let spaceContainer, space;

let editing;
let dragging;
let moved;
let movedFrom;
let offset;
let clicked;

document.addEventListener('mouseup', function(event) {
	clicked = false;
});

document.addEventListener('mousemove', function(event) {
	moved = true;
	if (dragging) {
		let left = event.clientX - spaceContainer.offsetLeft - offset.x;
		let top = event.clientY - spaceContainer.offsetTop - offset.y;
		dragging.style.left = `${left < 0 ? 0 : left}px`;
		dragging.style.top = `${top < 0 ? 0 : top}px`;
		save(dragging);
	}
	else if (clicked) {
		spaceContainer.scrollLeft -= event.movementX;
		spaceContainer.scrollTop -= event.movementY;
	}
});

let saving;
let queue;

function save(span) {
	if (saving) {
		queue = span;
		return;
	}
	saving = true;
	window.currentInstance.emit('save_span', {
		thread: window.currentThread.id,
		id: span.id ? span.id.slice(4) : '',
		content: span.innerText,
		x: span.style.left.slice(0, -2),
		y: span.style.top.slice(0, -2),
		scale: span.scale
	}, msg => {
		if (!msg.success)
			console.log('span save failed: ' + msg.message);
		if (!span.id)
			span.id = 'span' + msg.id;
		saving = false;
		if (queue) {
			save(queue);
			queue = null;
		}
	});
}

function add(s) {
	let span = document.createElement('span');
	span.classList.add('span');
	if (s.id)
		span.id = 'span' + s.id;
	span.innerText = s.content;
	span.contentEditable = true;
	span.spellcheck = false;
	span.scale = s.scale;
	span.style.left = `${s.x}px`;
	span.style.top = `${s.y}px`;
	span.style.transform = `translate(-50%, -50%) scale(${s.scale})`;
	span.onkeydown = function(event) {
		if (event.key === 'Enter' && !event.getModifierState('Shift')) {
			event.preventDefault();
			editing = null;
			span.blur();
		}
	};
	span.oninput = function(event) {
		save(this);
	};
	span.onblur = function(event) {
		if (this.innerText)
			return;
		this.remove();
		if (this.id)
			save(this);
	};
	span.onwheel = function(event) {
		event.preventDefault();
		event.stopPropagation();
		this.scale *= 1 - event.deltaY * .001;
		if (this.scale > 100)
			this.scale = 100;
		this.style.transform = `translate(-50%, -50%) scale(${this.scale})`;
		save(this);
	};
	span.onmousedown = function(event) {
		if (dragging || editing === this)
			return;
		event.preventDefault();
		if (event.button !== 0)
			return;
		dragging = this;
		offset = {
			x: event.clientX - (spaceContainer.offsetLeft + this.offsetLeft),
			y: event.clientY - (spaceContainer.offsetTop + this.offsetTop)
		};
	};
	span.onmouseup = function(event) {
		if (event.button !== 0)
			return;
		dragging = null;
		if (moved)
			return;
		this.focus();
		editing = this;
	};
	space.append(span);
	return span;
}

export default function loadSpace(callback) {
	let instance = window.currentInstance;

	let scale = 1;

	if (!instance.spaced) {
		spaceContainer = document.getElementById('space');
		space = document.getElementById('spacediv');

		spaceContainer.onwheel = function(event) {
			if (event.getModifierState('Shift'))
				return;
			event.preventDefault();
			scale *= 1 - event.deltaY * .001;
			if (scale < .5)
				scale = .5;
			space.style.transform = `scale(${scale})`;
			spaceContainer.scrollLeft += event.offsetX * (scale - scale / (1 - event.deltaY * .001));
			spaceContainer.scrollTop += event.offsetY * (scale - scale / (1 - event.deltaY * .001));
			//spaceContainer.scrollLeft += spaceContainer.clientWidth * (1 - spaceContainer.clientWidth / spaceContainer.scrollWidth + event.offsetX / spaceContainer.clientWidth) * (scale - scale / (1 - event.deltaY * .001));
			//spaceContainer.scrollTop += spaceContainer.clientHeight * (1 - spaceContainer.clientHeight / spaceContainer.scrollHeight + event.offsetY / spaceContainer.clientHeight) * (scale - scale / (1 - event.deltaY * .001));
		};
		spaceContainer.onmousedown = function(event) {
			if (event.button !== 0)
				return;
			clicked = true;
			moved = false;
			movedFrom = { x: event.offsetX, y: event.offsetY };
		};
		spaceContainer.onmouseup = function(event) {
			if (event.button !== 0)
				return;
			if (dragging) {
				dragging.onmouseup(event);
				return;
			}
			if (editing) {
				if (event.target !== editing)
					editing = null;
				return;
			}
			if (moved && (event.offsetX - movedFrom.x) * (event.offsetX - movedFrom.x)
				+ (event.offsetY - movedFrom.y) * (event.offsetY - movedFrom.y) > 100)
				return;
			editing = add({
				x: (event.offsetX + spaceContainer.scrollLeft) / scale,
				y: (event.offsetY + spaceContainer.scrollTop) / scale,
				scale: 1,
				content: ''
			});
			editing.focus();
		};

		instance.socket.on('span', msg => {
			if (msg.thread !== window.currentSpace.id || window.currentInstance !== instance)
				return;
			let span = document.getElementById('span' + msg.id);
			if (span) {
				span.innerText = msg.content;
				span.style.left = `${msg.x}px`;
				span.style.top = `${msg.y}px`;
				span.scale = msg.scale;
				span.style.transform = `translate(-50%, -50%) scale(${msg.scale})`;
			}
			else
				add(msg);
		});
		instance.spaced = true;
	}
	else if (window.currentSpace === window.currentThread)
		return;
	window.currentSpace = window.currentThread;
	space.innerHTML = '';
	space.style.transform = '';
	instance.emit('get_space', {
		thread: window.currentSpace.id
	}, msg => {
		if (!msg.success) {
			console.log('get space failed: ' + msg.message);
			return;
		}
		callback && callback(msg.spans);
		msg.spans.forEach(add);
	});
};