import {Injectable, Inject} from '@angular/core';
import {URLSearchParams, Response} from '@angular/http';
import {Observable} from 'rxjs/Observable';
import {SEARCH_CONFIG, ISearchConfig} from '../config/config.module';
import {ISearchFilter} from './search-filter';
import {AuthHttp} from 'angular2-jwt';
import _ from 'lodash';
import {
  OwsRecordTransformer
} from '../records/transformers/ows-record-transformer.service';
import {RecordCollection} from '../records/record-collection';

@Injectable()
export class OwsSearchService {
  constructor(
    private http: AuthHttp,
    @Inject(SEARCH_CONFIG) private config: ISearchConfig) {}

  get(
    docType: string,
    searchFilter: ISearchFilter)
  : Observable<RecordCollection> {
    return this.http.get(
        this.buildUrl(docType),
        {search: this.urlParams(searchFilter)}
      )
      .map(response => this.parseResponse(response, docType))
      .cache();
  }

  private urlParams(searchFilter: ISearchFilter): URLSearchParams {
    const urlParams = new URLSearchParams();

    _.forOwn(
      searchFilter,
      (val, key) =>
        urlParams.set(_.kebabCase(key), val));

    return urlParams;
  }

  private buildUrl(docType: string): string {
    return this.config.searchUrl.replace(/:docType/, docType);
  }

  private parseResponse(
    res: Response,
    docType: string)
  : RecordCollection {
    const transformer = new OwsRecordTransformer();

    return transformer.transform(
      res.json(),
      {
        label: _.startCase(docType),
        name: docType
      }
    );
  }
}