#!/usr/bin/env php
<?php
// PHP 8.0+ with HTTPS/OpenSSL and allow_url_fopen enabled. No packages required.
// Keep server credentials on your server.

function monotonicTime(): float
{
    return hrtime(true) / 1_000_000_000;
}

class PreparationTimeout extends RuntimeException {}

function waitToRetry(int $retry_number, ?float $deadline): void
{
    $delay = 2 ** $retry_number;
    if ($deadline !== null) {
        $remaining = $deadline - monotonicTime();
        if ($remaining <= 0) {
            throw new PreparationTimeout();
        }
        $delay = min($delay, $remaining);
    }
    usleep((int) ($delay * 1_000_000));
}

function request(
    string $base_url,
    string $authorization,
    string $path,
    string $method = 'GET',
    mixed $body = null,
    array $headers = [],
    ?float $deadline = null
): array {
    $binary = is_string($body);
    $payload = $body === null ? null : ($binary ? $body : json_encode($body, JSON_THROW_ON_ERROR));
    $request_headers = [
        'Authorization: ' . $authorization,
        'Content-Type: ' . ($binary ? 'application/octet-stream' : 'application/json'),
        'Connection: close',
    ];
    foreach ($headers as $name => $value) {
        $request_headers[] = $name . ': ' . $value;
    }
    if ($payload !== null) {
        $request_headers[] = 'Content-Length: ' . strlen($payload);
    }

    for ($retry_number = 0; ; $retry_number++) {
        $remaining = $deadline === null ? 120.0 : $deadline - monotonicTime();
        if ($remaining <= 0) {
            throw new PreparationTimeout();
        }
        $options = [
            'method' => $method,
            'header' => implode("\r\n", $request_headers),
            'ignore_errors' => true,
            'follow_location' => 0,
            'max_redirects' => 0,
            'timeout' => min(120.0, $remaining),
            'protocol_version' => 1.1,
        ];
        if ($payload !== null) {
            $options['content'] = $payload;
        }
        $context = stream_context_create([
            'http' => $options,
            'ssl' => ['verify_peer' => true, 'verify_peer_name' => true],
        ]);
        $http_response_header = [];
        $response = @file_get_contents($base_url . $path, false, $context);
        if ($deadline !== null && monotonicTime() >= $deadline) {
            throw new PreparationTimeout();
        }
        if ($response === false) {
            if ($retry_number >= 4) {
                throw new RuntimeException('Network request failed after retries.');
            }
            waitToRetry($retry_number, $deadline);
            continue;
        }

        $status = 0;
        foreach ($http_response_header as $header) {
            if (preg_match('/^HTTP\/\S+\s+(\d{3})\b/', $header, $match)) {
                $status = (int) $match[1];
            }
        }
        if ($status >= 300 && $status <= 399) {
            throw new RuntimeException('HTTP ' . $status . ': Redirects are not allowed.');
        }
        if ($retry_number < 4 && in_array($status, [409, 429, 500, 502, 503, 504], true)) {
            waitToRetry($retry_number, $deadline);
            continue;
        }
        $result = json_decode($response, true, 512, JSON_THROW_ON_ERROR);
        if (!is_array($result)) {
            throw new RuntimeException('The API returned a JSON value instead of an object.');
        }
        if ($status >= 200 && $status <= 299) {
            return $result;
        }
        throw new RuntimeException('HTTP ' . $status . ': ' . ($result['error'] ?? 'Request failed.'));
    }
}

try {
    $filename = $argv[1] ?? null;
    if ($filename === null) {
        throw new RuntimeException('Usage: php ' . basename($argv[0]) . ' path/to/course.zip');
    }
    $api_key = getenv('SCORMBOX_API_KEY');
    $api_secret = getenv('SCORMBOX_API_SECRET');
    $idempotency_key = getenv('SCORMBOX_IDEMPOTENCY_KEY');
    if ($api_key === false || $api_key === '' || $api_secret === false || $api_secret === '' ||
        $idempotency_key === false || $idempotency_key === '') {
        throw new RuntimeException('Set SCORMBOX_API_KEY, SCORMBOX_API_SECRET and a stable SCORMBOX_IDEMPOTENCY_KEY for this content version.');
    }
    $base_url = getenv('SCORMBOX_API_BASE_URL');
    $base_url = rtrim($base_url === false || $base_url === '' ? 'https://scormbox.com/api/v1' : $base_url, '/');
    $service = parse_url($base_url);
    $scheme = strtolower($service['scheme'] ?? '');
    $host = strtolower($service['host'] ?? '');
    if ($host === '' || ($scheme !== 'https' && !($scheme === 'http' && $host === 'localhost'))) {
        throw new RuntimeException('Use HTTPS for server credentials, or HTTP localhost for development.');
    }
    if (isset($service['user']) || isset($service['pass']) || isset($service['query']) || isset($service['fragment'])) {
        throw new RuntimeException('The API base URL must not include credentials, a query, or a fragment.');
    }
    if (!filter_var(ini_get('allow_url_fopen'), FILTER_VALIDATE_BOOL) ||
        !in_array('https', stream_get_wrappers(), true)) {
        throw new RuntimeException('Enable allow_url_fopen and HTTPS/OpenSSL support in PHP.');
    }
    $authorization = 'Basic ' . base64_encode($api_key . ':' . $api_secret);
    $size = filesize($filename);
    if ($size === false) {
        throw new RuntimeException('Could not read the package size.');
    }
    $options = ['filename' => basename($filename), 'size' => $size,
                'shareable' => getenv('SCORMBOX_SHAREABLE') === 'true'];
    $title = getenv('SCORMBOX_TITLE');
    if ($title !== false && $title !== '') {
        $options['title'] = $title;
    }
    $course = request($base_url, $authorization, '/courses', 'POST', $options,
                      ['Idempotency-Key' => $idempotency_key]);

    if (in_array($course['status'], ['awaiting_upload', 'uploading'], true)) {
        $upload = $course['upload'];
        $upload_path = '/uploads/' . rawurlencode($upload['upload_id']);
        $part_size = $upload['part_size'];
        $part_count = $upload['part_count'];
        if (!is_int($part_size) || $part_size <= 0 || !is_int($part_count) ||
            $part_count !== intdiv($size + $part_size - 1, $part_size)) {
            throw new RuntimeException('The API returned invalid upload part sizes.');
        }
        $saved_parts = array_fill_keys(array_column($upload['parts'], 'part_number'), true);
        $file = fopen($filename, 'rb');
        if ($file === false) {
            throw new RuntimeException('Could not open the package.');
        }
        try {
            for ($part_number = 1; $part_number <= $part_count; $part_number++) {
                if (isset($saved_parts[$part_number])) {
                    continue;
                }
                $offset = ($part_number - 1) * $part_size;
                $length = min($part_size, $size - $offset);
                if (fseek($file, $offset) !== 0) {
                    throw new RuntimeException('Could not seek in the package.');
                }
                $bytes = '';
                while (strlen($bytes) < $length) {
                    $chunk = fread($file, $length - strlen($bytes));
                    if ($chunk === false || $chunk === '') {
                        throw new RuntimeException('The package changed while being read.');
                    }
                    $bytes .= $chunk;
                    unset($chunk);
                }
                request($base_url, $authorization, $upload_path . '/parts/' . $part_number, 'PUT', $bytes);
                unset($bytes);
                echo 'Uploaded part ' . $part_number . ' of ' . $part_count . PHP_EOL;
            }
        } finally {
            fclose($file);
        }
        request($base_url, $authorization, $upload_path . '/complete', 'POST', new stdClass());
    }

    $course_id = $course['course_id'];
    $deadline = monotonicTime() + 20 * 60;
    while (true) {
        $course = request($base_url, $authorization, '/courses/' . rawurlencode($course_id), deadline: $deadline);
        if ($course['status'] === 'ready') {
            break;
        }
        if ($course['status'] === 'failed') {
            throw new RuntimeException($course['error'] ?? 'Package preparation failed.');
        }
        $preparation = $course['preparation'];
        echo 'Course ' . $course['status'] . ': ' . $preparation['completed_files'] .
             ' of ' . $preparation['total_files'] . ' files' . PHP_EOL;
        $remaining = $deadline - monotonicTime();
        if ($remaining <= 0) {
            throw new PreparationTimeout();
        }
        usleep((int) (min(2, $remaining) * 1_000_000));
    }
    echo json_encode(['course_id' => $course['course_id'], 'format' => $course['format'],
                      'management_url' => $course['management_url'], 'learner_url' => $course['learner_url']],
                     JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES | JSON_THROW_ON_ERROR) . PHP_EOL;
} catch (PreparationTimeout $error) {
    fwrite(STDERR, 'Preparation is still running. Check course_id ' . $course_id . ' before trying again.' . PHP_EOL);
    exit(1);
} catch (Throwable $error) {
    fwrite(STDERR, $error->getMessage() . PHP_EOL);
    exit(1);
}