feat(server): consolidate feedback stats (#713)

server/src/feedback/feedback-stats/feedback-stats.service.ts

@@ -1,60 +1,28 @@
 import { Injectable } from '@nestjs/common';
 import { FeedbackDbService } from '../feedback-db/feedback-db.service';
-
-type FeedbackHistory = {
-  createdAt: number;
-  updatedAt: number;
-  requested: boolean;
-  shared: boolean;
-  status: 'pending' | 'done';
-};
+import { FeedbackHistory } from './feedback-stats.types';
+import { buildHistoryByMonth, buildHistoryByMonthStats, buildHistoryStats } from './feedback-stats.utils';
 
 @Injectable()
 export class FeedbackStatsService {
-  /**
-   * List of unique users who have given at least 1 feedback
-   */
-  private giverEmailList = new Set<string>();
-
-  /**
-   * List of unique users who have received at least 1 feedback
-   */
-  private receiverEmailList = new Set<string>();
-
-  /**
-   * List of unique users who have given of received at least 1 feedback
-   */
-  private allEmailList = new Set<string>();
-
   private history = new Map<string, FeedbackHistory>();
 
   constructor(private feedbackDbService: FeedbackDbService) {
     this.feedbackDbService.onFeedbackChanges((feedbacks) => {
-      feedbacks.forEach(({ giverEmail, receiverEmail, requested, status }) => {
-        // For feedback requests, the `giverEmail` is not to be taken into account until he has replied.
-        if (!requested || status === 'done') {
-          this.giverEmailList.add(giverEmail);
-          this.allEmailList.add(giverEmail);
-        }
-
-        this.receiverEmailList.add(receiverEmail);
-        this.allEmailList.add(receiverEmail);
-      });
-
-      feedbacks.forEach(({ id, createdAt, updatedAt, requested, shared, status }) =>
-        this.history.set(id, { createdAt, updatedAt, requested, shared, status }),
+      feedbacks.forEach(({ id, giverEmail, receiverEmail, shared, requested, status, createdAt, updatedAt }) =>
+        this.history.set(id, { giverEmail, receiverEmail, shared, requested, status, createdAt, updatedAt }),
       );
     });
   }
 
   // Note that the first call to this method will trigger service creation and data supply.
   // As the method's return is synchronous, it's possible that there will be no data for the first few calls.
   getStats() {
+    const history = Array.from(this.history.values());
+
     return {
-      numberOfUniqueGivers: this.giverEmailList.size,
-      numberOfUniqueReceivers: this.receiverEmailList.size,
-      numberOfUniqueUsers: this.allEmailList.size,
-      history: Array.from(this.history.values()),
+      summary: buildHistoryStats(history),
+      details: buildHistoryByMonthStats(buildHistoryByMonth(history)),
     };
   }
 }

server/src/feedback/feedback-stats/feedback-stats.types.ts

@@ -0,0 +1,24 @@
+export type FeedbackHistory = {
+  giverEmail: string;
+  receiverEmail: string;
+  shared: boolean;
+  requested: boolean;
+  status: 'pending' | 'done';
+  createdAt: number;
+  updatedAt: number;
+};
+
+export type FeedbackHistoryStats = {
+  // User stats
+  uniqueGivers: number;
+  uniqueReceivers: number;
+  uniqueUsers: number;
+
+  // Feedback stats
+  spontaneousFeedback: number;
+  requestedFeedbackDone: number;
+  requestedFeedbackPending: number;
+  sharedFeedback: number;
+};
+
+export type FeedbackMonthHistoryStats = { month: string } & FeedbackHistoryStats;

server/src/feedback/feedback-stats/feedback-stats.utils.ts

@@ -0,0 +1,77 @@
+import { FeedbackHistory, FeedbackHistoryStats, FeedbackMonthHistoryStats } from './feedback-stats.types';
+
+export const buildHistoryStats = (history: FeedbackHistory[]): FeedbackHistoryStats => {
+  // List of unique users who have given at least 1 feedback
+  const giverEmailList = new Set<string>();
+
+  // List of unique users who have received at least 1 feedback (including users with pending feedback requests)
+  const receiverEmailList = new Set<string>();
+
+  // List of unique users who have given, received or requested at least 1 feedback
+  const allEmailList = new Set<string>();
+
+  let spontaneousFeedback = 0;
+  let requestedFeedbackDone = 0;
+  let requestedFeedbackPending = 0;
+  let sharedFeedback = 0;
+
+  history.forEach(({ giverEmail, receiverEmail, requested, status, shared }) => {
+    // For feedback requests, the `giverEmail` is not to be taken into account until he has replied.
+    if (!requested || status === 'done') {
+      giverEmailList.add(giverEmail);
+      allEmailList.add(giverEmail);
+    }
+
+    receiverEmailList.add(receiverEmail);
+    allEmailList.add(receiverEmail);
+
+    if (!requested) {
+      spontaneousFeedback += 1;
+    } else if (status === 'done') {
+      requestedFeedbackDone += 1;
+    } else {
+      requestedFeedbackPending += 1;
+    }
+
+    if (shared) {
+      sharedFeedback += 1;
+    }
+  });
+
+  return {
+    uniqueGivers: giverEmailList.size,
+    uniqueReceivers: receiverEmailList.size,
+    uniqueUsers: allEmailList.size,
+
+    spontaneousFeedback,
+    requestedFeedbackDone,
+    requestedFeedbackPending,
+    sharedFeedback,
+  };
+};
+
+// timestamp                    -> 1728166612791
+// toLocaleDateString('fr-FR')  -> '06/10/2024'
+// split/reverse/slice/join     -> '2024-10'
+const toYYYMM = (timestamp: number) =>
+  new Date(timestamp).toLocaleDateString('fr-FR').split('/').reverse().slice(0, 2).join('-');
+
+export const buildHistoryByMonth = (history: FeedbackHistory[]): Record<string, FeedbackHistory[]> =>
+  history.reduce(
+    (historyByMonth, event) => {
+      const month = toYYYMM(!event.requested || event.status === 'done' ? event.updatedAt : event.createdAt);
+
+      historyByMonth[month] ??= [];
+      historyByMonth[month].push(event);
+
+      return historyByMonth;
+    },
+    {} as Record<string, FeedbackHistory[]>,
+  );
+
+export const buildHistoryByMonthStats = (
+  historyByMonth: Record<string, FeedbackHistory[]>,
+): FeedbackMonthHistoryStats[] =>
+  Object.entries(historyByMonth)
+    .map(([month, history]) => ({ month, ...buildHistoryStats(history) }))
+    .sort(({ month: a }, { month: b }) => (a < b ? -1 : a > b ? 1 : 0));