import {throwError as observableThrowError, Observable} from 'rxjs';
import {Injectable} from '@angular/core';
import {Http, Response} from '@angular/http';



import { HttpClient } from '@angular/common/http';

import { ClaimResult} from  '../claimEntities.class';
import {map} from "rxjs/operators";
@Injectable()
export class SearchCrossrefService {
  constructor( private http: HttpClient ) {}


  searchCrossrefResults (term: string, size : number, page : number, apiUrl:string, parse:boolean = false):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)
                     .pipe(map(request => request['message']))
                     .pipe(map(request => (parse?this.parse(request.items):request)))
                     //.catch(this.handleError);

    }
    searchCrossrefByDOIs(DOIs: string[], apiUrl:string, parse:boolean = false):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)
                       .pipe(map(request => request['message']))
                       .pipe(map(request => (parse?this.parse(request.items):request)))
                       //.catch(this.handleError);

      }
      searchCrossrefByMultipleDOIs(dois: string[], apiUrl:string, parse:boolean = false):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)
                         .pipe(map(request => request['message']))
                         .pipe(map(request => (parse?this.parse(request.items):request)))
                         //.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 observableThrowError(error  || 'Server error');
  }
  parse(response):ClaimResult[]{
    var results:ClaimResult[] = [];
    for(var i=0; i<response.length; i++){
      var item=response[i];
      var result:ClaimResult = new ClaimResult();
      result.publisher =  null;
      result.journal =  null;
      result.DOI = item.DOI;
      result.id = item.DOI;
      result.title = item.title;
      result.url = item.URL;
      result.source = 'crossref';
      result.type = 'publication';
      if(item['published-print']){
        result.date = item['published-print']['date-parts'][0];
      }
      result.accessRights =  "OPEN";
      result.publisher = item.publisher;
      result.journal = null;
      result.result = item;
      if(item.author){
        for(var j=0; j<item.author.length; j++){
            result.authors.push(item.author[j].family+", "+item.author[j].given);
        }
      }
      if(item.editor){
        for(var j=0; j<item.editor.length; j++){
            result.editors.push(item.editor[j].family+", "+item.editor[j].given);
        }
      }
      results.push(result);
    }

    return results;

  }

}