<?php

declare(strict_types=1);

namespace WordPress\AiClient\Tools\DTO;

use WordPress\AiClient\Common\AbstractDataTransferObject;
use WordPress\AiClient\Common\Exception\InvalidArgumentException;

/**
 * Represents a response to a function call.
 *
 * This DTO encapsulates the result of executing a function that was
 * requested by the AI model through a FunctionCall.
 *
 * @since 0.1.0
 *
 * @phpstan-type FunctionResponseArrayShape array{id?: string, name?: string, response: mixed}
 *
 * @extends AbstractDataTransferObject<FunctionResponseArrayShape>
 */
class FunctionResponse extends AbstractDataTransferObject
{
    public const KEY_ID = 'id';
    public const KEY_NAME = 'name';
    public const KEY_RESPONSE = 'response';
    /**
     * @var string|null The ID of the function call this is responding to.
     */
    private ?string $id;

    /**
     * @var string|null The name of the function that was called.
     */
    private ?string $name;

    /**
     * @var mixed The response data from the function.
     */
    private $response;

    /**
     * Constructor.
     *
     * @since 0.1.0
     *
     * @param string|null $id The ID of the function call this is responding to.
     * @param string|null $name The name of the function that was called.
     * @param mixed $response The response data from the function.
     * @throws InvalidArgumentException If neither id nor name is provided.
     */
    public function __construct(?string $id, ?string $name, $response)
    {
        if ($id === null && $name === null) {
            throw new InvalidArgumentException('At least one of id or name must be provided.');
        }

        $this->id = $id;
        $this->name = $name;
        $this->response = $response;
    }

    /**
     * Gets the function call ID.
     *
     * @since 0.1.0
     *
     * @return string|null The function call ID.
     */
    public function getId(): ?string
    {
        return $this->id;
    }

    /**
     * Gets the function name.
     *
     * @since 0.1.0
     *
     * @return string|null The function name.
     */
    public function getName(): ?string
    {
        return $this->name;
    }

    /**
     * Gets the function response.
     *
     * @since 0.1.0
     *
     * @return mixed The response data.
     */
    public function getResponse()
    {
        return $this->response;
    }

    /**
     * {@inheritDoc}
     *
     * @since 0.1.0
     */
    public static function getJsonSchema(): array
    {
        return [
            'type' => 'object',
            'properties' => [
                self::KEY_ID => [
                    'type' => 'string',
                    'description' => 'The ID of the function call this is responding to.',
                ],
                self::KEY_NAME => [
                    'type' => 'string',
                    'description' => 'The name of the function that was called.',
                ],
                self::KEY_RESPONSE => [
                    'type' => ['string', 'number', 'boolean', 'object', 'array', 'null'],
                    'description' => 'The response data from the function.',
                ],
            ],
            'anyOf' => [
                [
                    'required' => [self::KEY_RESPONSE, self::KEY_ID],
                ],
                [
                    'required' => [self::KEY_RESPONSE, self::KEY_NAME],
                ],
            ],
        ];
    }

    /**
     * {@inheritDoc}
     *
     * @since 0.1.0
     *
     * @return FunctionResponseArrayShape
     */
    public function toArray(): array
    {
        $data = [];

        if ($this->id !== null) {
            $data[self::KEY_ID] = $this->id;
        }

        if ($this->name !== null) {
            $data[self::KEY_NAME] = $this->name;
        }

        $data[self::KEY_RESPONSE] = $this->response;

        return $data;
    }

    /**
     * {@inheritDoc}
     *
     * @since 0.1.0
     */
    public static function fromArray(array $array): self
    {
        static::validateFromArrayData($array, [self::KEY_RESPONSE]);

        return new self(
            $array[self::KEY_ID] ?? null,
            $array[self::KEY_NAME] ?? null,
            $array[self::KEY_RESPONSE]
        );
    }
}
