import * as File from WTK.File;
import * as Async from UnitJS.Async;
import compose from UnitJS.Fun;
import * as Dom from UnitJS.Dom;
import Toolbox;


var grid = {
	element: null,
	data: null
};
var down = false;

return {
	init: init
};

function init(size, elementId) {
	grid.element = document.getElementById(elementId || 'grid');
	for(var row = 0; row < size; row++) {
		grid.element.appendChild(
			makeRow({tag: 'td', attributes: bodyAttributes, row: row, size: size})
		);
	}
	grid.data = emptyGrid(size);
	grid.element.addEventListener('mouseleave', function() {
		down = false;
	});
	document.getElementById('load').addEventListener('click', load);
	document.getElementById('save').addEventListener('click', save);
}

function emptyGrid(size) {
	var result = {};
	for(var row = 0; row < size; row++) {
		result[row] = {};
	}
	return result;
}

function makeRow(config) {
	var cells = [];
	for(var column = 0; column < config.size; column++) {
		cells.push(Dom.make(config.tag, config.attributes(config.row, column)));
	}
	return Dom.make('tr', {}, cells);
}

function bodyAttributes(row, column) {
	return {
		onMousedown: function() {
			down = true;
			if(Toolbox.tool() == 'draw') {
				colorize(row, column);
			}
		},
		onMouseup: function() {
			down = false;
			if(Toolbox.tool() == 'paint') {
				paint(row, column);
			}
		},
		onMouseenter: function() {
			if(down && Toolbox.tool() == 'draw') {
				colorize(row, column);
			}
		}
	};
}

function colorize(row, column, color) {
	grid.data[row][column] = color || Toolbox.color();
	grid.element.children[row].children[column].className = grid.data[row][column];
}

function paint(i0, j0) {
	var originColor = grid.data[i0][j0];
	var size = grid.element.children.length;
	var done = emptyGrid(size);
	var queue = [{i: i0, j: j0}];
	while(queue.length > 0) {
		var p0 = queue[0];
		colorize(p0.i, p0.j);
		done[p0.i][p0.j] = true;
		for(var d = -1; d < 2; d += 2) {
			[{i: p0.i + d, j: p0.j}, {i: p0.i, j: p0.j + d}].forEach(function(p1) {
				if(p1.i >= 0 && p1.i < size && p1.j >= 0 && p1.j < size
					&& !done[p1.i][p1.j]
					&& grid.data[p1.i][p1.j] == originColor) {
					queue.push(p1);
				}
			});
		}
		queue.shift();
	}
}

function load() {
	Async.run(
		Async.bind(
			File.pick({accept: 'text/json,.json'}),
			function(input) {
				return File.load(input.files[0]);
			},
			Async.map(compose(setGridData, JSON.parse))
		)
	);
}

function setGridData(data) {
	if(data != undefined) {
		for(var row = 0; row < grid.element.children.length; row++) {
			for(var column = 0; column < grid.element.children[row].children.length; column++) {
				colorize(row, column, data[row][column]);
			}
		}
	}
}

function save() {
	File.save('data:text/json,' + JSON.stringify(grid.data), "grid.json");
}