Ability to bulk import or export articles as gzip, handle domain prefix logic in API and other smaller improvements

rest-api/db/migrations/20241029160539_export_articles.sql

@@ -0,0 +1,49 @@
+-- migrate:up
+CREATE FUNCTION api.export_articles_zip (website_id UUID)
+  RETURNS "*/*"
+  AS $$
+DECLARE
+  _has_access BOOLEAN;
+  _headers TEXT;
+  _article RECORD;
+  _markdown_dir TEXT := '/tmp/website-' || export_articles_zip.website_id;
+BEGIN
+  _has_access = internal.user_has_website_access (export_articles_zip.website_id, 20);
+
+  SELECT
+    FORMAT('[{ "Content-Type": "application/gzip" },'
+    '{ "Content-Disposition": "attachment; filename=\"%s\"" }]',
+    'archtika-export-articles-' || export_articles_zip.website_id || '.tar.gz') INTO _headers;
+  PERFORM
+    SET_CONFIG('response.headers', _headers, TRUE);
+
+  EXECUTE FORMAT('COPY (SELECT '''') TO PROGRAM ''mkdir -p %s''', _markdown_dir || '/articles');
+
+  FOR _article IN (
+    SELECT a.id, a.website_id, a.slug, a.main_content
+    FROM internal.article AS a
+    WHERE a.website_id = export_articles_zip.website_id)
+  LOOP
+    EXECUTE FORMAT(
+      'COPY (SELECT %L) TO ''%s''',
+      _article.main_content,
+      _markdown_dir || '/articles/' || _article.slug || '.md'
+    );
+  END LOOP;
+
+  EXECUTE FORMAT('COPY (SELECT '''') TO PROGRAM ''tar -czf %s -C %s articles && rm %s''',
+    _markdown_dir || '/export.tar.gz',
+    _markdown_dir,
+    _markdown_dir || '/articles/*.md'
+  );
+
+  RETURN pg_read_binary_file(_markdown_dir || '/export.tar.gz');
+END;
+$$
+LANGUAGE plpgsql
+SECURITY DEFINER;
+
+GRANT EXECUTE ON FUNCTION api.export_articles_zip TO authenticated_user;
+
+-- migrate:down
+DROP FUNCTION api.export_articles_zip;