Jinja Stable UUID with home-brewn hash

badHash.j2

{%- macro xor(a, b) %} {#- Macros can only return text #}
    {%- if (a and not b) or (not a and b) -%}
        1
    {%- else -%}
        0
    {%- endif %}
{%- endmacro -%}

{%- macro bitsToHex(bools) %}
    {%- for hex in (bools | batch(4)) %}
        {%- set sum = 0 %}

        {%- if hex[0] %}{%- set sum = sum + 8 %}{% endif %}
        {%- if hex[1] %}{%- set sum = sum + 4 %}{% endif %}
        {%- if hex[2] %}{%- set sum = sum + 2 %}{% endif %}
        {%- if hex[3] %}{%- set sum = sum + 1 %}{% endif %}

        {%- if sum < 10 %}{{ sum }}
            {%- elif sum == 10 %}a
            {%- elif sum == 11 %}b
            {%- elif sum == 12 %}c
            {%- elif sum == 13 %}d
            {%- elif sum == 14 %}e
            {%- elif sum == 15 %}f
        {%- endif %}

    {%- endfor %}
{%- endmacro %}

{%- macro badHash(input) %} {#- since there is no seedable randomness nor hashing available and cutting off parts of the input is just unacceptable as to allow self-inflicted pain #}
    {%- set bitstream = [] %}
    {%- for part in input.encode("utf-8") %}
        {%- for bit in '{:b}'.format(part) %}
            {%- do bitstream.append(bit == "1") %}
        {%- endfor %}
    {%- endfor -%}

    {%- set result = [False]*12*4 %} {#- 12 last UUID digits, 4 bits in one hex #}
    {%- for chunk in bitstream | batch(12*4) %}
        {%- for bit in chunk %}
            {%- do result.append(xor(result[0], bit) == "1"), result.pop(0) %}
        {%- endfor %}
    {%- endfor -%}

    {{- bitsToHex(result) }}
{%- endmacro -%}

{%- set labUUID = {} %}
{%- for i in instance %}
    {%- do labUUID.update({instance: '1ab00000-0000-0000-0000-'+badHash(i)}) %}
{%- endfor -%}