// var XLSX = require("xlsx");
// import XLSX from "xlsx";
import * as XLSX from 'xlsx/xlsx.mjs';
import TemporalUtils from '../utils/temporal-utils';
import { PortalUtils } from '../utils/utils';

export class ExcelReader {
	static readFileAsJson(result): Array<Array<string>> {
		let inputData = result;
		if (result.srcBase64) {
			inputData = result.srcBase64;
		}

		const data = new Uint8Array(inputData);
		const workbook = XLSX.read(data, {
			cellDates: true,
			type: 'array',
		});

		// So that the XLSX engine also includes first row
		const dummyHeader = [];
		for (let i = 0; i < 9999; i++) {
			dummyHeader.push(i);
		}

		// Transform data into some dummy JSON
		const firstSheet = workbook.Sheets[workbook.SheetNames[0]];
		const sheetData = XLSX.utils.sheet_to_json(firstSheet, {
			header: dummyHeader,
		});

		// Determine largest row index
		let largestIndex = 0;
		for (let i = 0, iLen = sheetData.length; i < iLen; i++) {
			const sheetRow: any = sheetData[i];
			for (const key in sheetRow) {
				const rowIndex = Number(key);
				if (rowIndex > largestIndex) {
					largestIndex = rowIndex;
				}
			}
		}

		// Transform data from the engine into array of arrays and transform data into friendly objects
		const retVal = [];
		while (sheetData.length > 0) {
			const sheetRow = sheetData.shift();
			const rowArr = [];
			retVal.push(rowArr);

			for (let i = 0; i <= largestIndex; i++) {
				let rowVal = sheetRow[i];
				if (rowVal != null) {
					if (rowVal != null && rowVal.getUTCFullYear) {
						rowVal = TemporalUtils.fromDate(rowVal);
					} else if (PortalUtils.isString(rowVal)) {
						rowVal = rowVal.trim();
					}
				}

				rowArr.push(rowVal);
			}
		}

		return retVal;
	}
}