var assert = require('assert')
var deepEqual = require('deep-equal')
var parse = require('..')

describe('parseRange(len, str)', function () {
  it('should reject non-string str', function () {
    assert.throws(parse.bind(null, 200, {}),
      /TypeError: argument str must be a string/)
  })

  it('should return -2 for invalid str', function () {
    assert.strictEqual(parse(200, 'malformed'), -2)
  })

  it('should return -1 if all specified ranges are invalid', function () {
    assert.strictEqual(parse(200, 'bytes=500-20'), -1)
    assert.strictEqual(parse(200, 'bytes=500-999'), -1)
    assert.strictEqual(parse(200, 'bytes=500-999,1000-1499'), -1)
  })

  it('should parse str', function () {
    var range = parse(1000, 'bytes=0-499')
    assert.strictEqual(range.type, 'bytes')
    assert.strictEqual(range.length, 1)
    deepEqual(range[0], { start: 0, end: 499 })
  })

  it('should cap end at size', function () {
    var range = parse(200, 'bytes=0-499')
    assert.strictEqual(range.type, 'bytes')
    assert.strictEqual(range.length, 1)
    deepEqual(range[0], { start: 0, end: 199 })
  })

  it('should parse str', function () {
    var range = parse(1000, 'bytes=40-80')
    assert.strictEqual(range.type, 'bytes')
    assert.strictEqual(range.length, 1)
    deepEqual(range[0], { start: 40, end: 80 })
  })

  it('should parse str asking for last n bytes', function () {
    var range = parse(1000, 'bytes=-400')
    assert.strictEqual(range.type, 'bytes')
    assert.strictEqual(range.length, 1)
    deepEqual(range[0], { start: 600, end: 999 })
  })

  it('should parse str with only start', function () {
    var range = parse(1000, 'bytes=400-')
    assert.strictEqual(range.type, 'bytes')
    assert.strictEqual(range.length, 1)
    deepEqual(range[0], { start: 400, end: 999 })
  })

  it('should parse "bytes=0-"', function () {
    var range = parse(1000, 'bytes=0-')
    assert.strictEqual(range.type, 'bytes')
    assert.strictEqual(range.length, 1)
    deepEqual(range[0], { start: 0, end: 999 })
  })

  it('should parse str with no bytes', function () {
    var range = parse(1000, 'bytes=0-0')
    assert.strictEqual(range.type, 'bytes')
    assert.strictEqual(range.length, 1)
    deepEqual(range[0], { start: 0, end: 0 })
  })

  it('should parse str asking for last byte', function () {
    var range = parse(1000, 'bytes=-1')
    assert.strictEqual(range.type, 'bytes')
    assert.strictEqual(range.length, 1)
    deepEqual(range[0], { start: 999, end: 999 })
  })

  it('should parse str with multiple ranges', function () {
    var range = parse(1000, 'bytes=40-80,81-90,-1')
    assert.strictEqual(range.type, 'bytes')
    assert.strictEqual(range.length, 3)
    deepEqual(range[0], { start: 40, end: 80 })
    deepEqual(range[1], { start: 81, end: 90 })
    deepEqual(range[2], { start: 999, end: 999 })
  })

  it('should parse str with some invalid ranges', function () {
    var range = parse(200, 'bytes=0-499,1000-,500-999')
    assert.strictEqual(range.type, 'bytes')
    assert.strictEqual(range.length, 1)
    deepEqual(range[0], { start: 0, end: 199 })
  })

  it('should parse non-byte range', function () {
    var range = parse(1000, 'items=0-5')
    assert.strictEqual(range.type, 'items')
    assert.strictEqual(range.length, 1)
    deepEqual(range[0], { start: 0, end: 5 })
  })

  describe('when combine: true', function () {
    it('should combine overlapping ranges', function () {
      var range = parse(150, 'bytes=0-4,90-99,5-75,100-199,101-102', { combine: true })
      assert.strictEqual(range.type, 'bytes')
      assert.strictEqual(range.length, 2)
      deepEqual(range[0], { start: 0, end: 75 })
      deepEqual(range[1], { start: 90, end: 149 })
    })

    it('should retain original order', function () {
      var range = parse(150, 'bytes=-1,20-100,0-1,101-120', { combine: true })
      assert.strictEqual(range.type, 'bytes')
      assert.strictEqual(range.length, 3)
      deepEqual(range[0], { start: 149, end: 149 })
      deepEqual(range[1], { start: 20, end: 120 })
      deepEqual(range[2], { start: 0, end: 1 })
    })
  })
})