function base32_nopad_encode(slice) {
	const encoder = new base32.Encoder({ type: "rfc4648", lc: true });
	const code = encoder.write(slice).finalize();
	return code.replaceAll('=', '');
}

function base64_decode(str_b64) {
	const raw_str = atob(str_b64);
	const length = raw_str.length;
	var b = [];
	for (var i = 0; i < length; i++) {
		b.push(raw_str.charCodeAt(i));
	}
	return b;
}

class Account {
	constructor(local_part, separator, domain, key) {
		this.local_part = local_part;
		this.domain = domain;
		this.separator = separator;
		if (Array.isArray(key)) {
			this.key = key;
		} else {
			this.key = base64_decode(key);
		}
	}

	getName() {
		return `${this.local_part}@${this.domain}`;
	}

	genSubAddr(sub_addr_name) {
		var hasher = sha256.hmac.create(this.key);
		hasher.update(this.local_part);
		hasher.update(this.separator);
		hasher.update(sub_addr_name);
		const hash = hasher.array();
		const offset = hash[hash.length - 1] & 0xf;
		const reduced_hash = hash.slice(offset, offset + 5);
		const code = base32_nopad_encode(reduced_hash);
		return `${this.local_part}${this.separator}${sub_addr_name}${this.separator}${code}@${this.domain}`
	}

	register() {
		localStorage.setItem(this.getName(), JSON.stringify(this));
	}
}

document.addEventListener('DOMContentLoaded', () => {
	// Functions to open and close a modal
	function openModal() {
		document.querySelector('#modal-add-account').classList.add('is-active');
	}

	function closeModal() {
		if (localStorage.length !== 0) {
			document.querySelector('#modal-add-account').classList.remove('is-active');
			syncAccountList();
		}
	}

	// Function to synchronize the account list
	function syncAccountList() {
		var acc_list = document.querySelector('#account-name');
		while (acc_list.lastElementChild) {
			acc_list.removeChild(acc_list.lastElementChild);
		}
		for (var i = 0, len = localStorage.length; i < len; ++i) {
			const account_string = localStorage.getItem(localStorage.key(i));
			const account_raw = JSON.parse(account_string);
			const account = new Account(
				account_raw.local_part,
				account_raw.separator,
				account_raw.domain,
				account_raw.key,
			);
			const new_elem = new Option(account.getName(), account.getName());
			acc_list.appendChild(new_elem);
		}
		if (localStorage.length === 0) {
			openModal();
		}
	}
	syncAccountList();

	// Add a click event on buttons to open a specific modal
	(document.querySelectorAll('.js-modal-trigger') || []).forEach(($trigger) => {
		$trigger.addEventListener('click', () => {
			openModal();
		});
	});

	// Add a click event on various child elements to close the parent modal
	(document.querySelectorAll('.modal-background, .modal-close, .modal-card-head .delete, .modal-card-foot .button-close') || []).forEach(($close) => {
		$close.addEventListener('click', () => {
			closeModal();
		});
	});

	// Add a keyboard event to close all modals
	document.addEventListener('keydown', (event) => {
		if (event.code === 'Escape') {
			closeModal();
		}
	});

	// Add a click event on the new account button to register the new account
	document.querySelector('#btn-new-account').addEventListener('click', (event) => {
		console.log('Adding new account…');
		const new_account = new Account(
			document.querySelector('#new-addr-local-part').value,
			document.querySelector('#new-addr-separator').value,
			document.querySelector('#new-addr-domain').value,
			document.querySelector('#new-addr-key').value,
		);
		console.log(new_account);
		new_account.register();
		console.log(`Account ${new_account.getName()} added.`);
		closeModal();
	});

	// Add a click event on the new address button to generate it
	document.querySelector('#btn-generate').addEventListener('click', (event) => {
		console.log('Generating a new address…');
		event.preventDefault();
		// TODO
	});
});

window.addEventListener('load', () => {
	if ('serviceWorker' in navigator) {
		navigator.serviceWorker.register('/sw.js');
	}
});