bug: tournament reassigments

Author: lukepolo

hasura/functions/match/can_reassign_winner.sql

@@ -0,0 +1,35 @@
+CREATE OR REPLACE FUNCTION public.can_reassign_winner(match public.matches, hasura_session json)
+RETURNS boolean
+LANGUAGE plpgsql STABLE
+AS $$
+DECLARE
+    bracket_id uuid;
+    blocking_downstream int;
+BEGIN
+    IF NOT is_match_organizer(match, hasura_session) THEN
+        RETURN false;
+    END IF;
+
+    IF match.status NOT IN ('Finished', 'Tie', 'Canceled', 'Forfeit', 'Surrendered') THEN
+        RETURN false;
+    END IF;
+
+    SELECT id INTO bracket_id
+    FROM tournament_brackets
+    WHERE match_id = match.id
+    LIMIT 1;
+
+    IF bracket_id IS NULL THEN
+        RETURN true;
+    END IF;
+
+    SELECT count(*) INTO blocking_downstream
+    FROM tournament_brackets tb
+    LEFT JOIN matches m ON m.id = tb.match_id
+    WHERE (tb.parent_bracket_id = bracket_id OR tb.loser_parent_bracket_id = bracket_id)
+      AND m.id IS NOT NULL
+      AND m.status NOT IN ('Scheduled', 'WaitingForCheckIn', 'Canceled');
+
+    RETURN blocking_downstream = 0;
+END;
+$$;