var utils = require('../utils');
var URShift = utils.URShift;

var DataMask = {};

DataMask.forReference = function (reference) {
	if (reference < 0 || reference > 7) {
		throw "System.ArgumentException";
	}
	return DataMask.DATA_MASKS[reference];
}

function DataMask000() {
	this.unmaskBitMatrix = function (bits, dimension) {
		for (var i = 0; i < dimension; i++) {
			for (var j = 0; j < dimension; j++) {
				if (this.isMasked(i, j)) {
					bits.flip(j, i);
				}
			}
		}
	}
	this.isMasked = function (i, j) {
		return ((i + j) & 0x01) == 0;
	}
}

function DataMask001() {
	this.unmaskBitMatrix = function (bits, dimension) {
		for (var i = 0; i < dimension; i++) {
			for (var j = 0; j < dimension; j++) {
				if (this.isMasked(i, j)) {
					bits.flip(j, i);
				}
			}
		}
	}
	this.isMasked = function (i, j) {
		return (i & 0x01) == 0;
	}
}

function DataMask010() {
	this.unmaskBitMatrix = function (bits, dimension) {
		for (var i = 0; i < dimension; i++) {
			for (var j = 0; j < dimension; j++) {
				if (this.isMasked(i, j)) {
					bits.flip(j, i);
				}
			}
		}
	}
	this.isMasked = function (i, j) {
		return j % 3 == 0;
	}
}

function DataMask011() {
	this.unmaskBitMatrix = function (bits, dimension) {
		for (var i = 0; i < dimension; i++) {
			for (var j = 0; j < dimension; j++) {
				if (this.isMasked(i, j)) {
					bits.flip(j, i);
				}
			}
		}
	}
	this.isMasked = function (i, j) {
		return (i + j) % 3 == 0;
	}
}

function DataMask100() {
	this.unmaskBitMatrix = function (bits, dimension) {
		for (var i = 0; i < dimension; i++) {
			for (var j = 0; j < dimension; j++) {
				if (this.isMasked(i, j)) {
					bits.flip(j, i);
				}
			}
		}
	}
	this.isMasked = function (i, j) {
		return (((URShift(i, 1)) + (j / 3)) & 0x01) == 0;
	}
}

function DataMask101() {
	this.unmaskBitMatrix = function (bits, dimension) {
		for (var i = 0; i < dimension; i++) {
			for (var j = 0; j < dimension; j++) {
				if (this.isMasked(i, j)) {
					bits.flip(j, i);
				}
			}
		}
	}
	this.isMasked = function (i, j) {
		var temp = i * j;
		return (temp & 0x01) + (temp % 3) == 0;
	}
}

function DataMask110() {
	this.unmaskBitMatrix = function (bits, dimension) {
		for (var i = 0; i < dimension; i++) {
			for (var j = 0; j < dimension; j++) {
				if (this.isMasked(i, j)) {
					bits.flip(j, i);
				}
			}
		}
	}
	this.isMasked = function (i, j) {
		var temp = i * j;
		return (((temp & 0x01) + (temp % 3)) & 0x01) == 0;
	}
}

function DataMask111() {
	this.unmaskBitMatrix = function (bits, dimension) {
		for (var i = 0; i < dimension; i++) {
			for (var j = 0; j < dimension; j++) {
				if (this.isMasked(i, j)) {
					bits.flip(j, i);
				}
			}
		}
	}
	this.isMasked = function (i, j) {
		return ((((i + j) & 0x01) + ((i * j) % 3)) & 0x01) == 0;
	}
}

DataMask.DATA_MASKS = new Array(new DataMask000(), new DataMask001(), new DataMask010(), new DataMask011(), new DataMask100(), new DataMask101(), new DataMask110(), new DataMask111());

module.exports = DataMask;