, MaintenanceUrgency.dueSoon);
      expect(oilPill.label, 'Due Soon (150 mi)');

      // Chain: last serviced at 2250 mi -> miles since service = 600 mi.
      // Interval = 600 mi -> remaining = 0 mi -> overdue!
      final chainPill = pills.firstWhere((p) => p.key == 'chain');
      expect(chainPill.milesRemaining, 0.0);
      expect(chainPill.urgency, MaintenanceUrgency.overdue);
      expect(chainPill.label, contains('OVERDUE'));
    });

    test('updateSpecJsonWithMaintenance preserves existing spec data without mutations', () {
      final original = json.encode({
        'year': 2024,
        'manufacturer': 'Ducati',
        'model': 'Panigale V2',
        'horsepower': 155.0,
        'displacementCc': 955.0,
      });

      final updated = MaintenanceData.updateSpecJsonWithMaintenance(
        originalSpecJson: original,
        baseOdometer: 3400.0,
        serviceRecords: [
          ServiceRecord(
            id: 'srv_1',
            date: DateTime(2026, 9, 1),
            odometer: 3000.0,
            serviceType: 'Desmo Service',
            cost: 850.0,
          ),
        ],
      );

      final decoded = json.decode(updated) as Map<String, dynamic>;
      expect(decoded['year'], 2024);
      expect(decoded['manufacturer'], 'Ducati');
      expect(decoded['model'], 'Panigale V2');
      expect(decoded['horsepower'], 155.0);
      expect(decoded['displacementCc'], 955.0);
      expect(decoded['baseOdometer'], 3400.0);

      final records = decoded['serviceRecords'] as List;
      expect(records.length, 1);
      expect(records[0]['serviceType'], 'Desmo Service');
      expect(records[0]['cost'], 850.0);
    });
  });
}