import BigNumber from 'bignumber.js'
import { assert } from 'chai'

import { dropsToXrp } from '../../src/utils'

describe('dropsToXrp', function () {
  it('works with a typical amount', function () {
    const xrp = dropsToXrp('2000000')
    assert.strictEqual(xrp, '2', '2 million drops equals 2 XRP')
  })

  it('works with fractions', function () {
    let xrp = dropsToXrp('3456789')
    assert.strictEqual(xrp, '3.456789', '3,456,789 drops equals 3.456789 XRP')

    xrp = dropsToXrp('3400000')
    assert.strictEqual(xrp, '3.4', '3,400,000 drops equals 3.4 XRP')

    xrp = dropsToXrp('1')
    assert.strictEqual(xrp, '0.000001', '1 drop equals 0.000001 XRP')

    xrp = dropsToXrp('1.0')
    assert.strictEqual(xrp, '0.000001', '1.0 drops equals 0.000001 XRP')

    xrp = dropsToXrp('1.00')
    assert.strictEqual(xrp, '0.000001', '1.00 drops equals 0.000001 XRP')
  })

  it('works with zero', function () {
    let xrp = dropsToXrp('0')
    assert.strictEqual(xrp, '0', '0 drops equals 0 XRP')

    // negative zero is equivalent to zero
    xrp = dropsToXrp('-0')
    assert.strictEqual(xrp, '0', '-0 drops equals 0 XRP')

    xrp = dropsToXrp('0.00')
    assert.strictEqual(xrp, '0', '0.00 drops equals 0 XRP')

    xrp = dropsToXrp('000000000')
    assert.strictEqual(xrp, '0', '000000000 drops equals 0 XRP')
  })

  it('works with a negative value', function () {
    const xrp = dropsToXrp('-2000000')
    assert.strictEqual(xrp, '-2', '-2 million drops equals -2 XRP')
  })

  it('works with a value ending with a decimal point', function () {
    let xrp = dropsToXrp('2000000.')
    assert.strictEqual(xrp, '2', '2000000. drops equals 2 XRP')

    xrp = dropsToXrp('-2000000.')
    assert.strictEqual(xrp, '-2', '-2000000. drops equals -2 XRP')
  })

  it('works with BigNumber objects', function () {
    let xrp = dropsToXrp(new BigNumber(2000000))
    assert.strictEqual(xrp, '2', '(BigNumber) 2 million drops equals 2 XRP')

    xrp = dropsToXrp(new BigNumber(-2000000))
    assert.strictEqual(xrp, '-2', '(BigNumber) -2 million drops equals -2 XRP')

    xrp = dropsToXrp(new BigNumber(2345678))
    assert.strictEqual(
      xrp,
      '2.345678',
      '(BigNumber) 2,345,678 drops equals 2.345678 XRP',
    )

    xrp = dropsToXrp(new BigNumber(-2345678))
    assert.strictEqual(
      xrp,
      '-2.345678',
      '(BigNumber) -2,345,678 drops equals -2.345678 XRP',
    )
  })

  it('works with a number', function () {
    // This is not recommended. Use strings or BigNumber objects to avoid precision errors.
    let xrp = dropsToXrp(2000000)
    assert.strictEqual(xrp, '2', '(number) 2 million drops equals 2 XRP')
    xrp = dropsToXrp(-2000000)
    assert.strictEqual(xrp, '-2', '(number) -2 million drops equals -2 XRP')
  })

  it('works with scientific notation', function () {
    const xrp = dropsToXrp('1e6')
    assert.strictEqual(
      xrp,
      '1',
      '(scientific notation string) 1e6 drops equals 1 XRP',
    )
  })

  it('throws with an amount with too many decimal places', function () {
    assert.throws(() => {
      dropsToXrp('1.2')
    }, /has too many decimal places/u)

    assert.throws(() => {
      dropsToXrp('0.10')
    }, /has too many decimal places/u)
  })

  it('throws with an invalid value', function () {
    assert.throws(() => {
      dropsToXrp('FOO')
    }, /invalid value/u)

    assert.throws(() => {
      dropsToXrp('1e-7')
    }, /decimal place/u)

    assert.throws(() => {
      dropsToXrp('2,0')
    }, /invalid value/u)

    assert.throws(() => {
      dropsToXrp('.')
    }, /dropsToXrp: invalid value '\.', should be a BigNumber or string-encoded number\./u)
  })

  it('throws with an amount more than one decimal point', function () {
    assert.throws(() => {
      dropsToXrp('1.0.0')
    }, /dropsToXrp: invalid value '1\.0\.0'/u)

    assert.throws(() => {
      dropsToXrp('...')
    }, /dropsToXrp: invalid value '\.\.\.'/u)
  })
})
