Add user and employee management enhancements with database schema updates

- Introduced new columns `status`, `created_by`, and `updated_by` in the `users` table to track user status and ownership.
- Updated the `employees` table to include a foreign key reference to the `users` table via `user_id`.
- Created migration script `0012_users_primary.sql` to apply these changes to the database schema.
- Enhanced the `EmployeesService` and `EmployeesRepository` to support user assignments and related data retrieval.
- Updated DTOs and service methods to reflect the new user and employee relationships.
- Added unit tests to validate the new functionality and ensure data integrity.
- Modified existing controllers to accommodate the new fields and relationships in user and employee management.

src/modules/configuration/employees/employees.repository.ts

@@ -10,6 +10,7 @@ import { PhoneNumber } from '../../../common/value-objects/phone-number/phone-nu
 import { Status } from '../../../common/value-objects/status/status';
 import { DRIZZLE, type DrizzleDB } from '../../../database/database.module';
 import { employees, type EmployeeRow } from '../../../database/employees-table';
+import { users } from '../../../database/schema';
 import type { EmployeePosition } from './employee-fields';
 import type {
   CreateEmployeeInput,
@@ -41,7 +42,11 @@ export class EmployeesRepository {
       .offset(filters.offset);
 
     return {
-      data: rows.map((row) => this.toDomain(row)),
+      data: await Promise.all(
+        rows.map(async (row) =>
+          this.toDomain(row, await this.loadAssignedUser(row.userId)),
+        ),
+      ),
       total: Number(totalRow?.total ?? 0),
     };
   }
@@ -55,13 +60,13 @@ export class EmployeesRepository {
   }
 
   async findById(id: string): Promise<Employee | null> {
-    const rows: EmployeeRow[] = await this.db
+    const rows = await this.db
       .select()
       .from(employees)
       .where(eq(employees.id, id))
       .limit(1);
     const row = rows[0];
-    return row ? this.toDomain(row) : null;
+    return row ? this.toDomain(row, await this.loadAssignedUser(row.userId)) : null;
   }
 
   async findByCode(code: string): Promise<Employee | null> {
@@ -71,7 +76,7 @@ export class EmployeesRepository {
       .where(eq(employees.code, code))
       .limit(1);
     const row = rows[0];
-    return row ? this.toDomain(row) : null;
+    return row ? this.toDomain(row, await this.loadAssignedUser(row.userId)) : null;
   }
 
   async create(input: CreateEmployeeInput): Promise<Employee> {
@@ -83,7 +88,7 @@ export class EmployeesRepository {
         .values(this.toInsertValues(input, status, now, input.userId))
         .returning();
       const row = inserted[0];
-      return this.toDomain(row);
+      return this.toDomain(row, await this.loadAssignedUser(row.userId));
     } catch (error) {
       this.rethrowUniqueViolation(error);
     }
@@ -125,11 +130,14 @@ export class EmployeesRepository {
           position: input.position ?? existing.position,
           updatedAt: now.value,
           updatedBy: input.userId,
+          ...(input.assignedUserId !== undefined
+            ? { userId: input.assignedUserId }
+            : {}),
         })
         .where(eq(employees.id, id))
         .returning();
       const row = updated[0];
-      return this.toDomain(row);
+      return this.toDomain(row, await this.loadAssignedUser(row.userId));
     } catch (error) {
       this.rethrowUniqueViolation(error);
     }
@@ -154,7 +162,7 @@ export class EmployeesRepository {
     if (!row) {
       throw new NotFoundException('Employee not found');
     }
-    return this.toDomain(row);
+    return this.toDomain(row, await this.loadAssignedUser(row.userId));
   }
 
   async bulkUpdateStatus(
@@ -216,6 +224,9 @@ export class EmployeesRepository {
     if (filters.status) {
       parts.push(eq(employees.status, filters.status));
     }
+    if (filters.userId) {
+      parts.push(eq(employees.userId, filters.userId));
+    }
     if (filters.search) {
       const search = or(
         ilike(employees.code, `%${filters.search}%`),
@@ -247,10 +258,41 @@ export class EmployeesRepository {
       updatedAt: now.value,
       createdBy: userId,
       updatedBy: userId,
+      userId: input.assignedUserId ?? null,
     };
   }
 
-  private toDomain(row: EmployeeRow): Employee {
+  private selectWithUser() {
+    return this.db
+      .select({
+        employee: employees,
+        user: {
+          id: users.id,
+          username: users.username,
+        },
+      })
+      .from(employees)
+      .leftJoin(users, eq(employees.userId, users.id));
+  }
+
+  private async loadAssignedUser(
+    userId: string | null,
+  ): Promise<{ id: string; username: string } | null> {
+    if (!userId) {
+      return null;
+    }
+    const rows = await this.db
+      .select({ id: users.id, username: users.username })
+      .from(users)
+      .where(eq(users.id, userId))
+      .limit(1);
+    return rows[0] ?? null;
+  }
+
+  private toDomain(
+    row: EmployeeRow,
+    user: { id: string; username: string } | null,
+  ): Employee {
     return {
       id: row.id,
       code: row.code,
@@ -262,29 +304,39 @@ export class EmployeesRepository {
       updatedAt: DateTime.fromUnixMs(row.updatedAt),
       createdBy: row.createdBy,
       updatedBy: row.updatedBy,
+      userId: row.userId ?? null,
+      user: user?.id ? { id: user.id, username: user.username } : null,
     };
   }
 
   private rethrowUniqueViolation(error: unknown): never {
     const err = this.unwrapDbError(error);
     if (err.code === '23505') {
+      const constraint = err.constraint ?? '';
+      if (constraint.includes('user_id')) {
+        throw new ConflictException('User is already assigned to an employee');
+      }
       throw new ConflictException('Employee code already exists');
     }
     throw error;
   }
 
-  private unwrapDbError(error: unknown): { code?: string } {
+  private unwrapDbError(error: unknown): { code?: string; constraint?: string } {
     let current: unknown = error;
     for (let i = 0; i < 5; i++) {
       if (!current || typeof current !== 'object') {
         break;
       }
-      const obj = current as { code?: string; cause?: unknown };
+      const obj = current as {
+        code?: string;
+        constraint?: string;
+        cause?: unknown;
+      };
       if (obj.code === '23505' || obj.code === '23503') {
-        return { code: obj.code };
+        return { code: obj.code, constraint: obj.constraint };
       }
       current = obj.cause;
     }
-    return error as { code?: string };
+    return error as { code?: string; constraint?: string };
   }
 }