<?php
/**
 * Proxy requests to Unsplash API and cache response.
 *
 * @author Dale Davies <dale@daledavies.co.uk>
 * @license MIT
 */

// Provided by composer for psr-4 style autoloading.
require __DIR__ .'/../vendor/autoload.php';

$config = new Jump\Config();
$cache = new Jump\Cache($config);

// If this script is run via CLI then clear the cache and repopulate it,
// otherwise if run via web then get image data from cache and run this
// script asynchronously to refresh the cache for next time.
if (http_response_code() === false) {
    $unsplashdata = load_cache_unsplash_data($config);
    $cache->save(cachename: 'unsplash', data: $unsplashdata);
    die('Cached data from Unsplash');
}

// Output header here so we can return early with a json response if there is a curl error.
header('Content-Type: application/json; charset=utf-8');

// Initialise a new session using the request object.
$session = new Nette\Http\Session((new Nette\Http\RequestFactory)->fromGlobals(), new Nette\Http\Response);
$session->setName($config->get('sessionname'));
$session->setExpiration($config->get('sessiontimeout'));

// Get a Nette session section for CSRF data.
$csrfsection = $session->getSection('csrf');

// Has a CSRF token been set up for the session yet?
if (!$csrfsection->offsetExists('token')){
   http_response_code(401);
   die(json_encode(['error' => 'Session not fully set up']));
}

// Check CSRF token saved in session against token provided via request.
$token = isset($_GET['token']) ? $_GET['token'] : false;
if (!$token || !hash_equals($csrfsection->get('token'), $token)) {
   http_response_code(401);
   die(json_encode(['error' => 'API token is incorrect or missing']));
}

$unsplashdata = $cache->load(cachename: 'unsplash');
if ($unsplashdata == null) {
    $unsplashdata = load_cache_unsplash_data($config);
    $cache->save(cachename: 'unsplash', data: $unsplashdata);
}

echo json_encode($unsplashdata);

shell_exec('/usr/bin/nohup /usr/bin/php -f unsplashdata.php >/dev/null 2>&1 &');

function load_cache_unsplash_data($config) {
    Crew\Unsplash\HttpClient::init([
        'utmSource' => 'jump_startpage',
        'applicationId'	=> $config->get('unsplashapikey'),
    ]);
    // Try to get a random image via the API.
    try {
        $photo = Crew\Unsplash\Photo::random([
            'collections' => $config->get('unsplashcollections', false),
        ]);
    } catch (Exception $e) {
        http_response_code(500);
        die(json_encode(['error' => json_decode($e->getMessage())]));
    }
    // Download the image data from Unsplash.
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_URL, $photo->urls['raw'].'&auto=compress&w=1920');
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
    curl_setopt($ch, CURLOPT_FAILONERROR, true);
    $response = curl_exec($ch);
    // Create the response and return it.
    $description = 'Photo';
    if ($photo->description !== null &&
        strlen($photo->description) <= 45) {
        $description = $photo->description;
    }
    $unsplashdata = new stdClass();
    $unsplashdata->color = $photo->color;
    $unsplashdata->attribution = '<a target="_blank" rel="noopener" href="'.$photo->links['html'].'">'.$description.' by '.$photo->user['name'].'</a>';
    $unsplashdata->imagedatauri = 'data: '.(new finfo(FILEINFO_MIME_TYPE))->buffer($response).';base64,'.base64_encode($response);
    return $unsplashdata;
}