var assert = require('assert');
var moment = require('moment');
var DataSet = require('../lib/DataSet');
var DataView = require('../lib/DataView');

// TODO: improve DataView tests, split up in one test per function
describe('DataView', function () {
  it('should work', function () {
    var groups = new DataSet();

// add items with different groups
    groups.add([
      {id: 1, content: 'Item 1', group: 1},
      {id: 2, content: 'Item 2', group: 2},
      {id: 3, content: 'Item 3', group: 2},
      {id: 4, content: 'Item 4', group: 1},
      {id: 5, content: 'Item 5', group: 3}
    ]);

    var group2 = new DataView(groups, {
      filter: function (item) {
        return item.group == 2;
      }
    });

// test getting the filtered data
    assert.deepEqual(group2.get(), [
      {id: 2, content: 'Item 2', group: 2},
      {id: 3, content: 'Item 3', group: 2}
    ]);
    assert.equal(group2.length, 2);

// test filtering the view contents
    assert.deepEqual(group2.get({
      filter: function (item) {
        return item.id > 2;
      }
    }), [
      {id: 3, content: 'Item 3', group: 2}
    ]);

// test event subscription
    var groupsTriggerCount = 0;
    groups.on('*', function () {
      groupsTriggerCount++;
    });
    var group2TriggerCount = 0;
    group2.on('*', function () {
      group2TriggerCount++;
    });

    groups.update({id:2, content: 'Item 2 (changed)'});
    assert.equal(groupsTriggerCount, 1);
    assert.equal(group2TriggerCount, 1);
    assert.equal(group2.length, 2);

    groups.update({id:5, content: 'Item 5 (changed)'});
    assert.equal(groupsTriggerCount, 2);
    assert.equal(group2TriggerCount, 1);
    assert.equal(group2.length, 2);

// detach the view from groups
    group2.setData(null);
    assert.equal(groupsTriggerCount, 2);
    assert.equal(group2TriggerCount, 2);
    assert.equal(group2.length, 0);

    groups.update({id:2, content: 'Item 2 (changed again)'});
    assert.equal(groupsTriggerCount, 3);
    assert.equal(group2TriggerCount, 2);

    // test updating of .length property
    group2.setData(groups);
    assert.equal(group2.length, 2);

    // add a new item
    groups.add({id: 6, content: 'Item 6', group: 2});
    assert.equal(group2.length, 3);

    // change an items group to 2
    groups.update({id: 4, group: 2});
    assert.equal(group2.length, 4);

    // change an items group to 1
    groups.update({id: 4, group: 1});
    assert.equal(group2.length, 3);

    // remove an item
    groups.remove(2);
    assert.equal(group2.length, 2);

    // remove all items
    groups.clear();
    assert.equal(group2.length, 0);
  });

});