import { assert, UnitTest } from '@ephox/bedrock';
import { Arr, Fun, Option } from '@ephox/katamari';
import * as PositionArray from 'ephox/polaris/api/PositionArray';
import { PArrayTestItem } from '../../module/ephox/polaris/test/Parrays';

UnitTest.test('api.PositionArray.generate', function () {
  const generator = function (item: string, start: number): Option<PArrayTestItem> {
    const firstletter = item[0];
    if (firstletter === 'a') { return Option.none(); }
    return Option.some({
      start: Fun.constant(start),
      finish: Fun.constant(start + item.length),
      item: Fun.constant(item)
    });
  };

  const check = function (expected: string[], input: string[], start?: number) {
    const result = PositionArray.generate(input, generator, start);
    assert.eq(expected, Arr.map(result, function (item) {
      return item.start() + '->' + item.finish() + '@ ' + item.item();
    }));
  };

  check([
    '0->3@ cat',
    '3->6@ dog',
    '6->11@ mogel',
    '11->11@ ',
    '11->13@ hi'
  ], [ 'cat', 'dog', 'ab', 'mogel', '', 'hi' ]);

  check([
    '10->13@ cat',
    '13->16@ dog',
    '16->21@ mogel',
    '21->21@ ',
    '21->23@ hi'
  ], [ 'cat', 'dog', 'ab', 'mogel', '', 'hi' ], 10);
});