var assert = require('assert'),
    error = require('../../../lib/error/index'),
    math = require('../../../index'),
    approx = require('../../../tools/approx'),
    pi = math.pi,
    complex = math.complex,
    matrix = math.matrix,
    unit = math.unit,
    csch = math.csch,
    bigmath = math.create({precision: 20}),
    biggermath = math.create({number: 'BigNumber', precision: 22});

describe('csch', function() {
  it('should return the csch of a boolean', function () {
    approx.equal(csch(true), 0.85091812823932);
    approx.equal(csch(false), Number.POSITIVE_INFINITY);
  });

  it('should return the csch of null', function () {
    approx.equal(csch(null), Number.POSITIVE_INFINITY);
  });

  it('should return the csch of a number', function() {
    approx.equal(csch(0), Number.POSITIVE_INFINITY);
    approx.equal(csch(pi), 0.086589537530047);
    approx.equal(csch(1), 0.85091812823932);
    approx.equal(csch(2), 0.27572056477178);
    approx.equal(csch(3), 0.099821569668823);
    approx.equal(csch(1e-22), Number.POSITIVE_INFINITY);
    approx.equal(csch(-1e-22), Number.NEGATIVE_INFINITY);
  });

  it('should return the csch of a bignumber', function() {
    var cschBig = bigmath.csch;
    var Big = bigmath.bignumber;

    assert.deepEqual(cschBig(Big(0)).toString(), 'Infinity');
    assert.deepEqual(cschBig(Big(1)), Big('0.85091812823932154512'));
    assert.deepEqual(cschBig(Big(2)), Big('0.27572056477178320776'));
    assert.deepEqual(cschBig(Big(3)), Big('0.099821569668822732851'));

    /* Pass in extra digits to pi. */
    assert.deepEqual(cschBig(biggermath.pi).toString(), '0.086589537530046941828');
  });

  it('should return the csch of a complex number', function() {
    approx.deepEqual(csch(complex('1')), complex(0.85091812823932, 0));
    approx.deepEqual(csch(complex('i')), complex(0, -1.1883951057781));
    approx.deepEqual(csch(complex('2 + i')), complex(0.14136302161241, -0.22837506559969));
  });

  it('should return the csch of an angle', function() {
    approx.equal(csch(unit('90deg')), 0.4345372080947);
    approx.equal(csch(unit('-45deg')), -1.1511838709208);

    assert(csch(unit(math.bignumber(90), 'deg')).isBigNumber);
    approx.equal(csch(unit(math.bignumber(90), 'deg')).toNumber(), 0.4345372080947);

    approx.deepEqual(csch(unit(complex('2 + i'), 'rad')), complex(0.14136302161241, -0.22837506559969));
  });

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

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

  var csch123 = [0.85091812823932, 0.27572056477178, 0.099821569668823];

  it('should return the csch of each element of an array', function() {
    approx.deepEqual(csch([1,2,3]), csch123);
  });

  it('should return the csch of each element of a matrix', function() {
    approx.deepEqual(csch(matrix([1,2,3])), matrix(csch123));
  });

  it('should throw an error in case of invalid number of arguments', function() {
    assert.throws(function () {csch()}, /TypeError: Too few arguments/);
    assert.throws(function () {csch(1, 2)}, /TypeError: Too many arguments/);
  });

  it('should LaTeX csch', function () {
    var expression = math.parse('csch(1)');
    assert.equal(expression.toTex(), '\\mathrm{csch}\\left(1\\right)');
  });
});
