feat: add Master Admin application functionality

src/app/features/global-masters/cities/data-access/city.service.ts

@@ -0,0 +1,46 @@
+import { HttpClient, HttpParams } from '@angular/common/http';
+import { Injectable, inject } from '@angular/core';
+import { Observable } from 'rxjs';
+
+import { CITY_ENDPOINTS } from './city.endpoints';
+import {
+  CityDto,
+  CreateCityRequest,
+  UpdateCityRequest
+} from '../models/city.model';
+import {
+  DataTableQuery,
+  DataTableResult
+} from '../../../../shared/components/data-table/data-table.types';
+
+@Injectable({ providedIn: 'root' })
+export class CityService {
+  private readonly http = inject(HttpClient);
+
+  getCityDataTable(
+    query: DataTableQuery,
+    countryId: string | null = null,
+    stateId: string | null = null
+  ): Observable<DataTableResult<CityDto>> {
+    let params = new HttpParams();
+    if (countryId) params = params.set('countryId', countryId);
+    if (stateId) params = params.set('stateId', stateId);
+    return this.http.post<DataTableResult<CityDto>>(
+      CITY_ENDPOINTS.dataTable,
+      query,
+      { params }
+    );
+  }
+
+  createCity(request: CreateCityRequest): Observable<CityDto> {
+    return this.http.post<CityDto>(CITY_ENDPOINTS.create, request);
+  }
+
+  updateCity(id: string, request: UpdateCityRequest): Observable<CityDto> {
+    return this.http.put<CityDto>(CITY_ENDPOINTS.update(id), request);
+  }
+
+  getCityById(id: string): Observable<CityDto> {
+    return this.http.get<CityDto>(CITY_ENDPOINTS.getById(id));
+  }
+}