index.php

<?php
// parameters
$hubVerifyToken = 'TOKEN123456abcd';
$accessToken = "EAADIZCSOHKUoBAOfBh6gzm1bLMDkkuLhl86v2RhfZCMFg1ije1ZBL82hEG1hXoJZCWSDD8VMbpEbxKyK8e6pxUpZCi5AmntoKINHYEXJDQi0yofFYMu8NxzZBKV9b8vu5W2Mk8ymelOARiTXUV4rU2BuIlZApa9WAPHxYLZAmGAPKQZDZD";
// check token at setup
if ($_REQUEST['hub_verify_token'] === $hubVerifyToken) {
	echo $_REQUEST['hub_challenge'];
	exit;
}
// handle bot's anwser
$input = json_decode(file_get_contents('php://input'), true);
$senderId = $input['entry'][0]['messaging'][0]['sender']['id'];
$messageText = $input['entry'][0]['messaging'][0]['message']['text'];
$special_command = $input['entry'][0]['messaging'][0]['postback']['payload'];

if (strpos($messageText, 'translate') !== false) {
	
$api_key = '90a6a10a5ff4d106deb662b627130ca6';
$text = 'word';
$source="en";
$target="fr";
 
$url = 'http://words.bighugelabs.com/api/2/' . $api_key . '/' . $text .'/json';
//$url .= '&target='.$target;
//$url .= '&source='.$source;
 
$response = file_get_contents($url);
$obj =json_decode($response,true); //true converts stdClass to associative array.
	foreach ($obj as $key => $value) {
    $tr= $tr +  "Key: $key; Value: $value\n";
}
if($obj != null)
{
    if(isset($obj['error']))
    {
        $tr = "Error is : ".$obj['error']['message'];
    }
    else
    {
        //$tr = "Translsated Text: ".$obj['data']['translations'][0]['translatedText']."n";
	$tr=$obj['noun']['syn'][0];
	    $response = [
		'recipient' => [ 'id' => $senderId ],
		'message' => [ 'text' =>  $tr]
		];
    }
}
else
$tr = 'Chouf m3a ayoub rah wa3er f loungli ach bghitini ana hahahahahah had lkhra meredni';	
//$tr='http://words.bighugelabs.com/api/2/' . $api_key . '/' . $text .'/json';		
	$response = [
		'recipient' => [ 'id' => $senderId ],
		'message' => [ 'text' =>  $tr]
	];
	
}elseif ($special_command == 'ASK_QUESTION') {
		$ask_message = 'Please write your question :) ';
		

		$response = [
			'recipient' => [ 'id' => $senderId ],
			'message' => [ 'text' => $ask_message ]
		];
	}
elseif ($special_command == 'USE_DIC') {
		$ask_message = 'Type: translate <word>';
		

		$response = [
			'recipient' => [ 'id' => $senderId ],
			'message' => [ 'text' => $ask_message ]
		];
	
	
}elseif(!empty($messageText)){
	$menu_message = [];
	$buttons = [];
	$buttons[] = ['type' => 'postback', 'title' => 'Ask us a Question', 'payload' => 'ASK_QUESTION'];
	$buttons[] = ['type' => 'postback', 'title' => 'Use Dictionary', 'payload' => 'USE_DIC'];
	$menu_message = [
	'type'    => 'template',
	'payload' => ['template_type' => 'button', 'text' => 'Welcome to our facebook page My Easy Way To Learn English', 'buttons' => $buttons]

	];

	$response = [
		'recipient' => [ 'id' => $senderId ],
		'message' => [ 'attachment' => $menu_message ]
	];
}
$ch = curl_init('https://graph.facebook.com/v2.6/me/messages?access_token='.$accessToken);
	curl_setopt($ch, CURLOPT_POST, 1);
	curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($response));
	curl_setopt($ch, CURLOPT_HTTPHEADER, ['Content-Type: application/json']);
	curl_exec($ch);
	curl_close($ch);