books.php

<?php
header("Access-Control-Allow-Origin: *");
header("Access-Control-Allow-Methods: GET, POST, DELETE, OPTIONS");
header("Access-Control-Allow-Headers: Content-Type, Authorization");
header("Content-Type: application/json");

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

$servername = "localhost";
$username = "root";
$password = "";
$dbname = "library_db";
$port = 3307;

$conn = new mysqli($servername, $username, $password, $dbname, $port);
if ($conn->connect_error) {
    http_response_code(500);
    echo json_encode(['error' => "Connection failed: " . $conn->connect_error]);
    exit;
}

$method = $_SERVER['REQUEST_METHOD'];

switch ($method) {
    case 'GET':
        if (isset($_GET['id'])) {
            $id = intval($_GET['id']);
            $sql = "SELECT id, book_title, author_name, genre, publication_year, quantity FROM library WHERE id=$id";
            $result = $conn->query($sql);
            $row = $result->fetch_assoc();
            echo json_encode($row ?: []);
        } else {
            $sql = "SELECT id, book_title, author_name, genre, publication_year, quantity FROM library";
            $result = $conn->query($sql);
            $rows = [];
            while ($row = $result->fetch_assoc()) {
                $rows[] = $row;
            }
            echo json_encode($rows);
        }
        break;

    case 'POST':
        // POST 包含新增和更新(带 id)
        $id = isset($_GET['id']) ? intval($_GET['id']) : 0;

        $book_title = $conn->real_escape_string($_POST['book_title'] ?? '');
        $author_name = $conn->real_escape_string($_POST['author_name'] ?? '');
        $genre = $conn->real_escape_string($_POST['genre'] ?? '');
        $publication_year = intval($_POST['publication_year'] ?? 0);
        $quantity = intval($_POST['quantity'] ?? 0);

        $imgData = null;
        if (isset($_FILES['book_cover']) && $_FILES['book_cover']['error'] === UPLOAD_ERR_OK) {
            $imgData = file_get_contents($_FILES['book_cover']['tmp_name']);
            $imgData = $conn->real_escape_string($imgData);
        }

        if ($id > 0) {
            // 更新
            $sql = "UPDATE library SET 
                    book_title='$book_title', 
                    author_name='$author_name', 
                    genre='$genre', 
                    publication_year=$publication_year, 
                    quantity=$quantity";

            if ($imgData !== null) {
                $sql .= ", book_cover='$imgData'";
            }
            $sql .= " WHERE id=$id";

            if ($conn->query($sql) === TRUE) {
                echo json_encode(['status' => 'updated']);
            } else {
                http_response_code(500);
                echo json_encode(['error' => $conn->error]);
            }
        } else {
            // 新增
            $sql = "INSERT INTO library (book_title, author_name, genre, publication_year, quantity, book_cover) VALUES (
                '$book_title', '$author_name', '$genre', $publication_year, $quantity, " .
                ($imgData !== null ? "'$imgData'" : "NULL") . ")";

            if ($conn->query($sql) === TRUE) {
                echo json_encode(['status' => 'success', 'id' => $conn->insert_id]);
            } else {
                http_response_code(500);
                echo json_encode(['error' => $conn->error]);
            }
        }
        break;

    case 'DELETE':
        if (!isset($_GET['id'])) {
            http_response_code(400);
            echo json_encode(['error' => 'Missing id']);
            exit;
        }
        $id = intval($_GET['id']);
        $sql = "DELETE FROM library WHERE id=$id";
        if ($conn->query($sql) === TRUE) {
            echo json_encode(['status' => 'deleted']);
        } else {
            http_response_code(500);
            echo json_encode(['error' => $conn->error]);
        }
        break;

    default:
        http_response_code(405);
        echo json_encode(['error' => 'Method not allowed']);
        break;
}

$conn->close();