Introduce processor

src/server/api/endpoints/aggregation/users/following.ts

@@ -0,0 +1,73 @@
+/**
+ * Module dependencies
+ */
+import $ from 'cafy';
+import User from '../../../models/user';
+import Following from '../../../models/following';
+
+/**
+ * Aggregate following of a user
+ *
+ * @param {any} params
+ * @return {Promise<any>}
+ */
+module.exports = (params) => new Promise(async (res, rej) => {
+	// Get 'user_id' parameter
+	const [userId, userIdErr] = $(params.user_id).id().$;
+	if (userIdErr) return rej('invalid user_id param');
+
+	// Lookup user
+	const user = await User.findOne({
+		_id: userId
+	}, {
+		fields: {
+			_id: true
+		}
+	});
+
+	if (user === null) {
+		return rej('user not found');
+	}
+
+	const startTime = new Date(new Date().setMonth(new Date().getMonth() - 1));
+
+	const following = await Following
+		.find({
+			follower_id: user._id,
+			$or: [
+				{ deleted_at: { $exists: false } },
+				{ deleted_at: { $gt: startTime } }
+			]
+		}, {
+			_id: false,
+			follower_id: false,
+			followee_id: false
+		}, {
+			sort: { created_at: -1 }
+		});
+
+	const graph = [];
+
+	for (let i = 0; i < 30; i++) {
+		let day = new Date(new Date().setDate(new Date().getDate() - i));
+		day = new Date(day.setMilliseconds(999));
+		day = new Date(day.setSeconds(59));
+		day = new Date(day.setMinutes(59));
+		day = new Date(day.setHours(23));
+
+		const count = following.filter(f =>
+			f.created_at < day && (f.deleted_at == null || f.deleted_at > day)
+		).length;
+
+		graph.push({
+			date: {
+				year: day.getFullYear(),
+				month: day.getMonth() + 1, // In JavaScript, month is zero-based.
+				day: day.getDate()
+			},
+			count: count
+		});
+	}
+
+	res(graph);
+});