feat: add modular services and repositories for improved code organization

Introduce repository pattern across multiple services, including `favorites`, `tags`, `sessions`, `reports`, `auth`, and more. Decouple crypto functionalities into modular services like `HashingService`, `JwtService`, and `EncryptionService`. Improve testability and maintainability by simplifying dependencies and consolidating utility logic.

backend/src/reports/reports.service.ts

@@ -1,37 +1,26 @@
 import { Injectable, Logger } from "@nestjs/common";
-import { desc, eq } from "drizzle-orm";
-import { DatabaseService } from "../database/database.service";
-import { reports } from "../database/schemas";
+import { ReportsRepository } from "./repositories/reports.repository";
 import { CreateReportDto } from "./dto/create-report.dto";
 
 @Injectable()
 export class ReportsService {
 	private readonly logger = new Logger(ReportsService.name);
 
-	constructor(private readonly databaseService: DatabaseService) {}
+	constructor(private readonly reportsRepository: ReportsRepository) {}
 
 	async create(reporterId: string, data: CreateReportDto) {
 		this.logger.log(`Creating report from user ${reporterId}`);
-		const [newReport] = await this.databaseService.db
-			.insert(reports)
-			.values({
-				reporterId,
-				contentId: data.contentId,
-				tagId: data.tagId,
-				reason: data.reason,
-				description: data.description,
-			})
-			.returning();
-		return newReport;
+		return await this.reportsRepository.create({
+			reporterId,
+			contentId: data.contentId,
+			tagId: data.tagId,
+			reason: data.reason,
+			description: data.description,
+		});
 	}
 
 	async findAll(limit: number, offset: number) {
-		return await this.databaseService.db
-			.select()
-			.from(reports)
-			.orderBy(desc(reports.createdAt))
-			.limit(limit)
-			.offset(offset);
+		return await this.reportsRepository.findAll(limit, offset);
 	}
 
 	async updateStatus(
@@ -39,10 +28,6 @@ export class ReportsService {
 		status: "pending" | "reviewed" | "resolved" | "dismissed",
 	) {
 		this.logger.log(`Updating report ${id} status to ${status}`);
-		return await this.databaseService.db
-			.update(reports)
-			.set({ status, updatedAt: new Date() })
-			.where(eq(reports.id, id))
-			.returning();
+		return await this.reportsRepository.updateStatus(id, status);
 	}
 }