import * as Excel from "exceljs";
import * as moment from "moment";
import * as speedtest from "speedtest-net";
import { existsSync } from "fs";

/**
 * Speedtest class
 */
export default class Speedtest {
	private path: string;

	constructor (path?: string) {
		this.path = path ? path : "./data.xlsx";
		if (!this._checks) return;
	};

	/**
	 * Run a speedtest and save the results
	 * @returns {void}
	 */
	run (): void {
		let test = speedtest({
			maxTime: 5000
		});
		if (!this._checks) return;
		test.on("data", (data: SpeedtestResults) => {
			const { download, upload } = data.speeds;
			let date: string = moment().format("YYYY-MM-DD H:mm:ss");
			console.log(`[${date}] Upload: ${upload}, Download: ${download}`);
			this._save(data);
		});
		test.on("error", (err: Error) => {
			throw err;
		});
	}

	/**
	 * Save the results to the file
	 * @param {SpeedtestResults} results - The test results to save
	 * @param {string} path - Where to save the results
	 * @private
	 */
	private _save (results: SpeedtestResults, path?: string) {
		if (path) this.path = path;
		if (!(this._checks)) return;
		let workbook = new Excel.Workbook();
		workbook
			.xlsx
			.readFile(this.path)
			.then((): Promise<void> => {
				let worksheet = workbook.getWorksheet("speedtest") || workbook.addWorksheet("speedtest");
				let date = moment().format("YYYY-MM-DD H:mm:ss");

				worksheet.columns = [
					{ header: "Date", key: "date" },
					{ header: "Download", key: "down_speed" },
					{ header: "Upload", key: "up_speed" },
					{ header: "Ping", key: "ping" },
					{ header: "Full Results", key: "full_results", hidden: true }
				];

				worksheet.addRow(
					{
						date: date,
						down_speed: results.speeds.download,
						up_speed: results.speeds.upload,
						ping: results.server.ping,
						full_results: results
					}
				);
				return workbook.xlsx.writeFile(this.path);
			});
	}

	/**
	 * Checks if the file exists and can be edited.
	 * @return {boolean} - The file exists
	 * @private
	 */
	private get _checks (): boolean {
		let tempPrefix = "~$";
		let path: string[] = this.path.split("/");
		let tempFile = tempPrefix + path[path.length - 1];
		let fileExt = tempFile.split(".").pop();
		let tempPath = path.slice(0, -1).join("/");

		if (existsSync(`${tempPath}/${tempFile}`)) {
			console.error("A temp file is present, meaning the log file cannot be edited. This is most likely caused by the file being used by another program.");
			return false;
		}
		if (!existsSync(this.path)) throw new Error(`There is no file located at ${require("path").resolve(this.path)}`);
		if (fileExt !== "xlsx") throw new Error("The log file must be an xlsx file.");
		return true;
	}
}

interface SpeedtestResults {
	speeds: {
		download: number;
		upload: number;
		originalDownload: number;
	},
	client: {
		ip: string;
		lat: number;
		lon: number;
		isp: string;
		isprating: number;
		rating: number;
		ispdlavg: number;
		ispulavg: number;
		country: string;
	},
	server: {
		host: string;
		lat: number;
		lon: number;
		location: string;
		country: string;
		cc: string;
		sponsor: string;
		distance: number;
		distanceMi: number;
		ping: number;
		id: number;
	}
}