CREATE FUNCTION _api.user_update()
RETURNS TRIGGER
LANGUAGE plpgsql VOLATILE
AS $BODY$
DECLARE
	_user_id INTEGER;
	_changed BOOLEAN;
BEGIN
	_user_id = _api.get_user_id();
	_changed = FALSE;

	IF OLD.id <> _user_id THEN
		PERFORM _api.raise_deny();
	END IF;

	-- username
	NEW.username = COALESCE(NEW.username, OLD.username);
	NEW.username := _api.trim(NEW.username);
	PERFORM _api.validate_text(
		_text => NEW.username,
		_column => 'username',
		_min => 1,
		_max => 24
	);

	IF NEW.username IS DISTINCT FROM OLD.username THEN
		PERFORM TRUE FROM admin.user
			WHERE username = NEW.username;
		IF FOUND THEN
			PERFORM _api.raise_unique('username');
		END IF;
		_changed = TRUE;
	END IF;

	-- password
	SELECT password
		INTO OLD.password
		FROM admin.user
		WHERE id = OLD.id;

	NEW.password = COALESCE(NEW.password, OLD.password);
	NEW.password := _api.trim(NEW.password);
	PERFORM _api.validate_text(
		_text => NEW.password,
		_column => 'password',
		_min => 1,
		_max => 256
	);

	IF NEW.password IS DISTINCT FROM OLD.password THEN
		_changed = TRUE;
	END IF;

	-- first name
	NEW.first_name = COALESCE(NEW.first_name, OLD.first_name);
	NEW.first_name := _api.trim(NEW.first_name);
	PERFORM _api.validate_text(
		_text => NEW.first_name,
		_column => 'first_name',
		_max => 256
	);

	IF NEW.first_name IS DISTINCT FROM OLD.first_name THEN
		_changed = TRUE;
	END IF;

	-- last name
	NEW.last_name = COALESCE(NEW.last_name, OLD.last_name);
	NEW.last_name := _api.trim(NEW.last_name);
	PERFORM _api.validate_text(
		_text => NEW.last_name,
		_column => 'last_name',
		_max => 256
	);

	IF NEW.last_name IS DISTINCT FROM OLD.last_name THEN
		_changed = TRUE;
	END IF;

	-- middle name
	NEW.middle_name = COALESCE(NEW.middle_name, OLD.middle_name);
	NEW.middle_name := _api.trim(NEW.middle_name);
	PERFORM _api.validate_text(
		_text => NEW.middle_name,
		_column => 'middle_name',
		_max => 256
	);

	IF NEW.middle_name IS DISTINCT FROM OLD.middle_name THEN
		_changed = TRUE;
	END IF;

	-- email
	NEW.email = COALESCE(NEW.email, OLD.email);
	NEW.email := _api.trim(NEW.email);
	PERFORM _api.validate_text(
		_text => NEW.email,
		_column => 'email',
		_max => 256
	);

	IF NEW.email IS DISTINCT FROM OLD.email THEN
		_changed = TRUE;
	END IF;

	-- gender
	NEW.gender = COALESCE(NEW.gender, OLD.gender);
	NEW.gender := _api.trim(NEW.gender);
	PERFORM _api.validate_text(
		_text => NEW.gender,
		_column => 'gender',
		_max => 256
	);

	IF NEW.gender IS DISTINCT FROM OLD.gender THEN
		_changed = TRUE;
	END IF;

	-- birth date
	NEW.birth_date = COALESCE(NEW.birth_date, OLD.birth_date);
	IF NEW.birth_date IS DISTINCT FROM OLD.birth_date THEN
		_changed = TRUE;
	END IF;

	-- profile bio
	NEW.profile_bio = COALESCE(NEW.profile_bio, OLD.profile_bio);
	NEW.profile_bio := _api.trim(NEW.profile_bio);
	PERFORM _api.validate_text(
		_text => NEW.profile_bio,
		_column => 'profile_bio',
		_max => 2048
	);

	IF NEW.profile_bio IS DISTINCT FROM OLD.profile_bio THEN
		_changed = TRUE;
	END IF;

	IF _changed THEN
		UPDATE admin.user SET
			username = NEW.username,
			password = NEW.password,
			first_name = NEW.first_name,
			last_name = NEW.last_name,
			middle_name = NEW.middle_name,
			email = NEW.email,
			gender = NEW.gender,
			birth_date = NEW.birth_date,
			profile_bio = NEW.profile_bio
			WHERE id = OLD.id;
	END IF;

	RETURN NEW;
END
$BODY$;

GRANT EXECUTE ON FUNCTION _api.user_update()
	TO rest_user;
GRANT UPDATE ON TABLE api.user
	TO rest_user;
GRANT UPDATE ON TABLE admin.user
	TO rest_user;

CREATE TRIGGER api_user_update_trgr
	INSTEAD OF UPDATE
			ON api.user
			FOR EACH ROW
				EXECUTE PROCEDURE _api.user_update();