<?php
session_start();
include 'db_connect.php';

if ($_SERVER["REQUEST_METHOD"] == "POST") {
    $sender_id = $_SESSION['user_id'];
    $receiver_id = $_POST['receiver_id'];
    $message = trim($_POST['message']);

    if (!empty($message)) {
        $stmt = $pdo->prepare("INSERT INTO messages (sender_id, receiver_id, message) VALUES (:sender_id, :receiver_id, :message)");
        $stmt->execute([
            ':sender_id' => $sender_id,
            ':receiver_id' => $receiver_id,
            ':message' => $message
        ]);
    }
}
header("Location: chat.php?user=$receiver_id");
exit();
?>