/*
 * test/20_nj-st-75-2017.js - dmul, drhtz, drhfz tests using NJ ST-75 for 2017
 *
 * @licstart  The following is the entire license notice for the
 * JavaScript code in this file.
 *
 * Copyright (C) 2017  Libiquity LLC
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * As additional permission under GNU GPL version 3 section 7, you
 * may distribute non-source (e.g. minimized or compacted) forms of
 * this program without the copy of the GNU GPL normally required by
 * section 4, provided you include this license notice and a URL
 * through which recipients can access the Corresponding Source.
 *
 * @licend  The above is the entire license notice
 * for the JavaScript code in this file.
 */

var assert = require("assert");
require("../lib/decmath.js");

describe("dmul(), drhtz(), and drhfz()", function() {
	/*
	 * There are 1000 test amounts between 0.01 and 10.00.  Six require
	 * tie-breaking when rounding the calculated tax, but NJ's ST-75 appears
	 * to use different tie-breaking rules for different amounts:
	 *
	 * Rate      Amt    Tax    ST-75  Rule
	 * ----------------------------------------
	 * 0.06875 * 0.80 = 0.055  0.06   Half up
	 *           2.40   0.165  0.17   Half up
	 *           4.00   0.275  0.27   Half down
	 *           5.60   0.385  0.38   Half down
	 *           7.20   0.495  0.49   Half down
	 *           8.80   0.605  0.60   Half down
	 *
	 * So in the below two-dimensional array, we test both rounding
	 * functions for all but these six anomalous amounts.  This means we are
	 * running 1000 * 2 - 6 tests.
	 */
	var tests = [
		/*From    To  Tax  Rounding fns*/
		[0.01,  0.07, .00, drhtz, drhfz],
		[0.08,  0.21, .01, drhtz, drhfz],
		[0.22,  0.36, .02, drhtz, drhfz],
		[0.37,  0.50, .03, drhtz, drhfz],
		[0.51,  0.65, .04, drhtz, drhfz],
		[0.66,  0.79, .05, drhtz, drhfz],
		[0.80,  0.80, .06,        drhfz],
		[0.81,  0.94, .06, drhtz, drhfz],
		[0.95,  1.09, .07, drhtz, drhfz],
		[1.10,  1.23, .08, drhtz, drhfz],
		[1.24,  1.38, .09, drhtz, drhfz],
		[1.39,  1.52, .10, drhtz, drhfz],
		[1.53,  1.67, .11, drhtz, drhfz],
		[1.68,  1.81, .12, drhtz, drhfz],
		[1.82,  1.96, .13, drhtz, drhfz],
		[1.97,  2.10, .14, drhtz, drhfz],
		[2.11,  2.25, .15, drhtz, drhfz],
		[2.26,  2.39, .16, drhtz, drhfz],
		[2.40,  2.40, .17,        drhfz],
		[2.41,  2.54, .17, drhtz, drhfz],
		[2.55,  2.69, .18, drhtz, drhfz],
		[2.70,  2.83, .19, drhtz, drhfz],
		[2.84,  2.98, .20, drhtz, drhfz],
		[2.99,  3.12, .21, drhtz, drhfz],
		[3.13,  3.27, .22, drhtz, drhfz],
		[3.28,  3.41, .23, drhtz, drhfz],
		[3.42,  3.56, .24, drhtz, drhfz],
		[3.57,  3.70, .25, drhtz, drhfz],
		[3.71,  3.85, .26, drhtz, drhfz],
		[3.86,  3.99, .27, drhtz, drhfz],
		[4.00,  4.00, .27, drhtz       ],
		[4.01,  4.14, .28, drhtz, drhfz],
		[4.15,  4.29, .29, drhtz, drhfz],
		[4.30,  4.43, .30, drhtz, drhfz],
		[4.44,  4.58, .31, drhtz, drhfz],
		[4.59,  4.72, .32, drhtz, drhfz],
		[4.73,  4.87, .33, drhtz, drhfz],
		[4.88,  5.01, .34, drhtz, drhfz],
		[5.02,  5.16, .35, drhtz, drhfz],
		[5.17,  5.30, .36, drhtz, drhfz],
		[5.31,  5.45, .37, drhtz, drhfz],
		[5.46,  5.59, .38, drhtz, drhfz],
		[5.60,  5.60, .38, drhtz       ],
		[5.61,  5.74, .39, drhtz, drhfz],
		[5.75,  5.89, .40, drhtz, drhfz],
		[5.90,  6.03, .41, drhtz, drhfz],
		[6.04,  6.18, .42, drhtz, drhfz],
		[6.19,  6.32, .43, drhtz, drhfz],
		[6.33,  6.47, .44, drhtz, drhfz],
		[6.48,  6.61, .45, drhtz, drhfz],
		[6.62,  6.76, .46, drhtz, drhfz],
		[6.77,  6.90, .47, drhtz, drhfz],
		[6.91,  7.05, .48, drhtz, drhfz],
		[7.06,  7.19, .49, drhtz, drhfz],
		[7.20,  7.20, .49, drhtz       ],
		[7.21,  7.34, .50, drhtz, drhfz],
		[7.35,  7.49, .51, drhtz, drhfz],
		[7.50,  7.63, .52, drhtz, drhfz],
		[7.64,  7.78, .53, drhtz, drhfz],
		[7.79,  7.92, .54, drhtz, drhfz],
		[7.93,  8.07, .55, drhtz, drhfz],
		[8.08,  8.21, .56, drhtz, drhfz],
		[8.22,  8.36, .57, drhtz, drhfz],
		[8.37,  8.50, .58, drhtz, drhfz],
		[8.51,  8.65, .59, drhtz, drhfz],
		[8.66,  8.79, .60, drhtz, drhfz],
		[8.80,  8.80, .60, drhtz       ],
		[8.81,  8.94, .61, drhtz, drhfz],
		[8.95,  9.09, .62, drhtz, drhfz],
		[9.10,  9.23, .63, drhtz, drhfz],
		[9.24,  9.38, .64, drhtz, drhfz],
		[9.39,  9.52, .65, drhtz, drhfz],
		[9.53,  9.67, .66, drhtz, drhfz],
		[9.68,  9.81, .67, drhtz, drhfz],
		[9.82,  9.96, .68, drhtz, drhfz],
		[9.97, 10.00, .69, drhtz, drhfz],
	];
	tests.forEach(function(test) {
		for (var i = test[0]; i <= test[1]; i = dadd(i, "0.01")) {
			test.slice(3).forEach(function(f) {
				var rule;
				switch (f) {
					case drhtz:
						rule = "toward zero";
						break;
					case drhfz:
						rule = "away from zero";
						break;
				}
				var t = f(dmul(i, "0.06875"), 2);
				it("correctly multiply " + i +
					" by 0.06875 and round " + rule +
					" to " + test[2], function() {
						assert.equal(t, test[2]);
				});
			});
		}
	});
});