// ori-desktop frontend — plain JavaScript, no bundler.
//
// The Wails runtime injects two globals into this page:
//   window.go.main.App.*  — the Go methods bound in main.go (each returns a Promise)
//   window.runtime.*      — the Wails runtime API (window title, browser, ...)
// Calling them directly (rather than through the generated frontend/wailsjs
// wrappers) keeps this frontend free of generated files.
//
// Loaded as an ES module (see index.html): strict mode and a private scope
// come for free, and the script runs once the document has been parsed.

const $ = (id) => document.getElementById(id);
const els = {
	connectScreen: $("connect-screen"),
	viewerScreen: $("viewer-screen"),
	form: $("connect-form"),
	url: $("server-url"),
	check: $("check-btn"),
	connect: $("connect-btn"),
	status: $("status"),
	settingsPath: $("settings-path"),
	viewerUrl: $("viewer-url"),
	reload: $("reload-btn"),
	browser: $("browser-btn"),
	disconnect: $("disconnect-btn"),
	frame: $("ori-frame"),
};

/** The Go-bound App, or null when the page is opened outside Wails. */
function app() {
	return window.go?.main?.App || null;
}

function setStatus(text, kind) {
	els.status.textContent = text || "";
	els.status.className = kind ? `status ${kind}` : "status";
}

function setBusy(busy) {
	els.check.disabled = busy;
	els.connect.disabled = busy;
	els.url.disabled = busy;
}

function setTitle(title) {
	if (window.runtime?.WindowSetTitle) {
		window.runtime.WindowSetTitle(title);
	}
	document.title = title;
}

// ---- screens --------------------------------------------------------

function showViewer(baseURL) {
	els.viewerUrl.textContent = baseURL;
	els.frame.src = `${baseURL}/`;
	els.connectScreen.hidden = true;
	els.viewerScreen.hidden = false;
	setTitle(`ori — ${baseURL}`);
}

function showConnect(message, kind) {
	els.frame.src = "about:blank";
	els.viewerScreen.hidden = true;
	els.connectScreen.hidden = false;
	setTitle("ori");
	setStatus(message, kind);
	els.url.focus();
	els.url.select();
}

// ---- actions --------------------------------------------------------

async function check() {
	const a = app();
	if (!a) return;
	setBusy(true);
	setStatus(`Checking ${els.url.value.trim()}/healthz …`);
	try {
		const rep = await a.CheckHealth(els.url.value);
		setStatus(rep.detail, rep.ok ? "ok" : "err");
	} catch (err) {
		setStatus(String(err), "err");
	} finally {
		setBusy(false);
	}
}

async function connect() {
	const a = app();
	if (!a) return;
	setBusy(true);
	setStatus("Connecting …");
	try {
		const base = await a.Connect(els.url.value);
		els.url.value = base;
		setStatus("");
		showViewer(base);
	} catch (err) {
		setStatus(String(err), "err");
	} finally {
		setBusy(false);
	}
}

async function openInBrowser() {
	const a = app();
	if (!a) return;
	try {
		await a.OpenInBrowser(els.viewerUrl.textContent || els.url.value);
	} catch (err) {
		console.error(err);
	}
}

/** Reloads the embedded ori page by re-assigning the frame's URL. */
function reloadFrame() {
	const current = els.frame.src;
	els.frame.src = current;
}

// ---- startup --------------------------------------------------------

async function init() {
	els.form.addEventListener("submit", (e) => {
		e.preventDefault();
		connect();
	});
	els.check.addEventListener("click", check);
	els.reload.addEventListener("click", reloadFrame);
	els.browser.addEventListener("click", openInBrowser);
	els.disconnect.addEventListener("click", () =>
		showConnect("Disconnected.", ""),
	);

	const a = app();
	if (!a) {
		setStatus(
			"Wails runtime not found — open this page from the ori-desktop app (wails dev / wails build).",
			"err",
		);
		setBusy(true);
		return;
	}

	try {
		const cfg = await a.GetConfig();
		els.url.value = cfg.serverUrl || "http://localhost:8888";
	} catch (err) {
		els.url.value = "http://localhost:8888";
		setStatus(`Could not read saved settings: ${err}`, "err");
	}
	try {
		const path = await a.SettingsPath();
		els.settingsPath.textContent = path ? `Remembered in ${path}` : "";
	} catch (_) {
		/* cosmetic only */
	}

	// Auto-connect when the remembered server already answers; otherwise
	// stay on this screen with the reason, so the user can fix the URL.
	await connect();
}

document.addEventListener("DOMContentLoaded", init);