Backend for delete post

website/queries/post.php

@@ -192,3 +192,56 @@ function deleteNietSlecht(int $postID, int $userID) {
     $stmt->execute();
     return $stmt->rowCount();
 }
+
+function deletePost(int $postID, int $userID) {
+    if (checkPermissionOnPost($postID, $userID)) {
+        $stmt = prepareQuery("
+        DELETE FROM
+            `post`
+        WHERE
+            `postID` = :postID
+        ");
+        $stmt->bindParam(":postID", $postID);
+        $stmt->execute();
+    }
+}
+
+function checkPermissionOnPost(int $postID, int $userID) : bool {
+    $getGroupID = prepareQuery("
+    SELECT
+        `author`,
+        `groupID`
+    FROM
+        `post`
+    WHERE
+        `postID` = :postID
+    ");
+    $getGroupID->bindParam(":postID", $postID);
+    $getGroupID->execute();
+    $postinfo = $getGroupID->fetch();
+
+    if ($postinfo["groupID"] == null) {
+        // User post
+        return ($userID == $postinfo["author"]);
+    } else {
+        // Group post
+        $roleInGroup = getRoleInGroup($userID, $postinfo["groupID"]);
+        return ($roleInGroup == "mod" or $roleInGroup == "admin");
+    }
+}
+
+function getRoleInGroup(int $userID, int $groupID) {
+    $stmt = prepareQuery("
+    SELECT
+        `role`
+    FROM
+        `group_member`
+    WHERE
+      `userID` = :userID AND
+      `groupID` = :groupID
+    ");
+    $stmt->bindParam(":userID", $userID);
+    $stmt->bindParam(":groupID", $groupID);
+    $stmt->execute();
+    return $stmt->fetch()["role"];
+}