inventory/backend/api/items.php

<?php
header("Access-Control-Allow-Origin: *");
header("Content-Type: application/json; charset=UTF-8");
header("Access-Control-Allow-Methods: GET, POST, PUT, DELETE, OPTIONS");
header("Access-Control-Allow-Headers: Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With");

if ($_SERVER['REQUEST_METHOD'] == 'OPTIONS') {
    exit(0);
}

require_once '../config/database.php';
require_once '../models/Item.php';

$database = new Database();
$db = $database->getConnection();

$item = new Item($db);

$request_method = $_SERVER['REQUEST_METHOD'];

switch($request_method) {
    case 'GET':
        if(isset($_GET['id'])) {
            $item->id = $_GET['id'];
            $item->readOne();
            
            if($item->name != null) {
                $item_arr = array(
                    "id" => $item->id,
                    "name" => $item->name,
                    "description" => $item->description,
                    "serial_number" => $item->serial_number,
                    "picture" => $item->picture,
                    "quantity" => $item->quantity,
                    "price" => $item->price,
                    "created_at" => $item->created_at,
                    "updated_at" => $item->updated_at
                );
                
                http_response_code(200);
                echo json_encode($item_arr);
            } else {
                http_response_code(404);
                echo json_encode(array("message" => "Item not found."));
            }
        } else {
            $stmt = $item->read();
            $num = $stmt->rowCount();
            
            if($num > 0) {
                $items_arr = array();
                $items_arr["records"] = array();
                
                while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
                    extract($row);
                    
                    $item_item = array(
                        "id" => $id,
                        "name" => $name,
                        "description" => $description,
                        "serial_number" => $serial_number,
                        "picture" => $picture,
                        "quantity" => $quantity,
                        "price" => $price,
                        "created_at" => $created_at,
                        "updated_at" => $updated_at
                    );
                    
                    array_push($items_arr["records"], $item_item);
                }
                
                http_response_code(200);
                echo json_encode($items_arr);
            } else {
                http_response_code(200);
                echo json_encode(array("records" => array()));
            }
        }
        break;
        
    case 'POST':
        $data = json_decode(file_get_contents("php://input"));
        
        if(!empty($data->name) && !empty($data->quantity) && !empty($data->price)) {
            $item->name = $data->name;
            $item->description = $data->description ?? '';
            $item->serial_number = $data->serial_number ?? '';
            $item->picture = $data->picture ?? '';
            $item->quantity = $data->quantity;
            $item->price = $data->price;
            
            if($item->create()) {
                http_response_code(201);
                echo json_encode(array("message" => "Item was created."));
            } else {
                http_response_code(503);
                echo json_encode(array("message" => "Unable to create item."));
            }
        } else {
            http_response_code(400);
            echo json_encode(array("message" => "Unable to create item. Data is incomplete."));
        }
        break;
        
    case 'PUT':
        $data = json_decode(file_get_contents("php://input"));
        
        if(!empty($data->id) && !empty($data->name) && !empty($data->quantity) && !empty($data->price)) {
            $item->id = $data->id;
            $item->name = $data->name;
            $item->description = $data->description ?? '';
            $item->serial_number = $data->serial_number ?? '';
            $item->picture = $data->picture ?? '';
            $item->quantity = $data->quantity;
            $item->price = $data->price;
            
            if($item->update()) {
                http_response_code(200);
                echo json_encode(array("message" => "Item was updated."));
            } else {
                http_response_code(503);
                echo json_encode(array("message" => "Unable to update item."));
            }
        } else {
            http_response_code(400);
            echo json_encode(array("message" => "Unable to update item. Data is incomplete."));
        }
        break;
        
    case 'DELETE':
        if(isset($_GET['id'])) {
            $item->id = $_GET['id'];
            
            if($item->delete()) {
                http_response_code(200);
                echo json_encode(array("message" => "Item was deleted."));
            } else {
                http_response_code(503);
                echo json_encode(array("message" => "Unable to delete item."));
            }
        } else {
            http_response_code(400);
            echo json_encode(array("message" => "Unable to delete item. ID is missing."));
        }
        break;
        
    default:
        http_response_code(405);
        echo json_encode(array("message" => "Method not allowed."));
        break;
}
?>