{% macro get_column_values(table, column, order_by='count(*) desc', max_records=none, default=none) -%}

{{ return(adapter.dispatch('get_column_values', 'dbt_utils')(table, column, order_by, max_records, default)) }}

{% endmacro %}

{% macro default__get_column_values(table, column, order_by='count(*) desc', max_records=none, default=none) -%}

{% if default is none %}

{% set default = [] %}

{% endif %}

{#-- Prevent querying of db in parsing mode. This works because this macro does not create any new refs. #}

{%- if not execute -%}

{{ return(default) }}

{% endif %}

{# Not all relations are tables. Renaming for internal clarity without breaking functionality for anyone using named arguments #}

{# TODO: Change the method signature in a future 0.x.0 release #}

{%- set target_relation = table -%}

{# adapter.load_relation is a convenience wrapper to avoid building a Relation when we already have one #}

{% set relation_exists = (load_relation(target_relation)) is not none %}

{%- call statement('get_column_values', fetch_result=true) %}

{%- if not relation_exists and default is none -%}

{{ exceptions.raise_compiler_error("In get_column_values(): relation " ~ target_relation ~ " does not exist and no default value was provided.") }}

{%- elif not relation_exists and default is not none -%}

{{ log("Relation " ~ target_relation ~ " does not exist. Returning the default value: " ~ default) }}

{{ return(default) }}

{%- else -%}

select

{{ column }} as value

from {{ target_relation }}

group by {{ column }}

order by {{ order_by }}

{% if max_records is not none %}

limit {{ max_records }}

{% endif %}

{% endif %}

{%- endcall -%}

{%- set value_list = load_result('get_column_values') -%}

{%- if value_list and value_list['data'] -%}

{%- set values = value_list['data'] | map(attribute=0) | list %}

{{ return(values) }}

{%- else -%}

{{ return(default) }}

{%- endif -%}

{%- endmacro %}