-- This is Free Software under GNU Affero General Public License v >= 3.0
-- without warranty, see README.md and license for details.

-- SPDX-License-Identifier: AGPL-3.0-or-later
-- License-Filename: LICENSES/AGPL-3.0.txt

-- Copyright (C) 2018, 2019 by via donau
--   – Österreichische Wasserstraßen-Gesellschaft mbH
-- Software engineering by Intevation GmbH

-- Author(s):
--  * Tom Gottried <tom@intevation.de>
--  * Sascha Wilde <sascha.wilde@intevation.de>
--  * Sascha L. Teichmann <sascha.teichmann@intevation.de>

BEGIN;

--
-- Roles, privileges and policies for the GEMMA database
--

-- We do not want any users to be able to create any objects
REVOKE ALL ON SCHEMA public FROM PUBLIC;

--
-- Privileges for waterway_user
--
GRANT USAGE ON SCHEMA public, users, waterway, systemconf, caching TO waterway_user;
GRANT SELECT ON ALL TABLES IN SCHEMA public, users, waterway TO waterway_user;
GRANT SELECT, UPDATE, DELETE, INSERT ON ALL TABLES IN SCHEMA caching TO waterway_user;
GRANT SELECT ON systemconf.feature_colours TO waterway_user;
GRANT UPDATE (pw, map_extent, email_address) ON users.list_users
    TO waterway_user;

--
-- Extended privileges for waterway_admin
--
GRANT INSERT, UPDATE, DELETE ON ALL TABLES IN SCHEMA waterway
    TO waterway_admin;
-- TODO: will there ever be UPDATEs and DELETEs or can we drop that for
-- imported data due to historicisation? Special tables like
-- import_configuration will further need UPDATE and DELETE privileges.

GRANT INSERT, UPDATE, DELETE ON
    users.templates TO waterway_admin;
-- Ensure templates are associated to the users country, if none is given
ALTER TABLE users.templates ALTER COLUMN country
    SET DEFAULT users.current_user_country();

GRANT USAGE ON SCHEMA import TO waterway_admin;
GRANT SELECT, INSERT ON ALL TABLES IN SCHEMA import TO waterway_admin;
GRANT UPDATE ON
    import.imports, import.import_configuration,
        import.import_configuration_attributes
    TO waterway_admin;
GRANT DELETE ON
    import.track_imports, import.import_configuration,
        import.import_configuration_attributes
    TO waterway_admin;

--
-- Extended privileges for sys_admin
--
GRANT INSERT, UPDATE, DELETE
    ON users.list_users, users.responsibility_areas TO sys_admin;
GRANT USAGE ON SCHEMA sys_admin TO sys_admin;
GRANT SELECT ON ALL TABLES IN SCHEMA sys_admin TO sys_admin;
GRANT UPDATE ON sys_admin.system_config TO sys_admin;
GRANT UPDATE ON systemconf.feature_colours TO sys_admin;
GRANT UPDATE ON sys_admin.published_services TO sys_admin;
GRANT INSERT, DELETE ON sys_admin.password_reset_requests TO sys_admin;

--
-- Privileges assigned directly to metamorph
--
-- Needed for GeoServer's system inspection run before session startup SQL
GRANT USAGE ON SCHEMA public TO metamorph;

--
-- RLS policies for waterway_user
--
-- Sometimes using FOR ALL because we rely on GRANTed privileges for allowing
-- data modifications generally.
-- Sometimes using 'username IN(SELECT username FROM users.list_users)' instead
-- of 'username = current_user', because waterway_admin is intentionally
-- allowed more with these policies (note that the subselect implies different
-- filtering on list_users depending on current_user).
--

-- Staging area
DO LANGUAGE plpgsql
$$
DECLARE the_table varchar;
BEGIN
    FOREACH the_table IN ARRAY ARRAY[
        'gauge_measurements',
        'stretches',
        'waterway_profiles',
        'fairway_dimensions',
        'bottlenecks',
        'sounding_results']
    LOOP
        EXECUTE format('CREATE POLICY hide_staging ON waterway.%I '
            'FOR SELECT TO waterway_user USING (staging_done)', the_table);
        EXECUTE format('CREATE POLICY sys_admin ON waterway.%I '
            'FOR ALL TO sys_admin USING (true)', the_table);
        EXECUTE format('ALTER TABLE waterway.%I ENABLE ROW LEVEL SECURITY',
            the_table);
    END LOOP;
END;
$$;

--
-- RLS policies for templates
--
CREATE POLICY select_templates ON users.templates FOR SELECT TO waterway_user
    USING (country IS NULL OR country = (SELECT country FROM users.list_users WHERE username = current_user));

CREATE POLICY user_templates ON users.templates FOR ALL TO waterway_admin
    USING (country = (SELECT country FROM users.list_users WHERE username = current_user));

CREATE POLICY admin_templates ON users.templates FOR ALL TO sys_admin
    USING (true);

ALTER TABLE users.templates ENABLE ROW LEVEL SECURITY;

--
-- RLS policies for waterway_admin
--

-- Staging area
-- TODO: add all relevant tables here

CREATE POLICY same_country ON waterway.gauge_measurements
    FOR ALL TO waterway_admin
    USING ((location).country_code
        = (SELECT country FROM users.list_users WHERE username = current_user)
    );

CREATE POLICY same_country ON waterway.waterway_profiles
    FOR ALL TO waterway_admin
    USING ((location).country_code = (SELECT country FROM users.list_users WHERE username = current_user));

CREATE POLICY responsibility_area ON waterway.bottlenecks
    FOR ALL TO waterway_admin
    USING (users.utm_covers(area));

CREATE POLICY responsibility_area ON waterway.sounding_results
    FOR ALL TO waterway_admin
    USING (users.utm_covers(area));

CREATE POLICY responsibility_area ON waterway.fairway_dimensions
    FOR ALL TO waterway_admin
    USING (users.utm_covers(area));

--
-- RLS policies for imports and import config
--

CREATE POLICY same_country ON import.imports
    FOR ALL TO waterway_admin
    USING (users.current_user_country() = (
        SELECT country FROM users.list_users lu
            WHERE lu.username = imports.username));
ALTER table import.imports ENABLE ROW LEVEL SECURITY;

-- The job running the import queue is running as sys_admin and login users
-- with that role should be able to run imports without restrictions anyhow
CREATE POLICY import_all ON import.imports
    FOR ALL TO sys_admin
    USING (true);

-- For the given table, check whether the given value is used as primary key,
-- bypassing row level security.
CREATE OR REPLACE FUNCTION import.is_new_key(
        tablename varchar,
        kv anyelement)
    RETURNS boolean
AS $$
DECLARE columnname varchar;
DECLARE ret boolean;
BEGIN
    columnname = (SELECT column_name
        FROM information_schema.key_column_usage k
        JOIN information_schema.table_constraints USING (constraint_name)
        WHERE k.table_name = tablename and constraint_type = 'PRIMARY KEY');
    EXECUTE format('SELECT NOT $1 = ANY(SELECT %I FROM import.%I)',
        columnname, tablename)
        INTO ret
        USING kv;
    RETURN ret;
END;
$$
    LANGUAGE plpgsql
    SECURITY DEFINER
    STABLE PARALLEL SAFE;

CREATE POLICY parent_allowed ON import.import_logs
    FOR ALL TO waterway_admin
    USING (import_id IN (SELECT id FROM import.imports))
    WITH CHECK (import.is_new_key('imports', import_id)
        OR import_id IN (SELECT id FROM import.imports));
ALTER table import.import_logs ENABLE ROW LEVEL SECURITY;

CREATE POLICY parent_allowed ON import.track_imports
    FOR ALL TO waterway_admin
    USING (import_id IN (SELECT id FROM import.imports))
    WITH CHECK (import.is_new_key('imports', import_id)
        OR import_id IN (SELECT id FROM import.imports));
ALTER table import.track_imports ENABLE ROW LEVEL SECURITY;

CREATE POLICY import_configuration_policy ON import.import_configuration
    FOR ALL TO waterway_admin
    USING (
        (SELECT country FROM users.list_users WHERE username = current_user) = (
            SELECT country FROM users.list_users lu
            WHERE lu.username = import.import_configuration.username));

CREATE POLICY import_configuration_policy_sys_admin ON import.import_configuration
    FOR ALL TO sys_admin
    USING (true);

ALTER table import.import_configuration ENABLE ROW LEVEL SECURITY;

CREATE POLICY parent_allowed ON import.import_configuration_attributes
    FOR ALL TO waterway_admin
    USING (import_configuration_id IN (
        SELECT id FROM import.import_configuration))
    WITH CHECK (
        import.is_new_key('import_configuration', import_configuration_id)
        OR import_configuration_id IN (
            SELECT id FROM import.import_configuration));
ALTER table import.import_configuration_attributes ENABLE ROW LEVEL SECURITY;

COMMIT;