"""jsonb_agg_uniq

Revision ID: a24e03d2a7ec
Revises: 6f872738dab7
Create Date: 2018-06-14 20:48:06.950616

"""

# revision identifiers, used by Alembic.
revision = 'a24e03d2a7ec'
down_revision = '6f872738dab7'
branch_labels = None
depends_on = None

from alembic import op
import sqlalchemy as sa


def upgrade():
    op.execute("""
CREATE OR REPLACE FUNCTION f_array_append_uniq (jsonb, jsonb)
RETURNS jsonb AS
$func$
SELECT CASE
   WHEN $1 is null then jsonb_build_array($2)
   WHEN ($1->-1) <> $2 THEN $1 || jsonb_build_array($2)
   ELSE $1
END
$func$ LANGUAGE sql IMMUTABLE;
    """)

    op.execute("""
CREATE AGGREGATE jsonb_agg_uniq(jsonb) (
   SFUNC = f_array_append_uniq
 , STYPE = jsonb
);
    """)

def downgrade():
    op.execute('''DROP AGGREGATE jsonb_agg_uniq(anyelement)''')
    op.execute('''drop FUNCTION f_array_append_uniq (jsonb, anyelement)''')