import { globalState } from '../../app/global-state';
import { PortalUtils } from './utils';

/**
 * Cross-browser clipboard handler
 */
export default class ClipboardProvider {
	/**
	 * Copy given text to the clipboard
	 *
	 * @param text Text for clipboard copy
	 */
	static copyToClipboard(text: string): boolean {
		let succeeded = false;
		let cleanUp = () => {};

		try {
			const container = document.createElement('div');
			document.body.appendChild(container);

			const dummyElem = document.createElement('textarea');
			dummyElem.id = `txt-${PortalUtils.randomString(8)}`;
			dummyElem.style.fontSize = '12pt';
			dummyElem.style.border = '0';
			dummyElem.style.padding = '0';
			dummyElem.style.margin = '0';
			dummyElem.style.position = 'absolute';
			dummyElem.style.left = '0';
			dummyElem.setAttribute('readonly', '');
			dummyElem.style.opacity = '0.001';

			const yPosition = globalState.pageYOffset || document.documentElement.scrollTop;
			dummyElem.style.top = `${yPosition}px`;
			dummyElem.value = text;

			let fakeHandler: any;
			let fakeHandlerCallback: any;
			cleanUp = () => {
				container.removeEventListener('click', fakeHandlerCallback);
				fakeHandler = null;
				fakeHandlerCallback = null;
				document.body.removeChild(container);
				cleanUp = null;
			};

			fakeHandlerCallback = () => {
				cleanUp();
			};
			fakeHandler = container.addEventListener('click', fakeHandlerCallback);

			container.appendChild(dummyElem);
			dummyElem.focus();
			dummyElem.select();
			dummyElem.setSelectionRange(0, dummyElem.value.length);

			succeeded = document.execCommand('copy');
		} catch (err) {
			succeeded = false;
			cleanUp();
		}

		return succeeded;
	}

	/**
	 * Copy given object array into format that can get consumed by excel
	 *
	 * @param rowArr Array of rows
	 */
	static copySheetToClipboard(rowArr: any[]): boolean {
		return this.copyToClipboard(this._stringifyObjForSheetExport(rowArr));
	}

	/**
	 * PRIVATE Powered by sheetclip
	 *
	 * @param arr
	 */
	private static _stringifyObjForSheetExport(arr: any[]) {
		let r;
		let rlen;
		let c;
		let clen;
		let str = '';
		let val;
		for (r = 0, rlen = arr.length; r < rlen; r += 1) {
			for (c = 0, clen = arr[r].length; c < clen; c += 1) {
				if (c > 0) {
					str += '\t';
				}

				val = arr[r][c];
				if (typeof val === 'string') {
					if (val.includes('\n')) {
						str += `"${val.replace(/"/g, '""')}"`;
					} else {
						str += val;
					}
				} else if (val === null || val === void 0) {
					// void 0 resolves to undefined
					str += '';
				} else {
					str += val;
				}
			}
			str += '\n';
		}
		return str;
	}
}