- ReqHandler added

- interface reworked

class/ReqHandler.php

@@ -0,0 +1,139 @@
+<?php
+
+
+// response types
+const RESP_NONE = "none";
+const RESP_PLAIN = "plain";
+const RESP_JSON = "json";
+
+// Request Handler Assignment class
+// Members get populated when instantiated by ReqHandler;
+// should not be used outside ReqHandler
+class ReqHandlerAssignment
+{
+    // members
+    public string $action; // action string
+    public array $params; // request parameters
+    public string $handler; // handler function
+    public string $hint; // human-readable hint about what this action performs
+    public string $level; // required command authentication level
+    public string $resp_type; // response type
+    public ReqHandler $rh; // reference to request handler
+
+    function __construct(string $action, array $params, string $level, string $handler, string $resp_type, string $hint, ReqHandler &$rh)
+    {
+        $this->action = $action;
+        $this->params = $params;
+        $this->level = $level;
+        $this->handler = $handler;
+        $this->resp_type = $resp_type;
+        $this->hint = $hint;
+        $this->rh = &$rh; // assign be reference
+    }
+}
+
+// Request Handler class
+class ReqHandler
+{
+    private array $mapping; // action-handler mapping
+    private array $request; // reference to $_REQUEST
+    private array $files; // reference to $_FILES
+    private string $level; // max privilege level
+
+    // Constructor
+    function __construct()
+    {
+        // create reference bindings
+        $this->request = &$_REQUEST;
+        $this->files = &$_FILES;
+
+        $this->mapping = [PRIVILEGE_NONE => [], PRIVILEGE_PLAYER => [], PRIVILEGE_CREATOR => [], PRIVILEGE_QUIZMASTER => []]; // create assignment categories
+        $this->level = PRIVILEGE_NONE;
+    }
+
+    // Add new handler
+    function add(string|array $actions, array $params, string $level, string $handler, string $resp_type, string $hint): bool
+    {
+        // convert single actions to array
+        $actions = is_string($actions) ? [$actions] : $actions;
+
+        // cannot assign more than one handler to the same action
+        foreach ($actions as $action) {
+            if (in_array($action, $this->mapping[$level])) {
+                return false;
+            }
+
+            // create the assignment object
+            $assignment = new ReqHandlerAssignment($action, $params, $level, $handler, $resp_type, $hint, $this);
+            $this->mapping[$level][$action] = $assignment;
+        }
+
+        return true;
+    }
+
+    const ACTION_KEY = "action";
+
+    // Process possible pending request. Also check access privilege.
+    function process(string $level = null, string $action_key = self::ACTION_KEY) : array {
+        // get action
+        $action = $this->request[$action_key] ?? "";
+
+        // don't process empty actions
+        if (trim($action) === "") {
+            return ["", false];
+        }
+
+        // if privilege level is specified, then store
+        $this->level = $level ?? $this->level;
+
+        $resp = "";
+        $success = false;
+
+        // look up action
+        $categories = array_keys($this->mapping);
+        $highest_category_index = array_search($this->level, $categories);
+        for ($i = 0; ($i < count($categories)) && ($i <= $highest_category_index); $i++) {
+            // get category
+            $category = &$this->mapping[$categories[$i]];
+
+            // find the command level category that includes this action
+            if (array_key_exists($action, $category)) {
+                // get assignment
+                $assignment = &$category[$action];
+
+                // check that all required parameters were passed
+                $all_params_passed = true;
+                foreach ($assignment->params as $param) {
+                    $all_params_passed &= array_key_exists($param, $this->request);
+                }
+
+                // if params were provided, then invoke the callback
+                if ($all_params_passed) {
+                    $handler = $assignment->handler;
+                    $raw_resp = $handler($this, $this->request);
+
+                    // convert response to preset response type
+                    if ($assignment->resp_type !== RESP_NONE) { // if command returns with anything at all
+                        if ($assignment->resp_type === RESP_JSON) { // JSON
+                            $resp = json_encode($raw_resp);
+                        } else if ($assignment->resp_type === RESP_PLAIN) { // PLAIN
+                            $resp = $raw_resp;
+                        }
+                    }
+
+                    // processing successful
+                    $success = true;
+
+                    break; // break the loop
+                }
+            }
+        }
+
+        return [$resp, $success];
+    }
+
+    // Set access privilege level
+    function set_privilege_level(string $level) {
+        $this->level = $level;
+    }
+}

interface.php

@@ -22,6 +22,9 @@ require_once "testmgr.php";
 
 require_once "controller.php";
 
+require_once "class/ReqHandler.php";
+
+// ------------------------
 function patch_through_image(string $gameid, string $img_url)
 {
     $game_dir = get_game_dir_by_gameid($gameid);
@@ -35,16 +38,24 @@ function patch_through_image(string $gameid, string $img_url)
     fclose($img_fp);
 }
 
+// ------------------------
+
 $action = $_REQUEST["action"];
 
 $result = "";
+$success = false;
+$privilege = PRIVILEGE_NONE;
 
-// no-login accessible actions
+// create request handler
-switch ($action) {
+$rh = new ReqHandler();
-    case "login":
+
+/* ------------ ACTIONS AVAILABLE WITHOUT LOGGING IN ---------- */
+
+// login the user
+function login(ReqHandler &$rh, array $params): string
 {
-            $nickname = $_REQUEST["nickname"];
+    $nickname = $params["nickname"];
-            $password = $_REQUEST["password"];
+    $password = $params["password"];
     if (check_user_credentials($nickname, $password)) {
         session_start();
         $_SESSION["nickname"] = $nickname;
@@ -52,13 +63,15 @@ switch ($action) {
     } else {
         $result = "FAIL";
     }
+
+    return $result;
 }
-        break;
+
-}
+$rh->add("login", ["nickname", "password"], PRIVILEGE_NONE, "login", RESP_PLAIN, "Log in the user.");
 
 // exit script if there's no live session or nickname is missing or the referenced user is non-existent
 if ((session_status() != PHP_SESSION_ACTIVE) || (!isset($_SESSION["nickname"])) || (count(get_user($_SESSION["nickname"])) == 0)) {
-    goto print_result;
+    goto process_and_print;
 }
 
 $user_data = get_user($_SESSION["nickname"]);
@@ -66,23 +79,26 @@ $nickname = $user_data["nickname"];
 $privilege = $user_data["privilege"];
 $is_quizmaster = $privilege === PRIVILEGE_QUIZMASTER;
 
-// login-requiring actions
+/* ---------- ACTIONS REQUIRING BEING LOGGED IN ------------ */
-switch ($action) {
+
-    case "logout":
+function logout(ReqHandler &$rh, array $params): string
 {
     $_SESSION = []; // clean up session data
     setcookie(SESSION_NAME, "", -1); // invalidate cookie
+    return "OK";
 }
-        break;
+
-    case "get_user_info":
+function get_user_info(ReqHandler &$rh, array $params): array
 {
+    global $user_data;
     $user_data_filtered = $user_data;
     unset($user_data_filtered["password"]);
-            $result = json_encode($user_data_filtered);
+    return $user_data_filtered;
 }
-        break;
+
-    case "get_available_games":
+function get_available_games(ReqHandler &$rh, array $params): array
 {
+    global $user_data;
     $games_by_groups = [];
     $groupids = $user_data["groups"];
     foreach ($groupids as $groupid) {
@@ -99,20 +115,21 @@ switch ($action) {
         }
         $games_by_groups[] = $game_collection;
     }
-            $result = json_encode($games_by_groups);
+
+    return $games_by_groups;
 }
-        break;
+
-    case "start_or_continue_test":
+function start_or_continue_test(ReqHandler &$rh, array $params): string
 {
-            $gameid = trim($_REQUEST["gameid"] ?? "");
+    global $nickname;
-            $testid = create_or_continue_test($gameid, $nickname);
+    $testid = create_or_continue_test($params["gameid"], $nickname);
-            $result = $testid;
+    return $testid;
 }
-        break;
+
-    case "get_results_overview":
+function get_results_overview(ReqHandler &$rh, array $params): array
 {
-            $gameid = trim($_REQUEST["gameid"] ?? "");
+    global $nickname;
-            $concluded_tests = get_concluded_tests($gameid, $nickname);
+    $concluded_tests = get_concluded_tests($params["gameid"], $nickname);
     $overviews = [];
     foreach ($concluded_tests as $ct) {
         $overview = [
@@ -123,80 +140,124 @@ switch ($action) {
         ];
         $overviews[] = $overview;
     }
-            $result = json_encode($overviews);
+    return $overviews;
-        }
-        break;
 }
 
+$rh->add("logout", [], PRIVILEGE_PLAYER, "logout", RESP_PLAIN, "Log out the user.");
+$rh->add("get_user_info", [], PRIVILEGE_PLAYER, "get_user_info", RESP_JSON, "Get user information.");
+$rh->add("get_available_games", [], PRIVILEGE_PLAYER, "get_available_games", RESP_JSON, "Get available games to the player.");
+$rh->add("start_or_continue_test", ["gameid"], PRIVILEGE_PLAYER, "start_or_continue_test", RESP_PLAIN, "Start new or continue an ongoing test.");
+$rh->add("get_results_overview", ["gameid"], PRIVILEGE_PLAYER, "get_results_overview", RESP_JSON, "Get a quick overview of player's results of a single game.");
+
+
 // test-related queries
-const TEST_RELATED_ACTIONS = ["get_test", "save_answer", "submit_test"];
+function does_test_belong_to_user(array $test_data): bool
-if (in_array($action, TEST_RELATED_ACTIONS)) {
+{
+    global $nickname;
+    return $test_data["nickname"] === $nickname;
+}
 
-    $testid = trim($_REQUEST["testid"] ?? "");
+function is_test_access_approved(array $test_data): bool
-    $test_data = ($testid !== "") ? get_test($testid) : [];
+{
-    $is_a_default_test_with_access = ($testid !== "") && ((count($test_data)) > 0) && (($test_data["nickname"] === $nickname));
+    global $nickname;
+    global $is_quizmaster;
 
-    $user_is_contributor_or_quizmaster = $is_quizmaster || is_user_contributor_to_game($test_data["gameid"], $nickname);
+    return does_test_belong_to_user($test_data) || is_user_contributor_to_game($test_data["gameid"], $nickname) || $is_quizmaster;
+}
 
-    if ($is_a_default_test_with_access || $user_is_contributor_or_quizmaster) {
+function access_test_data(string $testid): array|null
+{
+    $testid = trim($testid);
+    $test_data = ($testid !== "") ? get_test($testid) : null;
+
+    // fetch test data
+    if ($test_data === null) {
+        return [];
+    }
+
+    // check if access is approved to the specific test
+    if (!is_test_access_approved($test_data)) {
+        return [];
+    }
 
     // update the test if timed
     update_timed_tests([$test_data]);
 
-        switch ($action) {
+    return $test_data;
-            case "get_test":
+}
+
+
+function get_player_test(ReqHandler &$rh, array $params): array
 {
+    $result = [];
+    $test_data = access_test_data($params["testid"]);
+
+    if ($test_data !== null) {
         $test_data_with_current_time = $test_data;
         $test_data_with_current_time["current_time"] = time();
-                    $result = json_encode($test_data_with_current_time);
+        $result = $test_data_with_current_time;
     }
-                break;
+
-            case "save_answer":
+    return $result;
+}
+
+function save_player_answer(ReqHandler &$rh, array $params): string
 {
-                    $chidx = $_REQUEST["challenge_index"];
+    if (access_test_data($params["testid"] !== null)) {
-                    $answeridx = $_REQUEST["answer_index"];
+        save_answer($params["testid"], $params["challenge_index"], $params["answer_index"]);
-                    save_answer($testid, $chidx, $answeridx);
+        return "OK";
-                }
+    } else {
-                break;
+        return "FAIL";
-            case "submit_test":
-                {
-                    conclude_test($testid);
-                }
-                break;
     }
 }
 
-    // $user_has_access_to_game = does_user_access_game($nickname, $gameid);
+function submit_test(ReqHandler &$rh, array $params): string
+{
+    if (access_test_data($params["testid"] !== null)) {
+        conclude_test($params["testid"]);
+        return "OK";
+    } else {
+        return "FAIL";
+    }
+}
 
-    // get_image needs special treatment
+function get_image(ReqHandler &$rh, array $params): string
-    if ($action === "get_image") {
+{
-        if ($is_a_default_test_with_access || $user_is_contributor_or_quizmaster) { // default case
+    $img_url = trim($params["img_url"] ?? "");
-            $img_url = trim($_REQUEST["img_url"] ?? "");
     if ($img_url !== "") {
-                $gameid = $_REQUEST["gameid"];
+        $gameid = $params["gameid"];
         patch_through_image($gameid, $img_url);
     }
-        }
+
+    return "";
 }
 
+$rh->add("get_test", ["testid"], PRIVILEGE_PLAYER, "get_player_test", RESP_JSON, "Get player's test by ID.");
+$rh->add("save_answer", ["testid", "challenge_index", "answer_index"], PRIVILEGE_PLAYER, "save_player_answer", RESP_PLAIN, "Store player's answer.");
+$rh->add("submit_test", ["testid"], PRIVILEGE_PLAYER, "submit_test", RESP_PLAIN, "Finish player's test.");
+$rh->add("get_image", ["gameid", "img_url"], PRIVILEGE_PLAYER, "get_image", RESP_NONE, "Get image per game.");
+
+// execute query if user has the player privilege level
+if ($privilege === PRIVILEGE_PLAYER) {
+    goto process_and_print;
 }
 
-// creator or quizmaster actions
+/* --------------- CREATOR LEVEL ACTIONS ---------------- */
-if (($privilege !== PRIVILEGE_CREATOR) && ($privilege !== PRIVILEGE_QUIZMASTER)) {
-    goto print_result;
-}
 
 $requester_nickname = $is_quizmaster ? "*" : $nickname; // "*" means every game
 
-switch ($action) {
+function create_update_game(ReqHandler &$rh, array $params): array
-    case "create_game":
-    case "update_game":
 {
-            $update = $action === "update_game";
+    global $nickname;
-            $data = json_decode($_REQUEST["data"], true) ?? [];
+    global $is_quizmaster;
+
+    $update = $params[ReqHandler::ACTION_KEY] === "update_game";
+    $data = json_decode($params["data"], true) ?? [];
     if (($data === []) || (trim($data["name"] ?? "") === "")) { // no further processing
-                goto print_result; // ~exit...
+        return []; // ~exit...
     }
+
+    // fetch fields
     $gameid = $data["_id"];
     $name = $data["name"];
     $description = $data["description"];
@@ -205,15 +266,19 @@ switch ($action) {
     $groups = explode_list($data["groups"] ?? "");
     $properties = $data["properties"] ?? [];
 
+    // convert group compounds to group IDs
     $groupids = get_groupids_by_compounds($groups); // convert group compounds to _ids
 
     // remove group ID's this user cannot edit
-            $groupids_with_editor_access = [];
+//    $groupids_with_editor_access = [];
-            foreach ($groupids as $groupid) {
+//    foreach ($groupids as $groupid) {
-                if (is_user_editor_to_group($groupid, $nickname) || $is_quizmaster) {
+//        if (is_user_editor_to_group($groupid, $nickname) || $is_quizmaster) {
-                    $groupids_with_editor_access[] = $groupid;
+//            $groupids_with_editor_access[] = $groupid;
-                }
+//        }
-            }
+//    }
+
+    // result
+    $result = [];
 
     // create or update
     if (!$update) {
@@ -221,6 +286,7 @@ switch ($action) {
     } else if (is_user_contributor_to_game($gameid, $nickname) || $is_quizmaster) {
         $game_data = get_game($gameid);
         if (count($game_data) !== 0) {
+
             // group management
             $old_groupids = $game_data["groups"]; // retain old groupids
             $new_groupids = $groupids; // get new groupids
@@ -239,7 +305,7 @@ switch ($action) {
             // update game header data
             $game_data["name"] = $name;
             $game_data["description"] = $description;
-                    if (($game_data["owner"] === $nickname) || ($privilege === PRIVILEGE_QUIZMASTER)) {
+            if (($game_data["owner"] === $nickname) || $is_quizmaster) {
                 $game_data["owner"] = $owner;
             }
             $game_data["contributors"] = array_intersect($contributors, get_all_nicknames());
@@ -247,11 +313,7 @@ switch ($action) {
             $game_data["properties"]["repeatable"] = $properties["repeatable"];
 
             // process game public flag: a game might be only public if not being time-constrained and is allowed to be taken multiple times
-                    if (($properties["time_limit"] !== 0) || (!$properties["repeatable"])) {
+            $game_data["public"] = ($properties["time_limit"] !== 0) || (!$properties["repeatable"]) ? false : $data["public"];
-                        $game_data["public"] = false;
-                    } else {
-                        $game_data["public"] = $data["public"];
-                    }
 
             // update game data
             update_game($game_data);
@@ -270,7 +332,7 @@ switch ($action) {
                     if ($zip->open($file["tmp_name"])) {
 
                         $game_dir = get_game_dir_by_gameid($gameid); // get game directory
-                                $game_files = glob($game_dir); // get list of existing game files
+                        //$game_files = glob($game_dir); // get list of existing game files
                         // remove former files recursively
                         $dir_iter = new RecursiveDirectoryIterator($game_dir, FilesystemIterator::SKIP_DOTS);
                         foreach ($dir_iter as $dir_item) {
@@ -290,43 +352,56 @@ switch ($action) {
                 } else if ($file_type === "csv") { // a plain table was uploaded
                     $challenge_import_status = import_challenges_from_csv($file["tmp_name"], $gameid);
                 }
-                        $result = json_encode($challenge_import_status);
+                $result = $challenge_import_status;
             }
         }
     }
+
+    return $result;
 }
-        break;
+
-    case "get_all_game_headers":
+function get_all_game_headers(ReqHandler &$rh, array $params): array
 {
+    global $requester_nickname;
     $game_headers = get_all_game_data_by_contributor_nickname($requester_nickname);
     foreach ($game_headers as &$game_header) {
         resolve_groupids($game_header["groups"]);
     }
-            $result = json_encode($game_headers);
+    return $game_headers;
 }
-        break;
+
-    case "get_challenges":
+function get_challenges(ReqHandler &$rh, array $params): string
 {
-            $gameid = ($_REQUEST["gameid"] ?? "");
+    global $is_quizmaster;
+    global $requester_nickname;
+    $gameid = $params["gameid"];
     $game_data = get_game($gameid);
+    $result = "";
     if ((count($game_data) > 0) && ($is_quizmaster || (is_user_contributor_to_game($gameid, $requester_nickname)))) {
         $result = file_get_contents(get_game_file_by_gameid($gameid));
     }
+
+    return $result;
 }
-        break;
+
-    case "delete_games":
+function delete_games(ReqHandler &$rh, array $params): string
 {
-            $gameids = explode_list(trim($_REQUEST["ids"] ?? ""));
+    global $nickname;
+
+    $gameids = explode_list(trim($params["ids"]));
     foreach ($gameids as $gameid) {
         if (($gameid !== "") && (is_user_owner_of_the_game($gameid, $nickname))) { // only the owner may delete a game
             delete_game($gameid);
         }
     }
+
+    return "OK";
 }
-        break;
+
-    case "export_game_file_csv":
+function export_game_file_csv(ReqHandler &$rh, array $params): string
 {
-            $gameid = trim($_REQUEST["gameid"] ?? "");
+    global $nickname;
+    $gameid = trim($params["gameid"]);
     if (($gameid !== "") && is_user_contributor_to_game($gameid, $nickname)) {
         $f = tmpfile();
         header("Content-Type: text/csv");
@@ -335,62 +410,71 @@ switch ($action) {
         fseek($f, 0);
         fpassthru($f);
     }
+    return "";
 }
-        break;
+
-    case "get_results_by_gameid":
+function get_player_results_by_gameid(ReqHandler &$rh, array $params): array
 {
-            $gameid = trim($_REQUEST["gameid"] ?? "");
+    global $nickname;
-            $filter = trim($_REQUEST["filter"] ?? "");
+    global $is_quizmaster;
-            $ordering = trim($_REQUEST["orderby"] ?? "");
+
+    $gameid = trim($params["gameid"]);
+    $filter = trim($params["filter"] ?? "");
+    $ordering = trim($params["orderby"] ?? "");
+
+    $result = [];
     if (($gameid !== "") && (is_user_contributor_to_game($gameid, $nickname) || $is_quizmaster)) {
         $game_results = get_results_by_gameid($gameid, $filter, $ordering, true);
-                $result = json_encode($game_results);
+        $result = $game_results;
     }
+
+    return $result;
 }
-        break;
+
-    case "generate_detailed_stats":
+function generate_detailed_game_stats(ReqHandler &$rh, array $params): array
 {
-            $testids = json_decode(trim($_REQUEST["testids"] ?? "[]"), true);
+    $testids = json_decode(trim($params["testids"]), true);
-            $gameid = trim($_REQUEST["gameid"] ?? "");
+    $gameid = trim($params["gameid"]);
     $stats = generate_detailed_stats($gameid, $testids);
-            $result = json_encode($stats);
+    return $stats;
-        }
-        break;
-
-//    case "get_image":
-//        {
-//            $gameid = trim($_REQUEST["gameid"] ?? "");
-//            $img_url = trim($_REQUEST["img_url"] ?? "");
-//            patch_through_image($gameid, $img_url);
-//        }
-//        break;
 }
 
-// quizmaster actions
+$rh->add(["create_game", "update_game"], ["data"], PRIVILEGE_CREATOR, "create_update_game", RESP_JSON, "Create or update game.");
-if ($privilege !== PRIVILEGE_QUIZMASTER) {
+$rh->add("get_all_game_headers", [], PRIVILEGE_CREATOR, "get_all_game_headers", RESP_JSON, "Get all game headers.");
-    goto print_result;
+$rh->add("get_challenges", [], PRIVILEGE_CREATOR, "get_challenges", RESP_PLAIN, "Get game challenges.");
+$rh->add("delete_games", ["ids"], PRIVILEGE_CREATOR, "delete_games", RESP_PLAIN, "Delete games.");
+$rh->add("export_game_file_csv", ["gameid"], PRIVILEGE_CREATOR, "export_game_file_csv", RESP_NONE, "Export game CSV file.");
+$rh->add("get_results_by_gameid", ["gameid"], PRIVILEGE_CREATOR, "get_player_results_by_gameid", RESP_JSON, "Get game results.");
+$rh->add("generate_detailed_stats", ["gameid", "testids"], PRIVILEGE_CREATOR, "generate_detailed_game_stats", RESP_JSON, "Generate detailed game stats.");
+
+// execute processing if user is a creator
+if ($privilege === PRIVILEGE_CREATOR) {
+    goto process_and_print;
 }
 
-switch ($action) {
+
-    case "create_group":
+/* ------------------------ QUIZMASTER ACTIONS --------------------- */
-    case "update_group":
+
+function create_update_group(ReqHandler &$rh, array $params): string
 {
-            $update = $action === "update_group";
+    global $user_data;
-            $groupname = trim($_REQUEST["groupname"] ?? "");
+
-            $description = trim($_REQUEST["description"] ?? "");
+    $update = $params[ReqHandler::ACTION_KEY] === "update_group";
-            $editors = explode_list(trim($_REQUEST["editors"] ?? ""));
+    $groupname = trim($params["groupname"]);
-            $owner = (!$update) ? $user_data["nickname"] : trim($_REQUEST["owner"]);
+    $description = trim($params["description"]);
+    $editors = (!$update) ? [] : explode_list(trim($params["editors"]));
+    $owner = (!$update) ? $user_data["nickname"] : trim($params["owner"]);
+
+    $result = "FAIL";
     if ($owner === "") {
         $owner = $user_data["nickname"];
     }
     if ($groupname != "") {
-                switch ($action) {
+        if (!$update) {
-                    case "create_group":
             create_group($groupname, $owner, $description);
-                        break;
+            $result = "OK";
-                    case "update_group":
+        } else {
-                        {
+            $gid = $params["id"];
-                            $gid = $_REQUEST["id"];
             $group = get_group($gid);
             if (count($group) !== 0) {
                 $group["unique"] = manage_unique_in_siblings($gid, $groupname); // manage unique flag in case of renaming
@@ -399,48 +483,50 @@ switch ($action) {
                 $group["editors"] = array_intersect($editors, $group["users"]); // a user cannot be an editor if not part of the group
                 $group["owner"] = $owner;
                 update_group($group);
+                $result = "OK";
             }
         }
-                        break;
+    }
+    return $result;
 }
 
-            }
+function delete_groups(ReqHandler &$rh, array $params): string
-        }
-        break;
-    case "delete_groups":
 {
-            $groups = explode_list($_REQUEST["ids"] ?? "");
+    $groups = explode_list($params["ids"] ?? "");
     foreach ($groups as $g) {
         delete_group($g);
     }
+    return "OK";
 }
-        break;
+
-    case "get_all_groups":
+function get_all_player_groups(ReqHandler &$rh, array $params): array
-        $result = json_encode(get_all_groups());
-        break;
-    case "search_groups":
 {
-            $needle = $_REQUEST["needle"] ?? "";
+    return get_all_groups();
-            $result = json_encode(search_groups($needle));
 }
-        break;
+
-    case "create_user":
+function search_player_groups(ReqHandler &$rh, array $params): array
-    case "update_user":
 {
-            $update = $action === "update_user";
+    return search_groups($params["needle"]);
-            $target_nickname = trim($_REQUEST["nickname"] ?? "");
+}
-            $password = trim($_REQUEST["password"] ?? "");
+
-            $groups = explode_list($_REQUEST["groups"] ?? "");
+function create_update_user(ReqHandler &$rh, array $params): string
-            $realname = trim($_REQUEST["realname"] ?? "");
+{
-            $privilege = trim($_REQUEST["privilege"] ?? PRIVILEGE_PLAYER);
+    $update = $params[ReqHandler::ACTION_KEY] === "update_user";
+    $target_nickname = trim($params["nickname"]);
+    $password = trim($params["password"]);
+    $groups = explode_list($params["groups"]);
+    $realname = trim($params["realname"]);
+    $privilege = trim($params["privilege"]);
 
     $groupids = get_groupids_by_compounds($groups); // convert group compounds to _ids
 
+    $success = false;
     if (($target_nickname !== "")) {
         if ((!$update) && ($password !== "")) { // CREATE
-                    add_user($target_nickname, $password, $realname, $groupids, $privilege);
+            $success = add_user($target_nickname, $password, $realname, $groupids, $privilege);
         } else if ($update) { // UPDATE
             $user_data = get_user($target_nickname); // load user data
+            if (count ($user_data) > 0) {
 
                 // group management
                 $old_groupids = $user_data["groups"]; // retain old groupids
@@ -466,43 +552,55 @@ switch ($action) {
                     $user_data["password"] = password_hash($password, PASSWORD_DEFAULT);
                 }
 
-                    update_user($user_data);
+                $success = update_user($user_data);
+            }
         }
     }
 
+    return $success ? "OK" : "FAIL";
 }
-        break;
+
-    case "delete_users":
+function delete_users(ReqHandler &$rh, array $params): string {
-        {
+    $users = explode_list($params["users"]);
-            $users = explode_list($_REQUEST["users"] ?? "");
     foreach ($users as $g) {
         delete_user($g);
     }
+    return "OK";
 }
-        break;
+
-    case "get_all_users":
+function get_all_game_users(ReqHandler &$rh, array $params): array {
-        {
     $user_data_filtered = get_all_users();
     for ($i = 0; $i < count($user_data_filtered); $i++) {
         unset($user_data_filtered[$i]["password"]); // remove password from records
         resolve_groupids($user_data_filtered[$i]["groups"]);  // resolve group IDs
     }
-            $result = json_encode($user_data_filtered);
+    return $user_data_filtered;
 }
-        break;
+
-    case "import_users_from_csv":
+function import_users_from_csv(ReqHandler &$rh, array $params): string {
-        {
     if (!isset($_FILES["users_table"])) {
-                goto print_result;
+
     }
+    return "OK";
 }
-        break;
+
-}
+$rh->add("create_group", ["groupname", "description"], PRIVILEGE_QUIZMASTER, "create_update_group", RESP_PLAIN, "Create group.");
+$rh->add("update_group", ["groupname", "description", "owner", "editors", "id"], PRIVILEGE_QUIZMASTER, "create_update_group", RESP_PLAIN, "Update group.");
+$rh->add("delete_group", ["ids"], PRIVILEGE_QUIZMASTER, "delete_group", RESP_PLAIN, "Delete group.");
+$rh->add("get_all_groups", [], PRIVILEGE_QUIZMASTER, "get_all_player_groups", RESP_JSON, "Get all player groups.");
+$rh->add("search_groups", ["needle"], PRIVILEGE_QUIZMASTER, "search_player_groups", RESP_JSON, "Serach and fetch player groups.");
+
+$rh->add(["create_user", "update_user"], ["nickname", "password", "groups", "realname", "privilege"], PRIVILEGE_QUIZMASTER, "create_update_user", RESP_PLAIN, "Create or update user.");
+$rh->add("delete_users", ["users"], PRIVILEGE_QUIZMASTER, "delete_users", RESP_PLAIN, "Delete users.");
+$rh->add("get_all_game_users", [], PRIVILEGE_QUIZMASTER, "get_all_users", RESP_JSON, "Get all users.");
+$rh->add("import_users_from_csv", [], PRIVILEGE_QUIZMASTER, "import_", RESP_JSON, "Get all users.");
 
 // ----------
 
-print_result:
+process_and_print:
 
-if ($result !== "") {
+[$result, $success] = $rh->process($privilege);
+
+if ($success && ($result !== "")) {
     echo $result;
 }

style/spreadquiz_mobile.css

@@ -38,6 +38,10 @@
         width: calc(100vw - 3em);
     }
 
+    section.answer label {
+        max-width: 80%;
+    }
+
     section#infobox {
         top: unset;
         left: 0;

usermgr.php

@@ -7,6 +7,7 @@ require_once "controller.php";
 
 $userdb = new \SleekDB\Store(USERDB, DATADIR, ["timeout" => false]);
 
+const PRIVILEGE_NONE = "none";
 const PRIVILEGE_PLAYER = "player";
 const PRIVILEGE_CREATOR = "creator";
 const PRIVILEGE_QUIZMASTER = "admin"; // TODO: refactor!