const assert = require('assert')
const math = require('../../src/main')
const approx = require('../../tools/approx')
const number = math.number

describe('number', function () {
  it('should be 0 if called with no argument', function () {
    approx.equal(number(), 0)
  })

  it('should convert a boolean to a number', function () {
    approx.equal(number(true), 1)
    approx.equal(number(false), 0)
  })

  it('should convert null to a number', function () {
    approx.equal(number(null), 0)
  })

  it('should convert a bignumber to a number', function () {
    approx.equal(number(math.bignumber(0.1)), 0.1)
    approx.equal(number(math.bignumber('1.3e500')), Infinity)
  })

  it('should convert a fraction to a number', function () {
    approx.equal(number(math.fraction(2, 5)), 0.4)
  })

  it('should accept a number as argument', function () {
    approx.equal(number(3), 3)
    approx.equal(number(-3), -3)
  })

  it('should convert a unit to a number', function () {
    approx.equal(number(math.unit('52cm'), 'm'), 0.52)
  })

  it('should parse the string if called with a valid string', function () {
    approx.equal(number('2.1e3'), 2100)
    approx.equal(number(' 2.1e-3 '), 0.0021)
    approx.equal(number(''), 0)
    approx.equal(number(' '), 0)
  })

  it('should throw an error if called with an invalid string', function () {
    assert.throws(function () { number('2.3.4') }, SyntaxError)
    assert.throws(function () { number('23a') }, SyntaxError)
  })

  it('should convert the elements of a matrix to numbers', function () {
    assert.deepEqual(number(math.matrix(['123', true])), math.matrix([123, 1]))
  })

  it('should convert the elements of an array to numbers', function () {
    assert.deepEqual(number(['123', true]), [123, 1])
  })

  it('should throw an error if called with a wrong number of arguments', function () {
    assert.throws(function () { number(1, 2, 3) }, /TypeError: Too many arguments/)
  })

  it('should throw an error if called with a complex number', function () {
    assert.throws(function () { number(math.complex(2, 3)) }, TypeError)
  })

  it('should throw an error with wrong type of arguments', function () {
    assert.throws(function () { number(math.unit('5cm')) }, /Second argument with valueless unit expected/)
    // assert.throws(function () {number(math.unit('5cm'), 2)}, TypeError); // FIXME: this should also throw an error
    assert.throws(function () { number(math.unit('5cm'), new Date()) }, TypeError)
    assert.throws(function () { number('23', 2) }, TypeError)
  })

  it('should LaTeX number', function () {
    const expr1 = math.parse('number()')
    const expr2 = math.parse('number(1)')
    const expr3 = math.parse('number(1,cm)')

    assert.equal(expr1.toTex(), '0')
    assert.equal(expr2.toTex(), '\\left(1\\right)')
    assert.equal(expr3.toTex(), '\\left(\\left(1\\right)\\mathrm{cm}\\right)')
  })
})