CREATE OR REPLACE FUNCTION pg_catalog.citus_finish_pg_upgrade()
    RETURNS void
    LANGUAGE plpgsql
    SET search_path = pg_catalog
    AS $cppu$
DECLARE
    table_name regclass;
    command text;
    trigger_name text;
BEGIN
    --
    -- restore citus catalog tables
    --
    INSERT INTO pg_catalog.pg_dist_partition SELECT * FROM public.pg_dist_partition;
    INSERT INTO pg_catalog.pg_dist_shard SELECT * FROM public.pg_dist_shard;
    INSERT INTO pg_catalog.pg_dist_placement SELECT * FROM public.pg_dist_placement;
    INSERT INTO pg_catalog.pg_dist_node_metadata SELECT * FROM public.pg_dist_node_metadata;
    INSERT INTO pg_catalog.pg_dist_node SELECT * FROM public.pg_dist_node;
    INSERT INTO pg_catalog.pg_dist_local_group SELECT * FROM public.pg_dist_local_group;
    INSERT INTO pg_catalog.pg_dist_transaction SELECT * FROM public.pg_dist_transaction;
    INSERT INTO pg_catalog.pg_dist_colocation SELECT * FROM public.pg_dist_colocation;
    -- enterprise catalog tables
    INSERT INTO pg_catalog.pg_dist_authinfo SELECT * FROM public.pg_dist_authinfo;
    INSERT INTO pg_catalog.pg_dist_poolinfo SELECT * FROM public.pg_dist_poolinfo;

    ALTER TABLE pg_catalog.pg_dist_rebalance_strategy DISABLE TRIGGER pg_dist_rebalance_strategy_enterprise_check_trigger;
    INSERT INTO pg_catalog.pg_dist_rebalance_strategy SELECT
        name,
        default_strategy,
        shard_cost_function::regprocedure::regproc,
        node_capacity_function::regprocedure::regproc,
        shard_allowed_on_node_function::regprocedure::regproc,
        default_threshold,
        minimum_threshold
    FROM public.pg_dist_rebalance_strategy;
    ALTER TABLE pg_catalog.pg_dist_rebalance_strategy ENABLE TRIGGER pg_dist_rebalance_strategy_enterprise_check_trigger;

    --
    -- drop backup tables
    --
    DROP TABLE public.pg_dist_authinfo;
    DROP TABLE public.pg_dist_colocation;
    DROP TABLE public.pg_dist_local_group;
    DROP TABLE public.pg_dist_node;
    DROP TABLE public.pg_dist_node_metadata;
    DROP TABLE public.pg_dist_partition;
    DROP TABLE public.pg_dist_placement;
    DROP TABLE public.pg_dist_poolinfo;
    DROP TABLE public.pg_dist_shard;
    DROP TABLE public.pg_dist_transaction;

    --
    -- reset sequences
    --
    PERFORM setval('pg_catalog.pg_dist_shardid_seq', (SELECT MAX(shardid)+1 AS max_shard_id FROM pg_dist_shard), false);
    PERFORM setval('pg_catalog.pg_dist_placement_placementid_seq', (SELECT MAX(placementid)+1 AS max_placement_id FROM pg_dist_placement), false);
    PERFORM setval('pg_catalog.pg_dist_groupid_seq', (SELECT MAX(groupid)+1 AS max_group_id FROM pg_dist_node), false);
    PERFORM setval('pg_catalog.pg_dist_node_nodeid_seq', (SELECT MAX(nodeid)+1 AS max_node_id FROM pg_dist_node), false);
    PERFORM setval('pg_catalog.pg_dist_colocationid_seq', (SELECT MAX(colocationid)+1 AS max_colocation_id FROM pg_dist_colocation), false);

    --
    -- register triggers
    --
    FOR table_name IN SELECT logicalrelid FROM pg_catalog.pg_dist_partition
    LOOP
        trigger_name := 'truncate_trigger_' || table_name::oid;
        command := 'create trigger ' || trigger_name || ' after truncate on ' || table_name || ' execute procedure pg_catalog.citus_truncate_trigger()';
        EXECUTE command;
        command := 'update pg_trigger set tgisinternal = true where tgname = ' || quote_literal(trigger_name);
        EXECUTE command;
    END LOOP;

    --
    -- set dependencies
    --
    INSERT INTO pg_depend
    SELECT
        'pg_class'::regclass::oid as classid,
        p.logicalrelid::regclass::oid as objid,
        0 as objsubid,
        'pg_extension'::regclass::oid as refclassid,
        (select oid from pg_extension where extname = 'citus') as refobjid,
        0 as refobjsubid ,
        'n' as deptype
    FROM pg_catalog.pg_dist_partition p;

    -- restore pg_dist_object from the stable identifiers
    TRUNCATE citus.pg_dist_object;
    INSERT INTO citus.pg_dist_object (classid, objid, objsubid, distribution_argument_index, colocationid)
    SELECT
        address.classid,
        address.objid,
        address.objsubid,
        naming.distribution_argument_index,
        naming.colocationid
    FROM
        public.pg_dist_object naming,
        pg_catalog.pg_get_object_address(naming.type, naming.object_names, naming.object_args) address;

    DROP TABLE public.pg_dist_object;
END;
$cppu$;

COMMENT ON FUNCTION pg_catalog.citus_finish_pg_upgrade()
    IS 'perform tasks to restore citus settings from a location that has been prepared before pg_upgrade';
