var assert = require('assert'),
    math = require('../../../index.js'),
    approx = require('../../../tools/approx.js'),
    pi = math.pi,
    complex = math.complex,
    matrix = math.matrix,
    unit = math.unit,
    csc = math.csc;

describe('csc', function() {
  it('should return the cosecant of a boolean', function () {
    approx.equal(csc(true), 1.18839510577812);
    approx.equal(csc(false), Infinity);
  });

  it('should return the cosecant of a number', function() {
    approx.equal(1 / csc(0), 0);
    approx.equal(1 / csc(pi*1/4), 0.707106781186548);
    approx.equal(1 / csc(pi*1/8), 0.382683432365090);
    approx.equal(1 / csc(pi*2/4), 1);
    approx.equal(1 / csc(pi*3/4), 0.707106781186548);
    approx.equal(1 / csc(pi*4/4), 0);
    approx.equal(1 / csc(pi*5/4), -0.707106781186548);
    approx.equal(1 / csc(pi*6/4), -1);
    approx.equal(1 / csc(pi*7/4), -0.707106781186548);
    approx.equal(1 / csc(pi*8/4), 0);
    approx.equal(1 / csc(pi/4), math.sqrt(2)/2);
  });

  it('should return the cosecant of a complex number', function() {
    var re = 0.0904732097532074;
    var im = 0.0412009862885741;
    approx.deepEqual(csc(complex('2+3i')), complex(re, im));
    approx.deepEqual(csc(complex('2-3i')), complex(re, -im));
    approx.deepEqual(csc(complex('-2+3i')), complex(-re, im));
    approx.deepEqual(csc(complex('-2-3i')), complex(-re, -im));
    approx.deepEqual(csc(complex('i')), complex(0, -0.850918128239322));
    approx.deepEqual(csc(complex('1')), complex(1.18839510577812, 0));
    approx.deepEqual(csc(complex('1+i')), complex(0.621518017170428, -0.303931001628426));
  });

  it('should return the cosecant of an angle', function() {
    approx.equal(csc(unit('45deg')), 1.41421356237310);
    approx.equal(csc(unit('-45deg')), -1.41421356237310);
  });

  it('should throw an error if called with an invalid unit', function() {
    assert.throws(function () {csc(unit('5 celsius'))});
  });

  it('should throw an error if called with a string', function() {
    assert.throws(function () {csc('string')});
  });

  var csc123 = [1.18839510577812, 1.09975017029462, 7.08616739573719];

  it('should return the cosecant of each element of an array', function() {
    approx.deepEqual(csc([1,2,3]), csc123);
  });

  it('should return the cosecant of each element of a matrix', function() {
    approx.deepEqual(csc(matrix([1,2,3])), matrix(csc123));
  });

});