email sent when personal information changed

backend/services/email/core/EmailClient.js

@@ -11,8 +11,16 @@ const { htmlToPlainText } = require("./emailUtils");
  */
 class EmailClient {
   constructor() {
+    // Singleton pattern - return existing instance if already created
+    if (EmailClient.instance) {
+      return EmailClient.instance;
+    }
+
     this.sesClient = null;
     this.initialized = false;
+    this.initializationPromise = null;
+
+    EmailClient.instance = this;
   }
 
   /**
@@ -20,19 +28,30 @@ class EmailClient {
    * @returns {Promise<void>}
    */
   async initialize() {
+    // If already initialized, return immediately
     if (this.initialized) return;
 
-    try {
-      // Use centralized AWS configuration with credential profiles
-      const awsConfig = getAWSConfig();
-      this.sesClient = new SESClient(awsConfig);
-
-      this.initialized = true;
-      console.log("AWS SES Email Client initialized successfully");
-    } catch (error) {
-      console.error("Failed to initialize AWS SES Email Client:", error);
-      throw error;
+    // If initialization is in progress, wait for it
+    if (this.initializationPromise) {
+      return this.initializationPromise;
     }
+
+    // Start initialization and store the promise
+    this.initializationPromise = (async () => {
+      try {
+        // Use centralized AWS configuration with credential profiles
+        const awsConfig = getAWSConfig();
+        this.sesClient = new SESClient(awsConfig);
+
+        this.initialized = true;
+        console.log("AWS SES Email Client initialized successfully");
+      } catch (error) {
+        console.error("Failed to initialize AWS SES Email Client:", error);
+        throw error;
+      }
+    })();
+
+    return this.initializationPromise;
   }
 
   /**

backend/services/email/core/TemplateManager.js

@@ -11,8 +11,16 @@ const path = require("path");
  */
 class TemplateManager {
   constructor() {
+    // Singleton pattern - return existing instance if already created
+    if (TemplateManager.instance) {
+      return TemplateManager.instance;
+    }
+
     this.templates = new Map();
     this.initialized = false;
+    this.initializationPromise = null;
+
+    TemplateManager.instance = this;
   }
 
   /**
@@ -20,11 +28,22 @@ class TemplateManager {
    * @returns {Promise<void>}
    */
   async initialize() {
+    // If already initialized, return immediately
     if (this.initialized) return;
 
-    await this.loadEmailTemplates();
-    this.initialized = true;
-    console.log("Email Template Manager initialized successfully");
+    // If initialization is in progress, wait for it
+    if (this.initializationPromise) {
+      return this.initializationPromise;
+    }
+
+    // Start initialization and store the promise
+    this.initializationPromise = (async () => {
+      await this.loadEmailTemplates();
+      this.initialized = true;
+      console.log("Email Template Manager initialized successfully");
+    })();
+
+    return this.initializationPromise;
   }
 
   /**
@@ -34,6 +53,14 @@ class TemplateManager {
   async loadEmailTemplates() {
     const templatesDir = path.join(__dirname, "..", "..", "..", "templates", "emails");
 
+    // Critical templates that must load for the app to function
+    const criticalTemplates = [
+      "emailVerificationToUser.html",
+      "passwordResetToUser.html",
+      "passwordChangedToUser.html",
+      "personalInfoChangedToUser.html",
+    ];
+
     try {
       const templateFiles = [
         "conditionCheckReminderToUser.html",
@@ -41,6 +68,7 @@ class TemplateManager {
         "emailVerificationToUser.html",
         "passwordResetToUser.html",
         "passwordChangedToUser.html",
+        "personalInfoChangedToUser.html",
         "lateReturnToCS.html",
         "damageReportToCS.html",
         "lostItemToCS.html",
@@ -69,6 +97,8 @@ class TemplateManager {
         "forumCommentDeletionToAuthor.html",
       ];
 
+      const failedTemplates = [];
+
       for (const templateFile of templateFiles) {
         try {
           const templatePath = path.join(templatesDir, templateFile);
@@ -84,16 +114,39 @@ class TemplateManager {
           console.error(
             `  Template path: ${path.join(templatesDir, templateFile)}`
           );
+          failedTemplates.push(templateFile);
         }
       }
 
       console.log(
         `Loaded ${this.templates.size} of ${templateFiles.length} email templates`
       );
+
+      // Check if critical templates are missing
+      const missingCriticalTemplates = criticalTemplates.filter(
+        (template) => !this.templates.has(path.basename(template, ".html"))
+      );
+
+      if (missingCriticalTemplates.length > 0) {
+        const error = new Error(
+          `Critical email templates failed to load: ${missingCriticalTemplates.join(", ")}`
+        );
+        error.missingTemplates = missingCriticalTemplates;
+        throw error;
+      }
+
+      // Warn if non-critical templates failed
+      if (failedTemplates.length > 0) {
+        console.warn(
+          `⚠️  Non-critical templates failed to load: ${failedTemplates.join(", ")}`
+        );
+        console.warn("These templates will use fallback versions");
+      }
     } catch (error) {
       console.error("Failed to load email templates:", error);
       console.error("Templates directory:", templatesDir);
       console.error("Error stack:", error.stack);
+      throw error; // Re-throw to fail server startup
     }
   }