/**
 * UI i18n unit tests (node:test).
 * Pure modules only — no $app / i18n.svelte.ts ($state) imports.
 *
 * Run from apps/web:
 *   node --experimental-strip-types --test src/lib/i18n/*.test.ts
 */
import assert from "node:assert/strict";
import { describe, it } from "node:test";

import {
	DEFAULT_UI_LOCALE,
	UI_LOCALE_KEY,
	UI_LOCALES,
	buildUILocaleCookie,
	isUILocale,
	normalizeUILocale,
	persistUILocale,
	preferredAcceptLanguage,
	preferredAcceptLanguageFor,
	readPreferredUILocale,
	resolvePreferredUILocale
} from "./locales.ts";
import {
	MESSAGE_CATALOG,
	isRegisteredCatalogLocale,
	loadAllMessages,
	loadMessages,
	messagesFor
} from "./messages/catalog.ts";
import { en } from "./messages/en.ts";
import {
	baseMessageKeys,
	coverageSummary,
	missingKeysForLocale
} from "./coverage.ts";
import { resolveMessage } from "./resolve.ts";

/** Mirrors setLocale's in-memory switch (normalize + active locale). */
function setLocale(next: string): string {
	return normalizeUILocale(next);
}

describe("setLocale / locale switching", () => {
	it("normalizes supported codes and rejects unknown to English", () => {
		assert.equal(setLocale("es"), "es");
		assert.equal(setLocale("FR"), "fr");
		assert.equal(setLocale("  de  "), "de");
		assert.equal(setLocale("xx"), DEFAULT_UI_LOCALE);
		assert.equal(setLocale(""), DEFAULT_UI_LOCALE);
		assert.equal(setLocale(null as unknown as string), DEFAULT_UI_LOCALE);
	});

	it("isUILocale matches every UI_LOCALES entry", () => {
		for (const { code } of UI_LOCALES) {
			assert.equal(isUILocale(code), true, code);
		}
		assert.equal(isUILocale("xx"), false);
	});

	it("switching locale changes resolved pack strings", async () => {
		await loadMessages("es");
		const key = "common.cancel";
		const enText = resolveMessage("en", key);
		const esText = resolveMessage(setLocale("es"), key);
		assert.equal(enText, en[key]);
		assert.notEqual(esText, enText);
		assert.equal(esText, messagesFor("es")[key]);
	});
});

describe("English fallback for missing keys", () => {
	it("falls back to English when the active pack omits a key", () => {
		const key = "common.cancel";
		const english = en[key];
		assert.ok(english);
		const missingLocale = "zz";
		assert.deepEqual(messagesFor(missingLocale), {});
		assert.equal(resolveMessage(missingLocale, key), english);
	});

	it("falls back to the key itself when English also lacks it", () => {
		assert.equal(resolveMessage("en", "totally.missing.key"), "totally.missing.key");
		assert.equal(resolveMessage("es", "totally.missing.key"), "totally.missing.key");
	});

	it("HTML-escapes interpolation vars", () => {
		const sampleKey = Object.keys(en).find((k) => en[k]?.includes("{name}"));
		if (!sampleKey) {
			assert.equal(resolveMessage("en", "totally.missing.key"), "totally.missing.key");
			return;
		}
		const out = resolveMessage("en", sampleKey, { name: "<script>x</script>" });
		assert.match(out, /&lt;script&gt;/);
		assert.doesNotMatch(out, /<script>/);
	});
});

describe("pack key parity across UI_LOCALES vs en", () => {
	it("MESSAGE_CATALOG registers every UI_LOCALES code", () => {
		for (const { code } of UI_LOCALES) {
			assert.equal(
				isRegisteredCatalogLocale(code),
				true,
				`missing catalog entry for ${code}`
			);
		}
		assert.ok(MESSAGE_CATALOG.en);
	});

	it("every UI locale has the same keys as English (no blanks)", async () => {
		await loadAllMessages();
		const baseKeys = baseMessageKeys();
		assert.ok(baseKeys.length >= 350, `expected a full en catalog, got ${baseKeys.length}`);

		const summary = coverageSummary();
		assert.equal(summary.length, UI_LOCALES.length);

		for (const row of summary) {
			assert.equal(row.total, baseKeys.length, row.code);
			assert.equal(
				row.missing,
				0,
				`${row.code} missing: ${row.missing_keys.slice(0, 5).join(", ")}`
			);
			assert.equal(row.translated, baseKeys.length, row.code);
			assert.equal(row.registered, true, row.code);
			assert.deepEqual(missingKeysForLocale(row.code, baseKeys), []);
		}
	});

	
	it("feed schedule keys distinguish auto interval from manual Sync", () => {
		const interval = en["feeds.field.interval"];
		const hint = en["feeds.field.intervalHint"];
		const manual = en["feeds.syncManualTitle"];
		assert.ok(interval && /auto/i.test(interval), `interval label should say auto: ${interval}`);
		assert.ok(hint && /sync/i.test(hint) && /interval|schedule/i.test(hint), `hint should contrast Sync vs schedule: ${hint}`);
		assert.ok(manual && /one-off|manual|now/i.test(manual), `manual title should clarify one-off: ${manual}`);
		assert.notEqual(interval, "Sync interval (minutes)");
	});
	it("English key count is positive and matches Object.keys(en)", () => {
		const keys = baseMessageKeys();
		assert.equal(keys.length, Object.keys(en).length);
		assert.ok(keys.length >= 350, `expected a full catalog, got ${keys.length}`);
	});
});

type LocaleWindow = Window & { __UI_LOCALE__?: string };

function installLocaleStorageMocks(protocol: "http:" | "https:" = "http:") {
	const store = new Map<string, string>();
	let cookieJar = "";
	let lastCookieAssignment = "";
	const localStorageMock = {
		getItem(key: string) {
			return store.has(key) ? store.get(key)! : null;
		},
		setItem(key: string, value: string) {
			store.set(key, String(value));
		},
		removeItem(key: string) {
			store.delete(key);
		},
		clear() {
			store.clear();
		}
	};
	const documentMock = {
		get cookie() {
			return cookieJar;
		},
		set cookie(value: string) {
			lastCookieAssignment = String(value);
			const pair = String(value).split(";")[0] ?? "";
			const eq = pair.indexOf("=");
			if (eq <= 0) return;
			const name = pair.slice(0, eq);
			const rest = cookieJar
				.split(";")
				.map((p) => p.trim())
				.filter((p) => p && !p.startsWith(`${name}=`));
			rest.push(pair);
			cookieJar = rest.join("; ");
		}
	};
	const win = { __UI_LOCALE__: undefined as string | undefined } as LocaleWindow;
	const g = globalThis as typeof globalThis & {
		window?: LocaleWindow;
		localStorage?: typeof localStorageMock;
		document?: typeof documentMock;
		location?: { protocol: string };
	};
	const prev = {
		window: g.window,
		localStorage: g.localStorage,
		document: g.document,
		location: g.location
	};
	g.window = win as typeof g.window;
	g.localStorage = localStorageMock as typeof g.localStorage;
	g.document = documentMock as typeof g.document;
	g.location = { protocol } as typeof g.location;
	return {
		store,
		getCookie: () => cookieJar,
		getLastCookieAssignment: () => lastCookieAssignment,
		win,
		restore() {
			if (prev.window === undefined) (g as { window?: unknown }).window = undefined;
			else g.window = prev.window;
			if (prev.localStorage === undefined) (g as { localStorage?: unknown }).localStorage = undefined;
			else g.localStorage = prev.localStorage;
			if (prev.document === undefined) (g as { document?: unknown }).document = undefined;
			else g.document = prev.document;
			if (prev.location === undefined) (g as { location?: unknown }).location = undefined;
			else g.location = prev.location;
		}
	};
}

describe("persistUILocale / cookie+localStorage round-trip", () => {
	it("buildUILocaleCookie uses UI_LOCALE_KEY and optional Secure", () => {
		assert.equal(UI_LOCALE_KEY, "descrybe-ui-locale");
		assert.equal(
			buildUILocaleCookie("es"),
			`${UI_LOCALE_KEY}=es; Path=/; SameSite=Lax; Max-Age=31536000`
		);
		assert.equal(
			buildUILocaleCookie("FR", true),
			`${UI_LOCALE_KEY}=fr; Path=/; SameSite=Lax; Max-Age=31536000; Secure`
		);
	});

	it("set locale → descrybe-ui-locale → read back → normalize", () => {
		const mock = installLocaleStorageMocks("http:");
		try {
			const written = persistUILocale("  ES  ");
			assert.equal(written, "es");
			assert.equal(mock.store.get(UI_LOCALE_KEY), "es");
			assert.equal(mock.win.__UI_LOCALE__, "es");
			assert.match(mock.getCookie(), new RegExp(`(?:^|;\\s*)${UI_LOCALE_KEY}=es(?:;|$)`));
			assert.equal(readPreferredUILocale(), "es");

			// Prefer localStorage when window marker is cleared (reload / FOUC path).
			delete mock.win.__UI_LOCALE__;
			assert.equal(readPreferredUILocale(), "es");

			assert.equal(persistUILocale("FR"), "fr");
			assert.equal(mock.store.get(UI_LOCALE_KEY), "fr");
			assert.equal(readPreferredUILocale(), "fr");

			assert.equal(persistUILocale("xx"), DEFAULT_UI_LOCALE);
			assert.equal(mock.store.get(UI_LOCALE_KEY), DEFAULT_UI_LOCALE);
			assert.equal(readPreferredUILocale(), DEFAULT_UI_LOCALE);
		} finally {
			mock.restore();
		}
	});

	it("writes Secure cookie when location is https", () => {
		const mock = installLocaleStorageMocks("https:");
		try {
			persistUILocale("de");
			assert.equal(mock.store.get(UI_LOCALE_KEY), "de");
			assert.equal(
				mock.getLastCookieAssignment(),
				`${UI_LOCALE_KEY}=de; Path=/; SameSite=Lax; Max-Age=31536000; Secure`
			);
		} finally {
			mock.restore();
		}
	});

	it("SSR / no window: normalize only, no throw", () => {
		assert.equal(typeof window, "undefined");
		assert.equal(persistUILocale("ja"), "ja");
		assert.equal(readPreferredUILocale(), DEFAULT_UI_LOCALE);
	});
});

describe("preferredAcceptLanguage / readPreferredUILocale → header tag", () => {
	it("resolvePreferredUILocale prefers window override over stored", () => {
		assert.equal(resolvePreferredUILocale("nl", "en"), "nl");
		assert.equal(resolvePreferredUILocale("XX", "fr"), "fr");
		assert.equal(resolvePreferredUILocale(null, "de"), "de");
		assert.equal(resolvePreferredUILocale(undefined, undefined), DEFAULT_UI_LOCALE);
		assert.equal(resolvePreferredUILocale("", "  ES  "), "es");
	});

	it("preferredAcceptLanguageFor maps UI locale to BCP 47 Accept-Language tag", () => {
		for (const { code, htmlLang } of UI_LOCALES) {
			assert.equal(preferredAcceptLanguageFor(code), htmlLang, code);
		}
		assert.equal(preferredAcceptLanguageFor("NL"), "nl");
		assert.equal(preferredAcceptLanguageFor("xx"), "en");
	});

	it("preferredAcceptLanguage without window defaults to English tag", () => {
		assert.equal(typeof window, "undefined");
		assert.equal(readPreferredUILocale(), DEFAULT_UI_LOCALE);
		assert.equal(preferredAcceptLanguage(), "en");
		assert.equal(
			preferredAcceptLanguageFor(resolvePreferredUILocale("nl", "en")),
			"nl"
		);
	});
});