| 1 |
<?php |
| 2 |
/** |
| 3 |
* Service for routing MCP requests to appropriate handlers. |
| 4 |
* |
| 5 |
* @package McpAdapter |
| 6 |
*/ |
| 7 |
|
| 8 |
declare( strict_types=1 ); |
| 9 |
|
| 10 |
namespace WP\MCP\Transport\Infrastructure; |
| 11 |
|
| 12 |
use WP\MCP\Infrastructure\ErrorHandling\McpErrorFactory; |
| 13 |
use WP\MCP\Infrastructure\Observability\McpObservabilityHelperTrait; |
| 14 |
use WP\McpSchema\Common\AbstractDataTransferObject; |
| 15 |
use WP\McpSchema\Common\Content\DTO\TextContent; |
| 16 |
use WP\McpSchema\Common\JsonRpc\DTO\JSONRPCErrorResponse; |
| 17 |
use WP\McpSchema\Server\Tools\DTO\CallToolResult; |
| 18 |
|
| 19 |
/** |
| 20 |
* Service for routing MCP requests to appropriate handlers. |
| 21 |
* |
| 22 |
* Extracted from AbstractMcpTransport to be reusable across |
| 23 |
* all transport implementations via dependency injection. |
| 24 |
*/ |
| 25 |
class RequestRouter { |
| 26 |
|
| 27 |
/** |
| 28 |
* The transport context. |
| 29 |
* |
| 30 |
* @var \WP\MCP\Transport\Infrastructure\McpTransportContext |
| 31 |
*/ |
| 32 |
private McpTransportContext $context; |
| 33 |
|
| 34 |
/** |
| 35 |
* Initialize the request router. |
| 36 |
* |
| 37 |
* @param \WP\MCP\Transport\Infrastructure\McpTransportContext $context The transport context. |
| 38 |
*/ |
| 39 |
public function __construct( |
| 40 |
McpTransportContext $context |
| 41 |
) { |
| 42 |
$this->context = $context; |
| 43 |
} |
| 44 |
|
| 45 |
/** |
| 46 |
* Route a request to the appropriate handler. |
| 47 |
* |
| 48 |
* @param string $method The MCP method name. |
| 49 |
* @param array $params The request parameters. |
| 50 |
* @param mixed $request_id The request ID (for JSON-RPC) - string, number, or null. |
| 51 |
* @param string $transport_name Transport name for observability. |
| 52 |
* @param \WP\MCP\Transport\Infrastructure\HttpRequestContext|null $http_context HTTP context for session management. |
| 53 |
* |
| 54 |
* @return array |
| 55 |
*/ |
| 56 |
public function route_request( string $method, array $params, $request_id = 0, string $transport_name = 'unknown', ?HttpRequestContext $http_context = null ): array { |
| 57 |
// Track request start time. |
| 58 |
$start_time = microtime( true ); |
| 59 |
|
| 60 |
$new_session_id = null; |
| 61 |
$component_tags = $this->resolve_component_observability_context( $method, $params ); |
| 62 |
|
| 63 |
// Common tags for all metrics. |
| 64 |
$common_tags = array( |
| 65 |
'method' => $method, |
| 66 |
'transport' => $transport_name, |
| 67 |
'server_id' => $this->context->mcp_server->get_server_id(), |
| 68 |
'params' => $this->sanitize_params_for_logging( $params ), |
| 69 |
'request_id' => $request_id, |
| 70 |
'session_id' => $http_context ? $http_context->session_id : null, |
| 71 |
); |
| 72 |
|
| 73 |
$handlers = array( |
| 74 |
'initialize' => function () use ( $params, $request_id, $http_context, &$new_session_id ) { |
| 75 |
return $this->handle_initialize_with_session( $params, $request_id, $http_context, $new_session_id ); |
| 76 |
}, |
| 77 |
'ping' => fn() => $this->context->system_handler->ping(), |
| 78 |
'tools/list' => fn() => $this->context->tools_handler->list_tools(), |
| 79 |
'tools/list/all' => fn() => $this->context->tools_handler->list_all_tools(), |
| 80 |
'tools/call' => fn() => $this->context->tools_handler->call_tool( $params, $request_id ), |
| 81 |
'resources/list' => fn() => $this->context->resources_handler->list_resources(), |
| 82 |
'resources/read' => fn() => $this->context->resources_handler->read_resource( $params, $request_id ), |
| 83 |
'prompts/list' => fn() => $this->context->prompts_handler->list_prompts(), |
| 84 |
'prompts/get' => fn() => $this->context->prompts_handler->get_prompt( $params, $request_id ), |
| 85 |
); |
| 86 |
|
| 87 |
try { |
| 88 |
$handler_result = isset( $handlers[ $method ] ) ? $handlers[ $method ]() : $this->create_method_not_found_error( $method, $request_id ); |
| 89 |
|
| 90 |
// Calculate request duration. |
| 91 |
$duration = ( microtime( true ) - $start_time ) * 1000; // Convert to milliseconds. |
| 92 |
|
| 93 |
// Handle DTO results from migrated handlers. |
| 94 |
// DTOs are converted to arrays at the serialization boundary (here). |
| 95 |
if ( $handler_result instanceof JSONRPCErrorResponse ) { |
| 96 |
// Normalize to transport-level shape: only the JSON-RPC error object. |
| 97 |
// The JSON-RPC envelope is created by the transport boundary. |
| 98 |
$result = array( 'error' => $handler_result->getError()->toArray() ); |
| 99 |
$tags = array_merge( $common_tags, $component_tags, array( 'status' => 'error' ) ); |
| 100 |
$tags['error_code'] = $handler_result->getError()->getCode(); |
| 101 |
$tags['failure_reason'] = $handler_result->getError()->getMessage(); |
| 102 |
$this->context->observability_handler->record_event( 'mcp.request', $tags, $duration ); |
| 103 |
|
| 104 |
return $result; |
| 105 |
} |
| 106 |
|
| 107 |
if ( $handler_result instanceof AbstractDataTransferObject ) { |
| 108 |
// Success DTO (ListToolsResult, CallToolResult, etc.) - convert to array. |
| 109 |
// Note: If a future schema version ever returns nested DTO objects inside `toArray()`, |
| 110 |
// we may need to add a deep normalizer at this boundary (before JSON serialization) |
| 111 |
// to prevent placeholder `{}` objects in client output. |
| 112 |
$raw_result = $handler_result->toArray(); |
| 113 |
$result = $raw_result; |
| 114 |
|
| 115 |
if ( null !== $new_session_id ) { |
| 116 |
$component_tags['new_session_id'] = $new_session_id; |
| 117 |
$result['_session_id'] = $new_session_id; |
| 118 |
} |
| 119 |
|
| 120 |
$status = 'success'; |
| 121 |
if ( $handler_result instanceof CallToolResult && true === $handler_result->getIsError() ) { |
| 122 |
$status = 'error'; |
| 123 |
|
| 124 |
if ( ! isset( $component_tags['failure_reason'] ) ) { |
| 125 |
$content = $handler_result->getContent(); |
| 126 |
if ( isset( $content[0] ) && $content[0] instanceof TextContent ) { |
| 127 |
$component_tags['failure_reason'] = $content[0]->getText(); |
| 128 |
} |
| 129 |
} |
| 130 |
} |
| 131 |
|
| 132 |
$tags = array_merge( $common_tags, $component_tags, array( 'status' => $status ) ); |
| 133 |
$this->context->observability_handler->record_event( 'mcp.request', $tags, $duration ); |
| 134 |
|
| 135 |
return $result; |
| 136 |
} |
| 137 |
|
| 138 |
// Handlers should only return schema DTOs. |
| 139 |
$actual_type = is_object( $handler_result ) ? get_class( $handler_result ) : gettype( $handler_result ); |
| 140 |
$this->context->error_handler->log( |
| 141 |
sprintf( 'Handler for method "%s" returned unexpected type: %s', $method, $actual_type ), |
| 142 |
array( |
| 143 |
'method' => $method, |
| 144 |
'actual_type' => $actual_type, |
| 145 |
) |
| 146 |
); |
| 147 |
$unexpected_error = McpErrorFactory::internal_error( $request_id, 'Handler returned invalid response type.' ); |
| 148 |
$result = array( 'error' => $unexpected_error->getError()->toArray() ); |
| 149 |
$tags = array_merge( $common_tags, $component_tags, array( 'status' => 'error' ) ); |
| 150 |
$tags['error_code'] = $unexpected_error->getError()->getCode(); |
| 151 |
$this->context->observability_handler->record_event( 'mcp.request', $tags, $duration ); |
| 152 |
|
| 153 |
return $result; |
| 154 |
} catch ( \Throwable $exception ) { |
| 155 |
// Calculate request duration. |
| 156 |
$duration = ( microtime( true ) - $start_time ) * 1000; // Convert to milliseconds. |
| 157 |
|
| 158 |
// Track exception with categorization. |
| 159 |
$tags = array_merge( |
| 160 |
$common_tags, |
| 161 |
$component_tags, |
| 162 |
array( |
| 163 |
'status' => 'error', |
| 164 |
'error_type' => get_class( $exception ), |
| 165 |
'error_category' => $this->categorize_error( $exception ), |
| 166 |
) |
| 167 |
); |
| 168 |
$this->context->observability_handler->record_event( 'mcp.request', $tags, $duration ); |
| 169 |
|
| 170 |
// Create error response from exception. |
| 171 |
$unexpected_error = McpErrorFactory::internal_error( $request_id, 'Handler error occurred' ); |
| 172 |
|
| 173 |
return array( 'error' => $unexpected_error->getError()->toArray() ); |
| 174 |
} |
| 175 |
} |
| 176 |
|
| 177 |
/** |
| 178 |
* Resolve per-component observability tags for a request. |
| 179 |
* |
| 180 |
* This replaces legacy approaches that derived tags from DTO `_meta`. |
| 181 |
* |
| 182 |
* @param string $method MCP method name. |
| 183 |
* @param array $params Request parameters (root or nested under `params`). |
| 184 |
* |
| 185 |
* @return array<string, mixed> |
| 186 |
*/ |
| 187 |
private function resolve_component_observability_context( string $method, array $params ): array { |
| 188 |
$request_params = $params['params'] ?? $params; |
| 189 |
|
| 190 |
if ( ! is_array( $request_params ) ) { |
| 191 |
$request_params = array(); |
| 192 |
} |
| 193 |
|
| 194 |
switch ( $method ) { |
| 195 |
case 'tools/call': |
| 196 |
$tool_name = $request_params['name'] ?? null; |
| 197 |
$tool_name = is_string( $tool_name ) ? trim( $tool_name ) : null; |
| 198 |
|
| 199 |
if ( null === $tool_name || '' === $tool_name ) { |
| 200 |
return array(); |
| 201 |
} |
| 202 |
|
| 203 |
$mcp_tool = $this->context->mcp_server->get_mcp_tool( $tool_name ); |
| 204 |
if ( $mcp_tool ) { |
| 205 |
return $mcp_tool->get_observability_context(); |
| 206 |
} |
| 207 |
|
| 208 |
return array( |
| 209 |
'component_type' => 'tool', |
| 210 |
'tool_name' => $tool_name, |
| 211 |
); |
| 212 |
|
| 213 |
case 'prompts/get': |
| 214 |
$prompt_name = $request_params['name'] ?? null; |
| 215 |
$prompt_name = is_string( $prompt_name ) ? trim( $prompt_name ) : null; |
| 216 |
|
| 217 |
if ( null === $prompt_name || '' === $prompt_name ) { |
| 218 |
return array(); |
| 219 |
} |
| 220 |
|
| 221 |
$mcp_prompt = $this->context->mcp_server->get_mcp_prompt( $prompt_name ); |
| 222 |
if ( $mcp_prompt ) { |
| 223 |
return $mcp_prompt->get_observability_context(); |
| 224 |
} |
| 225 |
|
| 226 |
return array( |
| 227 |
'component_type' => 'prompt', |
| 228 |
'prompt_name' => $prompt_name, |
| 229 |
); |
| 230 |
|
| 231 |
case 'resources/read': |
| 232 |
$resource_uri = $request_params['uri'] ?? null; |
| 233 |
$resource_uri = is_string( $resource_uri ) ? trim( $resource_uri ) : null; |
| 234 |
|
| 235 |
if ( null === $resource_uri || '' === $resource_uri ) { |
| 236 |
return array(); |
| 237 |
} |
| 238 |
|
| 239 |
$mcp_resource = $this->context->mcp_server->get_mcp_resource( $resource_uri ); |
| 240 |
if ( $mcp_resource ) { |
| 241 |
return $mcp_resource->get_observability_context(); |
| 242 |
} |
| 243 |
|
| 244 |
return array( |
| 245 |
'component_type' => 'resource', |
| 246 |
'resource_uri' => $resource_uri, |
| 247 |
); |
| 248 |
} |
| 249 |
|
| 250 |
return array(); |
| 251 |
} |
| 252 |
|
| 253 |
/** |
| 254 |
* Sanitize request params for logging to remove sensitive data and limit size. |
| 255 |
* |
| 256 |
* @param array $params The request parameters to sanitize. |
| 257 |
* |
| 258 |
* @return array Sanitized parameters safe for logging. |
| 259 |
*/ |
| 260 |
private function sanitize_params_for_logging( array $params ): array { |
| 261 |
// Return early for empty parameters. |
| 262 |
if ( empty( $params ) ) { |
| 263 |
return array(); |
| 264 |
} |
| 265 |
|
| 266 |
$sanitized = array(); |
| 267 |
|
| 268 |
// Extract only safe, useful fields for observability |
| 269 |
$safe_fields = array( 'name', 'protocolVersion', 'uri' ); |
| 270 |
|
| 271 |
foreach ( $safe_fields as $field ) { |
| 272 |
if ( ! isset( $params[ $field ] ) || ! is_scalar( $params[ $field ] ) ) { |
| 273 |
continue; |
| 274 |
} |
| 275 |
|
| 276 |
$sanitized[ $field ] = $params[ $field ]; |
| 277 |
} |
| 278 |
|
| 279 |
// Add clientInfo name if available (useful for debugging) |
| 280 |
if ( isset( $params['clientInfo']['name'] ) ) { |
| 281 |
$sanitized['client_name'] = $params['clientInfo']['name']; |
| 282 |
} |
| 283 |
|
| 284 |
// Add arguments count for tool calls (but not the actual arguments to avoid logging sensitive data). |
| 285 |
// Also filter out sensitive-looking keys to avoid leaking secret names. |
| 286 |
if ( isset( $params['arguments'] ) && is_array( $params['arguments'] ) ) { |
| 287 |
$sanitized['arguments_count'] = count( $params['arguments'] ); |
| 288 |
|
| 289 |
// Filter argument keys to exclude sensitive-looking ones. |
| 290 |
$safe_keys = array(); |
| 291 |
foreach ( array_keys( $params['arguments'] ) as $arg_key ) { |
| 292 |
if ( McpObservabilityHelperTrait::is_sensitive_key( (string) $arg_key ) ) { |
| 293 |
$safe_keys[] = '[REDACTED]'; |
| 294 |
} else { |
| 295 |
$safe_keys[] = $arg_key; |
| 296 |
} |
| 297 |
} |
| 298 |
$sanitized['arguments_keys'] = $safe_keys; |
| 299 |
} |
| 300 |
|
| 301 |
return $sanitized; |
| 302 |
} |
| 303 |
|
| 304 |
/** |
| 305 |
* Handle initialize requests with session management. |
| 306 |
* |
| 307 |
* Converts InitializeResult DTO to array and adds session management. |
| 308 |
* |
| 309 |
* @param array $params The request parameters. |
| 310 |
* @param mixed $request_id The request ID. |
| 311 |
* @param \WP\MCP\Transport\Infrastructure\HttpRequestContext|null $http_context HTTP context for session management. |
| 312 |
* @param string|null $new_session_id Newly created session id, if any. |
| 313 |
* |
| 314 |
* @return \WP\McpSchema\Common\AbstractDataTransferObject |
| 315 |
*/ |
| 316 |
private function handle_initialize_with_session( array $params, $request_id, ?HttpRequestContext $http_context, ?string &$new_session_id = null ): AbstractDataTransferObject { |
| 317 |
// Extract client protocol version from params, defaulting to empty string if missing. |
| 318 |
$client_version = isset( $params['protocolVersion'] ) && is_string( $params['protocolVersion'] ) ? $params['protocolVersion'] : ''; |
| 319 |
|
| 320 |
// Get the initialize response from the handler (returns InitializeResult DTO). |
| 321 |
$init_result = $this->context->initialize_handler->handle( $client_version ); |
| 322 |
|
| 323 |
// Handle session creation if HTTP context is provided. |
| 324 |
// InitializeResult DTO never has errors - errors would be thrown as exceptions. |
| 325 |
if ( $http_context && ! $http_context->session_id ) { |
| 326 |
$session_result = HttpSessionValidator::create_session( $params ); |
| 327 |
|
| 328 |
if ( is_array( $session_result ) ) { |
| 329 |
$error = $session_result['error'] ?? array(); |
| 330 |
|
| 331 |
return McpErrorFactory::create_error_response( |
| 332 |
$request_id, |
| 333 |
isset( $error['code'] ) ? (int) $error['code'] : McpErrorFactory::INTERNAL_ERROR, |
| 334 |
(string) ( $error['message'] ?? __( 'Failed to create session', 'mcp-adapter' ) ), |
| 335 |
$error['data'] ?? null |
| 336 |
); |
| 337 |
} |
| 338 |
|
| 339 |
$new_session_id = $session_result; |
| 340 |
} |
| 341 |
|
| 342 |
return $init_result; |
| 343 |
} |
| 344 |
|
| 345 |
/** |
| 346 |
* Create a method not found error with generic format. |
| 347 |
* |
| 348 |
* @param string $method The method that was not found. |
| 349 |
* @param mixed $request_id The request ID. |
| 350 |
* |
| 351 |
* @return \WP\McpSchema\Common\JsonRpc\DTO\JSONRPCErrorResponse |
| 352 |
*/ |
| 353 |
private function create_method_not_found_error( string $method, $request_id ): JSONRPCErrorResponse { |
| 354 |
return McpErrorFactory::method_not_found( $request_id, $method ); |
| 355 |
} |
| 356 |
|
| 357 |
/** |
| 358 |
* Categorize an exception into a general error category. |
| 359 |
* |
| 360 |
* @param \Throwable $exception The exception to categorize. |
| 361 |
* |
| 362 |
* @return string |
| 363 |
*/ |
| 364 |
private function categorize_error( \Throwable $exception ): string { |
| 365 |
$error_categories = array( |
| 366 |
\ArgumentCountError::class => 'arguments', |
| 367 |
\TypeError::class => 'type', |
| 368 |
\InvalidArgumentException::class => 'validation', |
| 369 |
\LogicException::class => 'logic', |
| 370 |
\RuntimeException::class => 'execution', |
| 371 |
\Error::class => 'system', |
| 372 |
); |
| 373 |
|
| 374 |
foreach ( $error_categories as $class => $category ) { |
| 375 |
if ( $exception instanceof $class ) { |
| 376 |
return $category; |
| 377 |
} |
| 378 |
} |
| 379 |
|
| 380 |
return 'unknown'; |
| 381 |
} |
| 382 |
} |
| 383 |
|
