public/api/contributions.php

@@ -303,24 +303,51 @@ function handle_vote($input) {
 
     // Prepared SQL Statement
     try {
+        // Checks if Voter already voted on this Contribution
         $stmt = $pdo->prepare("
-            INSERT INTO votes (contribution_id, voter_name, vote_type)
+            SELECT vote_id, vote_type FROM votes
-            VALUES (:cid, :voter, :vtype)
+            WHERE contribution_id = :cid AND voter_name = :voter
         ");
+        $stmt->execute([':cid' => $input['contribution_id'], ':voter' => $input['voter_name']]);
+        $existing = $stmt->fetch();
 
-        $stmt->execute([
+        if ($existing) {
-            ':cid'   => $input['contribution_id'],
+            if ($existing['vote_type'] === $input['vote_type']) {
-            ':voter' => $input['voter_name'],
+                // Same Vote Type — Removes Vote
-            ':vtype' => $input['vote_type']
+                $stmt = $pdo->prepare("DELETE FROM votes WHERE vote_id = :vid");
-        ]);
+                $stmt->execute([':vid' => $existing['vote_id']]);
+                json_response(['message' => 'Vote removed.', 'action' => 'removed']);
+            } else {
+                // Different Vote Type — Switches Vote
+                $stmt = $pdo->prepare("DELETE FROM votes WHERE vote_id = :vid");
+                $stmt->execute([':vid' => $existing['vote_id']]);
 
-        json_response(['message' => 'Vote recorded successfully.'], 201);
+                $stmt = $pdo->prepare("
+                    INSERT INTO votes (contribution_id, voter_name, vote_type)
+                    VALUES (:cid, :voter, :vtype)
+                ");
+                $stmt->execute([
+                    ':cid'   => $input['contribution_id'],
+                    ':voter' => $input['voter_name'],
+                    ':vtype' => $input['vote_type']
+                ]);
+                json_response(['message' => 'Vote changed.', 'action' => 'changed'], 200);
+            }
+        } else {
+            // No existing Vote — Inserts Vote
+            $stmt = $pdo->prepare("
+                INSERT INTO votes (contribution_id, voter_name, vote_type)
+                VALUES (:cid, :voter, :vtype)
+            ");
+            $stmt->execute([
+                ':cid'   => $input['contribution_id'],
+                ':voter' => $input['voter_name'],
+                ':vtype' => $input['vote_type']
+            ]);
+            json_response(['message' => 'Vote recorded.', 'action' => 'created'], 201);
+        }
 
     } catch (PDOException $e) {
-        // UNIQUE Constraint Violation - Voter already voted on this Contribution
-        if ($e->getCode() == '23505') {
-            error_response('You have already voted on this Contribution.', 409);
-        }
         error_response('Database Error: ' . $e->getMessage(), 500);
     }
 }

public/js/app.js

@@ -572,6 +572,13 @@ function voteContribution(contributionId, voteType) {
             return;
         }
 
+        // Show Feedback based on Vote Action
+        if (response.action === 'removed') {
+            Swal.fire({ title: 'Bewertung zurückgenommen', icon: 'info', timer: 1500, showConfirmButton: false });
+        } else if (response.action === 'changed') {
+            Swal.fire({ title: 'Bewertung verändert', icon: 'success', timer: 1500, showConfirmButton: false });
+        }
+
         // Updates Vote Counts in the Popup without reloading everything
         loadContributions();
     });