import {Injectable} from '@angular/core';
import {Observable} from 'rxjs/internal/Observable';
import {catchError} from 'rxjs/operators';
import {HttpClient, HttpHeaders, HttpParams} from '@angular/common/http';
import {Employee} from './employee';
import {ErrorLoggerService} from '../core/error-logger.service';

const httpOptions = {
  headers: new HttpHeaders({'Content-Type': 'application/json'})
};

const url = '/api/employees';
const serviceName = 'EmployeeService';

@Injectable({providedIn: 'root'})
export class EmployeeService {

  constructor(private http: HttpClient, private log: ErrorLoggerService) {
  }

  get(id: string): Observable<Employee> {
    const getUrl: string = (id === null) ? `${url}` : `${url}/${id}`;
    return <Observable<Employee>>this.http.get<Employee>(getUrl)
      .pipe(
        catchError(this.log.handleError(serviceName, `get id=${id}`))
      );
  }

  list(): Observable<Employee[]> {
    return <Observable<Employee[]>>this.http.get<Employee[]>(`${url}/list`)
      .pipe(
        catchError(this.log.handleError(serviceName, 'list'))
      );
  }

  save(employee: Employee): Observable<Employee> {
    return <Observable<Employee>>this.http.post<Employee>(`${url}`, employee, httpOptions)
      .pipe(
        catchError(this.log.handleError(serviceName, 'save'))
      );
  }

  update(employee: Employee): Observable<Employee> {
    return <Observable<Employee>>this.http.put<Employee>(`${url}/${employee.id}`, employee, httpOptions)
      .pipe(
        catchError(this.log.handleError(serviceName, 'update'))
      );
  }

  saveOrUpdate(employee: Employee): Observable<Employee> {
    if (!employee.id) {
      return this.save(employee);
    } else {
      return this.update(employee);
    }
  }

  delete(id: string): Observable<Employee> {
    return <Observable<Employee>>this.http.delete<Employee>(`${url}/${id}`, httpOptions)
      .pipe(
        catchError(this.log.handleError(serviceName, 'delete'))
      );
  }

  autocomplete(term: string): Observable<Employee[]> {
    const options = {params: new HttpParams().set('q', term)};
    return <Observable<Employee[]>>this.http.get<Employee[]>(`${url}/query`, options)
      .pipe(
        catchError(this.log.handleError(serviceName, 'autocomplete'))
      );
  }
}