pezkuwi-apps/packages/react-components/src/IdentityIcon/RoboHash/index.tsx

// Copyright 2017-2025 @pezkuwi/react-components authors & contributors
// SPDX-License-Identifier: Apache-2.0

// Robots lovingly delivered by Robohash.org
// https://github.com/e1ven/Robohash
//
// The "set1" artwork (and robohash backgrounds) were created by Zikri Kader. They are available under CC-BY-3.0 or CC-BY-4.0 license.
// The "set2" artwork was created by Hrvoje Novakovic. They are available under CC-BY-3.0 license.
// The "set3" artwork was created by Julian Peter Arias. They are available under CC-BY-3.0 license.
// The Cats/"set4" were created by David Revoy, used under CC-BY-4.0 https://www.peppercarrot.com/en/article391/cat-avatar-generator
// The avatars used in "set5" were created by Pablo Stanley, for https://avataaars.com/ They are "Free for personal and commercial use. 😇"

import React, { useMemo } from 'react';

import { blake2AsU8a } from '@pezkuwi/util-crypto';

import { styled } from '../../styled.js';
import backgrounds from './backgrounds/index.js';
import sets from './sets/index.js';

interface Props {
  className?: string;
  publicKey: string;
  size: number;
}

interface HashRef {
  hash: Uint8Array;
  index: number;
}

function getIndex <T> (list: T[], hash: HashRef): T {
  let value = 0;

  // grab 48 bits worth of data (last increment before max int)
  // (6 also doesn't divide into 32, so we have a rolling window)
  for (let i = 0; i < 6; i++) {
    value = (value * 256) + hash.hash[hash.index];
    hash.index++;

    if (hash.index === 32) {
      hash.index = 0;
    }
  }

  return list[value % list.length];
}

function createInfo (value: string): string[] {
  const hash = {
    hash: blake2AsU8a(value),
    index: 0
  };
  const result = [getIndex(backgrounds, hash)];

  getIndex(sets, hash).forEach((section): void => {
    result.push(getIndex(section, hash));
  });

  return result;
}

function RoboHash ({ className, publicKey, size }: Props): React.ReactElement<Props> | null {
  const info = useMemo(
    () => createInfo(publicKey),
    [publicKey]
  );
  const style = useMemo(
    () => ({ height: `${size}px`, width: `${size}px` }),
    [size]
  );

  return (
    <StyledDiv
      className={className}
      style={style}
    >
      {info.map((src, index) =>
        <img
          key={index}
          src={src}
        />
      )}
    </StyledDiv>
  );
}

const StyledDiv = styled.div`
  background: var(--bg-page);
  border-radius: 50%;
  position: relative;
  overflow: hidden;

  img {
    height: 100%;
    left: 0;
    position: absolute;
    top: 0;
    width: 100%;

    &:first-child {
      opacity: 0.35;
    }
  }
`;

export default React.memo(RoboHash);