<?php

/**
 * Initialize method handler for MCP requests.
 *
 * @package McpAdapter
 */
declare (strict_types=1);
namespace PYS_PRO_GLOBAL\WP\MCP\Handlers\Initialize;

use PYS_PRO_GLOBAL\WP\MCP\Core\McpServer;
use PYS_PRO_GLOBAL\WP\MCP\Core\McpVersionNegotiator;
use PYS_PRO_GLOBAL\WP\McpSchema\Common\Lifecycle\DTO\Implementation;
use PYS_PRO_GLOBAL\WP\McpSchema\Common\Protocol\DTO\InitializeResult;
use PYS_PRO_GLOBAL\WP\McpSchema\Server\Lifecycle\DTO\ServerCapabilities;
/**
 * Handles the initialize MCP method.
 */
class InitializeHandler
{
    /**
     * The WordPress MCP instance.
     *
     * @var \WP\MCP\Core\McpServer
     */
    private McpServer $mcp;
    /**
     * Constructor.
     *
     * @param \WP\MCP\Core\McpServer $mcp The WordPress MCP instance.
     */
    public function __construct(McpServer $mcp)
    {
        $this->mcp = $mcp;
    }
    /**
     * Handles the initialize request.
     *
     * Negotiates the protocol version with the client using McpVersionNegotiator.
     * If the client requests a supported version, that version is used. Otherwise
     * the server falls back to the latest supported version.
     *
     * @since 0.5.0
     *
     * @param string $client_protocol_version The protocol version requested by the client.
     *
     * @return \WP\McpSchema\Common\Protocol\DTO\InitializeResult Response with server capabilities and information.
     */
    public function handle(string $client_protocol_version): InitializeResult
    {
        $negotiated_version = McpVersionNegotiator::negotiate($client_protocol_version);
        $server_info = Implementation::fromArray(array('name' => $this->mcp->get_server_name(), 'version' => $this->mcp->get_server_version()));
        // Capabilities should only be advertised if they are implemented end-to-end.
        // IMPORTANT: We set explicit boolean values (not empty arrays) to ensure proper JSON serialization.
        // Empty arrays `[]` serialize as JSON arrays `[]`, but MCP spec requires JSON objects `{}`.
        // Setting explicit values like `listChanged: false` produces associative arrays that serialize correctly.
        $capabilities = ServerCapabilities::fromArray(array('prompts' => array('listChanged' => \false), 'resources' => array('subscribe' => \false, 'listChanged' => \false), 'tools' => array('listChanged' => \false)));
        $result = InitializeResult::fromArray(array('protocolVersion' => $negotiated_version, 'capabilities' => $capabilities, 'serverInfo' => $server_info, 'instructions' => $this->mcp->get_server_description()));
        /**
         * Filters the initialize response before returning to the client.
         *
         * Use this filter to modify server capabilities, instructions, or
         * other initialization data dynamically. To modify the result, call
         * `$result->toArray()`, change the data, and return
         * `InitializeResult::fromArray( $modified_data )`.
         *
         * @since 0.5.0
         *
         * @param \WP\McpSchema\Common\Protocol\DTO\InitializeResult $result The initialize result DTO.
         * @param \WP\MCP\Core\McpServer                             $server The MCP server instance.
         */
        return apply_filters('mcp_adapter_initialize_response', $result, $this->mcp);
    }
}