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| <?php
class UssdNode {
private $name = '';
private $parent = '';
private $title = '';
private $address = '';
private $children = array();
private $index = 0;
function __construct($title, $name, $parent) {
$this->name = $name;
$this->parent = $parent;
$this->title = $title;
}
function addChildNode(UssdNode $childNode) {
$this->children[] = $childNode;
}
function setIndex($index) {
$this->index = $index;
}
function hasChildren() {
return count($this->children) > 0;
}
function setAddress($address) {
$this->address = $address;
}
function getName() {
return $this->name;
}
function getParent() {
return $this->parent;
}
function getAddress() {
return $this->address;
}
function getTitle() {
return $this->title;
}
function getChildren() {
return $this->children;
}
function getNameFromIndex($index) {
return $this->children[$index - 1]->getName();
}
function toString() {
$objectString = '';
$items = $this->children;
$bufferLimit = (count($items) == 0) ? 1 : $this->getBufferLimit() + 1;
do {
$bufferLimit -= 1;
$objectString = $this->recurseMenu($items, $bufferLimit);
} while (strlen($objectString) > 160);
$this->index = $bufferLimit;
return $objectString;
}
function getBufferLimit() {
$len = count($this->children);
$margin = $len - $this->index;
if ($margin < 5)
return $this->index + $margin;
else
return $this->index + 5; // LIMITE LE NOMBRE DE MENU A AFFICHER
}
function recurseMenu($items, $bufferLimit) {
$objectString = $this->getTitle() . PHP_EOL;
$lastMenu = false;
if (count($items) > 0) {
for ($i = $this->index; $i < $bufferLimit; $i++) {
$item = $items[$i];
$num = $i + 1;
// get node by name
$userSessions = $_SESSION['userSessions'];
$currUserSession = $userSessions[$this->address];
$node = $currUserSession->getNode($item->getName());
$title = $node->getTitle();
$objectString = $objectString . PHP_EOL . $num . '. ' . $title;
}
} else {
$objectString = $objectString . PHP_EOL . 'NO DATA AVAILABLE, TRY AGAIN LATER';
}
$lastMenu = $bufferLimit == count($items);
$objectString = $objectString . PHP_EOL . PHP_EOL . '0. Exit';
if ($this->getParent() != '0') {
$objectString = $objectString . PHP_EOL . '#. Back';
}
if ($lastMenu === false) {
$rem = count($items) - $this->getBufferLimit();
$objectString = $objectString . PHP_EOL . '77. Next (' . $rem . ')';
}
return $objectString;
}
}
class MyTree {
private $rootNode;
function __construct() {
$this->initTree();
}
function initTree() {
$rootNode = new UssdNode('Welcome to Cheggen USSD Menu', 'root', '0');
$childNode1 = new UssdNode('Option 1', 'option1', 'root');
$childNode1->addChildNode(new UssdNode('Sub-option 1', 'suboption1', 'option1'));
$childNode1->addChildNode(new UssdNode('Sub-option 2', 'suboption2', 'option1'));
$childNode2 = new UssdNode('Option 2', 'option2', 'root');
$childNode2->addChildNode(new UssdNode('Sub-option 3', 'suboption3', 'option2'));
$childNode2->addChildNode(new UssdNode('Sub-option 4', 'suboption4', 'option2'));
$childNode3 = new UssdNode('Option 3', 'option3', 'root');
$childNode3->addChildNode(new UssdNode('Sub-option 4', 'suboption4', 'option3'));
$childNode3->addChildNode(new UssdNode('Sub-option 5', 'suboption5', 'option3'));
$childNode4 = new UssdNode('Option 4', 'option4', 'root');
$childNode4->addChildNode(new UssdNode('Sub-option 6', 'suboption6', 'option4'));
$childNode4->addChildNode(new UssdNode('Sub-option 7', 'suboption7', 'option4'));
$childNode5 = new UssdNode('Option 5', 'option5', 'root');
$childNode5->addChildNode(new UssdNode('Sub-option 8', 'suboption8', 'option5'));
$childNode5->addChildNode(new UssdNode('Sub-option 9', 'suboption9', 'option5'));
$childNode6 = new UssdNode('Option 6', 'option6', 'root');
$childNode6->addChildNode(new UssdNode('Sub-option 10', 'suboption10', 'option6'));
$childNode6->addChildNode(new UssdNode('Sub-option 11', 'suboption11', 'option6'));
$childNode7 = new UssdNode('Option 7', 'option7', 'root');
$childNode7->addChildNode(new UssdNode('Sub-option 12', 'suboption12', 'option7'));
$childNode7->addChildNode(new UssdNode('Sub-option 13', 'suboption13', 'option7'));
$rootNode->addChildNode($childNode1);
$rootNode->addChildNode($childNode2);
$rootNode->addChildNode($childNode3);
$rootNode->addChildNode($childNode4);
$rootNode->addChildNode($childNode5);
$rootNode->addChildNode($childNode6);
$rootNode->addChildNode($childNode7);
$this->rootNode = $rootNode;
}
function getRootNode() {
return $this->rootNode;
}
}
class MyUssdUserSession {
private $ussdTree;
private $currentNode;
private $address;
function __construct($address, $ussdTree) {
$this->address = $address;
$this->ussdTree = $ussdTree;
$this->currentNode = $ussdTree->getRootNode();
}
function getNode($input) {
$children = $this->currentNode->getChildren();
foreach ($children as $index => $child) {
if ((is_int($input) ? $index : $child->getName()) == $input) {
return $child;
}
}
return null;
}
function processUssdInput($input) {
// Check if Detect A Page Refresh Or New Page Entered
$is_page_refreshed = (isset($_SERVER['HTTP_CACHE_CONTROL']) && $_SERVER['HTTP_CACHE_CONTROL'] == 'max-age=0');
// var_dump($is_page_refreshed);
if(session_status() === PHP_SESSION_ACTIVE) { // Check if Session is Enabled (Active)
if($is_page_refreshed) { // If this Page has been Refresh (true)
// Exit
session_destroy();
}
}
if ($input === '') {
// Initial menu
return $this->currentNode->toString();
} elseif ($input === '0' or $input === 0) {
// Exit
return 'Thanks, end of session';
session_destroy();
} elseif ($input === '#') { // 'Invalid input';
// Back
$parentName = $this->currentNode->getParent();
$parentNode = $this->getNode($parentName);
if ($parentNode !== null) {
$this->currentNode = $parentNode;
return $this->currentNode->toString();
} else {
return 'Invalid input';
}
} elseif ($input === '77' || $input === 77) {
// Next
$index = $this->currentNode->getIndex() + 5;
$this->currentNode->setIndex($index);
return $this->currentNode->toString();
} else {
// Check if the input matches any child node
$childNode = $this->getNode($input);
if ($childNode !== null) {
$this->currentNode = $childNode;
return $this->currentNode->toString();
} else {
return 'Invalid input';
}
}
}
}
// Start the USSD session
session_start();
// Create the USSD tree
$ussdTree = new MyTree();
// Get the user's address (phone number)
$address = $_POST['address'] ?? '';
// Create or retrieve the user session
$userSessions = $_SESSION['userSessions'] ?? [];
$userSession = $userSessions[$address] ?? null;
if ($userSession === null) {
$userSession = new MyUssdUserSession($address, $ussdTree);
$userSessions[$address] = $userSession;
$_SESSION['userSessions'] = $userSessions;
}
// Get the USSD input from the request
// $input = '#';
$input = $_POST['ussdInput'] ?? '';
// Process the USSD input and get the response
$response = $userSession->processUssdInput($input);
// Send the response back to the USSD gateway
header('Content-type: text/plain');
echo $response; |
