import { SlickDataView, SlickGrid, SlickGroupTotals } from "slickgrid";

import { deleteDoubleQuotes, removeHtml } from "shared/lib/strings";
import {
	IColumn,
	IDownloadManager,
	ISlickRow,
	ISlickTable,
} from "shared/model/types";

import { selectedRows } from "../../../lib";

/** Causes the circular dependencies issue */
const ignore = ["FormatterStatus", "FormatterNumber"]; // todo Use FORMATTER_NUMBER, FORMATTER_STATUS

export class DownloadManager implements IDownloadManager {
	table: ISlickTable | null = null;

	download(table: ISlickTable, clientId: number, name: string) {
		if (!this.table) this.table = table;
		this.table = table;
		const grid = table.grid;
		if (!grid) return;
		const output = this.createCSV(table);

		const a = document.createElement("a");
		a.href = "data:text/csv;charset=utf-8," + encodeURIComponent(output);
		a.target = "_blank";
		a.download = `${clientId}-${name}-${table.id}.csv`;
		a.click();
	}

	createCSV(table: ISlickTable): string {
		if (!this.table) this.table = table;
		const grid = table.grid;
		if (!grid) return "";
		const title = this.getTitle();
		const header = this.getCSVHeader(grid);
		const body = this.getCSVBody(grid);
		return `${title}${header}${body}`;
	}

	getTitle(): string {
		return "";
	}

	getCSVHeader(grid: SlickGrid): string {
		const columns: IColumn[] = grid.getColumns();
		const columnsForPrinting = columns.filter((el) => el.forPrint);

		const header = columnsForPrinting.reduce((acc: string, column) => {
			if (typeof column.name === "string") {
				const name = deleteDoubleQuotes(column.name);
				return acc.concat(`"${name}",`);
			} else {
				return acc.concat('" ",');
			}
		}, "");

		return this.addRowSeparator(header);
	}

	getCSVBody(grid: SlickGrid): string {
		const dataView: SlickDataView<ISlickRow> = grid.getData();
		const columns: IColumn[] = grid.getColumns();
		const columnsForPrinting = columns.filter((el) => el.forPrint);

		return selectedRows(grid).reduce((acc: string, rowIndex) => {
			const metaData = dataView.getItemMetadata(rowIndex);
			const row = dataView.getItem(rowIndex);
			const isGroupTitle = row.__group;
			const isGroupTotal = row.__groupTotals;
			let csvRow = "";
			if (isGroupTitle) {
				const valueWithoutQuotes = deleteDoubleQuotes(removeHtml(row.title));
				csvRow += `"${valueWithoutQuotes}",`;
			} else {
				for (let i = 0; i < columnsForPrinting.length; ++i) {
					const column = columnsForPrinting[i];
					const field = column.field;
					const formatterSpecific = metaData?.columns?.[field]?.formatter;
					const formatter =
						column.printer || formatterSpecific || column.formatter;
					let value = row[field];
					if (isGroupTotal) {
						const totalsFormatter = column.groupTotalsFormatter;
						value = totalsFormatter
							? totalsFormatter(
									row as unknown as SlickGroupTotals,
									column,
									grid,
								)
							: "";
					} else {
						if (formatter && !ignore.includes(formatter.name)) {
							value = formatter(0, 0, value, column, row, grid);
						}
					}
					const valueWithoutQuotes = deleteDoubleQuotes(value);
					csvRow += `"${valueWithoutQuotes}",`;
				}
			}
			return this.addRowSeparator(`${acc}${csvRow}`);
		}, "");
	}

	addRowSeparator(str: string): string {
		return `${str}\n`;
	}
}