yumechi-no-kuni/src/api/endpoints/posts/likes/delete.ts

/**
 * Module dependencies
 */
import $ from 'cafy';
import Like from '../../../models/like';
import Post from '../../../models/post';
import User from '../../../models/user';
// import event from '../../../event';

/**
 * Unlike a post
 *
 * @param {any} params
 * @param {any} user
 * @return {Promise<any>}
 */
module.exports = (params, user) => new Promise(async (res, rej) => {
	// Get 'post_id' parameter
	const [postId, postIdErr] = $(params.post_id).id().$;
	if (postIdErr) return rej('invalid post_id param');

	// Get likee
	const post = await Post.findOne({
		_id: postId
	});

	if (post === null) {
		return rej('post not found');
	}

	// if already liked
	const exist = await Like.findOne({
		post_id: post._id,
		user_id: user._id,
		deleted_at: { $exists: false }
	});

	if (exist === null) {
		return rej('already not liked');
	}

	// Delete like
	await Like.update({
		_id: exist._id
	}, {
			$set: {
				deleted_at: new Date()
			}
		});

	// Send response
	res();

	// Decrement likes count
	Post.update({ _id: post._id }, {
		$inc: {
			likes_count: -1
		}
	});

	// Decrement user likes count
	User.update({ _id: user._id }, {
		$inc: {
			likes_count: -1
		}
	});

	// Decrement user liked count
	User.update({ _id: post.user_id }, {
		$inc: {
			liked_count: -1
		}
	});
});