refactoring

Resolve #7779

packages/backend/src/server/api/endpoints/users/get-frequently-replied-users.ts

@@ -0,0 +1,105 @@
+import $ from 'cafy';
+import { ID } from '@/misc/cafy-id';
+import define from '../../define';
+import { maximum } from '@/prelude/array';
+import { ApiError } from '../../error';
+import { getUser } from '../../common/getters';
+import { Not, In, IsNull } from 'typeorm';
+import { Notes, Users } from '@/models/index';
+
+export const meta = {
+	tags: ['users'],
+
+	requireCredential: false as const,
+
+	params: {
+		userId: {
+			validator: $.type(ID),
+		},
+
+		limit: {
+			validator: $.optional.num.range(1, 100),
+			default: 10
+		},
+	},
+
+	res: {
+		type: 'array' as const,
+		optional: false as const, nullable: false as const,
+		items: {
+			type: 'object' as const,
+			optional: false as const, nullable: false as const,
+			ref: 'User',
+		}
+	},
+
+	errors: {
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: 'e6965129-7b2a-40a4-bae2-cd84cd434822'
+		}
+	}
+};
+
+export default define(meta, async (ps, me) => {
+	// Lookup user
+	const user = await getUser(ps.userId).catch(e => {
+		if (e.id === '15348ddd-432d-49c2-8a5a-8069753becff') throw new ApiError(meta.errors.noSuchUser);
+		throw e;
+	});
+
+	// Fetch recent notes
+	const recentNotes = await Notes.find({
+		where: {
+			userId: user.id,
+			replyId: Not(IsNull())
+		},
+		order: {
+			id: -1
+		},
+		take: 1000,
+		select: ['replyId']
+	});
+
+	// 投稿が少なかったら中断
+	if (recentNotes.length === 0) {
+		return [];
+	}
+
+	// TODO ミュートを考慮
+	const replyTargetNotes = await Notes.find({
+		where: {
+			id: In(recentNotes.map(p => p.replyId)),
+		},
+		select: ['userId']
+	});
+
+	const repliedUsers: any = {};
+
+	// Extract replies from recent notes
+	for (const userId of replyTargetNotes.map(x => x.userId.toString())) {
+		if (repliedUsers[userId]) {
+			repliedUsers[userId]++;
+		} else {
+			repliedUsers[userId] = 1;
+		}
+	}
+
+	// Calc peak
+	const peak = maximum(Object.values(repliedUsers));
+
+	// Sort replies by frequency
+	const repliedUsersSorted = Object.keys(repliedUsers).sort((a, b) => repliedUsers[b] - repliedUsers[a]);
+
+	// Extract top replied users
+	const topRepliedUsers = repliedUsersSorted.slice(0, ps.limit!);
+
+	// Make replies object (includes weights)
+	const repliesObj = await Promise.all(topRepliedUsers.map(async (user) => ({
+		user: await Users.pack(user, me, { detail: true }),
+		weight: repliedUsers[user] / peak
+	})));
+
+	return repliesObj;
+});