import {Injectable} from '@angular/core';
import {Http, Response} from '@angular/http';
import {Observable}     from 'rxjs/Observable';
import 'rxjs/add/observable/of';
import 'rxjs/add/operator/do';
import 'rxjs/add/operator/share';
@Injectable()
export class SearchCrossrefService {
  constructor( private http: Http ) {}


  searchCrossrefResults (term: string, size : number, page : number, apiUrl:string):any {
     let url = apiUrl+'?query='+term+'&rows='+size+'&offset='+(size*(page-1));
     let key = url;

     return this.http.get(url)
                     .map(request => <any> request.json().message)
                     .do(items => console.log("Crossref Results: total results = "+items['total-results']+" keyword = "+term));
                     //.catch(this.handleError);

    }
    searchCrossrefByDOIs(DOIs: string[], apiUrl:string):any {

      var doisParams = "";
      for(var i =0 ;i < DOIs.length; i++){
        doisParams+=(doisParams.length > 0?",":"")+'doi:'+DOIs[i];
      }
       let url = apiUrl+'?filter='+doisParams;
       let key = url;


       return this.http.get(url)
                       .map(request => <any> request.json().message)
                       .do(items => console.log("Crossref Results: total results = "+items['total-results']+" for doi = "+doisParams));
                       //.catch(this.handleError);

      }
      searchCrossrefByMultipleDOIs(dois: string[], apiUrl:string):any {
        let url = apiUrl+'?filter=doi:';
        for(var i=0; i<dois.length; i++){
          url=url+(url.length==0?'':',')+'doi:'+dois[i];
        }
        url = apiUrl+'?filter='+url;
        let key = url;


         return this.http.get(url)
                         .map(request => <any> request.json().message)
                         .do(items => console.log("Crossref Results: total results = "+items['total-results']));
                         //.catch(this.handleError);

        }

  private handleError (error: Response) {
    // in a real world app, we may send the error to some remote logging infrastructure
    // instead of just logging it to the console
    console.log(error);
    return Observable.throw(error  || 'Server error');
  }

}