/*
Copyright (C) 2021 Yarmo Mackenbach

This program is free software: you can redistribute it and/or modify it under
the terms of the GNU Affero General Public License as published by the Free
Software Foundation, either version 3 of the License, or (at your option)
any later version.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
details.

You should have received a copy of the GNU Affero General Public License along
with this program. If not, see <https://www.gnu.org/licenses/>.

Also add information on how to contact you by electronic and paper mail.

If your software can interact with users remotely through a computer network,
you should also make sure that it provides a way for users to get its source.
For example, if your program is a web application, its interface could display
a "Source" link that leads users to an archive of the code. There are many
ways you could offer source, and different solutions will be better for different
programs; see section 13 for the specific requirements.

You should also get your employer (if you work as a programmer) or school,
if any, to sign a "copyright disclaimer" for the program, if necessary. For
more information on this, and how to apply and follow the GNU AGPL, see <https://www.gnu.org/licenses/>.
*/
import { webcrypto as crypto } from 'crypto'

export async function computeWKDLocalPart(localPart) {
    const localPartEncoded = new TextEncoder().encode(localPart.toLowerCase());
    const localPartHashed = new Uint8Array(await crypto.subtle.digest('SHA-1', localPartEncoded));
    return encodeZBase32(localPartHashed);
}

export function generatePageTitle(type, data) {
    switch (type) {
        case 'profile':
            try {
                return `${data.keyData.users[data.keyData.primaryUserIndex].userData.name} - Keyoxide`
            } catch (error) {
                return 'Profile - Keyoxide'
            }
            break

        default:
            return 'Keyoxide'
            break
    }
}

// Copied from https://github.com/openpgpjs/wkd-client/blob/0d074519e011a5139a8953679cf5f807e4cd2378/src/wkd.js
function encodeZBase32(data) {
    if (data.length === 0) {
        return "";
    }
    const ALPHABET = "ybndrfg8ejkmcpqxot1uwisza345h769";
    const SHIFT = 5;
    const MASK = 31;
    let buffer = data[0];
    let index = 1;
    let bitsLeft = 8;
    let result = '';
    while (bitsLeft > 0 || index < data.length) {
        if (bitsLeft < SHIFT) {
            if (index < data.length) {
                buffer <<= 8;
                buffer |= data[index++] & 0xff;
                bitsLeft += 8;
            } else {
                const pad = SHIFT - bitsLeft;
                buffer <<= pad;
                bitsLeft += pad;
            }
        }
        bitsLeft -= SHIFT;
        result += ALPHABET[MASK & (buffer >> bitsLeft)];
    }
    return result;
}