[rbdr/forum] / src / lib / utils / glyph_hash.ts

export type GlyphHash = GlyphHashFragment[];
type GlyphHashFragment = {
        glyph: string;
        color: string;
};

const internals = {
        kDehyphenRegex: /[-]/g,
        kSplitterRegex: /.{1,8}/g,
        kGlyphs: ['☽', '☆', '♢', '♡', '╱', '╲', '╳', '〰', '▷', '⏊', '〒', '▢', '◯', '⏃', '⏀', '⏆'],
        unexpectedUUIDLength: class UnexpectedUUIDLength extends Error {
                name = 'UnexpectedUUIDLength';
                message =
                        'The provided string was not a valid UUIDv4, please provide a 32 character long string';
        }
};

// Return a glyph with color based on a 4 byte fragment of a UUIDv4
const getGlyphHashFragment = function (uuidFragment: string): GlyphHashFragment {
        const glyphIndex = parseInt(uuidFragment.substring(0, 2), 16) % 16;
        return {
                glyph: internals.kGlyphs[glyphIndex],
                color: `#${uuidFragment.substring(2, 8)}`
        };
};

// Return an array of glyphs based on a UUIDv4
export const getGlyphHash = function (uuid: string): GlyphHash {
        const dehyphenedUuid = uuid.replace(/[-]/g, '');

        if (dehyphenedUuid.length !== 32) {
                throw new internals.unexpectedUUIDLength();
        }

        const hashFragments = dehyphenedUuid.match(internals.kSplitterRegex);
        return hashFragments.map(getGlyphHashFragment);
};