request_handler.php

<?php
session_start();
if (!isset($_SESSION["user_id"])){
    exit("Page ERROR!");
}
require_once("sql_connect.php");
if (isset($_POST["request"])){
    $time = date("l h:i:sa");
    $sql1 = "SELECT * FROM users WHERE userID='{$_POST["request"]}'";
    $result1 = $conn->query($sql1);
    if($result1->num_rows > 0){
        $valid = $result1->fetch_assoc();
        if($valid["userID"] == $_SESSION["user_id"]){
            exit("Cannot link self!");
        }else{

            $sql2 = "SELECT * FROM linked WHERE person1='{$_SESSION["user_id"]}' AND person2='{$_POST["request"]}' OR person1='{$_POST["request"]}' AND person2='{$_SESSION["user_id"]}'";
            $result2 = $conn->query($sql2);
            if($result2->num_rows > 0){
                exit("Already Linked!");
            }else{
                $sql3 = "SELECT * FROM requests WHERE request_from='{$_SESSION["user_id"]}' AND request_to='{$_POST["request"]}' OR request_from='{$_POST["request"]}' AND request_to='{$_SESSION["user_id"]}'";
                $result3 = $conn->query($sql3);
                if($result3->num_rows > 0){
                    exit("Already sent!");
                }
                $data = $conn->prepare("INSERT INTO requests(request_from, request_to, request_date)VALUES(?, ?, ?)");
                $data->bind_param("sss", $_SESSION["user_id"], $_POST["request"], $time);
               
                $data->execute() or die("Error tryagain!");
  
                // SEND A NOTIFICATION 
                $sql3 = "SELECT * FROM users WHERE userID='{$_SESSION["user_id"]}'";
                $result3 = $conn->query($sql3);
                if($result3->num_rows > 0){
                    $valid3 = $result3->fetch_assoc();
                    $mesg = "You have a new link request from ".$valid3["username"]."";
                    $time2 = date("l h:i:sa");
                    $data2 = $conn->prepare("INSERT INTO notifications(notification_from, notification_to, message, time)VALUES(?, ?, ?, ?)");
                    $data2->bind_param("ssss", $_SESSION["user_id"], $_POST["request"],$mesg, $time2);
                   
                    $data2->execute();
                }
               
               exit("Sent");
            }
          
        }
    }else{
        exit("Cannot find host!");
    }



}


?>