-- citus--10.0-3--10.0-4

-- This migration file aims to fix 2 issues with upgrades on clusters

-- 1. a bug in public schema dependency for citus_tables view.
--
-- Users who do not have public schema in their clusters were unable to upgrade
-- to Citus 10.x due to the citus_tables view that used to be created in public
-- schema


DO $$
declare
citus_tables_create_query text;
BEGIN
citus_tables_create_query=$CTCQ$
    CREATE OR REPLACE VIEW %I.citus_tables AS
    SELECT
        logicalrelid AS table_name,
        CASE WHEN partkey IS NOT NULL THEN 'distributed' ELSE 'reference' END AS citus_table_type,
        coalesce(column_to_column_name(logicalrelid, partkey), '<none>') AS distribution_column,
        colocationid AS colocation_id,
        pg_size_pretty(citus_total_relation_size(logicalrelid, fail_on_error := false)) AS table_size,
        (select count(*) from pg_dist_shard where logicalrelid = p.logicalrelid) AS shard_count,
        pg_get_userbyid(relowner) AS table_owner,
        amname AS access_method
    FROM
        pg_dist_partition p
    JOIN
        pg_class c ON (p.logicalrelid = c.oid)
    LEFT JOIN
        pg_am a ON (a.oid = c.relam)
    WHERE
        partkey IS NOT NULL OR repmodel = 't'
    ORDER BY
        logicalrelid::text;
$CTCQ$;

IF EXISTS (SELECT 1 FROM pg_namespace WHERE nspname = 'public') THEN
    EXECUTE format(citus_tables_create_query, 'public');
    GRANT SELECT ON public.citus_tables TO public;
ELSE
    EXECUTE format(citus_tables_create_query, 'citus');
    ALTER VIEW citus.citus_tables SET SCHEMA pg_catalog;
    GRANT SELECT ON pg_catalog.citus_tables TO public;
END IF;

END;
$$;


-- 2. a bug in our PG upgrade functions
--
-- Users who took the 9.5-2--10.0-1 upgrade path already have the fix, but users
-- who took the 9.5-1--10.0-1 upgrade path do not. Hence, we repeat the CREATE OR
-- REPLACE from the 9.5-2 definition for citus_prepare_pg_upgrade.


CREATE OR REPLACE FUNCTION pg_catalog.citus_prepare_pg_upgrade()
    RETURNS void
    LANGUAGE plpgsql
    SET search_path = pg_catalog
    AS $cppu$
BEGIN
    --
    -- Drop existing backup tables
    --
    DROP TABLE IF EXISTS public.pg_dist_partition;
    DROP TABLE IF EXISTS public.pg_dist_shard;
    DROP TABLE IF EXISTS public.pg_dist_placement;
    DROP TABLE IF EXISTS public.pg_dist_node_metadata;
    DROP TABLE IF EXISTS public.pg_dist_node;
    DROP TABLE IF EXISTS public.pg_dist_local_group;
    DROP TABLE IF EXISTS public.pg_dist_transaction;
    DROP TABLE IF EXISTS public.pg_dist_colocation;
    DROP TABLE IF EXISTS public.pg_dist_authinfo;
    DROP TABLE IF EXISTS public.pg_dist_poolinfo;
    DROP TABLE IF EXISTS public.pg_dist_rebalance_strategy;
    DROP TABLE IF EXISTS public.pg_dist_object;

    --
    -- backup citus catalog tables
    --
    CREATE TABLE public.pg_dist_partition AS SELECT * FROM pg_catalog.pg_dist_partition;
    CREATE TABLE public.pg_dist_shard AS SELECT * FROM pg_catalog.pg_dist_shard;
    CREATE TABLE public.pg_dist_placement AS SELECT * FROM pg_catalog.pg_dist_placement;
    CREATE TABLE public.pg_dist_node_metadata AS SELECT * FROM pg_catalog.pg_dist_node_metadata;
    CREATE TABLE public.pg_dist_node AS SELECT * FROM pg_catalog.pg_dist_node;
    CREATE TABLE public.pg_dist_local_group AS SELECT * FROM pg_catalog.pg_dist_local_group;
    CREATE TABLE public.pg_dist_transaction AS SELECT * FROM pg_catalog.pg_dist_transaction;
    CREATE TABLE public.pg_dist_colocation AS SELECT * FROM pg_catalog.pg_dist_colocation;
    -- enterprise catalog tables
    CREATE TABLE public.pg_dist_authinfo AS SELECT * FROM pg_catalog.pg_dist_authinfo;
    CREATE TABLE public.pg_dist_poolinfo AS SELECT * FROM pg_catalog.pg_dist_poolinfo;
    CREATE TABLE public.pg_dist_rebalance_strategy AS SELECT
        name,
        default_strategy,
        shard_cost_function::regprocedure::text,
        node_capacity_function::regprocedure::text,
        shard_allowed_on_node_function::regprocedure::text,
        default_threshold,
        minimum_threshold
    FROM pg_catalog.pg_dist_rebalance_strategy;

    -- store upgrade stable identifiers on pg_dist_object catalog
    CREATE TABLE public.pg_dist_object AS SELECT
       address.type,
       address.object_names,
       address.object_args,
       objects.distribution_argument_index,
       objects.colocationid
    FROM citus.pg_dist_object objects,
         pg_catalog.pg_identify_object_as_address(objects.classid, objects.objid, objects.objsubid) address;
END;
$cppu$;

COMMENT ON FUNCTION pg_catalog.citus_prepare_pg_upgrade()
    IS 'perform tasks to copy citus settings to a location that could later be restored after pg_upgrade is done';

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;
    DROP TABLE public.pg_dist_rebalance_strategy;

    --
    -- 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;

    PERFORM citus_internal.columnar_ensure_objects_exist();
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';


