<?php

/**
 * MCP Tool component.
 *
 * @package McpAdapter
 */
declare (strict_types=1);
namespace PYS_PRO_GLOBAL\WP\MCP\Domain\Tools;

use PYS_PRO_GLOBAL\WP\MCP\Domain\Contracts\McpComponentInterface;
use PYS_PRO_GLOBAL\WP\MCP\Domain\Utils\AbilityArgumentNormalizer;
use PYS_PRO_GLOBAL\WP\MCP\Domain\Utils\McpValidator;
use PYS_PRO_GLOBAL\WP\MCP\Infrastructure\Observability\FailureReason;
use PYS_PRO_GLOBAL\WP\McpSchema\Server\Tools\DTO\Tool as ToolDto;
use PYS_PRO_GLOBAL\WP\McpSchema\Server\Tools\DTO\ToolAnnotations;
use WP_Error;
/**
 * Tool component providing unified execution and permission checks.
 *
 * This class provides multiple flexible ways to create MCP tools:
 *
 * 1. Array configuration:
 * ```php
 * $tool = McpTool::fromArray([
 *     'name'        => 'uppercase-text',
 *     'title'       => 'Uppercase Text',
 *     'description' => 'Converts text to uppercase',
 *     'inputSchema' => ['type' => 'object', 'properties' => [...]],
 *     'handler'     => fn($args) => ['result' => strtoupper($args['text'])],
 *     'permission'  => fn() => true,
 *     'annotations' => ['readOnlyHint' => true],
 * ]);
 * ```
 *
 * 2. From WordPress Ability (ability-backed):
 * ```php
 * $tool = McpTool::fromAbility($ability);
 * ```
 *
 * McpTool wraps a protocol-only ToolDto for MCP serialization. Internal
 * adapter metadata and execution wiring live on this class and are never
 * exposed to MCP clients. Use get_protocol_dto() for protocol responses.
 *
 * @since 0.5.0
 */
final class McpTool implements McpComponentInterface
{
    // =========================================================================
    // Runtime Properties
    // =========================================================================
    /**
     * Clean Tool DTO (protocol-only).
     *
     * @var \WP\McpSchema\Server\Tools\DTO\Tool
     */
    private ToolDto $tool;
    /**
     * Ability used for execution/permission checks (ability-backed tools).
     *
     * @var \WP_Ability|null
     */
    private ?\WP_Ability $ability = null;
    /**
     * Direct execution handler (callable-backed tools).
     *
     * @var callable|null
     */
    private $handler = null;
    /**
     * Direct permission callback (callable-backed tools).
     *
     * @var callable|null
     */
    private $permission_callback = null;
    /**
     * Internal adapter metadata (never exposed to clients).
     *
     * @var array<string, mixed>
     */
    private array $adapter_meta = array();
    /**
     * Observability context tags for logging/metrics.
     *
     * @var array<string, mixed>
     */
    private array $observability_context = array();
    // =========================================================================
    // Constructor
    // =========================================================================
    /**
     * Private constructor - use factory methods.
     *
     * @param \WP\McpSchema\Server\Tools\DTO\Tool $tool The Tool DTO.
     */
    private function __construct(ToolDto $tool)
    {
        $this->tool = $tool;
    }
    // =========================================================================
    // Factory Methods
    // =========================================================================
    /**
     * Create a tool definition from an array configuration.
     *
     * @param array $config The tool configuration array.
     *
     * @return self|\WP_Error
     */
    public static function fromArray(array $config)
    {
        if (empty($config['name'])) {
            return new WP_Error('mcp_tool_missing_name', 'Tool configuration must include a "name" field.');
        }
        if (!isset($config['handler']) || !is_callable($config['handler'])) {
            return new WP_Error('mcp_tool_missing_handler', 'Tool configuration must include a callable "handler" field.');
        }
        // Prepare input schema - ensure it's an object type for MCP compliance.
        $input_schema = $config['inputSchema'] ?? array('type' => 'object');
        if (!isset($input_schema['type'])) {
            $input_schema['type'] = 'object';
        }
        // Build tool data array.
        $tool_data = array('name' => $config['name'], 'inputSchema' => $input_schema);
        // Optional fields.
        if (isset($config['title'])) {
            $tool_data['title'] = $config['title'];
        }
        if (isset($config['description'])) {
            $tool_data['description'] = $config['description'];
        }
        if (isset($config['outputSchema']) && is_array($config['outputSchema'])) {
            $tool_data['outputSchema'] = $config['outputSchema'];
        }
        // Validate and prepare icons if set.
        if (isset($config['icons']) && is_array($config['icons']) && !empty($config['icons'])) {
            $icons_result = McpValidator::validate_icons_array($config['icons']);
            if (!empty($icons_result['valid'])) {
                $tool_data['icons'] = $icons_result['valid'];
            }
        }
        // Preserve user-provided _meta as-is.
        if (isset($config['meta']) && is_array($config['meta']) && !empty($config['meta'])) {
            $tool_data['_meta'] = $config['meta'];
        }
        // Create the Tool DTO - wrap in try-catch since ToolAnnotations::fromArray() and ToolDto::fromArray() can throw.
        try {
            // Process annotations inside try-catch since ToolAnnotations::fromArray() can throw.
            if (isset($config['annotations']) && is_array($config['annotations']) && !empty($config['annotations'])) {
                $tool_data['annotations'] = ToolAnnotations::fromArray($config['annotations']);
            }
            $tool = ToolDto::fromArray($tool_data);
        } catch (\Throwable $e) {
            return new WP_Error('mcp_tool_dto_creation_failed', sprintf(
                /* translators: %s: error message */
                __('Failed to create Tool DTO: %s', 'mcp-adapter'),
                $e->getMessage()
            ), array('exception' => $e));
        }
        // Optional deep validation if enabled.
        $mcp_validation_enabled = apply_filters('mcp_adapter_validation_enabled', \false);
        if ($mcp_validation_enabled) {
            $validation_result = McpToolValidator::validate_tool_dto($tool);
            if (is_wp_error($validation_result)) {
                return $validation_result;
            }
        }
        $instance = new self($tool);
        $instance->handler = $config['handler'];
        if (isset($config['permission']) && is_callable($config['permission'])) {
            $instance->permission_callback = $config['permission'];
        }
        $instance->observability_context = array('component_type' => 'tool', 'tool_name' => $config['name'], 'source' => 'array');
        return $instance;
    }
    /**
     * Create an ability-backed MCP tool.
     *
     * @param \WP_Ability $ability WordPress ability.
     *
     * @return self|\WP_Error
     */
    public static function fromAbility(\WP_Ability $ability)
    {
        $tool_data = RegisterAbilityAsMcpTool::build($ability);
        if ($tool_data instanceof WP_Error) {
            return $tool_data;
        }
        $instance = new self($tool_data['tool']);
        $instance->adapter_meta = $tool_data['adapter_meta'];
        $instance->ability = $ability;
        $instance->observability_context = array('component_type' => 'tool', 'tool_name' => $tool_data['tool']->getName(), 'ability_name' => $ability->get_name(), 'source' => 'ability');
        return $instance;
    }
    // =========================================================================
    // McpComponentInterface Implementation
    // =========================================================================
    /**
     * Get the clean protocol DTO for MCP responses.
     *
     * @return \WP\McpSchema\Server\Tools\DTO\Tool
     */
    public function get_protocol_dto(): ToolDto
    {
        return $this->tool;
    }
    /**
     * Execute the tool.
     *
     * @param mixed $arguments Tool arguments.
     *
     * @return mixed
     */
    public function execute($arguments)
    {
        $args = $this->unwrap_input_if_needed($arguments);
        if (null !== $this->ability) {
            $args = AbilityArgumentNormalizer::normalize($this->ability, $args);
            try {
                $result = $this->ability->execute($args);
            } catch (\Throwable $throwable) {
                return new WP_Error('mcp_execution_failed', $throwable->getMessage(), array('error_type' => get_class($throwable)));
            }
        } elseif (null !== $this->handler) {
            try {
                $result = call_user_func($this->handler, $args);
            } catch (\Throwable $throwable) {
                return new WP_Error('mcp_execution_failed', $throwable->getMessage(), array('error_type' => get_class($throwable)));
            }
        } else {
            return new WP_Error('mcp_tool_no_handler', 'No tool execution strategy configured.');
        }
        if ($result instanceof WP_Error) {
            return $result;
        }
        $result = $this->wrap_output_if_needed($result);
        if (!is_array($result)) {
            $result = array('result' => $result);
        }
        return $result;
    }
    /**
     * Unwrap tool input arguments when the input schema was transformed (flattened → object wrapper).
     *
     * @param mixed $arguments Raw tool arguments.
     *
     * @return mixed
     */
    private function unwrap_input_if_needed($arguments)
    {
        $is_transformed = \true === ($this->adapter_meta['input_schema_transformed'] ?? \false);
        if (!$is_transformed) {
            return $arguments;
        }
        $wrapper = $this->adapter_meta['input_schema_wrapper'] ?? 'input';
        $wrapper = is_string($wrapper) && '' !== trim($wrapper) ? $wrapper : 'input';
        return is_array($arguments) ? $arguments[$wrapper] ?? null : null;
    }
    /**
     * Wrap tool results when the output schema was transformed (flattened → object wrapper).
     *
     * @param mixed $result Raw result.
     *
     * @return mixed
     */
    private function wrap_output_if_needed($result)
    {
        $is_transformed = \true === ($this->adapter_meta['output_schema_transformed'] ?? \false);
        if (!$is_transformed) {
            return $result;
        }
        $wrapper = $this->adapter_meta['output_schema_wrapper'] ?? 'result';
        $wrapper = is_string($wrapper) && '' !== trim($wrapper) ? $wrapper : 'result';
        return array($wrapper => $result);
    }
    /**
     * Check whether the current request has permission to execute this tool.
     *
     * @param mixed $arguments Tool arguments.
     *
     * @return bool|\WP_Error
     */
    public function check_permission($arguments)
    {
        $args = $this->unwrap_input_if_needed($arguments);
        // Ability-backed tools delegate to the ability's permission system.
        if (null !== $this->ability) {
            $args = AbilityArgumentNormalizer::normalize($this->ability, $args);
            try {
                return $this->ability->check_permissions($args);
            } catch (\Throwable $throwable) {
                return new WP_Error('mcp_permission_check_failed', $throwable->getMessage(), array('error_type' => get_class($throwable)));
            }
        }
        // Callable-backed tools use their required permission callback.
        if (null !== $this->permission_callback) {
            try {
                $result = call_user_func($this->permission_callback, $args);
                return $result instanceof WP_Error ? $result : (bool) $result;
            } catch (\Throwable $throwable) {
                return new WP_Error('mcp_permission_check_failed', $throwable->getMessage(), array('error_type' => get_class($throwable)));
            }
        }
        // Defensive fallback: should never reach here if factories are used correctly.
        return new WP_Error('mcp_permission_denied', 'Access denied.', array('failure_reason' => FailureReason::NO_PERMISSION_STRATEGY, 'tool_name' => $this->tool->getName()));
    }
    // =========================================================================
    // Private Helper Methods
    // =========================================================================
    /**
     * Get internal adapter metadata for this tool.
     *
     * @return array<string, mixed>
     */
    public function get_adapter_meta(): array
    {
        return $this->adapter_meta;
    }
    /**
     * Get observability context tags for logging/metrics.
     *
     * @return array<string, mixed>
     */
    public function get_observability_context(): array
    {
        return $this->observability_context;
    }
}