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')))
    );
  }
}