/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
import {Injectable} from '@angular/core';
import {Http} from '@angular/http';
import {Observable} from 'rxjs/Observable';
import {Country} from './model/country.model';
import {TranslateService} from '@ngx-translate/core';
import {escapeRegexPattern} from '../../common/regex/escape';

@Injectable()
export class CountryService {

  private countries: Country[] = [];

  constructor(private http: Http, private translateService: TranslateService) {
  }

  init(): void {
    this.getCountries()
      .map(countries => this.translate(countries))
      .subscribe(countries => this.countries = countries);

    this.translateService.onLangChange
      .map(() => this.translate(this.countries))
      .subscribe(countries => this.countries = countries);
  }

  fetchCountries(term): Country[] {
    const regTerm = new RegExp(`^${escapeRegexPattern(term)}`, 'gi');

    let result: Country[];

    if (term) {
      result = this.countries.filter((country: Country) => regTerm.test(country.displayName));
    } else {
      result = this.countries.slice();
    }
    return result;
  }

  fetchByCountryCode(countryCode: string): Country {
    return this.countries.find((country: Country) => country.alpha2Code === countryCode);
  }

  private translate(countries: Country[]): Country[] {
    return countries.map(country => this.mapTranslation(country));
  }

  private mapTranslation(country: Country): Country {
    const currentLang = this.translateService.currentLang;
    return Object.assign({}, country, {
      displayName: currentLang !== 'en' && country.translations[currentLang] ? country.translations[currentLang] : country.name
    });
  }

  private getCountries(): Observable<Country[]> {
    return this.http.get('https://restcountries.eu/rest/v2/all?fields=name;alpha2Code;translations')
      .map(response => response.json());
  }

}