<?php

require_once __DIR__.'/../bootstrap.php';

use App\Classes\ApiHandler;
use GuzzleHttp\Client;

class BookImportHandler extends ApiHandler
{
    private string $bookImportToken;

    public function __construct()
    {
        parent::__construct();

        $this->ensureCliAccess();
        $this->bookImportToken = $_ENV['BOOK_IMPORT_TOKEN'] ?? getenv('BOOK_IMPORT_TOKEN');
    }

    public function handleRequest(): void
    {
        $input = json_decode(file_get_contents('php://input'), true);

        if (! $input) {
            $this->sendErrorResponse('Invalid or missing JSON body', 400);
        }

        $providedToken = $input['token'] ?? null;
        $isbn = $input['isbn'] ?? null;

        if ($providedToken !== $this->bookImportToken) {
            $this->sendErrorResponse('Unauthorized access', 401);
        }
        if (! $isbn) {
            $this->sendErrorResponse('isbn parameter is required', 400);
        }

        try {
            $bookData = $this->fetchBookData($isbn);
            $this->processBook($bookData);
            $this->sendResponse(['message' => 'Book imported successfully'], 200);
        } catch (\Exception $e) {
            $this->sendErrorResponse('Error: '.$e->getMessage(), 500);
        }
    }

    private function fetchBookData(string $isbn): array
    {
        $client = new Client();
        $response = $client->get('https://openlibrary.org/api/books', [
            'query' => [
                'bibkeys' => "ISBN:{$isbn}",
                'format' => 'json',
                'jscmd' => 'data',
            ],
            'headers' => ['Accept' => 'application/json'],
        ]);

        $data = json_decode($response->getBody(), true);
        $bookKey = "ISBN:{$isbn}";

        if (empty($data[$bookKey])) {
            throw new \Exception("Book data not found for ISBN: {$isbn}");
        }

        return $data[$bookKey];
    }

    private function processBook(array $bookData): void
    {
        $isbn =
          $bookData['identifiers']['isbn_13'][0] ??
          ($bookData['identifiers']['isbn_10'][0] ?? null);
        $title = $bookData['title'] ?? null;
        $author = $bookData['authors'][0]['name'] ?? null;
        $description = $bookData['description'] ?? ($bookData['notes'] ?? '');

        if (! $isbn || ! $title || ! $author) {
            throw new \Exception('Missing essential book data (title, author, or ISBN).');
        }

        $existingBook = $this->getBookByISBN($isbn);

        if ($existingBook) {
            throw new \Exception("Book with ISBN {$isbn} already exists.");
        }

        $bookPayload = [
            'isbn' => $isbn,
            'title' => $title,
            'author' => $author,
            'description' => $description,
            'read_status' => 'want to read',
            'slug' => '/reading/books/'.$isbn,
        ];

        $this->makeRequest('POST', 'books', ['json' => $bookPayload]);
    }

    private function getBookByISBN(string $isbn): ?array
    {
        $response = $this->fetchFromApi('books', 'isbn=eq.'.urlencode($isbn));

        return $response[0] ?? null;
    }
}

$handler = new BookImportHandler();
$handler->handleRequest();