import { describe, expect, it } from 'vitest';
import { readFileSync } from 'node:fs';
import { resolve } from 'node:path';
import { formatDocumentDate } from './documentDate';
import { m } from '$lib/paraglide/messages.js';

// ─── Shared drift-guard fixture ─────────────────────────────────────────────
// The same table is asserted by the Java DocumentTitleFormatter test so the two
// label implementations cannot drift. Expected values are the German canonical
// form (see docs/date-label-fixtures.json).
type FixtureCase = {
	name: string;
	precision: string;
	anchor: string | null;
	end: string | null;
	raw: string | null;
	expected: string;
};

type LocaleFixtureCase = FixtureCase & { locale: string };

const fixtures = JSON.parse(
	readFileSync(resolve(process.cwd(), '../docs/date-label-fixtures.json'), 'utf-8')
) as { cases: FixtureCase[]; localeCases: LocaleFixtureCase[] };

describe('formatDocumentDate – shared fixture table (de)', () => {
	for (const c of fixtures.cases) {
		it(c.name, () => {
			expect(
				formatDocumentDate(
					c.anchor,
					c.precision as Parameters<typeof formatDocumentDate>[1],
					c.end,
					c.raw,
					'de'
				)
			).toBe(c.expected);
		});
	}
});

// TS-only locale parity (the Java title formatter is German-only by design, so
// localeCases are asserted here and never fed to DocumentTitleFormatterTest).
describe('formatDocumentDate – shared fixture table (en/es locale parity)', () => {
	for (const c of fixtures.localeCases) {
		it(`${c.name} [${c.locale}]`, () => {
			expect(
				formatDocumentDate(
					c.anchor,
					c.precision as Parameters<typeof formatDocumentDate>[1],
					c.end,
					c.raw,
					c.locale
				)
			).toBe(c.expected);
		});
	}
});

// ─── Anti-fabrication: suppressed components never leak ──────────────────────

describe('formatDocumentDate – suppressed precision components', () => {
	it('YEAR of a June date renders the year only, never the month', () => {
		const label = formatDocumentDate('1916-06-15', 'YEAR');
		expect(label).toBe('1916');
		expect(label).not.toContain('Juni');
		expect(label).not.toContain('15');
	});

	it('MONTH never renders the day-of-month', () => {
		const label = formatDocumentDate('1916-06-01', 'MONTH', null, 'Juni 1916');
		expect(label).toBe('Juni 1916');
		expect(label).not.toMatch(/\b1\.\s/);
	});
});

// ─── i18n: localized structured label ───────────────────────────────────────

describe('formatDocumentDate – localization', () => {
	it('localizes the UNKNOWN label per locale', () => {
		expect(formatDocumentDate(null, 'UNKNOWN', null, '?', 'en')).toBe(
			m.date_precision_unknown(undefined, { locale: 'en' })
		);
	});

	it('localizes the APPROX prefix per locale', () => {
		expect(formatDocumentDate('1920-01-01', 'APPROX', null, null, 'en')).toBe(
			`${m.date_precision_approx_prefix(undefined, { locale: 'en' })} 1920`
		);
	});

	it('localizes the SEASON word per locale when raw is absent', () => {
		expect(formatDocumentDate('1916-07-01', 'SEASON', null, null, 'en')).toBe(
			`${m.date_season_summer(undefined, { locale: 'en' })} 1916`
		);
	});

	it('localizes the SEASON word even when the raw cell is verbatim German (Decision 4)', () => {
		expect(formatDocumentDate('1916-06-01', 'SEASON', null, 'Sommer 1916', 'en')).toBe(
			`${m.date_season_summer(undefined, { locale: 'en' })} 1916`
		);
	});

	// DAY precision must honour the active locale (regression: it was hard-wired
	// to de-DE, so an English/Spanish reader saw "24. Dezember 1943").
	it('localizes the DAY month name in English', () => {
		expect(formatDocumentDate('1943-12-24', 'DAY', null, null, 'en')).toBe(
			new Intl.DateTimeFormat('en', { day: 'numeric', month: 'long', year: 'numeric' }).format(
				new Date('1943-12-24T12:00:00')
			)
		);
	});

	it('localizes the DAY month name in Spanish', () => {
		expect(formatDocumentDate('1943-12-24', 'DAY', null, null, 'es')).toBe(
			new Intl.DateTimeFormat('es', { day: 'numeric', month: 'long', year: 'numeric' }).format(
				new Date('1943-12-24T12:00:00')
			)
		);
	});

	it('localizes the MONTH month name in English', () => {
		expect(formatDocumentDate('1916-06-01', 'MONTH', null, 'Juni 1916', 'en')).toBe(
			new Intl.DateTimeFormat('en', { month: 'long', year: 'numeric' }).format(
				new Date('1916-06-01T12:00:00')
			)
		);
	});

	it('localizes the MONTH month name in Spanish', () => {
		expect(formatDocumentDate('1916-06-01', 'MONTH', null, 'Juni 1916', 'es')).toBe(
			new Intl.DateTimeFormat('es', { month: 'long', year: 'numeric' }).format(
				new Date('1916-06-01T12:00:00')
			)
		);
	});
});

// ─── Security: untrusted raw must never influence the structured label ───────

describe('formatDocumentDate – security', () => {
	it('ignores a malicious raw value for the structured label (raw is rendered separately, escaped)', () => {
		const label = formatDocumentDate(null, 'UNKNOWN', null, '<img src=x onerror=alert(1)>');
		expect(label).toBe('Datum unbekannt');
		expect(label).not.toContain('<img');
	});
});

// ─── Defensive null handling ─────────────────────────────────────────────────

describe('formatDocumentDate – defensive null handling', () => {
	it('renders the unknown label when the anchor is null but precision is not UNKNOWN', () => {
		expect(formatDocumentDate(null, 'DAY')).toBe('Datum unbekannt');
	});

	it('falls back to start-day only for a RANGE whose end is null', () => {
		expect(formatDocumentDate('1917-01-10', 'RANGE', null)).toBe('ab 10. Jan. 1917');
	});
});