ALTER TABLE internal.user_profiles
    ADD CHECK(to_regrole(quote_ident(username)) IS NOT NULL);

CREATE OR REPLACE FUNCTION internal.create_user() RETURNS trigger
AS $$
BEGIN
    IF NEW.map_extent IS NULL
    THEN
        NEW.map_extent = ST_Extent(CAST(area AS geometry))
            FROM users.stretches st
                JOIN users.stretch_countries stc ON stc.stretch_id = st.id
            WHERE stc.country = NEW.country;
    END IF;

    IF NEW.username IS NOT NULL
    -- otherwise let the constraint on user_profiles speak
    THEN
        EXECUTE format(
            'CREATE ROLE %I IN ROLE %I LOGIN PASSWORD %L',
            NEW.username,
            NEW.rolname,
            internal.check_password(NEW.pw));
    END IF;

    INSERT INTO internal.user_profiles (
        username, country, map_extent, email_address)
        VALUES (NEW.username, NEW.country, NEW.map_extent, NEW.email_address);

    -- Do not leak new password
    NEW.pw = '';
    RETURN NEW;
END;
$$
    LANGUAGE plpgsql
    SECURITY DEFINER;

CREATE OR REPLACE FUNCTION internal.update_user() RETURNS trigger
AS $$
DECLARE
    cur_username varchar;
BEGIN
    cur_username = OLD.username;

    IF NEW.username <> cur_username
    THEN
        EXECUTE format(
            'ALTER ROLE %I RENAME TO %I', cur_username, NEW.username);
        cur_username = NEW.username;
    END IF;

    UPDATE internal.user_profiles p
        SET (username, country, map_extent, email_address)
        = (NEW.username, NEW.country, NEW.map_extent, NEW.email_address)
        WHERE p.username = cur_username;

    IF NEW.rolname <> OLD.rolname
    THEN
        EXECUTE format(
            'REVOKE %I FROM %I', OLD.rolname, cur_username);
        EXECUTE format(
            'GRANT %I TO %I', NEW.rolname, cur_username);
    END IF;

    IF NEW.pw IS NOT NULL AND NEW.pw <> ''
    THEN
        EXECUTE format(
            'ALTER ROLE %I PASSWORD %L',
            cur_username,
            internal.check_password(NEW.pw));
    END IF;

    -- Do not leak new password
    NEW.pw = '';
    RETURN NEW;
END;
$$
    LANGUAGE plpgsql
    SECURITY DEFINER;