-- Access method dependencies, pg9.6+ (requires contrib bloom).
CREATE EXTENSION bloom;
-- Remove all the hypothetical indexes if any
SELECT hypopg_reset();
CREATE TABLE hypo_inval_am(a integer);
CREATE FUNCTION hypo_inval_am_func(integer) RETURNS integer
    LANGUAGE SQL IMMUTABLE AS 'SELECT $1 + 1';

DO $$
DECLARE
    action text;
    plain_idx oid;
    bloom_idx oid;
    expr_idx oid;
    expected_inval_count integer;
    is_inval bool;
BEGIN
    FOREACH action IN ARRAY ARRAY['function', 'drop']
    LOOP
        PERFORM hypopg_reset();
        SELECT indexrelid INTO plain_idx FROM hypopg_create_index(
            'CREATE INDEX ON hypo_inval_am (a)');
        SELECT indexrelid INTO bloom_idx FROM hypopg_create_index(
            'CREATE INDEX ON hypo_inval_am USING bloom (a)');
        SELECT indexrelid INTO expr_idx FROM hypopg_create_index(
            'CREATE INDEX ON hypo_inval_am USING bloom (hypo_inval_am_func(a))');

        -- Changes to an unrelated AM must leave all indexes valid.
        CREATE ACCESS METHOD hypo_inval_unrelated TYPE INDEX HANDLER bthandler;
        DROP ACCESS METHOD hypo_inval_unrelated;
        IF EXISTS (SELECT 1 FROM hypopg() WHERE invalidated) THEN
            RAISE WARNING 'unrelated access method invalidated an index: %', action;
        END IF;

        -- An update on pg_am will send an invalidation for AMOID cache and the
        -- uderlying access method oid, even if the update is a no-op.  So
        -- forcing an invalidation message for a core AM should not invalidate
        -- any hypothetical index.
        UPDATE pg_catalog.pg_am SET amname = amname WHERE amname = 'btree';
        IF EXISTS (SELECT 1 FROM hypopg() WHERE invalidated) THEN
            RAISE WARNING 'core access method invalidated an index: %', action;
        END IF;

        IF action = 'function' THEN
            -- Send an invalidation for hypo_inval_am_func, so only the
            -- hypothetical index using it should be invalidated
            ALTER FUNCTION hypo_inval_am_func(integer) COST 200;
            expected_inval_count := 1;
        ELSE
            -- Removing the extension also changes operator families and their
            -- members, which now invalidate every hypothetical index.
            DROP EXTENSION bloom;
            expected_inval_count := 3;
        END IF;

        -- We should have the expected number of invalidated indexes
        IF (SELECT count(*) FROM hypopg() WHERE invalidated) <> expected_inval_count THEN
            RAISE WARNING 'incorrect access method/function invalidation: %', action;
        END IF;

        -- Check the exact hypothetical indexes invalidated

        -- The plain index is affected only by broad invalidation on extension drop.
        IF (SELECT invalidated FROM hypopg() WHERE indexrelid = plain_idx) <> (action = 'drop') THEN
            RAISE WARNING 'incorrect plain_idx invalidation: %', action;
        END IF;

        -- expr_idx depends on both bloom and the function so in both cases
        -- it's invalidated
        IF (SELECT invalidated FROM hypopg() WHERE indexrelid = expr_idx) <> true THEN
            RAISE WARNING 'expr_idx should always be invalidated';
        END IF;

        -- bloom_idx only depends on bloom so it should only be invalidated for
        -- the "drop" case
        SELECT invalidated INTO is_inval FROM hypopg() WHERE indexrelid = bloom_idx;
        IF is_inval <> (action = 'drop') THEN
            RAISE WARNING 'bloom_idx should only be invalidated for scenario drop, after % invalidated is %',
                action, is_inval;
        END IF;
    END LOOP;
END
$$;

DROP FUNCTION hypo_inval_am_func(integer);
DROP TABLE hypo_inval_am;