Add metrics

src/analytics/users_counter.ts

@@ -0,0 +1,41 @@
+export default class UsersCounter {
+    static bots: {[key: string]: Set<number>} = {};
+    static allUsers: Set<number> = new Set();
+
+    static take(userId: number, bot: string) {
+        const isExists = this.bots[bot];
+
+        if (!isExists) {
+            this.bots[bot] = new Set();
+        }
+
+        this.bots[bot].add(userId);
+        this.allUsers.add(userId);
+    }
+
+    static getAllUsersCount(): number {
+        return this.allUsers.size;
+    }
+
+    static getUsersByBots(): {[bot: string]: number} {
+        const result: {[bot: string]: number} = {};
+
+        Object.keys(this.bots).forEach((bot: string) => result[bot] = this.bots[bot].size);
+
+        return result;
+    }
+
+    static getMetrics(): string {
+        const lines = [];
+
+        lines.push(`all_users_count ${this.getAllUsersCount()}`);
+
+        const usersByBots = this.getUsersByBots();
+
+        Object.keys(usersByBots).forEach((bot: string) => {
+            lines.push(`users_count{bot="${bot}"} ${usersByBots[bot]}`)
+        });
+
+        return lines.join("\n");
+    }
+}