let match_state, user_rem, boat_rem;
let oi_timeout;
let prompt_handler;
let delay_ms = 1000;

const POINT_CLASSES = [180, 140, 100, 60, 40, 20, 1, 0];

function stcall(f, ret_type, arg_types, args) {
	return Module.ccall(f, ret_type,
		arg_types ? ['number'].concat(arg_types) : ['number'],
		args ? [match_state].concat(args) : [match_state]);
}

let prompt_handler_visit = {
	append(val) {
		let elem = document.getElementById('prompt');
		if (elem.textContent.length < 3) {
			elem.textContent += val;
			promptUpdateRem();
		}
	},

	backspace() {
		let elem = document.getElementById('prompt');
		elem.textContent = elem.textContent.slice(0, -1);
		promptUpdateRem();
	},

	clear() {
		document.getElementById('prompt').textContent = '';
		promptUpdateRem();
	},

	submit(pts_is_rem) {
		let elem = document.getElementById('prompt');
		let pts = elem.textContent;
		if (!pts) return;
		promptClear();

		if (pts_is_rem)
			pts = user_rem - pts;

		if (!stcall('user_visit', 'number', ['number'], [pts])) {
			oi();
			return;
		}

		clearMatchLog();
		stcall('draw_match');

		if (!stcall('is_match_over', 'number')) {
			setBoatActive();
			stcall('boat_visit', 'number', ['number'], [delay_ms]);
		}
	},

	submit_rem() {
		this.submit(true);
	}
}

let prompt_handler_num_darts = {
	append(val) {
		let elem = document.getElementById('prompt');
		if (elem.textContent.length < 3)
			elem.textContent += val;
	},

	backspace() {
		let elem = document.getElementById('prompt');
		elem.textContent = elem.textContent.slice(0, -1);
	},

	clear() {
		document.getElementById('prompt').textContent = '';
	},

	submit() {
		let elem = document.getElementById('prompt');
		let val = elem.textContent;
		if (!val) return;
		promptClear();

		if (stcall('resp_numdarts', null, ['number'], [val]))
			prompt_handler = prompt_handler_init; //FIXME
		else
			oi();
	}
}

let prompt_handler_init = {
	submit() {
		initMatch();
	}
}

function promptAppend(...args) {
	clearOi();
	prompt_handler?.append?.(...args);
}

function promptClear(...args) {
	clearOi();
	prompt_handler?.clear?.(...args);
}

function promptBackspace(...args) {
	clearOi();
	prompt_handler?.backspace?.(...args);
}

function promptSubmit(...args) {
	clearOi();
	prompt_handler?.submit?.(...args);
}

function promptSubmitRem(...args) {
	clearOi();
	prompt_handler?.submit_rem?.(...args);
}

function clearMatchLog() {
	document.getElementById('match').textContent = '';
}

function initMatch() {
	if (match_state)
		stcall('free_match');
	updateDelay(delay_ms);
	match_state = stcall('start_match', 'number');
	setUserActive();
	clearMatchLog();
	promptSuggStr('');
	stcall('draw_match');
}

function oi() {
	document.getElementById('oi').style.visibility = 'visible';

	oi_timeout = setTimeout(function() { oi_timeout = null; clearOi() }, 3000);
}

function clearOi() {
	document.getElementById('oi').style.visibility = 'hidden';

	if (oi_timeout) {
		clearTimeout(oi_timeout);
		oi_timeout = null;
	}
}

function updateUserRem(rem) {
	user_rem = rem;
	updateUserStateRem(rem);
}

function updateBoatRem(rem) {
	boat_rem = rem;
	updateBoatStateRem(rem);
}

function updateUserStateRem(rem) {
	let elem = document.getElementById('user-rem');
	elem.textContent = rem < 0 || rem == 1 ? 'BUST' : rem;
	Module.ccall('get_suggested', null, ['number', 'number'], [rem, 1]);
}

function updateBoatStateRem(rem) {
	let elem = document.getElementById('boat-rem');
	elem.textContent = rem < 0 || rem == 1 ? 'BUST' : rem;
	Module.ccall('get_suggested', null, ['number', 'number'], [rem, 2]);
}

function userSugg(p) {
	document.getElementById('user-sugg').textContent = UTF8ToString(p);
}

function boatSugg(p) {
	document.getElementById('boat-sugg').textContent = UTF8ToString(p);
}

function updateUserAvg(avg) {
	document.getElementById('user-avg').textContent = avg.toFixed(2);
}

function updateBoatAvg(avg) {
	document.getElementById('boat-avg').textContent = avg.toFixed(2);
}

function promptMsg(p) {
	document.getElementById('prompt-msg').textContent = UTF8ToString(p);
}

function promptMsgStr(str) {
	document.getElementById('prompt-msg').textContent = str;
}

function promptSuggStr(str) {
	document.getElementById('prompt-sugg').textContent = str;
}

function promptUpdateRem() {
	let elem = document.getElementById('user-rem');
	let pts = document.getElementById('prompt').textContent;

	updateUserStateRem(pts ? user_rem - pts : user_rem);
}

function promptNumDarts() {
	promptMsgStr('Darts needed?');
	prompt_handler = prompt_handler_num_darts;
}

function setBoatActive() {
	document.getElementById('user-state').classList.remove('active');
	document.getElementById('boat-state').classList.add('active');
	prompt_handler = null;
}

function setUserActive() {
	document.getElementById('boat-state').classList.remove('active');
	document.getElementById('user-state').classList.add('active');
	prompt_handler = prompt_handler_visit;
}

function drawBoatThrowing(pts, str) {
	updateBoatStateRem(boat_rem - pts);
	document.getElementById('prompt').textContent = pts;
	promptSuggStr(str);
}

function scheduleBoatThrowing(pts, ptr, delay_ms) {
	// ptr to c string must be copied before returning
	let str = UTF8ToString(ptr);
	setTimeout(function() { drawBoatThrowing(pts, str); }, delay_ms);
}

function endBoatThrowing(rem, avg) {
	updateBoatRem(rem);
	updateBoatAvg(avg);
	document.getElementById('prompt').textContent = '';
	clearMatchLog();
	promptSuggStr('');
	stcall('draw_match');
	if (!stcall('is_match_over', 'number'))
		setUserActive();
}

function scheduleEndBoatThrowing(rem, avg, delay_ms) {
	setTimeout(function() { endBoatThrowing(rem, avg); }, delay_ms);
}

function matchOver() {
	prompt_handler = prompt_handler_init;
	promptSuggStr('Press OK to play again.');
	document.getElementById('user-state').className = '';
}

function drawVisit(visit_no, u_pts, u_rem, b_pts, b_rem, b_darts) {
	let elem = document.getElementById('match');

	for (let [i, ptr] of [u_pts, u_rem, visit_no, b_rem, b_pts, b_darts].entries()) {
		let div = document.createElement('div');
		let v = div.textContent = UTF8ToString(ptr);
		if (i == 0 || i == 4) {
			div.className = `p${POINT_CLASSES.find(x => x <= v)}`;
		} else if (i == 5) {
			if (v) div.textContent = `… ${v}`;
		}
		div.className += ` visit-col${i+1}`;
		elem.append(div);
	}

	elem.scrollTop = elem.scrollHeight;
}

function stdevChanged(val) {
	Module.ccall('change_stdev', null, ['number', 'number'], [val, val]);
}

function updateStdev(val) {
	document.getElementById('stdev').value = val;
}

function delayChanged(val) {
	delay_ms = val;
}

function updateDelay(val) {
	document.getElementById('delay').value = val;
}

function processKey(data) {
	if (data.altKey || data.ctrlKey || data.metaKey || data.target.type == 'text')
		return;
	let key = data.key;

	if (isFinite(key))
		promptAppend(key);
	else if (key == 'Enter')
		promptSubmit();
	else if (key == 'Backspace')
		promptBackspace();
	else if (key == 'r')
		promptSubmitRem();
}

function modal(id) {
	document.getElementById(id).style.display = 'block';
}

window.onclick = function(e) {
	if (e.target.classList.contains('modal')) e.target.style.display = 'none';
}

document.addEventListener('keydown', processKey);