// game.js - round management, timer, submit

import { submitScore } from "./api.js";
import { getRandomCountries, loadCountries } from "./countries.js";
import { clear, getPoints, init as initDrawing, setCities } from "./drawing.js";
import { calculateScore, getGrade } from "./scoring.js";
import { getLobbyName, getPlayerName, saveGameState } from "./storage.js";

const TOTAL_ROUNDS = 3;
const ROUND_DURATION = 60; // seconds

/** @type {import('./countries.js').Country[]} */
let roundCountries = [];
let currentRound = 0;
/** @type {number[]} */
let scores = [];
let timerInterval = null;
let timeLeft = ROUND_DURATION;

let elCountryName;
let elCountryHint;
let elRoundNum;
let elTimerNum;
let elTimerBar;
let elTimerWrap;
let elBtnClear;
let elBtnSubmit;

/** Initialise DOM refs, drawing, events, countries, and the first round. */
async function initGame() {
	elCountryName = document.getElementById("country-name");
	elCountryHint = document.getElementById("country-hint");
	elRoundNum = document.getElementById("round-num");
	elTimerNum = document.getElementById("timer-num");
	elTimerBar = document.getElementById("timer-bar");
	elTimerWrap = document.querySelector(".game-timer");
	elBtnClear = document.getElementById("btn-clear");
	elBtnSubmit = document.getElementById("btn-submit");

	const canvas = document.getElementById("draw-canvas");
	const wrap = document.getElementById("canvas-wrap");
	initDrawing(canvas);

	document.getElementById("player-name-display").textContent = getPlayerName();
	canvas.addEventListener("pointerdown", () => {
		wrap.classList.add("has-drawing");
	});

	elBtnClear.addEventListener("click", () => clear());
	elBtnSubmit.addEventListener("click", () => submitRound(false));

	await loadCountries();
	roundCountries = getRandomCountries(TOTAL_ROUNDS);
	currentRound = 0;
	scores = [];
	startRound();
}

/** Set up UI and timer for the current round. */
function startRound() {
	const country = roundCountries[currentRound];

	elRoundNum.textContent = currentRound + 1;
	elCountryName.textContent = country.name;
	elCountryHint.textContent = country.hint || "";

	updateRoundPips(currentRound + 1);

	document.getElementById("canvas-wrap")?.classList.remove("has-drawing");

	setCities(country.cities || []);
	clear();

	timeLeft = ROUND_DURATION;
	updateTimerUI();
	clearInterval(timerInterval);
	timerInterval = setInterval(tickTimer, 1000);

	elBtnSubmit.disabled = false;
	elBtnSubmit.textContent =
		currentRound < TOTAL_ROUNDS - 1
			? "Submit & Next Round →"
			: "Submit & See Results →";
}

/** Decrement timer by one second and auto-submit when time runs out. */
function tickTimer() {
	timeLeft--;
	updateTimerUI();
	if (timeLeft <= 0) {
		clearInterval(timerInterval);
		submitRound(true);
	}
}

/**
 * Sync timer bar width and apply urgency CSS classes.
 * Uses `.timer--warning` and `.timer--danger` instead of inline styles.
 */
function updateTimerUI() {
	elTimerNum.textContent = timeLeft;
	elTimerBar.style.width = `${(timeLeft / ROUND_DURATION) * 100}%`;

	elTimerWrap.classList.toggle("timer--danger", timeLeft <= 10);
	elTimerWrap.classList.toggle(
		"timer--warning",
		timeLeft > 10 && timeLeft <= 20,
	);
}

/**
 * Submit the current round, record the score, and advance or finish.
 * @param {boolean} [auto=false] - True when triggered by timer expiry.
 */
function submitRound(auto = false) {
	clearInterval(timerInterval);
	elBtnSubmit.disabled = true;

	const points = getPoints();
	const score = calculateScore(points);
	scores.push(score);

	updateScoreDisplay(currentRound, score);
	showScoreFeedback(score);

	setTimeout(
		() => {
			if (currentRound < TOTAL_ROUNDS - 1) {
				currentRound++;
				startRound();
			} else {
				finishGame();
			}
		},
		auto ? 400 : 1200,
	);
}

/**
 * Briefly display the score grade overlay on the canvas.
 * @param {number} score
 */
function showScoreFeedback(score) {
	const grade = getGrade(score);
	const el = document.getElementById("score-feedback");
	el.textContent = `${score}%  ${grade.label}`;
	el.style.color = grade.color;
	el.style.opacity = "1";
	el.style.transform = "translateY(0)";
	setTimeout(() => {
		el.style.opacity = "0";
		el.style.transform = "translateY(-10px)";
	}, 900);
}

/** Persist game state, update leaderboard, and navigate to results. */
async function finishGame() {
	const totalScore = scores.reduce((sum, s) => sum + s, 0);
	const state = {
		currentRound: TOTAL_ROUNDS,
		scores,
		totalScore,
		countries: roundCountries.map((c) => c.name),
	};
	saveGameState(state);

	try {
		await submitScore({
			lobbyName: getLobbyName(),
			playerName: getPlayerName(),
			totalScore,
			scores,
			countries: state.countries,
		});
	} catch (error) {
		console.warn("Could not submit score to backend.", error);
	}

	location.href = "results.html";
}

/** @param {number} round */
function updateRoundPips(round) {
	for (let i = 1; i <= 3; i++) {
		const pip = document.getElementById(`pip-${i}`);
		pip.className = `round-pip${i < round ? " done" : ""}${
			i === round ? " active" : ""
		}`;
	}
}

/**
 * @param {number} roundIdx
 * @param {number} score
 */
function updateScoreDisplay(roundIdx, score) {
	const el = document.getElementById(`score-r${roundIdx + 1}`);
	if (el) {
		el.textContent = `${score}%`;
		el.classList.add("filled");
	}
}

window.addEventListener("DOMContentLoaded", initGame);