feat(backend): #28 templates email validation compte (Handlebars)

- Templates .hbs parent principal, co-parent, AM + lien create-password
- app_name / app_url / expéditeur via ConfigService (sendEmail)
- validateUser: renouvelle token création MDP + envoi email si sans password
- Dist: assets *.hbs (nest-cli)
- Tests unitaires MailService (mock sendEmail)
- Doc liste tickets #28 terminé

Made-with: Cursor

backend/src/modules/mail/mail.service.ts

@@ -1,12 +1,80 @@
 import { Injectable, Logger } from '@nestjs/common';
+import { readFileSync } from 'fs';
+import { join } from 'path';
+import * as Handlebars from 'handlebars';
 import { AppConfigService } from '../config/config.service';
 
+/** Ticket #28 — quel template d'email envoyer après validation de compte */
+export type ValidationAccountEmailKind = 'parent_primary' | 'parent_coparent' | 'am';
+
 @Injectable()
 export class MailService {
   private readonly logger = new Logger(MailService.name);
 
+  /** Cache des templates Handlebars compilés (fichiers .hbs) */
+  private readonly compiledTemplates = new Map<ValidationAccountEmailKind, Handlebars.TemplateDelegate>();
+
   constructor(private readonly configService: AppConfigService) {}
 
+  private templateBasename(kind: ValidationAccountEmailKind): string {
+    const map: Record<ValidationAccountEmailKind, string> = {
+      parent_primary: 'account-validated-parent-primary',
+      parent_coparent: 'account-validated-parent-coparent',
+      am: 'account-validated-am',
+    };
+    return map[kind];
+  }
+
+  private getCompiledTemplate(kind: ValidationAccountEmailKind): Handlebars.TemplateDelegate {
+    let compiled = this.compiledTemplates.get(kind);
+    if (!compiled) {
+      const filePath = join(__dirname, 'templates', `${this.templateBasename(kind)}.hbs`);
+      const source = readFileSync(filePath, 'utf8');
+      compiled = Handlebars.compile(source);
+      this.compiledTemplates.set(kind, compiled);
+    }
+    return compiled;
+  }
+
+  /**
+   * Email post-validation : lien création MDP (token existant ou régénéré côté appelant).
+   * Ticket #28 — app_name, app_url, expéditeur via ConfigService (sendEmail).
+   */
+  async sendValidatedAccountPasswordSetupEmail(
+    recipient: {
+      email: string;
+      prenom: string;
+      nom: string;
+      token: string;
+      numeroDossier?: string | null;
+    },
+    kind: ValidationAccountEmailKind,
+  ): Promise<void> {
+    const appName = this.configService.get<string>('app_name', "P'titsPas");
+    const appUrl = (this.configService.get<string>('app_url', 'https://app.ptits-pas.fr') || '').replace(/\/+$/, '');
+
+    const createPasswordUrl = `${appUrl}/create-password?token=${encodeURIComponent(recipient.token)}`;
+
+    const data: Record<string, string> = {
+      prenom: recipient.prenom || '',
+      nom: recipient.nom || '',
+      appName,
+      appUrl,
+      createPasswordUrl,
+      numeroDossier: recipient.numeroDossier || '',
+    };
+
+    const html = this.getCompiledTemplate(kind)(data) as string;
+
+    const subjects: Record<ValidationAccountEmailKind, string> = {
+      parent_primary: `${appName} — Compte validé : créez votre mot de passe`,
+      parent_coparent: `${appName} — Co-parent : créez votre mot de passe`,
+      am: `${appName} — Inscription validée : créez votre mot de passe`,
+    };
+
+    await this.sendEmail(recipient.email, subjects[kind], html);
+  }
+
   /**
    * Envoi d'un email générique
    * @param to Destinataire