import id from UnitJS.Fun;
import size from Config;
import {asAFunction, iter, map, set, square} from Grid.Util;
import {diagonal, zero} from Geometry.Vector;
import * as CellSet from Geometry.CellSet;

var zoneNames = ['colors', 'rows', 'columns'];

return {
	setCell: setCell,
	start: start,
	fork: fork
};

function start(coloring) {
	var empty = Array.from({length: size});
	return {
		constellation: square(size),
		getColor: asAFunction(coloring),
		missing: CellSet.rectangle(zero(), diagonal(size)),
		zones: {
			colors: getColors(coloring),
			rows: empty.map(function(_, i) {return CellSet.row(i);}),
			columns: empty.map(function(_, i) {return CellSet.column(i);})
		}
	};
}

function getColors(grid) {
	var colors = Array.from({length: size});
	iter(grid, function(color, cell) {
		if(colors[color] == undefined) {
			colors[color] = new CellSet.CellSet();
		}
		colors[color].add(cell);
	});
	return colors;
}

function fork(state) {
	var zones = {};
	zoneNames.forEach(function(name) {
		zones[name] = state.zones[name].map(function(s) {return s.copy();});
	});
	return {
		constellation: map(state.constellation, id),
		getColor: state.getColor,
		missing: state.missing.copy(),
		zones: zones
	};
}

function setCells(solvingState, value) {
	return function(cellSet) {
		for(var i = 0; i < zoneNames.length; i++) {
			for(var j = 0; j < size; j++) {
				f(solvingState.zones[field][j], cellSet)
			}
		}
				var field = zoneNames[i];
				var zone = solvingState.zones[field][j];
				if(zone.size() > 0) {
					var diff = 
		});
		solvingState.colorZones
			.concat(solvingState.rows)
			.concat(solvingState.columns)
			.concat(solvingState.missing)
			.forEach(function(cellSet) {cellSet.remove(cell);});
		solvingState.missing
		set(solvingState.constellation, cell, value);
}

function f(zone, cellSet) {
	if(zone.size() > 0) {
		var diff = zone.difference(cellSet);
		if(diff.
	}
}