import {Component, ElementRef, OnInit, ViewChild} from '@angular/core';
  import {VesselsService} from '../../service/vessels.service';
  import {Vessel} from '../../model/vessel';
  
  @Component({
    selector: 'app-import-vessels',
    templateUrl: './import-vessels.component.html',
    styleUrls: ['./import-vessels.component.scss']
  })
  export class ImportVesselsComponent implements OnInit {
    vessels: Map<number, Vessel>;
  
  
    constructor(private vesselsService: VesselsService) {
    }
  
    @ViewChild('fileDropRef', {static: false}) fileDropEl: ElementRef;
    files: any[] = [];
  
    ngOnInit(): void {
      this.vesselsService.currentVessels.subscribe(vessels => this.vessels = vessels);
    }
  
    /**
     * on file drop handler
     */
    onFileDropped($event): void {
      this.prepareFilesList($event);
    }
  
    /**
     * handle file from browsing
     */
    fileBrowseHandler(files): void {
      this.prepareFilesList(files);
    }
  
    /**
     * Delete file from files list
     * @param index (File index)
     */
    deleteFile(index: number): void {
      if (this.files[index].progress < 100) {
        return;
      }
      this.files.splice(index, 1);
    }
  
  
    uploadFilesSimulator(index: number): void {
      const fileReader = new FileReader();
      let nbLine: number;
  
      fileReader.onload = (e) => {
        const lines: string[] = (fileReader.result as string).split('
  ');
        nbLine = lines.length;
        for (const line of lines) {
          const splitLine = line.split(',');
          const newVessel = new Vessel(splitLine);
          this.vessels.set(Number(newVessel.mmsi), newVessel);
        }
      };
  
      fileReader.onprogress = (e ) => {
        if (e.lengthComputable) {
          this.files[index].progress = Math.round(((e.loaded / e.total) * 100));
        }
      };
  
      fileReader.readAsText(this.files[index]);
    }
  
    prepareFilesList(files: Array<any>): void {
      for (const item of files) {
        item.progress = 0;
        this.files.push(item);
      }
      this.fileDropEl.nativeElement.value = '';
      this.uploadFilesSimulator(0);
    }
  
    formatBytes(bytes, decimals = 2): string {
      if (bytes === 0) {
        return '0 Bytes';
      }
      const k = 1024;
      const dm = decimals <= 0 ? 0 : decimals;
      const sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'];
      const i = Math.floor(Math.log(bytes) / Math.log(k));
      return parseFloat((bytes / Math.pow(k, i)).toFixed(dm)) + ' ' + sizes[i];
    }
  }