import { get } from 'svelte/store';
import { entropyToMnemonic, mnemonicToSeedSync } from 'bip39';
import { Buffer } from 'buffer';
import { bech32m } from 'bech32';
import { bip32, post, stretch } from '$lib/utils';
import { calculateId, signId } from 'nostr';
import { password as pw, passwordPrompt } from '$lib/store';

const { decode, fromWords } = bech32m;

let signing;

pw.subscribe((nv, ov) => {
	if (!signing) return;
	sign(signing);
});

export let sign = async ({ event, user }) => {
	signing = { event, user };
	let { cipher, username, salt } = user;

	let password = get(pw);

	if (!password) {
		passwordPrompt.set(true);
		return;
	}

	try {
		await post('/password', { password });
	} catch (e) {
		console.log(e);
		passwordPrompt.set(true);
		return;
	}

	let mnemonic, key, seed, entropy, child, privkey;
	entropy = Buffer.from(
		await crypto.subtle.decrypt(
			{ name: 'AES-GCM', iv: new Uint8Array(16) },
			await stretch(password, Buffer.from(salt, 'hex')),
			Uint8Array.from(fromWords(decode(cipher, 180).words))
		),
		'hex'
	).toString('hex');

	mnemonic = entropyToMnemonic(entropy);
	seed = mnemonicToSeedSync(mnemonic);
	key = bip32.fromSeed(seed);
	child = key.derivePath("m/44'/1237'/0'/0/0");
	privkey = child.privateKey;

	event.id = await calculateId(event);
	event.sig = await signId(privkey, event.id);

	signing = false;
};

export let send = (event) => {
	return post('/events', { event });
};