<?php  
include("includes/db_config.php"); 

if(isset($_POST["it_id"])) {
    $it_id = $_POST["it_id"];

    // Fetch item details
    $query = "SELECT * FROM ah_item_details WHERE id = ?";
    $stmt = mysqli_prepare($conn, $query);
    mysqli_stmt_bind_param($stmt, "i", $it_id);
    mysqli_stmt_execute($stmt);
    $result = mysqli_stmt_get_result($stmt);
    $item = mysqli_fetch_array($result, MYSQLI_ASSOC);

    if (!$item) {
        echo json_encode(["error" => "Item not found"]);
        exit;
    }

    // Check existing stock
    $check_item = "SELECT id, opening_stock, min_stock_quatity FROM ah_item_tracking_details WHERE item_id = ?";
    $stmt = mysqli_prepare($conn, $check_item);
    mysqli_stmt_bind_param($stmt, "i", $it_id);
    mysqli_stmt_execute($stmt);
    $result = mysqli_stmt_get_result($stmt);
    
    if ($row = mysqli_fetch_assoc($result)) {
        // Calculate total units
        $totalunit = $item['conversion_rate'] * $item['sunit'];
        $updated_qty = (int)$row['opening_stock'] - $totalunit;

        // If stock goes negative, return an error message
        if ($updated_qty < 0) {
            echo json_encode(array("status"=>"error","msg"=>'Insufficient stock! Please add stock before proceeding.'));
            die;
        }
    } else {
        echo json_encode(array("status"=>"error","msg"=>'Stock record not found.'));
            die;
    }
    // Fetch primary unit name
        $unit1_query = mysqli_query($conn, "SELECT unit FROM primery_unit WHERE id = '".$item['punit']."'");
        $unit1 = mysqli_fetch_array($unit1_query);
        $primary_unit = $unit1['unit'] ?? '1';

        // Fetch secondary unit name
        $unit2_query = mysqli_query($conn, "SELECT unit FROM primery_unit WHERE id = '".$item['sunit']."'");
        $unit2 = mysqli_fetch_array($unit2_query);
        $secondary_unit = $unit2['unit'] ?? '2';

        // Create unit details description
        $item['unit_details'] = "1 " . $primary_unit . " = " . $item['conversion_rate'] . " " . $secondary_unit;
        //$item['sale_price'] = $item['conversion_rate'] * $item['sale_price'];
        echo json_encode(array("status"=>"success","items"=>$item));
                    die;
}
?>