"use strict";

async function postJSON(url, data) {
	const response = await fetch(url, {
		method: 'POST',
		headers: {
			'Content-Type': 'application/json'
		},
		body: JSON.stringify(data),
	});
	if (!response.ok) {
		if (response.statusText) {
			throw new Error(response.statusText);
		} else {
			throw new Error("Something went wrong");
		}
	}
	return response.json();
}

async function getJSON(url) {
	const response = await fetch(url);
	if (!response.ok) {
		if (response.statusText) {
			throw new Error(response.statusText);
		} else {
			throw new Error("Something went wrong");
		}
	}
	return response.json();
}

function verifySig(pubkey, signature, data) {
	return window.crypto.subtle.verify(
		{
			name: "ECDSA",
			hash: { name: "SHA-256" },
		},
		pubkey,
		signature,
		data,
	);
}

function signData(privkey, data) {
	return window.crypto.subtle.sign(
		{
			name: "ECDSA",
			hash: { name: "SHA-256" },
		},
		privkey,
		data,
	);
}

function ab2str(buf) {
	let binary = '';
	const bytes = new Uint8Array(buf);
	for (let i = 0, len = bytes.byteLength; i < len; i++) {
		binary += String.fromCharCode(bytes[i]);
	}
	return binary;
}

// PEM key import code from:
// https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto/importKey#pkcs_8_import

function str2ab(str) {
	const buf = new ArrayBuffer(str.length);
	const bufView = new Uint8Array(buf);
	for (let i = 0, len = str.length; i < len; i++) {
		bufView[i] = str.charCodeAt(i);
	}
	return buf;
}

function importPrivateKey(pem) {
	// fetch the part of the PEM string between header and footer
	const pemHeader = "-----BEGIN PRIVATE KEY-----";
	const pemFooter = "-----END PRIVATE KEY-----";
	if (pem.length < pemHeader.length + pemFooter.length + 90 ||
		  pem.indexOf(pemHeader) < 0 ||
		  pem.indexOf(pemFooter) < 0) {
		throw new Error("Invalid PEM key format");
	}
	const pemContents = pem.substring(
		pem.indexOf(pemHeader) + pemHeader.length,
		pem.indexOf(pemFooter),
	);
	// base64 decode the string to get the binary data
	const binaryDerString = window.atob(pemContents);
	// convert from a binary string to an ArrayBuffer
	const binaryDer = str2ab(binaryDerString);

	return window.crypto.subtle.importKey(
		"pkcs8",
		binaryDer,
		{
			name: "ECDSA",
			namedCurve: "P-256",
		},
		false,
		["sign"],
	);
}

function adminPublicKey() {
	const pemContents = "MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEG4nMe1/gySwCCGQxHL4nlwmpcOYllW1PDH0nQhoNYhGHK/UBtfgUKG9u/XjcWfEYFY2cvZWGrPyHzhzxVnV8bA==";
	// base64 decode the string to get the binary data
	const binaryDerString = window.atob(pemContents);
	// convert from a binary string to an ArrayBuffer
	const binaryDer = str2ab(binaryDerString);

	return window.crypto.subtle.importKey(
		"spki",
		binaryDer,
		{
			name: "ECDSA",
			namedCurve: "P-256",
		},
		false,
		["verify"],
	);
}