const db = uniCloud.database();
const _ = db.command;

module.exports = {
	_before: function () {

	},

	async likeArticle(query) {
		let user_id = query.user_id;
		let article_id = query.article_id;
		let datetime = new Date().getTime();
		
		const transaction = await db.startTransaction();
		try {
			const exist = await transaction.collection('cms-articles-like')
				.where({
					user_id: user_id,
					article_id: article_id,
					create_time: datetime
				}).count();

			if (exist.total > 0) throw new Error('已点喜欢');

			await transaction.collection('cms-articles-like').add({
				user_id: user_id,
				article_id: article_id,
				create_time: datetime
				
			});

			await transaction.collection('uni-cms-articles').doc(article_id)
				.update({
					like_count: _.inc(1)
				});

			await transaction.commit();
			return {
				code: 200
			};
		} catch (e) {
			await transaction.rollback();
			return {
				code: 500,
				msg: e.message
			};
		}
	},

	async relikeArticle(query) {
		
		try {
			let user_id = query.user_id;
			let article_id = query.article_id;
			let datetime = new Date().getTime();
			
			const likeRes = await db.collection('cms-articles-like')
				.where({
					user_id: user_id,
					article_id: article_id,
				}).remove();

			if (likeRes.deleted === 0) throw new Error('未找到点赞记录');

			await db.collection('uni-cms-articles').doc(article_id)
				.update({
					like_count: _.inc(-1)
				});

			return {
				code: 200
			};
		} catch (e) {
			return {
				code: 500,
				msg: e.message
			};
		}
	},
}