/**
 * Reopening the last folder on launch.
 *
 * Three cases matter: the folder is remembered when you open one, it comes
 * back by itself next launch, and a folder that has since moved or been
 * ejected leaves the launch screen up rather than an error — with the stale
 * path dropped so it can't fail twice.
 *
 * Run: npm i jsdom && node build/test-restore.js
 */

const fs = require("fs");
const os = require("os");
const path = require("path");
const assert = require("assert");
const { JSDOM, VirtualConsole } = require("jsdom");
const { build } = require("./make-sample.js");

const INDEX = path.join(__dirname, "..", "mac-app", "dist", "index.html");
const STORAGE_KEY = "bwfa_last_folder";

const root = fs.mkdtempSync(path.join(os.tmpdir(), "bwf-restore-"));
const card = path.join(root, "Day 14 PR-2");
fs.mkdirSync(card, { recursive: true });
["A001.wav", "A002.wav"].forEach((name, i) =>
	fs.writeFileSync(path.join(card, name), build({ scene: "1", take: i + 1 })));

const results = [];
function check(name, fn) {
	try {
		fn();
		results.push(["PASS", name]);
	} catch (e) {
		results.push(["FAIL", name + " — " + e.message]);
	}
}

function waitFor(fn, label, timeout = 10000) {
	return new Promise((resolve, reject) => {
		const started = Date.now();
		(function poll() {
			let value;
			try {
				value = fn();
			} catch (e) {
				return reject(e);
			}
			if (value) return resolve(value);
			if (Date.now() - started > timeout) return reject(new Error("timed out waiting for " + label));
			setTimeout(poll, 30);
		})();
	});
}

/** A window, with the Rust commands mirrored and a note of what was asked. */
function launch({ remembered, dialogAnswers = [] } = {}) {
	const asked = { dialog: 0 };
	const dialogQueue = dialogAnswers.slice();

	const dom = new JSDOM(fs.readFileSync(INDEX, "utf8"), {
		runScripts: "dangerously",
		url: "http://tauri.localhost/",
		pretendToBeVisual: true,
		virtualConsole: new VirtualConsole(),
		beforeParse(win) {
			win.HTMLCanvasElement.prototype.getContext = () => new Proxy({}, {
				get: (target, prop) => (prop === "canvas" ? null : () => {}),
				set: () => true,
			});
			win.URL.createObjectURL = () => "blob:stub";
			win.URL.revokeObjectURL = () => {};
			if (remembered !== undefined) {
				win.localStorage.setItem(STORAGE_KEY, remembered);
			}

			const toRealm = (buffer) => {
				const view = new win.Uint8Array(buffer.length);
				view.set(buffer);
				return view.buffer;
			};

			win.__TAURI__ = {
				event: { listen: () => Promise.resolve(() => {}) },
				core: {
					invoke(command, payload) {
						if (command === "plugin:dialog|open") {
							asked.dialog++;
							const next = dialogQueue.shift();
							return Promise.resolve(next === undefined ? null : next);
						}
						if (command === "bwf_list_dir") {
							// Rejects for a folder that isn't there, exactly as the
							// Rust command does.
							if (!fs.existsSync(payload.path)) {
								return Promise.reject(new Error(payload.path + ": No such file or directory"));
							}
							return Promise.resolve(fs.readdirSync(payload.path).sort().map((name) => ({
								name,
								path: path.join(payload.path, name),
								kind: fs.statSync(path.join(payload.path, name)).isDirectory() ? "directory" : "file",
							})));
						}
						if (command === "bwf_stat") {
							const stat = fs.statSync(payload.path);
							return Promise.resolve({
								path: payload.path,
								relativePath: path.basename(payload.path),
								name: path.basename(payload.path),
								size: stat.size,
								lastModified: Math.floor(stat.mtimeMs),
							});
						}
						if (command === "bwf_read_range") {
							const size = fs.statSync(payload.path).size;
							if (payload.offset >= size || !payload.length) return Promise.resolve(toRealm(Buffer.alloc(0)));
							const take = Math.min(payload.length, size - payload.offset);
							const fd = fs.openSync(payload.path, "r");
							const buffer = Buffer.alloc(take);
							fs.readSync(fd, buffer, 0, take, payload.offset);
							fs.closeSync(fd);
							return Promise.resolve(toRealm(buffer));
						}
						if (command === "bwf_read_all") {
							return Promise.resolve(toRealm(fs.readFileSync(payload.path)));
						}
						return Promise.reject(new Error("unexpected command " + command));
					},
				},
			};
		},
	});

	return new Promise((resolve) => {
		dom.window.addEventListener("load", () => resolve({ dom, window: dom.window, asked }));
	});
}

const rowsIn = (doc) => Array.from(doc.querySelectorAll("[data-bwfa-table-body] tr"));

(async () => {
	/* --- opening a folder is remembered --- */

	const first = await launch({ dialogAnswers: [card] });
	first.window.document.querySelector("[data-bwfa-edit-folder]")
		.dispatchEvent(new first.window.MouseEvent("click", { bubbles: true }));
	await waitFor(() => rowsIn(first.window.document).length === 2, "first open");

	check("opening a folder remembers it", () =>
		assert.strictEqual(first.window.localStorage.getItem(STORAGE_KEY), card,
			"stored: " + first.window.localStorage.getItem(STORAGE_KEY)));
	first.window.close();

	/* --- next launch reopens it, with no dialog --- */

	const again = await launch({ remembered: card });
	await waitFor(() => rowsIn(again.window.document).length === 2, "reopen on launch");
	const doc = again.window.document;

	check("the folder comes back on the next launch", () => {
		assert.strictEqual(rowsIn(doc).length, 2, "got " + rowsIn(doc).length + " rows");
		assert.strictEqual(again.asked.dialog, 0, "it opened a file dialog instead of restoring");
		assert.strictEqual(doc.querySelector("[data-bwfa-current-folder]").textContent, "Day 14 PR-2");
		assert(doc.querySelector("[data-bwfa-app]").classList.contains("has-folder"),
			"still showing the launch screen");
	});

	check("it comes back read-write, not read-only", () =>
		assert.strictEqual(doc.querySelector("[data-bwfa-editing-note]").hidden, false,
			"restored without edit mode, so saving would be impossible"));
	again.window.close();

	/* --- a folder that has gone leaves the launch screen up --- */

	const missing = path.join(root, "Ejected Card");
	const gone = await launch({ remembered: missing });
	// Nothing to wait for, so give the check a beat to have happened.
	await new Promise((r) => setTimeout(r, 300));
	const goneDoc = gone.window.document;

	check("a folder that isn't there leaves the launch screen alone", () => {
		assert.strictEqual(rowsIn(goneDoc).length, 0, "it loaded something");
		assert.strictEqual(goneDoc.querySelector("[data-bwfa-app]").classList.contains("has-folder"), false,
			"the app left its launch state for a folder that doesn't exist");
		assert.strictEqual(gone.asked.dialog, 0, "it prompted on launch, which is not the ask");
		assert.strictEqual(goneDoc.querySelector("[data-bwfa-status]").textContent.trim(), "",
			"an error was left on screen: " + goneDoc.querySelector("[data-bwfa-status]").textContent);
	});

	check("the stale path is dropped so it can't fail twice", () =>
		assert.strictEqual(gone.window.localStorage.getItem(STORAGE_KEY), null,
			"still remembered: " + gone.window.localStorage.getItem(STORAGE_KEY)));
	gone.window.close();

	/* --- eject puts the app back to a first run --- */

	const open = await launch({ dialogAnswers: [card] });
	const openDoc = open.window.document;
	openDoc.querySelector("[data-bwfa-edit-folder]")
		.dispatchEvent(new open.window.MouseEvent("click", { bubbles: true }));
	await waitFor(() => rowsIn(openDoc).length === 2, "open before reset");

	check("eject only offers itself once a folder is open", () => {
		const reset = openDoc.querySelector("[data-bwfa-reset]");
		assert(reset, "no reset control in the markup");
		assert.notStrictEqual(open.window.getComputedStyle(reset).display, "none",
			"reset is hidden while a folder is open");
	});

	openDoc.querySelector("[data-bwfa-reset]")
		.dispatchEvent(new open.window.MouseEvent("click", { bubbles: true }));
	await waitFor(() => rowsIn(openDoc).length === 0, "reset to clear the table", 5000);

	check("eject returns the app to its empty state", () => {
		const app = openDoc.querySelector("[data-bwfa-app]");
		assert.strictEqual(app.classList.contains("has-folder"), false, "still in folder mode");
		assert.strictEqual(openDoc.querySelector("[data-bwfa-results]").hidden, true,
			"the results panel survived");
		assert.strictEqual(openDoc.querySelector("[data-bwfa-player]").hidden, true,
			"the player survived");
		assert.strictEqual(openDoc.querySelector("[data-bwfa-current-folder]").hidden, true,
			"the folder name is still shown");
		assert(/open folder/i.test(openDoc.querySelector("[data-bwfa-edit-folder]").textContent),
			"the button still says Change Folder: " +
				openDoc.querySelector("[data-bwfa-edit-folder]").textContent);
		assert.strictEqual(openDoc.querySelector("[data-bwfa-status]").textContent.trim(), "",
			"a status message was left behind");
		assert.strictEqual(open.window.getComputedStyle(
			openDoc.querySelector("[data-bwfa-reset]")).display, "none",
			"reset is still offered with nothing open");
	});

	check("eject also forgets what to reopen", () =>
		assert.strictEqual(open.window.localStorage.getItem(STORAGE_KEY), null,
			"next launch would reopen " + open.window.localStorage.getItem(STORAGE_KEY)));
	open.window.close();

	console.log("");
	results.forEach(([s, n]) => console.log((s === "PASS" ? "  ok  " : "  FAIL") + "  " + n));
	const failed = results.filter(([s]) => s === "FAIL").length;
	console.log("\n" + (results.length - failed) + "/" + results.length + " checks passed");
	fs.rmSync(root, { recursive: true, force: true });
	process.exit(failed ? 1 : 0);
})().catch((e) => {
	console.error("harness error:", e);
	process.exit(1);
});