import { TestBed } from '@angular/core/testing';
import { provideZonelessChangeDetection } from '@angular/core';
import { CalendarSettingsService } from './calendar-settings-service';
import { vi } from '../../testing/vitest-compat';

describe('CalendarSettingsService', () => {
	let service: CalendarSettingsService;

	beforeEach(() => {
		localStorage.clear();
		vi.useFakeTimers({ toFake: ['Date'] });
		vi.setSystemTime(new Date('2026-10-04T22:30:00Z'));
		TestBed.configureTestingModule({
			providers: [provideZonelessChangeDetection()],
		});
		service = TestBed.inject(CalendarSettingsService);
	});

	afterEach(() => {
		vi.useRealTimers();
		vi.restoreAllMocks();
		localStorage.clear();
	});

	it('should be created', () => {
		expect(service).toBeTruthy();
	});

	it('defaults to the Paris date and displays the day before the anniversary as the last planning date', () => {
		expect(service.planningDates()).toEqual({
			start: '2026-10-05',
			lastPlanningDate: '2027-10-04',
		});
		expect(service.planningHorizon()).toEqual({ start: '2026-10-05', end: '2027-10-05' });
		expect(localStorage.getItem('calendarSettings.planningDates')).toBeNull();
	});

	it('saves and restores fixed historical dates before applying a later default', () => {
		service.setPlanningDates('2024-02-29', '2026-02-28');
		vi.setSystemTime(new Date('2029-08-01T12:00:00Z'));
		const restored = TestBed.runInInjectionContext(() => new CalendarSettingsService());
		expect(restored.planningDates()).toEqual({
			start: '2024-02-29',
			lastPlanningDate: '2026-02-28',
		});
		expect(restored.planningHorizon()).toEqual({ start: '2024-02-29', end: '2026-03-01' });
	});

	it('uses the existing February 29 anniversary convention for the unsaved default', () => {
		vi.setSystemTime(new Date('2024-02-29T12:00:00Z'));
		const leapDay = TestBed.runInInjectionContext(() => new CalendarSettingsService());
		expect(leapDay.planningDates()).toEqual({
			start: '2024-02-29',
			lastPlanningDate: '2025-02-27',
		});
		expect(leapDay.planningHorizon()).toEqual({ start: '2024-02-29', end: '2025-02-28' });
	});

	it.each([
		['2024-02-29', '2024-03-01'],
		['2026-03-29', '2026-03-30'],
		['2026-10-25', '2026-10-26'],
		['2026-12-31', '2027-01-01'],
	])(
		'converts a single inclusive planning date %s across leap days, clock changes and years',
		(date, end) => {
			const previousTimeZone = process.env['TZ'];
			process.env['TZ'] = 'Pacific/Auckland';
			try {
				service.setPlanningDates(date, date);
				expect(service.planningHorizon()).toEqual({ start: date, end });
			} finally {
				if (previousTimeZone === undefined) delete process.env['TZ'];
				else process.env['TZ'] = previousTimeZone;
			}
		},
	);

	it.each([
		['2024-02-30', '2024-03-01', 'invalidDate'],
		['2024-02-29', '2024-13-01', 'invalidDate'],
		['29/02/2024', '2024-03-01', 'invalidDate'],
		['', '2024-03-01', 'invalidDate'],
		['2024-03-02', '2024-03-01', 'horizonOrder'],
	])(
		'keeps invalid input visible without replacing the last valid saved dates (%s, %s)',
		(start, last, error) => {
			service.setPlanningDates('2024-02-29', '2027-02-28');
			service.setPlanningDates(start, last);
			expect(service.planningDates()).toEqual({ start, lastPlanningDate: last });
			expect(service.planningHorizon()).toBeNull();
			expect(service.planningHorizonError()).toBe(error);
			const restored = TestBed.runInInjectionContext(() => new CalendarSettingsService());
			expect(restored.planningHorizon()).toEqual({ start: '2024-02-29', end: '2027-03-01' });
		},
	);

	it.each([
		'{',
		'null',
		'{}',
		'{"start":"2024-02-30","lastPlanningDate":"2024-03-01"}',
		'{"start":"2024-03-02","lastPlanningDate":"2024-03-01"}',
	])('uses an unsaved default when saved dates are unreadable: %s', (saved) => {
		vi.spyOn(console, 'warn').mockImplementation(() => {});
		localStorage.setItem('calendarSettings.planningDates', saved);
		const restored = TestBed.runInInjectionContext(() => new CalendarSettingsService());
		expect(restored.planningHorizon()).toEqual({ start: '2026-10-05', end: '2027-10-05' });
		expect(localStorage.getItem('calendarSettings.planningDates')).toBe(saved);
	});

	it('should initialize with default values', () => {
		expect(service.get('showWeekNumbers')()).toBe(false);
	});

	it('should allow updating showWeekNumbers', () => {
		service.get('showWeekNumbers').set(true);
		expect(service.get('showWeekNumbers')()).toBe(true);
	});

	it('should provide settings array for UI iteration', () => {
		const settingsArray = service.settingsArray;
		expect(settingsArray.length).toBe(1);
		expect(settingsArray[0].id).toBe('showWeekNumbers');
	});

	it('should return correct descriptions', () => {
		expect(service.getDescription('showWeekNumbers')).toBe('Afficher les numéros de semaine');
	});
});