ap

<?php

 require_once 'DbConnect.php';

 $response = array();

 if(isset($_GET['apicall'])){

 switch($_GET['apicall']){

 case 'signup':
 if(isTheseParametersAvailable(array('username','email','password','gender'))){
 $username = $_POST['username'];
 $email = $_POST['email'];
 $password = md5($_POST['password']);
 $gender = $_POST['gender'];

 $stmt = $conn->prepare("SELECT id FROM users WHERE username = ? OR email = ?");
 $stmt->bind_param("ss", $username, $email);
 $stmt->execute();
 $stmt->store_result();

 if($stmt->num_rows > 0){
 $response['error'] = true;
 $response['message'] = 'User already registered';
 $stmt->close();
 }else{
 $stmt = $conn->prepare("INSERT INTO users (username, email, password, gender) VALUES (?, ?, ?, ?)");
 $stmt->bind_param("ssss", $username, $email, $password, $gender);

 if($stmt->execute()){
 $stmt = $conn->prepare("SELECT id, id, username, email, gender FROM users WHERE username = ?");
 $stmt->bind_param("s",$username);
 $stmt->execute();
 $stmt->bind_result($userid, $id, $username, $email, $gender);
 $stmt->fetch();

 $user = array(
 'id'=>$id,
 'username'=>$username,
 'email'=>$email,
 'gender'=>$gender
 );

 $stmt->close();

 $response['error'] = false;
 $response['message'] = 'User registered successfully';
 $response['user'] = $user;
 }
 }

 }else{
 $response['error'] = true;
 $response['message'] = 'required parameters are not available';
 }

 break;

 case 'login':

 if(isTheseParametersAvailable(array('username', 'password'))){

 $username = $_POST['username'];
 $password = md5($_POST['password']);

 $stmt = $conn->prepare("SELECT id, username, email, gender FROM users WHERE username = ? AND password = ?");
 $stmt->bind_param("ss",$username, $password);

 $stmt->execute();

 $stmt->store_result();

 if($stmt->num_rows > 0){

 $stmt->bind_result($id, $username, $email, $gender);
 $stmt->fetch();

 $user = array(
 'id'=>$id,
 'username'=>$username,
 'email'=>$email,
 'gender'=>$gender
 );

 $response['error'] = false;
 $response['message'] = 'Login successfull';
 $response['user'] = $user;
 }else{
 $response['error'] = false;
 $response['message'] = 'Invalid username or password';
 }
 }
 break;

 default:
 $response['error'] = true;
 $response['message'] = 'Invalid Operation Called';
 }

 }else{
 $response['error'] = true;
 $response['message'] = 'Invalid API Call';
 }

 echo json_encode($response);

 function isTheseParametersAvailable($params){

 foreach($params as $param){
 if(!isset($_POST[$param])){
 return false;
 }
 }
 return true;
 }