import Vue from 'vue';
import mountComponent from 'spec/helpers/vue_mount_component_helper';
import { TEST_HOST } from 'spec/test_constants';
import BoardsSelector from '~/boards/components/boards_selector.vue';
import boardsStore from '~/boards/stores/boards_store';

const throttleDuration = 1;

function boardGenerator(n) {
  return new Array(n).fill().map((board, id) => {
    const name = `board${id}`;

    return {
      id,
      name,
    };
  });
}

describe('BoardsSelector', () => {
  let vm;
  let allBoardsResponse;
  let recentBoardsResponse;
  let fillSearchBox;
  const boards = boardGenerator(20);
  const recentBoards = boardGenerator(5);

  beforeEach(done => {
    setFixtures('<div class="js-boards-selector"></div>');
    window.gl = window.gl || {};

    boardsStore.setEndpoints({
      boardsEndpoint: '',
      recentBoardsEndpoint: '',
      listsEndpoint: '',
      bulkUpdatePath: '',
      boardId: '',
    });

    allBoardsResponse = Promise.resolve({
      data: boards,
    });
    recentBoardsResponse = Promise.resolve({
      data: recentBoards,
    });

    spyOn(boardsStore, 'allBoards').and.returnValue(allBoardsResponse);
    spyOn(boardsStore, 'recentBoards').and.returnValue(recentBoardsResponse);

    const Component = Vue.extend(BoardsSelector);
    vm = mountComponent(
      Component,
      {
        throttleDuration,
        currentBoard: {
          id: 1,
          name: 'Development',
          milestone_id: null,
          weight: null,
          assignee_id: null,
          labels: [],
        },
        milestonePath: `${TEST_HOST}/milestone/path`,
        boardBaseUrl: `${TEST_HOST}/board/base/url`,
        hasMissingBoards: false,
        canAdminBoard: true,
        multipleIssueBoardsAvailable: true,
        labelsPath: `${TEST_HOST}/labels/path`,
        projectId: 42,
        groupId: 19,
        scopedIssueBoardFeatureEnabled: true,
        weights: [],
      },
      document.querySelector('.js-boards-selector'),
    );

    // Emits gl-dropdown show event to simulate the dropdown is opened at initialization time
    vm.$children[0].$emit('show');

    Promise.all([allBoardsResponse, recentBoardsResponse])
      .then(() => vm.$nextTick())
      .then(done)
      .catch(done.fail);

    fillSearchBox = filterTerm => {
      const { searchBox } = vm.$refs;
      const searchBoxInput = searchBox.$el.querySelector('input');
      searchBoxInput.value = filterTerm;
      searchBoxInput.dispatchEvent(new Event('input'));
    };
  });

  afterEach(() => {
    vm.$destroy();
  });

  describe('filtering', () => {
    it('shows all boards without filtering', done => {
      vm.$nextTick()
        .then(() => {
          const dropdownItem = vm.$el.querySelectorAll('.js-dropdown-item');

          expect(dropdownItem.length).toBe(boards.length + recentBoards.length);
        })
        .then(done)
        .catch(done.fail);
    });

    it('shows only matching boards when filtering', done => {
      const filterTerm = 'board1';
      const expectedCount = boards.filter(board => board.name.includes(filterTerm)).length;

      fillSearchBox(filterTerm);

      vm.$nextTick()
        .then(() => {
          const dropdownItems = vm.$el.querySelectorAll('.js-dropdown-item');

          expect(dropdownItems.length).toBe(expectedCount);
        })
        .then(done)
        .catch(done.fail);
    });

    it('shows message if there are no matching boards', done => {
      fillSearchBox('does not exist');

      vm.$nextTick()
        .then(() => {
          const dropdownItems = vm.$el.querySelectorAll('.js-dropdown-item');

          expect(dropdownItems.length).toBe(0);
          expect(vm.$el).toContainText('No matching boards found');
        })
        .then(done)
        .catch(done.fail);
    });
  });

  describe('recent boards section', () => {
    it('shows only when boards are greater than 10', done => {
      vm.$nextTick()
        .then(() => {
          const headerEls = vm.$el.querySelectorAll('.dropdown-bold-header');

          const expectedCount = 2; // Recent + All

          expect(expectedCount).toBe(headerEls.length);
        })
        .then(done)
        .catch(done.fail);
    });

    it('does not show when boards are less than 10', done => {
      spyOn(vm, 'initScrollFade');
      spyOn(vm, 'setScrollFade');

      vm.$nextTick()
        .then(() => {
          vm.boards = vm.boards.slice(0, 5);
        })
        .then(vm.$nextTick)
        .then(() => {
          const headerEls = vm.$el.querySelectorAll('.dropdown-bold-header');
          const expectedCount = 0;

          expect(expectedCount).toBe(headerEls.length);
        })
        .then(done)
        .catch(done.fail);
    });

    it('does not show when recentBoards api returns empty array', done => {
      vm.$nextTick()
        .then(() => {
          vm.recentBoards = [];
        })
        .then(vm.$nextTick)
        .then(() => {
          const headerEls = vm.$el.querySelectorAll('.dropdown-bold-header');
          const expectedCount = 0;

          expect(expectedCount).toBe(headerEls.length);
        })
        .then(done)
        .catch(done.fail);
    });

    it('does not show when search is active', done => {
      fillSearchBox('Random string');

      vm.$nextTick()
        .then(() => {
          const headerEls = vm.$el.querySelectorAll('.dropdown-bold-header');
          const expectedCount = 0;

          expect(expectedCount).toBe(headerEls.length);
        })
        .then(done)
        .catch(done.fail);
    });
  });
});