/**
 * Test dependencies.
 */

'use strict';

const start = require('./common');

const Aggregate = require('../lib/aggregate');
const assert = require('assert');
const random = require('./util').random;

const mongoose = start.mongoose;
const Schema = mongoose.Schema;

/**
 * Setup.
 */

const userSchema = new Schema({
  name: String,
  age: Number
});

describe('model aggregate', function() {
  this.timeout(4500);

  const group = { $group: { _id: null, maxAge: { $max: '$age' } } };
  const project = { $project: { maxAge: 1, _id: 0 } };
  let db, A, maxAge;

  before(async function() {
    db = start();
    A = db.model('Test', userSchema);

    const authors = 'guillermo nathan tj damian marco'.split(' ');
    const num = 10;
    const docs = [];
    maxAge = 0;


    for (let i = 0; i < num; ++i) {
      const age = Math.random() * 100 | 0;
      maxAge = Math.max(maxAge, age);
      docs.push({ author: authors[i % authors.length], age: age });
    }

    await A.create(docs);
  });

  after(async function() {
    await db.close();
  });

  describe('works', function() {
    it('when return promise', async function() {
      const res = await A.aggregate([group, project]);

      assert.ok(res);
      assert.equal(1, res.length);
      assert.ok('maxAge' in res[0]);
      assert.equal(maxAge, res[0].maxAge);
    });

    it('with arrays', async function() {
      const res = await A.aggregate([group, project]);

      assert.ok(res);
      assert.equal(res.length, 1);
      assert.ok('maxAge' in res[0]);
      assert.equal(res[0].maxAge, maxAge);
    });

    it('with Aggregate syntax', async function() {
      const res = await A.aggregate()
        .group(group.$group)
        .project(project.$project)
        .exec();

      assert.ok(res);
      assert.equal(res.length, 1);
      assert.ok('maxAge' in res[0]);
      assert.equal(res[0].maxAge, maxAge);
    });

    it('with Aggregate syntax if callback not provided', async function() {
      const promise = A.aggregate()
        .group(group.$group)
        .project(project.$project)
        .exec();

      const res = await promise;

      assert.ok(promise instanceof Promise);
      assert.ok(res);
      assert.equal(res.length, 1);
      assert.ok('maxAge' in res[0]);
      assert.equal(maxAge, res[0].maxAge);
    });

    it('when returning Aggregate', function() {
      assert(A.aggregate([project]) instanceof Aggregate);
    });

    it('can use helper for $out', async function() {
      const outputCollection = 'aggregate_output_' + random();
      await A.aggregate()
        .group(group.$group)
        .project(project.$project)
        .out(outputCollection)
        .exec();

      const documents = await A.db.collection(outputCollection).find().toArray();

      assert.equal(documents.length, 1);
      assert.ok('maxAge' in documents[0]);
      assert.equal(maxAge, documents[0].maxAge);
    });
  });
});