import { Injectable } from '@angular/core';
import { HttpClient, HttpResponse, HttpHeaders } from '@angular/common/http';
import { Observable, throwError as _throw } from 'rxjs';
import { catchError, tap, map } from 'rxjs/operators';
import { saveAs } from 'file-saver';
import { TranslateService } from '@ngx-translate/core';

import { ConfigService } from '@arrow/bom/config';
import { QueryParams } from './util/http';
import { MessageBusService } from './message-bus/message-bus.service';
import { AnalyticsService } from './analytics.service';

@Injectable()
export class DownloadService {
  private readonly _dataUrl: string;

  constructor(
    private _http: HttpClient,
    private _config: ConfigService,
    private _messageBus: MessageBusService,
    private _analyticsService: AnalyticsService,
    private _translate: TranslateService
  ) {
    this._dataUrl = `${this._config.apiUrl}`;
  }

  private _handleBlobResponse(response: HttpResponse<Blob>): void {
    const fileName = this._getFileNameFromHeaders(response.headers);
    saveAs(response.body, fileName);
  }

  /**
   * @param headers
   */
  private _getFileNameFromHeaders(headers: HttpHeaders) {
    if (!headers) return '';
    const contentDispositionHeader: string = headers.get('Content-Disposition');
    if (!contentDispositionHeader) return '';

    const contentDisposition = {};
    const contentDispositionParts: Array<
      string
    > = contentDispositionHeader.split(';');
    for (const contentDispositionPart of contentDispositionParts) {
      const keyValuePair = contentDispositionPart.split('=');
      const key = keyValuePair[0].trim();
      const value = (keyValuePair[1] || '').trim();
      contentDisposition[key] = value;
    }
    return contentDisposition['filename'] || '';
  }

  private _handleError(error: any): any {
    this._messageBus.to('ch:loader', { payload: false });
    return _throw(error.message || 'Server error');
  }

  /**
   * Gets the current bom as a xlsx file
   * @param bomId - bomId.
   * @param params? - bom file params
   * @returns Observable any.
   */
  downloadBom(bomId: string, params?: QueryParams): Observable<any> {
    const baseUrl = this._config.apiUrl.substring(
      0,
      this._config.apiUrl.length - 3
    );
    const url = `${baseUrl}/api/boms/${bomId}/excel?${
      params ? params.toString() : ''
    }`;

    return this._http
      .get(url, {
        observe: 'response',
        responseType: 'blob',
        withCredentials: true
      })
      .pipe(
        catchError(() => {
          const message = `${this._translate.instant(
            'BOM.Cannot-download-BOM.'
          )}
          ${this._translate.instant('BOM.Please-try-again-later.')}
          ${this._translate.instant(
            'BOM.If-the-problem-persists-please-contact-us.'
          )}`;

          return this._handleError(message);
        }),
        map((response: HttpResponse<Blob>) =>
          this._handleBlobResponse(response)
        )
      );
  }

  downloadGeneratedBomFile(fileId: string): Observable<any> {
    const baseUrl = this._config.apiUrl.substring(
      0,
      this._config.apiUrl.length - 3
    );
    const url = `${baseUrl}/api/boms/files/${fileId}`;

    return this._http
      .get(url, {
        observe: 'response',
        responseType: 'blob'
      })
      .pipe(
        catchError(() => {
          const message = `${this._translate.instant(
            'BOM.Cannot-download-BOM.'
          )}
          ${this._translate.instant('BOM.Please-try-again-later.')}
          ${this._translate.instant(
            'BOM.If-the-problem-persists-please-contact-us.'
          )}`;

          return this._handleError(message);
        }),
        map((response: HttpResponse<Blob>) =>
          this._handleBlobResponse(response)
        )
      );
  }

  /**
   * Sends the bom email request to the API.
   * @param bomId  The bom Id.
   * @param emailData  email data supplied in the form.
   * @returns Observable any.
   */
  emailBom(bomId: string, emailData: any): Observable<any> {
    const payload = {
      targetEmails: emailData.recipient.split(',').map(email => email.trim()),
      senderEmail: emailData.sender,
      optionalMessage: emailData.message,
      columnIds: emailData.columnIds,
      includeCrosses: emailData.includeCrosses
    };
    const newApi = this._dataUrl.substring(0, this._dataUrl.length - 3);
    const url = `${newApi}/api/boms/${bomId}/email`;

    return this._http
      .post(url, payload, { withCredentials: true })
      .pipe(catchError(error => this._handleError(error)));
  }
}