let encrypt = function() {
	key = document.getElementById("key").value;
	string = document.getElementById("plaintext").value;
	if (typeof key !== "number") {
		throw new Error("Key must be a number");
	}
	let resultArray = []
	for (let i = 0; i < string.length; i++) {
		if (string.charCodeAt(i) < 97 || string.charCodeAt(i) > 122) {
			resultArray.push(string[i]);
			continue;
		}
		let code = string.charCodeAt(i) + key;
		while (code > 122) {
			code = (code - 122) + 96;
		}
		resultArray.push(String.fromCharCode(code))
	}

	document.getElementById("encoded").value = resultArray.join(" ");
}

let bruteforce = function() {
	let know_element = document.getElementById("know_element").value;
	let string = document.getElementById("encoded").value;
	if (typeof key !== "number") {
		throw new Error("Key must be a number");
	}

	let resultArray = []
	let workingKeys = []

	for (key = 0; key < 26; key++) {
		resultArray = decrypt(key, string);
		if (resultArray.includes(know_element)) {
			workingKeys.push(key);
		}
	}
	document.getElementById("key").value = workingKeys.join(",");
}

let decrypt = function(key, string) {
	resultArray = []
	for (let i = 0; i < string.length; i++) {
		if (string.charCodeAt(i) < 97 || string.charCodeAt(i) > 122) {
			resultArray.push(string[i]);
			continue;
		}
		let code = string.charCodeAt(i) - key;
		while (code - 96) {
			code = (code + 122) - 96;
		}
		resultArray.push(String.fromCharCode(code))
	}
	return resultArray.join(" ");
}

let manual_decrypt = function() {
	let key = document.getElementById("key").value;
	let string = document.getElementById("encoded").value;
	document.getElementById("plaintext").value = decrypt(key, string);
}