<?php
session_start();
require_once 'db/config.php';

if (!isset($_SESSION['loggedin']) || $_SESSION['loggedin'] !== true) {
    header("location: login.php");
    exit;
}

if ($_SERVER["REQUEST_METHOD"] == "POST") {
    $item_type = trim($_POST["item_type"]);
    $quantity = trim($_POST["quantity"]);
    $user_id = $_SESSION['user_id'];

    if (empty($item_type) || empty($quantity) || !is_numeric($quantity) || $quantity <= 0) {
        $_SESSION['error_message'] = "Please enter a valid item and quantity.";
        header("location: dashboard.php");
        exit;
    }

    // Basic points system: 10 points per item
    $points_awarded = $quantity * 10;

    try {
        $db = db();
        
        // Insert submission
        $sql = "INSERT INTO waste_submissions (user_id, item_type, quantity, points_awarded) VALUES (:user_id, :item_type, :quantity, :points_awarded)";
        $stmt = $db->prepare($sql);
        $stmt->bindParam(':user_id', $user_id, PDO::PARAM_INT);
        $stmt->bindParam(':item_type', $item_type, PDO::PARAM_STR);
        $stmt->bindParam(':quantity', $quantity, PDO::PARAM_INT);
        $stmt->bindParam(':points_awarded', $points_awarded, PDO::PARAM_INT);
        $stmt->execute();

        // Update user points
        $sql_update_points = "UPDATE users SET points = points + :points_awarded WHERE id = :user_id";
        $stmt_update_points = $db->prepare($sql_update_points);
        $stmt_update_points->bindParam(':points_awarded', $points_awarded, PDO::PARAM_INT);
        $stmt_update_points->bindParam(':user_id', $user_id, PDO::PARAM_INT);
        $stmt_update_points->execute();

        $_SESSION['success_message'] = "E-waste submitted successfully! You earned " . $points_awarded . " points.";

    } catch (PDOException $e) {
        $_SESSION['error_message'] = "Oops! Something went wrong. Please try again later.";
        error_log("E-waste submission failed: " . $e->getMessage());
    }

    header("location: dashboard.php");
    exit;
}
?>