import csv from "csv-parser";
import fs from "fs";
import path from "path";

export type User = {
	name: string;
	email: string;
	password: string;
	accessLevel: string;
};

/**
 * @returns {array} - Array of Objects containing user data
 */
export async function readUserCsv(): Promise<User[]> {
	return new Promise((resolve, reject) => {
		// Dynamic CSV location generation
		let csvPath = path.dirname(__dirname); // /login
		csvPath = path.dirname(csvPath); // /api
		csvPath = path.dirname(csvPath); // /app
		csvPath = path.dirname(csvPath); // /src
		csvPath = path.dirname(csvPath); // /[project]
		csvPath = path.dirname(csvPath); // /termor-tracker
		csvPath = path.join(csvPath, "src", "databases", "Users.csv");

		// Forms array for user data
		let results: User[] = [];
		// Reads data and adds it to results
		fs.createReadStream(csvPath)
			.pipe(csv())
			.on("data", (data) => results.push(data))
			.on("end", () => {
				resolve(results);
			})
			.on("error", (error) => {
				reject(error);
			});
	});
}

export function findUserByEmail(users: User[], email: string): User | undefined {
	return users.find((user) => user.email === email);
}

export async function passwordStrengthCheck(password: string): Promise<string> {
	if (password.length < 8) {
		return "short";
	} else if (password.length > 16) {
		return "long";
	}
	const lowercaseRegex = /[a-z]/;
	const uppercaseRegex = /[A-Z]/;
	const digitRegex = /\d/;
	const specialCharRegex = /[!@#$%^&*]/;
	if (!lowercaseRegex.test(password)) {
		return "no lower";
	} else if (!uppercaseRegex.test(password)) {
		return "no upper";
	} else if (!digitRegex.test(password)) {
		return "no digit";
	} else if (!specialCharRegex.test(password)) {
		return "no special";
	} else {
		return "secure";
	}
	return "end of function";
}

/**
 * Writes User objects to the Users.csv file
 * @param users {User[]} Array of User objects to write to the CSV file
 * @returns {Promise<void>}
 */
export async function writeUserCsv(users: User[]): Promise<void> {
	return new Promise((resolve, reject) => {
		// Dynamic CSV location generation
		let csvPath = path.dirname(__dirname); // /login
		csvPath = path.dirname(csvPath); // /api
		csvPath = path.dirname(csvPath); // /app
		csvPath = path.dirname(csvPath); // /src
		csvPath = path.dirname(csvPath); // /[project]
		csvPath = path.dirname(csvPath); // /termor-tracker
		csvPath = path.join(csvPath, "src", "databases", "Users.csv");

		// Prepare CSV data as a string
		const headers = "name,email,password,level"; // CSV headers
		const rows = users.map((user) => `${user.name},${user.email},${user.password},${user.accessLevel}`);
		const csvData = `${headers}\n${rows.join("\n")}`;

		// Write data to the file
		fs.writeFile(csvPath, csvData, (error) => {
			if (error) {
				reject(error); // Reject promise on error
			} else {
				resolve(); // Resolve the promise if successful
			}
		});
	});
}