-- migrate:up
ALTER TABLE internal.user ENABLE ROW LEVEL SECURITY;
ALTER TABLE internal.website ENABLE ROW LEVEL SECURITY;
ALTER TABLE internal.media ENABLE ROW LEVEL SECURITY;
ALTER TABLE internal.settings ENABLE ROW LEVEL SECURITY;
ALTER TABLE internal.header ENABLE ROW LEVEL SECURITY;
ALTER TABLE internal.home ENABLE ROW LEVEL SECURITY;
ALTER TABLE internal.article ENABLE ROW LEVEL SECURITY;
ALTER TABLE internal.footer ENABLE ROW LEVEL SECURITY;
ALTER TABLE internal.collab ENABLE ROW LEVEL SECURITY;

CREATE FUNCTION internal.user_has_website_access(
  website_id UUID,
  required_permission INTEGER,
  collaborator_permission_level INTEGER DEFAULT NULL,
  collaborator_user_id UUID DEFAULT NULL,
  article_user_id UUID DEFAULT NULL,
  raise_error BOOLEAN DEFAULT true
)
RETURNS BOOLEAN AS $$
DECLARE
  _user_id UUID;
  _has_access BOOLEAN;
BEGIN
  _user_id := (current_setting('request.jwt.claims', true)::json->>'user_id')::UUID;

  SELECT EXISTS (
    SELECT 1
    FROM internal.website
    WHERE id = website_id AND user_id = _user_id
  ) INTO _has_access;
  
  IF _has_access THEN
    RETURN _has_access;
  END IF;

  SELECT EXISTS (
    SELECT 1
    FROM internal.collab c
    WHERE c.website_id = user_has_website_access.website_id
    AND c.user_id = (current_setting('request.jwt.claims', true)::json->>'user_id')::UUID
    AND c.permission_level >= user_has_website_access.required_permission
    AND (
      user_has_website_access.article_user_id IS NULL
      OR
      (
        c.permission_level = 30
        OR
        user_has_website_access.article_user_id = _user_id
      )
    )
    AND (
      user_has_website_access.collaborator_permission_level IS NULL
      OR
      (
        user_has_website_access.collaborator_user_id != _user_id
        AND
        user_has_website_access.collaborator_permission_level < 30
      )
    )
  ) INTO _has_access;

  IF NOT _has_access AND user_has_website_access.raise_error THEN
    RAISE insufficient_privilege USING MESSAGE = 'You do not have the required permissions for this action.';
  END IF;

  RETURN _has_access;
END;
$$ LANGUAGE plpgsql SECURITY DEFINER;


CREATE POLICY view_user ON internal.user
FOR SELECT
USING (true);

CREATE POLICY view_websites ON internal.website
FOR SELECT
USING (internal.user_has_website_access(id, 10, raise_error => false));

CREATE POLICY update_website ON internal.website
FOR UPDATE
USING (internal.user_has_website_access(id, 20));

CREATE POLICY delete_website ON internal.website
FOR DELETE
USING (internal.user_has_website_access(id, 40));


CREATE POLICY view_media ON internal.media
FOR SELECT
USING (internal.user_has_website_access(website_id, 10));

CREATE POLICY insert_media ON internal.media
FOR INSERT
WITH CHECK (internal.user_has_website_access(website_id, 20));


CREATE POLICY view_settings ON internal.settings
FOR SELECT
USING (internal.user_has_website_access(website_id, 10));

CREATE POLICY update_settings ON internal.settings
FOR UPDATE
USING (internal.user_has_website_access(website_id, 20));


CREATE POLICY view_header ON internal.header
FOR SELECT
USING (internal.user_has_website_access(website_id, 10));

CREATE POLICY update_header ON internal.header
FOR UPDATE
USING (internal.user_has_website_access(website_id, 20));


CREATE POLICY view_home ON internal.home
FOR SELECT
USING (internal.user_has_website_access(website_id, 10));

CREATE POLICY update_home ON internal.home
FOR UPDATE
USING (internal.user_has_website_access(website_id, 20));


CREATE POLICY view_articles ON internal.article
FOR SELECT
USING (internal.user_has_website_access(website_id, 10));

CREATE POLICY update_article ON internal.article
FOR UPDATE
USING (internal.user_has_website_access(website_id, 20));

CREATE POLICY delete_article ON internal.article
FOR DELETE
USING (internal.user_has_website_access(website_id, 20, article_user_id => user_id));

CREATE POLICY insert_article ON internal.article
FOR INSERT
WITH CHECK (internal.user_has_website_access(website_id, 20));


CREATE POLICY view_footer ON internal.footer
FOR SELECT
USING (internal.user_has_website_access(website_id, 10));

CREATE POLICY update_footer ON internal.footer
FOR UPDATE
USING (internal.user_has_website_access(website_id, 20));


CREATE POLICY view_collaborations ON internal.collab
FOR SELECT
USING (internal.user_has_website_access(website_id, 10));

CREATE POLICY insert_collaborations ON internal.collab
FOR INSERT
WITH CHECK (internal.user_has_website_access(website_id, 30, collaborator_permission_level => permission_level, collaborator_user_id => user_id));

CREATE POLICY update_collaborations ON internal.collab
FOR UPDATE
USING (internal.user_has_website_access(website_id, 30, collaborator_permission_level => permission_level, collaborator_user_id => user_id));

CREATE POLICY delete_collaborations ON internal.collab
FOR DELETE
USING (internal.user_has_website_access(website_id, 30, collaborator_permission_level => permission_level, collaborator_user_id => user_id));


-- migrate:down
DROP POLICY view_user ON internal.user;
DROP POLICY view_websites ON internal.website;
DROP POLICY delete_website ON internal.website;
DROP POLICY update_website ON internal.website;
DROP POLICY view_media ON internal.media;
DROP POLICY insert_media ON internal.media;
DROP POLICY view_settings ON internal.settings;
DROP POLICY update_settings ON internal.settings;
DROP POLICY view_header ON internal.header;
DROP POLICY update_header ON internal.header;
DROP POLICY view_home ON internal.home;
DROP POLICY update_home ON internal.home;
DROP POLICY view_articles ON internal.article;
DROP POLICY update_article ON internal.article;
DROP POLICY delete_article ON internal.article;
DROP POLICY insert_article ON internal.article;
DROP POLICY view_footer ON internal.footer;
DROP POLICY update_footer ON internal.footer;
DROP POLICY view_collaborations ON internal.collab;
DROP POLICY insert_collaborations ON internal.collab;
DROP POLICY update_collaborations ON internal.collab;
DROP POLICY delete_collaborations ON internal.collab;
DROP FUNCTION internal.user_has_website_access(UUID, INTEGER, INTEGER, UUID, UUID, BOOLEAN);

ALTER TABLE internal.user DISABLE ROW LEVEL SECURITY;
ALTER TABLE internal.website DISABLE ROW LEVEL SECURITY;
ALTER TABLE internal.media DISABLE ROW LEVEL SECURITY;
ALTER TABLE internal.settings DISABLE ROW LEVEL SECURITY;
ALTER TABLE internal.header DISABLE ROW LEVEL SECURITY;
ALTER TABLE internal.home DISABLE ROW LEVEL SECURITY;
ALTER TABLE internal.article DISABLE ROW LEVEL SECURITY;
ALTER TABLE internal.footer DISABLE ROW LEVEL SECURITY;
ALTER TABLE internal.collab DISABLE ROW LEVEL SECURITY;