import {Injectable} from "@angular/core";
import {HttpClient} from "@angular/common/http";
import {Observable} from "rxjs";
import {EnvProperties} from "../../utils/properties/env-properties";
import {map} from "rxjs/operators";
import {properties} from "../../../../environments/environment";

export interface AnnotationTarget {
  id: string;
  url: string;
}

export interface Annotation {
  text: string;
  type: 'semantic' | 'keyword' | 'comment';
  targets?: AnnotationTarget[];
  targetSize?: number;
}

@Injectable({
  providedIn: "root"
})
export class AnnotationService {
  
  api = 'api/';
  
  constructor(private http: HttpClient) {
  }
  
  getAllAnnotations(source: string): Observable<Annotation[]> {
    let url = properties.b2noteAPIURL + this.api + 'annotations?target-id[]=' + encodeURIComponent(source);
    return this.http.get<Annotation[]>(url).pipe(map((response: any[]) => {
      return this.parseAnnotations(response);
    }));
  }
  
  getAnnotationTargets(value: string, type: 'semantic' | 'keyword' | 'comment'): Observable<AnnotationTarget[]> {
    let url = properties.b2noteAPIURL + this.api + 'annotations?value=' + encodeURIComponent(value) + '&type[]=' + type;
    return this.http.get<AnnotationTarget[]>(url).pipe(map((response: any[]) => {
      return this.parseAnnotationTargets(response);
    }));
  }
  
  private parseAnnotations(response: any[]): Annotation[] {
    let annotations: Annotation[] = [];
    if (response && response.length > 0) {
      response.forEach(value => {
        if (value.visibility === 'public') {
          let body = value.body;
          if (body.type === 'TextualBody') {
            if (body.purpose === 'tagging') {
              annotations.push({
                text: body.value,
                type: "keyword"
              });
            } else {
              annotations.push({
                text: body.value,
                type: "comment"
              });
            }
          } else {
            let items = body.items;
            let text: string = null;
            items.forEach(item => {
              if (item.type === 'TextualBody') {
                text = item.value;
              }
            });
            annotations.push({
              text: text,
              type: "semantic"
            });
          }
        }
      });
    }
    return annotations;
  }
  
  private parseAnnotationTargets(response: any[]): AnnotationTarget[] {
    let targets: AnnotationTarget[] = [];
    if (response && response.length > 0) {
      response.forEach(value => {
        if (value.visibility === 'public') {
          targets.push({
            id: value.target.id,
            url: value.target.source
          });
        }
      });
    }
    return  targets;
  }
}