import { BomRegion } from "@arrow/bom/core";

export class BomPreviewModel {
  id: string;
  fileName: string;
  name: string;

  /**
   * File size with notation (in user friendly form)
   */
  fileSize: any;

  /**
   * File size in number of bytes
   */
  fileSizeBytes: number;

  numberOfLines: number;
  headerRow: number;
  dataRow: number;
  sheetData: Array<any> = [];
  sheetList: Array<string> = [];
  sheetName: string;
  rows: Array<any> = [];
  headers: Array<any> = [];
  columns: Array<any> = [];
  colAmount: number;
  maxValue: number = 25;
  metadata: any;
  sheetStats: any;
  bomRegions: BomRegion[];

  constructor(data: any) {
    this.id = data.jsonId;
    // strips the file type to get only the file name
    this.name = data.metadata.fileName;
    // convert file size number to data unit string
    this.fileSize = this.fileSizeConverter(data.metadata.fileSizeInBytes);
    this.fileSizeBytes = data.metadata.fileSizeInBytes;
    this.sheetData = data.previews;
    // get list of xml sheets
    this.sheetList = Object.keys(this.sheetData);
    // set first sheet as default view
    this.sheetName = this.sheetList[0];
    this.metadata = data.metadata;
    this._refreshSheetStats();
    this.rows = this.sheetData[this.sheetName];
    this.columns = data.columns;
    this.headerRow = 1;
    this.dataRow = this.findDataRow(this.rows);
    // once everything is setup, update view
    this.bomRegions = data.bomRegions;
    this.update();
  }

  private _refreshSheetStats(): void {
    const sheetStats = this.metadata.sheets
      .filter((s: any) => {
        return s.sheetName === this.sheetName;
      })
      .pop();
    this.numberOfLines = sheetStats.rows;
    this.colAmount = sheetStats.columns;
  }

  /**
   * Converts a number to its data unit string equivalent.
   * @param bytes  Number to be converted.
   */
  fileSizeConverter(bytes: number): string {
    const units = [' bytes', 'k', 'm', 'g'];
    let unit = 0;

    while (bytes >= 1024) {
      bytes /= 1024;
      unit++;
    }

    return bytes.toFixed() + units[unit];
  }

  /**
   * Searches data object to find the next row with valid data, then return the index of the element.
   * Only runs at instantiation.
   * @param data      Array of rows of data.
   * @return number  Index of data.
   */
  findDataRow(data: Array<any>): number {
    return data.findIndex(row => row.find((item: any) => {
      return item ? !!item.length : 0
    }));
  }

  /**
   * Triggered by change of the sheet or row number change, updates preview view.
   */
  update(): void {
    this._refreshSheetStats();
    this.rows = this.sheetData[this.sheetName];
    this.headers = this.rows[this.headerRow - 1];
  }
}