import React, { act } from "react";
import assert from "node:assert/strict";
import { afterEach, test } from "node:test";
import { parseHTML } from "linkedom";
import { finishDictation, useDictation, type Dictation } from "../components/dictation.tsx";
import { I18nProvider, useI18n } from "../components/i18n.tsx";
import { notifySettingsSaved } from "../components/settings-signal.ts";
import { isDictationActive, useDictationActive } from "../components/dictation-state.ts";
import type { GeneralSettings, UserSettings } from "../src/core/index.ts";

function deferred<T>() {
	let resolve!: (value: T) => void;
	const promise = new Promise<T>((done) => { resolve = done; });
	return { promise, resolve };
}

class Socket extends EventTarget {
	static CONNECTING = 0;
	static OPEN = 1;
	static all: Socket[] = [];
	readyState = 0;
	sent: unknown[] = [];
	constructor(public url: string) { super(); Socket.all.push(this); }
	get language() { return new URL(this.url).searchParams.get("language"); }
	open() { this.readyState = 1; this.dispatchEvent(new Event("open")); }
	send(value: unknown) { this.sent.push(value); }
	close() { this.readyState = 3; }
	end(code = 1000) { this.close(); this.dispatchEvent(Object.assign(new Event("close"), { code })); }
	final(text: string) {
		this.dispatchEvent(Object.assign(new Event("message"), {
			data: JSON.stringify({ type: "Results", is_final: true, channel: { alternatives: [{ transcript: text }] } }),
		}));
	}
}

class AudioGraph {
	state = "running";
	destination = {};
	audioWorklet = { addModule: async () => {} };
	createMediaStreamSource() { return { connect() {}, disconnect() {} }; }
}
class Worklet {
	static latest: Worklet;
	static autoFlush = true;
	disconnected = false;
	port = {
		onmessage: (_event: { data: unknown }) => {},
		postMessage: (_message: unknown) => { if (Worklet.autoFlush) queueMicrotask(() => this.flush()); },
	};
	constructor() { Worklet.latest = this; }
	flush() {
		this.port.onmessage({ data: { type: "audio", buffer: new Int16Array([7]).buffer } });
		this.port.onmessage({ data: { type: "flushed" } });
	}
	connect() {}
	disconnect() { this.disconnected = true; }
}

const globals = globalThis as Record<string, unknown>;
let restore: (() => void) | undefined;
let dispose: (() => Promise<void>) | undefined;

async function fixture(general: GeneralSettings = { sttLanguage: "ru" }) {
	const dom = parseHTML("<html><body><div id='root'></div></body></html>");
	const state = {
		// The contradictory upstream preference must never control recording.
		record: { version: 1, general, dictation: { language: "pl" } } as UserSettings,
		nextRead: undefined as Promise<Response> | undefined,
		nextWrite: undefined as Promise<Response> | undefined,
		nextMic: undefined as Promise<{ getTracks: () => { stop: () => void }[] }> | undefined,
		nextToken: undefined as (() => Promise<Response>) | undefined,
		readFails: false,
		reads: 0,
		active: false,
		captures: 0,
		stops: 0,
		appends: [] as string[],
	};
	Socket.all = [];
	Worklet.autoFlush = true;
	const previous = new Map<string, PropertyDescriptor | undefined>();
	for (const [key, value] of Object.entries({
		React, window: dom.window, document: dom.document, CustomEvent: dom.window.CustomEvent,
		navigator: { userAgent: "node", languages: ["en-US"], mediaDevices: { getUserMedia: async () => {
			state.captures++;
			if (state.nextMic) return state.nextMic;
			return { getTracks: () => [{ stop() { state.stops++; } }] };
		} } },
		WebSocket: Socket, AudioContext: AudioGraph, AudioWorkletNode: Worklet,
		IS_REACT_ACT_ENVIRONMENT: true,
		fetch: async (url: string, init?: RequestInit) => {
			if (url === "/api/stt/token") return state.nextToken ? state.nextToken() : Response.json({ token: "test-token" });
			if (url === "/api/settings") {
				state.reads++;
				if (state.nextRead) { const response = state.nextRead; state.nextRead = undefined; return response; }
				return state.readFails ? Response.json({}, { status: 500 }) : Response.json({ settings: state.record });
			}
			assert.equal(url, "/api/settings/general");
			assert.equal(init?.method, "PUT");
			if (state.nextWrite) { const response = state.nextWrite; state.nextWrite = undefined; return response; }
			state.record = { ...state.record, general: JSON.parse(init!.body as string) };
			return Response.json({ settings: state.record });
		},
	})) {
		previous.set(key, Object.getOwnPropertyDescriptor(globalThis, key));
		Object.defineProperty(globalThis, key, { configurable: true, writable: true, value });
	}
	restore = () => {
		for (const [key, descriptor] of previous) {
			if (descriptor) Object.defineProperty(globalThis, key, descriptor);
			else delete globals[key];
		}
	};
	const { createRoot } = await import("react-dom/client");
	let latest!: Dictation;
	let setting!: ReturnType<typeof useI18n>;
	function Harness() {
		latest = useDictation({ append: (text) => state.appends.push(text) });
		setting = useI18n();
		state.active = useDictationActive();
		return null;
	}
	let root = createRoot(document.getElementById("root")!);
	const mount = async () => {
		await act(async () => { root.render(<I18nProvider initialGeneral={state.record.general}><Harness /></I18nProvider>); });
	};
	dispose = async () => { await act(async () => root.unmount()); };
	return {
		state,
		get dictation() { return latest; },
		get setting() { return setting; },
		mount,
		unmount: () => dispose!(),
		remount: async () => { await dispose!(); root = createRoot(document.getElementById("root")!); await mount(); },
	};
}

afterEach(async () => { await dispose?.(); restore?.(); dispose = undefined; restore = undefined; });

test("general language and hints are snapshotted; reconnect and final delivery retain them", async () => {
	const f = await fixture({ sttLanguage: "multi", sttPreferredLanguages: ["ru", "en"] });
	await f.mount();
	await act(async () => { f.dictation.toggle(); });
	assert.equal(f.state.active, true);
	const first = Socket.all[0]!;
	assert.equal(first.language, "multi");
	assert.deepEqual(new URL(first.url).searchParams.getAll("language_hint"), ["ru", "en"]);
	await act(async () => { first.open(); first.final("Первое"); });
	await act(async () => { await f.setting.saveGeneral({ sttLanguage: "en", sttPreferredLanguages: [] }); });
	await act(async () => { first.end(1006); });
	const retry = Socket.all[1]!;
	assert.equal(retry.url, first.url);
	await act(async () => { retry.open(); retry.final("second"); });
	let finished = false;
	let done!: Promise<void>;
	await act(async () => { done = f.dictation.finish().then(() => { finished = true; }); });
	assert.equal(finished, false);
	assert.deepEqual(f.state.appends, []);
	assert.equal(retry.sent.at(-1), '{"type":"CloseStream"}');
	assert(retry.sent.at(-2) instanceof ArrayBuffer, "the final PCM frame precedes CloseStream");
	await act(async () => { retry.final("last"); retry.end(); await done; });
	assert.deepEqual(f.state.appends, ["Первое second last"]);
	assert.equal(f.state.active, false);
	await act(async () => { retry.final("stale"); retry.end(); });
	assert.deepEqual(f.state.appends, ["Первое second last"]);
	await act(async () => { f.dictation.toggle(); });
	assert.equal(Socket.all[2]!.language, "en");
});

for (const [selection, expected] of [[undefined, "en"], ["en", "en"], ["ru", "ru"], ["multi", "multi"]] as const) {
	test(`fork language ${selection ?? "system"} ignores contradictory dictation.language`, async () => {
		const f = await fixture({ sttLanguage: selection });
		await f.mount();
		await act(async () => { f.dictation.toggle(); });
		assert.equal(Socket.all[0]!.language, expected);
		assert.equal(f.state.reads, 0, "recording does not load an independent preference");
	});
}

test("a failed general save retains the confirmed language, including a shortcut during saving", async () => {
	const f = await fixture(); await f.mount();
	const write = deferred<Response>(); f.state.nextWrite = write.promise;
	let saved!: Promise<void>;
	await act(async () => { saved = f.setting.saveGeneral({ sttLanguage: "multi" }); saved.catch(() => {}); });
	await act(async () => { window.dispatchEvent(new window.Event("lh:kbd-toggle-dictation")); });
	assert.equal(Socket.all[0]!.language, "ru");
	await act(async () => { write.resolve(Response.json({}, { status: 500 })); await assert.rejects(saved, /Could not save/); });
	assert.equal(f.setting.sttLanguage, "ru");
});

test("confirmed general choices survive navigation and a failed refresh does not substitute upstream defaults", async () => {
	const f = await fixture(); await f.mount();
	await act(async () => { await f.setting.saveGeneral({ sttLanguage: "multi" }); });
	await f.remount();
	f.state.readFails = true;
	await act(async () => { notifySettingsSaved("general"); });
	await act(async () => { f.dictation.toggle(); });
	assert.equal(Socket.all[0]!.language, "multi");
	assert.equal(f.dictation.error, null);
});

test("capture uses the confirmed general choice while a save is pending and the new one on the next run", async () => {
	const f = await fixture(); await f.mount();
	const write = deferred<Response>(); f.state.nextWrite = write.promise;
	let saved!: Promise<void>;
	await act(async () => { saved = f.setting.saveGeneral({ sttLanguage: "multi" }); });
	await act(async () => { f.dictation.toggle(); });
	assert.equal(Socket.all[0]!.language, "ru");
	f.state.record.general = { sttLanguage: "multi" };
	await act(async () => { write.resolve(Response.json({ settings: f.state.record })); await saved; });
	await act(async () => { f.dictation.cancel(); f.dictation.toggle(); });
	assert.equal(Socket.all[1]!.language, "multi");
});

test("a stale general refresh cannot overwrite a newer confirmed choice", async () => {
	const f = await fixture(); await f.mount();
	const read = deferred<Response>(); f.state.nextRead = read.promise;
	await act(async () => { notifySettingsSaved("general"); });
	await act(async () => { await f.setting.saveGeneral({ sttLanguage: "multi" }); });
	await act(async () => { read.resolve(Response.json({ settings: { general: { sttLanguage: "ru" } } })); });
	assert.equal(f.setting.sttLanguage, "multi");
	await act(async () => { f.dictation.toggle(); });
	assert.equal(Socket.all[0]!.language, "multi");
});

test("cancel while microphone permission is pending prevents orphaned capture", async () => {
	const f = await fixture(); await f.mount();
	const mic = deferred<{ getTracks: () => { stop: () => void }[] }>(); f.state.nextMic = mic.promise;
	await act(async () => { f.dictation.toggle(); f.dictation.cancel(); });
	await act(async () => { mic.resolve({ getTracks: () => [{ stop() { f.state.stops++; } }] }); });
	assert.equal(f.state.stops, 1);
	assert.equal(Socket.all.length, 0);
	assert.equal(isDictationActive(), false);
});

test("finish in the start turn cancels a pending microphone without hanging", async () => {
	const f = await fixture(); await f.mount();
	const mic = deferred<{ getTracks: () => { stop: () => void }[] }>(); f.state.nextMic = mic.promise;
	await act(async () => { f.dictation.toggle(); await finishDictation(); });
	assert.equal(f.dictation.phase, "idle");
	await act(async () => { mic.resolve({ getTracks: () => [{ stop() { f.state.stops++; } }] }); });
	assert.equal(f.state.stops, 1);
	assert.equal(Socket.all.length, 0);
});

test("Stop while the socket connects drains PCM and waits for the final transcript", async () => {
	const f = await fixture(); await f.mount();
	await act(async () => { f.dictation.toggle(); });
	const socket = Socket.all[0]!;
	let done!: Promise<void>; let finished = false;
	await act(async () => { done = finishDictation().then(() => { finished = true; }); });
	assert.equal(f.dictation.phase, "stopping");
	assert.equal(finished, false);
	await act(async () => { socket.open(); });
	assert.equal(f.dictation.phase, "stopping");
	assert(socket.sent[0] instanceof ArrayBuffer);
	assert.equal(socket.sent[1], '{"type":"CloseStream"}');
	await act(async () => { socket.final("tail"); socket.end(); await done; });
	assert.deepEqual(f.state.appends, ["tail"]);
});

test("a socket opening during drain cannot close the stream before the tail PCM", async () => {
	const f = await fixture(); await f.mount(); Worklet.autoFlush = false;
	await act(async () => { f.dictation.toggle(); });
	const socket = Socket.all[0]!;
	let done!: Promise<void>;
	await act(async () => { done = finishDictation(); socket.open(); });
	assert.equal(socket.sent.length, 0);
	assert.equal(f.dictation.phase, "stopping");
	await act(async () => { Worklet.latest.flush(); });
	assert(socket.sent[0] instanceof ArrayBuffer);
	assert.equal(socket.sent[1], '{"type":"CloseStream"}');
	await act(async () => { socket.final("complete"); socket.end(); await done; });
	assert.deepEqual(f.state.appends, ["complete"]);
});

test("a reconnect while stopping retains its session and still finishes exactly once", async () => {
	const f = await fixture(); await f.mount();
	await act(async () => { f.dictation.toggle(); });
	const socket = Socket.all[0]!;
	await act(async () => { socket.open(); socket.final("before"); });
	let done!: Promise<void>;
	await act(async () => { done = finishDictation(); });
	await act(async () => { socket.end(1006); });
	const retry = Socket.all[1]!;
	assert.equal(retry.url, socket.url);
	await act(async () => { retry.open(); });
	assert.equal(retry.sent.at(-1), '{"type":"CloseStream"}');
	assert.equal(f.dictation.phase, "stopping");
	await act(async () => { retry.final("after"); retry.end(); await done; });
	assert.deepEqual(f.state.appends, ["before after"]);
	assert.equal(f.state.active, false);
});

test("cancel during drain resolves finish and ignores late worklet/socket messages", async () => {
	const f = await fixture(); await f.mount(); Worklet.autoFlush = false;
	await act(async () => { f.dictation.toggle(); });
	await act(async () => { Socket.all[0]!.open(); Socket.all[0]!.final("discard"); });
	let done!: Promise<void>;
	await act(async () => { done = f.dictation.finish(); f.dictation.cancel(); await done; });
	await act(async () => { Worklet.latest.flush(); Socket.all[0]!.final("late"); Socket.all[0]!.end(1006); });
	assert.deepEqual(f.state.appends, []);
	assert.equal(Socket.all.length, 1);
	assert.equal(f.state.active, false);
});

test("unmount during a pending general refresh prevents orphaned capture", async () => {
	const f = await fixture(); await f.mount();
	const read = deferred<Response>(); f.state.nextRead = read.promise;
	await act(async () => { notifySettingsSaved("general"); });
	await f.unmount();
	await act(async () => { read.resolve(Response.json({ settings: f.state.record })); });
	assert.equal(f.state.captures, 0);
	assert.equal(Socket.all.length, 0);
	assert.equal(isDictationActive(), false);
});

test("unmount releases an active stream/socket and discards deferred finals", async () => {
	const f = await fixture(); await f.mount();
	await act(async () => { f.dictation.toggle(); });
	const socket = Socket.all[0]!;
	await act(async () => { socket.open(); socket.final("do not append into another page"); });
	await f.unmount();
	assert.equal(f.state.stops, 1);
	assert.equal(socket.readyState, 3);
	assert.equal(isDictationActive(), false);
	assert.deepEqual(f.state.appends, []);
	await act(async () => { socket.final("late event"); socket.end(1006); });
	assert.equal(Socket.all.length, 1);
	assert.deepEqual(f.state.appends, []);
});

test("system STT follows the fork's detected Russian locale, not dictation.language", async () => {
	const f = await fixture({});
	Object.defineProperty(globalThis, "navigator", { configurable: true, value: {
		userAgent: "node", languages: ["ru-RU"],
		mediaDevices: { getUserMedia: async () => ({ getTracks: () => [{ stop() { f.state.stops++; } }] }) },
	} });
	await f.mount();
	await act(async () => { f.dictation.toggle(); });
	assert.equal(Socket.all[0]!.language, "ru");
});

test("a failed token request releases capture and leaves an honest error", async () => {
	const f = await fixture();
	f.state.nextToken = async () => Response.json({ message: "token denied" }, { status: 500 });
	await f.mount();
	await act(async () => { f.dictation.toggle(); });
	assert.equal(f.dictation.error, "token denied");
	assert.equal(f.dictation.phase, "idle");
	assert.equal(f.state.stops, 1);
	assert.equal(Socket.all.length, 0);
	assert.equal(isDictationActive(), false);
});

test("one reconnect is allowed and a second socket failure ends the run", async () => {
	const f = await fixture(); await f.mount();
	await act(async () => { f.dictation.toggle(); });
	await act(async () => { Socket.all[0]!.open(); Socket.all[0]!.final("kept"); Socket.all[0]!.end(1006); });
	assert.equal(Socket.all.length, 2);
	await act(async () => { Socket.all[1]!.end(1006); });
	assert.equal(f.dictation.error, "Deepgram connection lost (1006)");
	assert.equal(f.dictation.phase, "idle");
	assert.deepEqual(f.state.appends, ["kept"]);
	assert.equal(f.state.stops, 1);
});

test("a missing drain acknowledgement fails visibly and resolves submit waiters", async () => {
	const f = await fixture(); await f.mount(); Worklet.autoFlush = false;
	await act(async () => { f.dictation.toggle(); });
	await act(async () => { Socket.all[0]!.open(); });
	let done!: Promise<void>;
	await act(async () => { done = finishDictation(); });
	await act(async () => { await done; });
	assert.equal(f.dictation.error, "Could not finish microphone capture");
	assert.equal(f.dictation.phase, "idle");
	assert.equal(Worklet.latest.disconnected, true);
	assert.equal(isDictationActive(), false);
});

test("microphone permission resolving after unmount immediately stops the late stream", async () => {
	const f = await fixture(); await f.mount();
	const mic = deferred<{ getTracks: () => { stop: () => void }[] }>(); f.state.nextMic = mic.promise;
	await act(async () => { f.dictation.toggle(); });
	await f.unmount();
	await act(async () => { mic.resolve({ getTracks: () => [{ stop() { f.state.stops++; } }] }); });
	assert.equal(f.state.stops, 1);
	assert.equal(Socket.all.length, 0);
	assert.equal(isDictationActive(), false);
});