feat: add CommonModule with PurgeService and global exception filter

Introduced CommonModule to centralize shared functionality. Added PurgeService for automated database cleanup and a global exception filter for unified error handling.

backend/src/common/common.module.ts

@@ -0,0 +1,11 @@
+import { Global, Module } from "@nestjs/common";
+import { DatabaseModule } from "../database/database.module";
+import { PurgeService } from "./services/purge.service";
+
+@Global()
+@Module({
+	imports: [DatabaseModule],
+	providers: [PurgeService],
+	exports: [PurgeService],
+})
+export class CommonModule {}

backend/src/common/filters/http-exception.filter.ts

@@ -0,0 +1,56 @@
+import {
+	ArgumentsHost,
+	Catch,
+	ExceptionFilter,
+	HttpException,
+	HttpStatus,
+	Logger,
+} from "@nestjs/common";
+import * as Sentry from "@sentry/nestjs";
+import { Request, Response } from "express";
+
+@Catch()
+export class AllExceptionsFilter implements ExceptionFilter {
+	private readonly logger = new Logger("ExceptionFilter");
+
+	catch(exception: unknown, host: ArgumentsHost) {
+		const ctx = host.switchToHttp();
+		const response = ctx.getResponse<Response>();
+		const request = ctx.getRequest<Request>();
+
+		const status =
+			exception instanceof HttpException
+				? exception.getStatus()
+				: HttpStatus.INTERNAL_SERVER_ERROR;
+
+		const message =
+			exception instanceof HttpException
+				? exception.getResponse()
+				: "Internal server error";
+
+		const errorResponse = {
+			statusCode: status,
+			timestamp: new Date().toISOString(),
+			path: request.url,
+			method: request.method,
+			message:
+				typeof message === "object" && message !== null
+					? (message as Record<string, unknown>).message || message
+					: message,
+		};
+
+		if (status === HttpStatus.INTERNAL_SERVER_ERROR) {
+			Sentry.captureException(exception);
+			this.logger.error(
+				`${request.method} ${request.url} - Error: ${exception instanceof Error ? exception.message : "Unknown error"}`,
+				exception instanceof Error ? exception.stack : "",
+			);
+		} else {
+			this.logger.warn(
+				`${request.method} ${request.url} - Status: ${status} - Message: ${JSON.stringify(message)}`,
+			);
+		}
+
+		response.status(status).json(errorResponse);
+	}
+}

backend/src/common/interfaces/request.interface.ts

@@ -0,0 +1,8 @@
+import { Request } from "express";
+
+export interface AuthenticatedRequest extends Request {
+	user: {
+		sub: string;
+		username: string;
+	};
+}

backend/src/common/services/purge.service.ts

@@ -0,0 +1,63 @@
+import { Injectable, Logger } from "@nestjs/common";
+import { Cron, CronExpression } from "@nestjs/schedule";
+import { and, eq, isNotNull, lte } from "drizzle-orm";
+import { DatabaseService } from "../../database/database.service";
+import { contents, reports, sessions, users } from "../../database/schemas";
+
+@Injectable()
+export class PurgeService {
+	private readonly logger = new Logger(PurgeService.name);
+
+	constructor(private readonly databaseService: DatabaseService) {}
+
+	// Toutes les nuits à minuit
+	@Cron(CronExpression.EVERY_DAY_AT_MIDNIGHT)
+	async purgeExpiredData() {
+		this.logger.log("Starting automatic data purge...");
+
+		try {
+			const now = new Date();
+
+			// 1. Purge des sessions expirées
+			const deletedSessions = await this.databaseService.db
+				.delete(sessions)
+				.where(lte(sessions.expiresAt, now))
+				.returning();
+			this.logger.log(`Purged ${deletedSessions.length} expired sessions.`);
+
+			// 2. Purge des signalements obsolètes
+			const deletedReports = await this.databaseService.db
+				.delete(reports)
+				.where(lte(reports.expiresAt, now))
+				.returning();
+			this.logger.log(`Purged ${deletedReports.length} obsolete reports.`);
+
+			// 3. Purge des utilisateurs supprimés (Soft Delete > 30 jours)
+			const thirtyDaysAgo = new Date();
+			thirtyDaysAgo.setDate(thirtyDaysAgo.getDate() - 30);
+
+			const deletedUsers = await this.databaseService.db
+				.delete(users)
+				.where(
+					and(eq(users.status, "deleted"), lte(users.deletedAt, thirtyDaysAgo)),
+				)
+				.returning();
+			this.logger.log(
+				`Purged ${deletedUsers.length} users marked for deletion more than 30 days ago.`,
+			);
+
+			// 4. Purge des contenus supprimés (Soft Delete > 30 jours)
+			const deletedContents = await this.databaseService.db
+				.delete(contents)
+				.where(
+					and(isNotNull(contents.deletedAt), lte(contents.deletedAt, thirtyDaysAgo)),
+				)
+				.returning();
+			this.logger.log(
+				`Purged ${deletedContents.length} contents marked for deletion more than 30 days ago.`,
+			);
+		} catch (error) {
+			this.logger.error("Error during data purge", error);
+		}
+	}
+}