-- ============================================================================
-- COMPREHENSIVE OWNERSHIP CHANGE SCRIPT
-- ============================================================================
-- Purpose:
-- This script transfers ownership of all tables, sequences, and functions
-- in the 'public' schema to a specified user. This is crucial for allowing
-- a non-superuser (like the application user) to manage the database schema
-- during deployments or resets.
--
-- Usage:
-- Connect to the database as a superuser (e.g., 'postgres') and run this
-- entire script.

DO $$
DECLARE
    -- Define the new owner for all objects.
    new_owner TEXT := 'flyer_crawler_user';
    
    -- Variables for iterating through object names.
    tbl_name TEXT;
    seq_name TEXT;
    
    -- Variables for handling function signatures.
    func_record RECORD;
    func_signature TEXT;
BEGIN
    -- 1. Change Ownership of all TABLES in the public schema
    RAISE NOTICE 'Changing ownership of all tables in schema "public" to "%"...', new_owner;
    FOR tbl_name IN SELECT tablename FROM pg_tables WHERE schemaname = 'public' LOOP
        EXECUTE format('ALTER TABLE public.%I OWNER TO %I;', tbl_name, new_owner);
    END LOOP;
    RAISE NOTICE 'Table ownership change complete.';

    -- 2. Change Ownership of all SEQUENCES in the public schema
    RAISE NOTICE 'Changing ownership of all sequences in schema "public" to "%"...', new_owner;
    FOR seq_name IN SELECT sequence_name FROM information_schema.sequences WHERE sequence_schema = 'public' LOOP
        EXECUTE format('ALTER SEQUENCE public.%I OWNER TO %I;', seq_name, new_owner);
    END LOOP;
    RAISE NOTICE 'Sequence ownership change complete.';

    -- 3. Change Ownership of all FUNCTIONS in the public schema
    RAISE NOTICE 'Changing ownership of all functions in schema "public" to "%"...', new_owner;
    FOR func_record IN SELECT p.proname AS function_name, pg_get_function_identity_arguments(p.oid) AS argument_list FROM pg_proc p JOIN pg_namespace n ON p.pronamespace = n.oid WHERE n.nspname = 'public' LOOP
        func_signature := format('public.%I(%s)', func_record.function_name, func_record.argument_list);
        EXECUTE format('ALTER FUNCTION %s OWNER TO %I;', func_signature, new_owner);
    END LOOP;
    RAISE NOTICE 'Function ownership change complete.';

    RAISE NOTICE '✅ All ownership changes completed successfully.';
END $$;


-- long version of step 3 for clarity:
-- DO $$
-- DECLARE
--     -- Declare a record variable to hold the results of our query for each function.
--     func_record RECORD;
--     -- Declare a variable to hold the full, formatted function signature.
--     func_signature TEXT;
-- BEGIN
--     -- Loop through all functions in the 'public' schema.
--     -- We use pg_proc and pg_namespace for a more detailed and reliable query
--     -- than the information_schema.
--     FOR func_record IN
--         SELECT
--             p.proname AS function_name,
--             -- pg_get_function_identity_arguments() is a powerful built-in function
--             -- that returns the argument list of a function as a string (e.g., 'integer, text').
--             -- This is the key to handling overloaded functions correctly.
--             pg_get_function_identity_arguments(p.oid) AS argument_list
--         FROM
--             pg_proc p
--         JOIN
--             pg_namespace n ON p.pronamespace = n.oid
--         WHERE
--             n.nspname = 'public'
--     LOOP
--         -- Construct the full function signature, which includes the name and the argument list.
--         -- For example: public.my_function(integer, text)
--         func_signature := format('public.%I(%s)', func_record.function_name, func_record.argument_list);
-- 
--         -- Construct and execute the ALTER FUNCTION statement using the full signature.
--         -- This command is now unambiguous and will work for all functions, including overloaded ones.
--         EXECUTE format('ALTER FUNCTION %s OWNER TO flyer_crawler_user;', func_signature);
--     END LOOP;
-- END $$;