import { HttpClient, HttpEvent, HttpEventType, HttpHeaders, HttpRequest, HttpResponse } from '@angular/common/http';
import { Injectable } from '@angular/core';
import { FileStatus, FileUploadEvent } from '@core/typings/file.typing';
import { VirusScanResult, VirusScanResultType } from '@core/typings/virus-scan.typing';
import { I18nService } from '@yourcause/common/i18n';
import { NotifierService } from '@yourcause/common/notifier';
import { filter, map, mergeMap, Observable } from 'rxjs';


@Injectable({ providedIn: 'root' })
export class VirusScanService {
  constructor (
    private i18n: I18nService,
    private http: HttpClient,
    private notifier: NotifierService
  ) { }

  private fetchVirusScanToken () {
    const tokenRequest = this.http.post<{ fileScanToken: string }>('/api/token/FileScanToken', null);

    return tokenRequest;
  }

  scanFileForVirusesNew (file: File | Blob): Observable<FileUploadEvent<string>> {
    return this.fetchVirusScanToken()
      .pipe(mergeMap((token) => {

        const virusBody = new FormData();
        virusBody.append('file', file);
        virusBody.append('ApiKey', token.fileScanToken);

        const virusRequest = new HttpRequest('POST', '/filescan/upload', virusBody, {
          reportProgress: true,
          headers: new HttpHeaders({ 'ngsw-bypass': 'true' }),
          responseType: 'text'
        });

        return this.http.request<string>(virusRequest)
          .pipe(map(((event: HttpEvent<string>) => {
            let returnValue: FileUploadEvent<string>|null = null;
            switch (event.type) {
              case HttpEventType.UploadProgress:
                returnValue = {
                  progress: event.loaded / event.total,
                  status: FileStatus.UPLOAD_VIRUS_SCAN
                };
                break;
              case HttpEventType.Sent:
                returnValue = {
                  status: FileStatus.AWAITING_VIRUS_SCAN
                };
                break;
              case HttpEventType.Response:
                const response: VirusScanResult = JSON.parse((<HttpResponse<string>>event).body);
                if (response.scanResult.result === VirusScanResultType.Valid) {
                  returnValue = {
                    status: FileStatus.COMPLETE_VIRUS_SCAN,
                    result: response.scanToken
                  };
                } else {
                  returnValue = {
                    status: FileStatus.FAILED_VIRUS_SCAN,
                    result: response.scanToken
                  };
                }

                break;
            }

            return returnValue;
          })))
          .pipe(filter((e) => e !== null));
      }));
  }

  async scanFileForViruses (file: File | Blob): Promise<VirusScanResult> {
    const token = await this.fetchVirusScanToken().toPromise();

    const virusBody = new FormData();
    virusBody.append('file', file);
    virusBody.append('ApiKey', token.fileScanToken);

    const virusRequest = new HttpRequest('POST', '/filescan/upload', virusBody, {
      reportProgress: true,
      headers: new HttpHeaders({ 'ngsw-bypass': 'true' }),
      responseType: 'text'
    });

    const virusResponse = await this.http.request(virusRequest).pipe(
      filter(event => event instanceof HttpResponse),
      map(event => JSON.parse((<HttpResponse<string>>event).body)))
      .toPromise();

    const fileName = 'name' in file ?
      file.name :
      this.i18n.translate('common:textTheFile', {}, 'The file');

    this.evaluateVirusScanResult(virusResponse, fileName);

    return virusResponse;
  }

  private evaluateVirusScanResult (
    virusResponse: VirusScanResult,
    fileName: string
  ) {
    if (virusResponse.scanResult.result === VirusScanResultType.Invalid) {
      this.notifier.error(
        this.i18n.translate(
          'common:notificationVirusDetectedInFileName',
          {
            fileName
          },
          '__fileName__ failed the virus scan. Please use a different file.'
        )
      );

      throw new Error('Virus detected in file upload');
    }
  }
}