MessagePart

38class MessagePart extends AbstractDataTransferObject39{40    public const KEY_CHANNEL = 'channel';41    public const KEY_TYPE = 'type';42    public const KEY_THOUGHT_SIGNATURE = 'thoughtSignature';43    public const KEY_TEXT = 'text';44    public const KEY_FILE = 'file';45    public const KEY_FUNCTION_CALL = 'functionCall';46    public const KEY_FUNCTION_RESPONSE = 'functionResponse';47    /**48     * @var MessagePartChannelEnum The channel this message part belongs to.49     */50    private MessagePartChannelEnum $channel;51    /**52     * @var MessagePartTypeEnum The type of this message part.53     */54    private MessagePartTypeEnum $type;55    /**56     * @var string|null Thought signature for extended thinking.57     */58    private ?string $thoughtSignature = null;59    /**60     * @var string|null Text content (when type is TEXT).61     */62    private ?string $text = null;63    /**64     * @var File|null File data (when type is FILE).65     */66    private ?File $file = null;67    /**68     * @var FunctionCall|null Function call request (when type is FUNCTION_CALL).69     */70    private ?FunctionCall $functionCall = null;71    /**72     * @var FunctionResponse|null Function response (when type is FUNCTION_RESPONSE).73     */74    private ?FunctionResponse $functionResponse = null;75    /**76     * Constructor that accepts various content types and infers the message part type.77     *78     * @since 0.1.079     *80     * @param mixed $content The content of this message part.81     * @param MessagePartChannelEnum|null $channel The channel this part belongs to. Defaults to CONTENT.82     * @param string|null $thoughtSignature Optional thought signature for extended thinking.83     * @throws InvalidArgumentException If an unsupported content type is provided.84     */85    public function __construct($content, ?MessagePartChannelEnum $channel = null, ?string $thoughtSignature = null)86    {87        $this->channel = $channel ?? MessagePartChannelEnum::content();88        $this->thoughtSignature = $thoughtSignature;89        if (is_string($content)) {90            $this->type = MessagePartTypeEnum::text();91            $this->text = $content;92        } elseif ($content instanceof File) {93            $this->type = MessagePartTypeEnum::file();94            $this->file = $content;95        } elseif ($content instanceof FunctionCall) {96            $this->type = MessagePartTypeEnum::functionCall();97            $this->functionCall = $content;98        } elseif ($content instanceof FunctionResponse) {99            $this->type = MessagePartTypeEnum::functionResponse();100            $this->functionResponse = $content;101        } else {102            $type = is_object($content) ? get_class($content) : gettype($content);103            throw new InvalidArgumentException(sprintf('Unsupported content type %s. Expected string, File, ' . 'FunctionCall, or FunctionResponse.', $type));104        }105    }106    /**107     * Gets the channel this message part belongs to.108     *109     * @since 0.1.0110     *111     * @return MessagePartChannelEnum The channel.112     */113    public function getChannel(): MessagePartChannelEnum114    {115        return $this->channel;116    }117    /**