ServerSideAdInsertion.php

<?php

require './vendor/autoload.php';

require_once('./common/ConfigProvider.php');

/**
 * This example demonstrates how to create multiple fMP4 renditions with Server-Side Ad Insertion
 * (SSAI)
 *
 * <p>The following configuration parameters are expected:
 *
 * <ul>
 *   <li>BITMOVIN_API_KEY - Your API key for the Bitmovin API
 *   <li>BITMOVIN_TENANT_ORG_ID - (optional) The ID of the Organisation in which you want to perform the encoding.
 *   <li>HTTP_INPUT_HOST - The Hostname or IP address of the HTTP server hosting your input files,
 *       e.g.: my-storage.biz
 *   <li>HTTP_INPUT_FILE_PATH - The path to your input file on the provided HTTP server Example:
 *       videos/1080p_Sintel.mp4
 *   <li>S3_OUTPUT_BUCKET_NAME - The name of your S3 output bucket. Example: my-bucket-name
 *   <li>S3_OUTPUT_ACCESS_KEY - The access key of your S3 output bucket
 *   <li>S3_OUTPUT_SECRET_KEY - The secret key of your S3 output bucket
 *   <li>S3_OUTPUT_BASE_PATH - The base path on your S3 output bucket where content will be written.
 *       Example: /outputs
 * </ul>
 *
 * <p>Configuration parameters will be retrieved from these sources in the listed order:
 *
 * <ol>
 *   <li>command line arguments (eg BITMOVIN_API_KEY=xyz)
 *   <li>properties file located in the root folder of the PHP examples at ./examples.properties
 *       (see examples.properties.template as reference)
 *   <li>environment variables
 *   <li>properties file located in the home folder at ~/.bitmovin/examples.properties (see
 *       examples.properties.template as reference)
 * </ol>
 */

use BitmovinApiSdk\BitmovinApi;
use BitmovinApiSdk\Common\BitmovinApiException;
use BitmovinApiSdk\Common\Logging\ConsoleLogger;
use BitmovinApiSdk\Configuration;
use BitmovinApiSdk\Models\AacAudioConfiguration;
use BitmovinApiSdk\Models\AclEntry;
use BitmovinApiSdk\Models\AclPermission;
use BitmovinApiSdk\Models\AudioMediaInfo;
use BitmovinApiSdk\Models\CodecConfiguration;
use BitmovinApiSdk\Models\CustomTag;
use BitmovinApiSdk\Models\Encoding;
use BitmovinApiSdk\Models\EncodingOutput;
use BitmovinApiSdk\Models\Fmp4Muxing;
use BitmovinApiSdk\Models\H264VideoConfiguration;
use BitmovinApiSdk\Models\HlsManifest;
use BitmovinApiSdk\Models\HttpInput;
use BitmovinApiSdk\Models\Input;
use BitmovinApiSdk\Models\Keyframe;
use BitmovinApiSdk\Models\Manifest;
use BitmovinApiSdk\Models\ManifestGenerator;
use BitmovinApiSdk\Models\ManifestResource;
use BitmovinApiSdk\Models\MessageType;
use BitmovinApiSdk\Models\MuxingStream;
use BitmovinApiSdk\Models\Output;
use BitmovinApiSdk\Models\PositionMode;
use BitmovinApiSdk\Models\PresetConfiguration;
use BitmovinApiSdk\Models\S3Output;
use BitmovinApiSdk\Models\StartEncodingRequest;
use BitmovinApiSdk\Models\Status;
use BitmovinApiSdk\Models\Stream;
use BitmovinApiSdk\Models\StreamInfo;
use BitmovinApiSdk\Models\StreamInput;
use BitmovinApiSdk\Models\StreamMode;
use BitmovinApiSdk\Models\StreamSelectionMode;
use BitmovinApiSdk\Models\Task;

$exampleName = 'ServerSideAdInsertion';

$configProvider = new ConfigProvider();

try {
    $bitmovinApi = new BitmovinApi(Configuration::create()
        ->apiKey($configProvider->getBitmovinApiKey())
        // uncomment the following line if you are working with a multi-tenant account
        // ->tenantOrgId($configProvider->getBitmovinTenantOrgId())        
        ->logger(new ConsoleLogger())
    );

    $encoding = createEncoding($exampleName, "Encoding Example - SSAI conditioned HLS streams");

    $input = createHttpInput($configProvider->getHttpInputHost());
    $inputFilePath = $configProvider->getHttpInputFilePath();

    $output = createS3Output(
        $configProvider->getS3OutputBucketName(),
        $configProvider->getS3OutputAccessKey(),
        $configProvider->getS3OutputSecretKey()
    );

    $videoConfigurations = [
        createH264Config(1080, 4800000),
        createH264Config(720, 2400000),
        createH264Config(480, 1200000),
        createH264Config(360, 800000),
        createH264Config(240, 400000)
    ];

    $videoMuxings = [];
    foreach ($videoConfigurations as $videoConfiguration) {
        $videoStream = createStream($encoding, $input, $inputFilePath, $videoConfiguration, StreamMode::STANDARD());
        $outputPath = "video/" . $videoConfiguration->height;
        $videoMuxings[] = createFmp4Muxing($encoding, $output, $outputPath, $videoStream);
    }

    // Add an AAC audio stream to the encoding
    $aacConfig = createAacConfig();
    $aacStream = createStream($encoding, $input, $inputFilePath, $aacConfig, StreamMode::STANDARD());
    $audioMuxing = createFmp4Muxing($encoding, $output, 'audio', $aacStream);

    // Seconds in which to add a custom HLS tag for ad placement, as well as when to insert a
    // keyframe/split a segment
    $adBreakPlacements = [5.0, 15.0];
    $keyframes = createKeyframes($encoding, $adBreakPlacements);

    $manifest = createHlsMasterManifest($output, '');

    $audioMediaInfo = createAudioMediaPlaylist($encoding, $manifest, $audioMuxing, 'audio');
    placeAudioAdvertisementTags($manifest, $audioMediaInfo, $keyframes);

    for ($i = 0; $i < sizeof($videoConfigurations); $i++) {
        $streamInfo = createVideoStreamPlaylist(
            $encoding,
            $manifest,
            "video_" . $videoConfigurations[$i]->height . ".m3u8",
            $videoMuxings[$i],
            "video/" . $videoConfigurations[$i]->height,
            $audioMediaInfo
        );

        placeVideoAdvertisementTags($manifest, $streamInfo, $keyframes);
    }

    $startEncodingRequest = new StartEncodingRequest();
    $startEncodingRequest->manifestGenerator(ManifestGenerator::V2());
    $startEncodingRequest->vodHlsManifests([buildManifestResource($manifest)]);

    executeEncoding($encoding, $startEncodingRequest);

} catch (Exception $exception) {
    echo $exception;
}

/**
 * Starts the HLS manifest creation and periodically polls its status until it reaches a final
 * state
 *
 * <p>API endpoints:
 * https://bitmovin.com/docs/encoding/api-reference/sections/manifests#/Encoding/PostEncodingManifestsHlsStartByManifestId
 * https://bitmovin.com/docs/encoding/api-reference/sections/manifests#/Encoding/GetEncodingManifestsHlsStatusByManifestId
 *
 * @param HlsManifest $manifest The HLS manifest to be created
 * @throws BitmovinApiException
 * @throws Exception
 */
function executeHlsManifestCreation(HlsManifest $manifest)
{
    global $bitmovinApi;

    $bitmovinApi->encoding->manifests->hls->start($manifest->id);

    do {
        sleep(1);
        $task = $bitmovinApi->encoding->manifests->hls->status($manifest->id);
    } while ($task->status != Status::FINISHED() && $task->status != Status::ERROR());

    if ($task->status == Status::ERROR()) {
        logTaskErrors($task);
        throw new Exception("HLS manifest creation failed");
    }

    echo "HLS manifest creation finished successfully" . PHP_EOL;
}

/**
 * Adds custom tags for ad-placement to an HLS video stream playlist at given keyframe positions
 *
 * @param HlsManifest $manifest The master manifest to which the playlist belongs to
 * @param StreamInfo $streamInfo The video stream playlist to which the tags should be added
 * @param Keyframe[] keyframes A list of keyframes specifying the positions where tags will be inserted
 * @throws BitmovinApiException
 */
function placeVideoAdvertisementTags(HlsManifest $manifest, StreamInfo $streamInfo, array $keyframes)
{
    global $bitmovinApi;

    foreach ($keyframes as $keyframe) {
        $customTag = createAdvertisementTag($keyframe);
        $bitmovinApi->encoding->manifests->hls->streams->customTags->create(
            $manifest->id,
            $streamInfo->id,
            $customTag
        );
    }
}

/**
 * Creates an HLS video playlist
 *
 * @param Encoding $encoding The encoding to which the manifest belongs to
 * @param HlsManifest $manifestHls The manifest to which the playlist should be added
 * @param string $filename The filename to be used for the playlist file
 * @param Fmp4Muxing $muxing The audio muxing for which the playlist should be generated
 * @param string $segmentPath The path containing the audio segments to be referenced by the playlist
 * @param AudioMediaInfo $audioMediaInfo The audio media playlist containing the associated audio group id
 * @return StreamInfo
 * @throws BitmovinApiException
 */
function createVideoStreamPlaylist(Encoding $encoding, HlsManifest $manifestHls, string $filename, Fmp4Muxing $muxing,
                                   string $segmentPath, AudioMediaInfo $audioMediaInfo): StreamInfo
{
    global $bitmovinApi;

    $streamInfo = new StreamInfo();
    $streamInfo->uri($filename);
    $streamInfo->encodingId($encoding->id);
    $streamInfo->streamId($muxing->streams[0]->streamId);
    $streamInfo->muxingId($muxing->id);
    $streamInfo->audio($audioMediaInfo->groupId);
    $streamInfo->segmentPath($segmentPath);

    return $bitmovinApi->encoding->manifests->hls->streams->create($manifestHls->id, $streamInfo);
}

/**
 * Creates custom tags containing an ad-placement-tag for each keyframe.
 *
 * @param HlsManifest $manifestHls The master manifest to which the playlist belongs to
 * @param AudioMediaInfo $audioMediaInfo the audioMediaInfo of the audio stream
 * @param array $keyframes the list of keyframes where the advertisement tags will be placed.
 * @throws BitmovinApiException
 */
function placeAudioAdvertisementTags(HlsManifest $manifestHls, AudioMediaInfo $audioMediaInfo, array $keyframes)
{
    global $bitmovinApi;

    foreach ($keyframes as $keyframe) {
        $customTag = createAdvertisementTag($keyframe);
        $bitmovinApi->encoding->manifests->hls->media->customTags->create($manifestHls->id, $audioMediaInfo->id, $customTag);
    }
}

/**
 * Creates a custom hls tag which represents an advertisement opportunity at the given keyframe
 * position
 *
 * @param Keyframe $keyframe
 * @return CustomTag
 */
function createAdvertisementTag(Keyframe $keyframe): CustomTag
{
    $customTag = new CustomTag();
    $customTag->keyframeId($keyframe->id);
    $customTag->positionMode(PositionMode::KEYFRAME());
    $customTag->data('#AD-PLACEMENT-OPPORTUNITY');

    return $customTag;
}

/**
 * Creates an HLS audio media playlist
 *
 * @param Encoding $encoding The encoding to which the manifest belongs to
 * @param Manifest $manifestHls The manifest to which the playlist should be added
 * @param Fmp4Muxing $audioMuxing The audio muxing for which the playlist should be generated
 * @param string $segmentPath The path containing the audio segments to be referenced by the playlist
 * @return AudioMediaInfo
 * @throws BitmovinApiException
 */
function createAudioMediaPlaylist(Encoding $encoding, Manifest $manifestHls, Fmp4Muxing $audioMuxing, string $segmentPath): AudioMediaInfo
{
    global $bitmovinApi;

    $audioMediaInfo = new AudioMediaInfo();
    $audioMediaInfo->name('audio.m3u8');
    $audioMediaInfo->uri('audio.m3u8');
    $audioMediaInfo->groupId('audio');
    $audioMediaInfo->encodingId($encoding->id);
    $audioMediaInfo->streamId($audioMuxing->streams[0]->streamId);
    $audioMediaInfo->muxingId($audioMuxing->id);
    $audioMediaInfo->language('en');
    $audioMediaInfo->assocLanguage('en');
    $audioMediaInfo->autoselect(false);
    $audioMediaInfo->isDefault(false);
    $audioMediaInfo->forced(false);
    $audioMediaInfo->segmentPath($segmentPath);

    return $bitmovinApi->encoding->manifests->hls->media->audio->create($manifestHls->id, $audioMediaInfo);
}

/**
 * Creates an HLS master manifest
 *
 * @param Output $output The output resource to which the manifest will be written to
 * @param string $outputPath The path where the manifest will be written to
 * @return HlsManifest
 * @throws BitmovinApiException
 * @throws Exception
 */
function createHlsMasterManifest(Output $output, string $outputPath): HlsManifest
{
    global $bitmovinApi;

    $manifest = new HlsManifest();
    $manifest->name("master.m3u8");
    $manifest->manifestName("master.m3u8");
    $manifest->outputs([buildEncodingOutput($output, $outputPath)]);

    return $bitmovinApi->encoding->manifests->hls->create($manifest);
}

/**
 * Starts the actual encoding process and periodically polls its status until it reaches a final
 * state
 *
 * <p>API endpoints:
 * https://bitmovin.com/docs/encoding/api-reference/all#/Encoding/PostEncodingEncodingsStartByEncodingId
 * https://bitmovin.com/docs/encoding/api-reference/sections/encodings#/Encoding/GetEncodingEncodingsStatusByEncodingId
 *
 * <p>Please note that you can also use our webhooks API instead of polling the status. For more
 * information consult the API spec:
 * https://bitmovin.com/docs/encoding/api-reference/sections/notifications-webhooks
 *
 * @param Encoding $encoding The encoding to be started
 * @param StartEncodingRequest $startEncodingRequest The request object to be sent with the start call
 * @throws BitmovinApiException
 * @throws Exception
 */
function executeEncoding(Encoding $encoding, StartEncodingRequest $startEncodingRequest)
{
    global $bitmovinApi;

    $bitmovinApi->encoding->encodings->start($encoding->id, $startEncodingRequest);

    do {
        sleep(5);
        $task = $bitmovinApi->encoding->encodings->status($encoding->id);
        echo 'Encoding status is ' . $task->status . ' (progress: ' . $task->progress . ' %)' . PHP_EOL;
    } while ($task->status != Status::FINISHED() && $task->status != Status::ERROR());

    if ($task->status == Status::ERROR()) {
        logTaskErrors($task);
        throw new Exception('Encoding failed');
    }

    echo 'Encoding finished successfully' . PHP_EOL;
}

/**
 * Creates a Keyframe for each entry in the provided list.
 *
 * @param Encoding $encoding The encoding to which keyframes should be added
 * @param array $adBreakPlacements The points in time where keyframes should be inserted (specified in
 *     seconds)
 * @return Keyframe[]
 * @throws BitmovinApiException
 */
function createKeyframes(Encoding $encoding, array $adBreakPlacements): array
{
    global $bitmovinApi;
    $keyframes = [];

    foreach ($adBreakPlacements as $adBreak) {
        $keyframe = new Keyframe();
        $keyframe->time($adBreak);

        $keyframes[] = $bitmovinApi->encoding->encodings->keyframes->create($encoding->id, $keyframe);
    }

    return $keyframes;
}

/**
 * Creates a fragmented MP4 muxing. This will generate segments with a given segment length for
 * adaptive streaming.
 *
 * <p>API endpoint:
 * https://bitmovin.com/docs/encoding/api-reference/all#/Encoding/PostEncodingEncodingsMuxingsFmp4ByEncodingId
 *
 * @param Encoding $encoding The encoding to add the muxing to
 * @param Output $output The output that should be used for the muxing to write the segments to
 * @param string $outputPath The output path where the fragments will be written to
 * @param Stream $stream The stream that is associated with the muxing
 * @return Fmp4Muxing
 * @throws BitmovinApiException
 * @throws Exception
 */
function createFmp4Muxing(Encoding $encoding, Output $output, string $outputPath, Stream $stream): Fmp4Muxing
{
    global $bitmovinApi;

    $muxingStream = new MuxingStream();
    $muxingStream->streamId($stream->id);

    $muxing = new Fmp4Muxing();
    $muxing->outputs([buildEncodingOutput($output, $outputPath)]);
    $muxing->segmentLength(4.0);
    $muxing->streams[] = $muxingStream;

    return $bitmovinApi->encoding->encodings->muxings->fmp4->create($encoding->id, $muxing);
}

/**
 * Creates a configuration for the H.264 video codec to be applied to video streams.
 *
 * <p>The output resolution is defined by setting the height to 1080 pixels. Width will be
 * determined automatically to maintain the aspect ratio of your input video.
 *
 * <p>To keep things simple, we use a quality-optimized VoD preset configuration, which will apply
 * proven settings for the codec. See <a
 * href="https://bitmovin.com/docs/encoding/tutorials/how-to-optimize-your-h264-codec-configuration-for-different-use-cases">How
 * to optimize your H264 codec configuration for different use-cases</a> for alternative presets.
 *
 * <p>API endpoint:
 * https://bitmovin.com/docs/encoding/api-reference/sections/configurations#/Encoding/PostEncodingConfigurationsVideoH264
 *
 * @param int $height The height of the output video
 * @param int $bitrate The target bitrate of the output video
 * @return H264VideoConfiguration
 * @throws BitmovinApiException
 */
function createH264Config(int $height, int $bitrate): H264VideoConfiguration
{
    global $bitmovinApi;

    $h264Config = new H264VideoConfiguration();
    $h264Config->name("H.264 " . $height . "p");
    $h264Config->presetConfiguration(PresetConfiguration::VOD_STANDARD());
    $h264Config->height($height);
    $h264Config->bitrate($bitrate);

    return $bitmovinApi->encoding->configurations->video->h264->create($h264Config);
}

/**
 * Creates a configuration for the AAC audio codec to be applied to audio streams.
 *
 * <p>API endpoint:
 * https://bitmovin.com/docs/encoding/api-reference/sections/configurations#/Encoding/PostEncodingConfigurationsAudioAac
 * @return AacAudioConfiguration
 * @throws BitmovinApiException
 */
function createAacConfig(): AacAudioConfiguration
{
    global $bitmovinApi;

    $aacConfig = new AacAudioConfiguration();
    $aacConfig->name("AAC 128 kbit/s");
    $aacConfig->bitrate(128000);

    return $bitmovinApi->encoding->configurations->audio->aac->create($aacConfig);
}

/**
 * Adds a video or audio stream to an encoding
 *
 * <p>API endpoint:
 * https://bitmovin.com/docs/encoding/api-reference/sections/encodings#/Encoding/PostEncodingEncodingsStreamsByEncodingId
 *
 * @param Encoding $encoding The encoding to which the stream will be added
 * @param Input $input The input resource providing the input file
 * @param string $inputPath The path to the input file
 * @param CodecConfiguration $codecConfiguration The codec configuration to be applied to the stream
 * @param StreamMode $streamMode
 * @return Stream
 * @throws BitmovinApiException
 */
function createStream(Encoding $encoding, Input $input, string $inputPath, CodecConfiguration $codecConfiguration, StreamMode $streamMode): Stream
{
    global $bitmovinApi;

    $streamInput = new StreamInput();
    $streamInput->inputId($input->id);
    $streamInput->inputPath($inputPath);
    $streamInput->selectionMode(StreamSelectionMode::AUTO());

    $stream = new Stream();
    $stream->inputStreams([$streamInput]);
    $stream->codecConfigId($codecConfiguration->id);
    $stream->mode($streamMode);

    return $bitmovinApi->encoding->encodings->streams->create($encoding->id, $stream);
}

/**
 * Creates a resource representing an AWS S3 cloud storage bucket to which generated content will
 * be transferred. For alternative output methods see <a
 * href="https://bitmovin.com/docs/encoding/articles/supported-input-output-storages">list of
 * supported input and output storages</a>
 *
 * <p>The provided credentials need to allow <i>read</i>, <i>write</i> and <i>list</i> operations.
 * <i>delete</i> should also be granted to allow overwriting of existings files. See <a
 * href="https://bitmovin.com/docs/encoding/faqs/how-do-i-create-a-aws-s3-bucket-which-can-be-used-as-output-location">creating
 * an S3 bucket and setting permissions</a> for further information
 *
 * <p>For reasons of simplicity, a new output resource is created on each execution of this
 * example. In production use, this method should be replaced by a <a
 * href="https://bitmovin.com/docs/encoding/api-reference/sections/outputs#/Encoding/GetEncodingOutputsS3">get
 * call</a> retrieving an existing resource.
 *
 * <p>API endpoint:
 * https://bitmovin.com/docs/encoding/api-reference/sections/outputs#/Encoding/PostEncodingOutputsS3
 *
 * @param string $bucketName The name of the S3 bucket
 * @param string $accessKey The access key of your S3 account
 * @param string $secretKey The secret key of your S3 account
 * @return S3Output
 * @throws BitmovinApiException
 */
function createS3Output(string $bucketName, string $accessKey, string $secretKey): S3Output
{
    global $bitmovinApi;

    $output = new S3Output();
    $output->bucketName($bucketName);
    $output->accessKey($accessKey);
    $output->secretKey($secretKey);

    return $bitmovinApi->encoding->outputs->s3->create($output);
}

/**
 * Creates a resource representing an HTTP server providing the input files. For alternative input
 * methods see <a
 * href="https://bitmovin.com/docs/encoding/articles/supported-input-output-storages">list of
 * supported input and output storages</a>
 *
 * <p>For reasons of simplicity, a new input resource is created on each execution of this
 * example. In production use, this method should be replaced by a <a
 * href="https://bitmovin.com/docs/encoding/api-reference/sections/inputs#/Encoding/GetEncodingInputsHttpByInputId">get
 * call</a> to retrieve an existing resource.
 *
 * <p>API endpoint:
 * https://bitmovin.com/docs/encoding/api-reference/sections/inputs#/Encoding/PostEncodingInputsHttp
 *
 * @param string $host The hostname or IP address of the HTTP server e.g.: my-storage.biz
 * @return HttpInput
 * @throws BitmovinApiException
 */
function createHttpInput(string $host): HttpInput
{
    global $bitmovinApi;

    $input = new HttpInput();
    $input->host($host);

    return $bitmovinApi->encoding->inputs->http->create($input);
}

/**
 * Creates an Encoding object. This is the base object to configure your encoding.
 *
 * <p>API endpoint:
 * https://bitmovin.com/docs/encoding/api-reference/sections/encodings#/Encoding/PostEncodingEncodings
 *
 * @param string $name A name that will help you identify the encoding in our dashboard (required)
 * @param string $description description A description of the encoding (optional)
 * @return Encoding
 * @throws BitmovinApiException
 */
function createEncoding(string $name, string $description): Encoding
{
    global $bitmovinApi;

    $encoding = new Encoding();
    $encoding->name($name);
    $encoding->description($description);

    return $bitmovinApi->encoding->encodings->create($encoding);
}

/**
 * Builds an EncodingOutput object which defines where the output content (e.g. of a muxing) will
 * be written to. Public read permissions will be set for the files written, so they can be
 * accessed easily via HTTP.
 *
 * @param Output $output The output resource to be used by the EncodingOutput
 * @param string $outputPath The path where the content will be written to
 * @return EncodingOutput
 * @throws Exception
 */
function buildEncodingOutput(Output $output, string $outputPath): EncodingOutput
{
    $aclEntry = new AclEntry();
    $aclEntry->permission(AclPermission::PUBLIC_READ());

    $encodingOutput = new EncodingOutput();
    $encodingOutput->outputPath(buildAbsolutePath($outputPath));
    $encodingOutput->outputId($output->id);
    $encodingOutput->acl([$aclEntry]);

    return $encodingOutput;
}

/**
 * Builds an absolute path by concatenating the S3_OUTPUT_BASE_PATH configuration parameter, the
 * name of this example and the given relative path
 *
 * <p>e.g.: /s3/base/path/exampleName/relative/path
 *
 * @param string $relativePath The relaitve path that is concatenated
 * @return string
 * @throws Exception
 */
function buildAbsolutePath(string $relativePath): string
{
    global $exampleName, $configProvider;

    return $configProvider->getS3OutputBasePath() . $exampleName . DIRECTORY_SEPARATOR . trim($relativePath, DIRECTORY_SEPARATOR);
}

/**
 * Wraps a manifest ID into a ManifestResource object, so it can be referenced in one of the
 * StartEncodingRequest manifest lists.
 * @param Manifest $manifest The manifest to be generated at the end of the encoding process
 * @return ManifestResource
 */
function buildManifestResource(Manifest $manifest): ManifestResource
{
    $manifestResource = new ManifestResource();
    $manifestResource->manifestId($manifest->id);
    return $manifestResource;
}

function logTaskErrors(Task $task)
{
    if ($task->messages == null) {
        return;
    }

    $messages = array_filter($task->messages, function ($msg) {
        return $msg->type == MessageType::ERROR();
    });

    foreach ($messages as $message) {
        echo $message->text . PHP_EOL;
    }
}