First release

server/api.php

@@ -0,0 +1,146 @@
+<?php
+/**
+ * Fun with Binary - a fun way of introducing binary
+ * Copyright (C) 2018, Diogo Cordeiro.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *
+ * api.php
+ *
+ * Fun with Binary
+ * Web Server
+ *
+ * Diogo Peralta Cordeiro
+ * up201705417@fc.up.pt
+ *
+ * Generates the chalenges and controls the arduino
+ */
+header('Access-Control-Allow-Origin: *');
+
+class game
+{
+    /*
+     * ==Warning==
+     * You must add www-data to dialout group
+     * for serial port communication to work!
+     */
+
+    // Arduino related
+    protected $comPort = "/dev/ttyACM0";
+    protected $arduino_available = true;
+
+    // Storage related
+    public $correct_answer_path = "/var/www/answer.txt";
+    public $current_answer_path = "/var/www/current_binary_digit.txt";
+
+    /**
+     * Prepares everything for a new game
+     */
+    public function reset()
+    {
+        // Reset current binary digit for a potential new game
+        $fp = fopen($this->current_answer_path, "w");
+        fwrite($fp, "000000");
+
+        // Sends reset command to Arduino
+        if ($this->arduino_available) {
+            $fp = fopen($this->comPort, "wb");
+            fwrite($fp, 9); // 9 is the Reset Byte
+        }
+    }
+
+    /**
+     * Starts game
+     */
+    public function start()
+    {
+        // Generates a 6-bit random number
+        $number = rand(0, 63);
+
+        // Memorizes the correct binary answer
+        $fp = fopen($this->correct_answer_path, "w");
+        fwrite($fp, sprintf("%06d", decbin($number)));
+
+        return $number;
+    }
+
+    /**
+     * Turn current answer bits accordingly
+     */
+    public function change_state($led_id)
+    {
+        // Update and memorize the new current answer
+        $current_binary_digit = file_get_contents($this->current_answer_path);
+        $current_binary_digit[(int)$led_id] = ($current_binary_digit[(int)$led_id] == 1) ? 0 : 1;
+        $fp = fopen($this->current_answer_path, "w");
+        fwrite($fp, $current_binary_digit);
+
+        // Updates Arduino output
+        if ($this->arduino_available) {
+            $fp = fopen($this->comPort, "wb");
+            fwrite($fp, (int)$led_id);
+        }
+    }
+
+    /**
+     * Compares the given answer with the right answer and tells the result
+     * Returns true if won, false otherwise
+     */
+    public function end($given_answer, $correct_answer)
+    {
+        if ($given_answer == $correct_answer) { // Won
+                        // Sends Won command to Arduino
+            if ($this->arduino_available) {
+                $fp = fopen($this->comPort, "wb");
+                fwrite($fp, 7); // 7 is the Won Byte
+            }
+
+            return true;
+        } else { // Lost
+                        // Sends Lost command to Arduino
+            if ($this->arduino_available) {
+                $fp = fopen($this->comPort, "wb");
+                fwrite($fp, 8); // 8 is the Lost Byte
+            }
+
+            return false;
+        }
+    }
+}
+
+/**
+ * API Handler
+ */
+$game = new game();
+
+if (isset($_GET["start"])) {
+    $game->reset();
+    $number = $game->start();
+
+    // Print out the number and let the games begin
+    echo $number;
+} elseif (isset($_GET["change_state"])) {
+    $led_id = $_GET["change_state"];
+    $game->change_state($led_id);
+} elseif (isset($_GET["end"])) { // Game Over
+    $given_answer = file_get_contents($game->current_answer_path);
+    $correct_answer = file_get_contents($game->correct_answer_path);
+
+    if ($game->end($given_answer, $correct_answer)) {
+        echo "That's right!";
+    } else {
+        echo "Oops, the answer was: ".$correct_answer;
+    }
+}