import { PortalUtils } from '../utils/utils';

export interface ExcelExportDataSource {
	sheets: ExcelExportSheet[];
	outputFileName: string;
}

export interface ExcelExportSheet {
	headers: ExcelExportHeader[];
	rows: string[][];
	sheetName: string;
}

export interface ExcelExportHeader {
	caption: string;
	width?: number;
}

export class ExcelJsProvider {
	private static _excelJs: any = null;
	static getExcelJs(): Promise<any> {
		if (ExcelJsProvider.excelJsInstance() != null) {
			return new Promise((resolve, reject) => {
				resolve(ExcelJsProvider._excelJs);
			});
		}

		return new Promise((resolve, reject) => {
			import('exceljs/dist/exceljs.js')
				.then((excelWrapper) => {
					ExcelJsProvider._excelJs = excelWrapper;
					resolve(excelWrapper);
				})
				.catch((reason) => {
					reject(reason);
				});
		});
	}

	static exportToExcel(args: ExcelExportDataSource): Promise<any> {
		return new Promise((resolve, reject) => {
			ExcelJsProvider.getExcelJs()
				.then(() => {
					let colArr = [];
					const workbook = new (ExcelJsProvider.excelJsInstance().Workbook)();
					workbook.created = new Date();
					workbook.modified = new Date();
					workbook.lastPrinted = new Date();

					args.sheets.forEach((sheet) => {
						sheet.headers.forEach((item) => {
							colArr.push({
								header: item.caption,
								width: item.width != null ? item.width : 25,
							});
						});

						const worksheet = workbook.addWorksheet(sheet.sheetName);
						worksheet.columns = colArr;
						colArr = [];
						worksheet.views = [{ state: 'frozen', xSplit: 0, ySplit: 1 }];

						const firstRow = worksheet.getRow(1);
						firstRow.font = {
							name: 'Arial',
							family: 4,
							size: 10,
							bold: true,
							color: { argb: '00000000' },
							bgColor: { argb: '80EF1C1C' },
						};
						firstRow.alignment = { vertical: 'middle', horizontal: 'center' };
						firstRow.height = 20;
						firstRow._cells.forEach((cell) => {
							cell.fill = {
								type: 'pattern',
								pattern: 'solid',
								fgColor: { argb: 'cccccc' },
							};
						});

						sheet.rows.forEach((rowArr) => {
							const rowExportData = [];
							rowArr.forEach((rowItem) => {
								rowExportData.push(rowItem);
							});

							worksheet.addRow(rowExportData);
						});
					});

					const mySelf = this;
					workbook.xlsx
						.writeBuffer()
						.then((data: any) => {
							const blob = new Blob([data], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
							PortalUtils.downloadBlob(
								blob,
								args.outputFileName,
								() => {
									resolve(null);
								},
							);
						})
						.catch((err) => {
							reject(err);
						});
				})
				.catch((err) => {
					reject(err);
				});
		});
	}

	static excelJsInstance(): any {
		return ExcelJsProvider._excelJs;
	}
}