From 158d477bd9ea2871a05ad2f5f36af27135859815 Mon Sep 17 00:00:00 2001
From: Tim Otten <totten@civicrm.org>
Date: Tue, 14 Dec 2021 21:10:15 -0800
Subject: [PATCH] Civi::pipe - Extract class JsonRpc

---
 Civi/Pipe/JsonRpc.php        | 120 +++++++++++++++++++++++++++++++++++
 Civi/Pipe/JsonRpcSession.php |  65 +++----------------
 2 files changed, 128 insertions(+), 57 deletions(-)
 create mode 100644 Civi/Pipe/JsonRpc.php

diff --git a/Civi/Pipe/JsonRpc.php b/Civi/Pipe/JsonRpc.php
new file mode 100644
index 0000000000..0712dea0d4
--- /dev/null
+++ b/Civi/Pipe/JsonRpc.php
@@ -0,0 +1,120 @@
+<?php
+/*
+ +--------------------------------------------------------------------+
+ | Copyright CiviCRM LLC. All rights reserved.                        |
+ |                                                                    |
+ | This work is published under the GNU AGPLv3 license with some      |
+ | permitted exceptions and without any warranty. For full license    |
+ | and copyright information, see https://civicrm.org/licensing       |
+ +--------------------------------------------------------------------+
+ */
+
+namespace Civi\Pipe;
+
+class JsonRpc {
+
+  /**
+   * Execute a JSON-RPC request and return a result.
+   *
+   * This adapter handles decoding, encoding, and conversion of exceptions.
+   *
+   * @code
+   * $input = '{"jsonrpc":"2.0","method":"greet","id":1}';
+   * $output = JsonRpc::run($input, function(string $method, array $params) {
+   *   if ($method === 'greet') return 'hello world';
+   *   else throw new \InvalidArgumentException('Method not found', -32601);
+   * });
+   * assert $output === '{"jsonrpc":"2.0","result":"hello world","id":1}';
+   * @endCode
+   *
+   * @param string $requestLine
+   *   JSON formatted RPC request
+   * @param callable $dispatcher
+   *   Dispatch function - given a parsed/well-formed request, compute the result.
+   *   Signature: function(string $method, mixed $params): mixed
+   * @return string
+   *   JSON formatted RPC response
+   */
+  public static function run(string $requestLine, callable $dispatcher): string {
+    $parsed = \json_decode($requestLine, TRUE);
+
+    if ($parsed === NULL) {
+      throw new \InvalidArgumentException('Parse error', -32700);
+    }
+
+    if (isset($parsed[0])) {
+      $response = [];
+      foreach ($parsed as $request) {
+        $response[] = static::handleMethodCall($request, $dispatcher);
+      }
+    }
+    elseif (isset($parsed['method'])) {
+      $response = static::handleMethodCall($parsed, $dispatcher);
+    }
+    else {
+      throw new \InvalidArgumentException('Invalid Request', -32600);
+    }
+
+    return \json_encode($response);
+  }
+
+  protected static function handleMethodCall($request, $dispatcher): array {
+    try {
+      if ($request === NULL) {
+        throw new \InvalidArgumentException('Parse error', -32700);
+      }
+      if (($request['jsonrpc'] ?? '') !== '2.0' || !is_string($request['method'])) {
+        throw new \InvalidArgumentException('Invalid Request', -32600);
+      }
+
+      $result = $dispatcher($request['method'], $request['params'] ?? []);
+      return static::createResponseSuccess($request, $result);
+    }
+    catch (\Throwable $t) {
+      return static::createResponseError($request, $t);
+    }
+  }
+
+  /**
+   * Create a response object (successful).
+   *
+   * @link https://www.jsonrpc.org/specification#response_object
+   * @param array{jsonrpc: string, method: string, params: array, id: ?mixed} $request
+   * @param mixed $result
+   *   The result-value of the method call.
+   * @return array{jsonrpc: string, result: mixed, id: ?mixed}
+   */
+  public static function createResponseSuccess(array $request, $result): array {
+    $id = array_key_exists('id', $request) ? ['id' => $request['id']] : [];
+    return [
+      'jsonrpc' => '2.0',
+      'result' => $result,
+    ] + $id;
+  }
+
+  /**
+   * Create a response object (unsuccessful).
+   *
+   * @link https://www.jsonrpc.org/specification#response_object
+   * @param array{jsonrpc: string, method: string, params: array, id: ?mixed} $request
+   * @param \Throwable $t
+   *   The exception which caused the request to fail.
+   * @return array{jsonrpc: string, error: array, id: ?mixed}
+   */
+  public static function createResponseError(array $request, \Throwable $t): array {
+    $isJsonErrorCode = $t->getCode() >= -32999 && $t->getCode() <= -32000;
+    $errorData = \CRM_Core_Config::singleton()->debug
+      ? ['class' => get_class($t), 'trace' => $t->getTraceAsString()]
+      : NULL;
+    $id = array_key_exists('id', $request) ? ['id' => $request['id']] : [];
+    return [
+      'jsonrpc' => $request['jsonrpc'] ?? '2.0',
+      'error' => [
+        'code' => $isJsonErrorCode ? $t->getCode() : -32099,
+        'message' => $t->getMessage(),
+        'data' => $errorData,
+      ],
+    ] + $id;
+  }
+
+}
diff --git a/Civi/Pipe/JsonRpcSession.php b/Civi/Pipe/JsonRpcSession.php
index 15c665e731..681c8cfa2e 100644
--- a/Civi/Pipe/JsonRpcSession.php
+++ b/Civi/Pipe/JsonRpcSession.php
@@ -37,75 +37,26 @@ class JsonRpcSession {
    * @inheritDoc
    */
   protected function onRequest(string $requestLine): ?string {
-    $request = \json_decode($requestLine, TRUE);
-
-    if ($request === NULL) {
-      throw new \InvalidArgumentException('Parse error', -32700);
-    }
-
-    if (!is_array($request)) {
-      throw new \InvalidArgumentException('Invalid Request', -32600);
-    }
-
-    if (isset($request[0])) {
-      $response = array_map([$this, 'handleRequest'], $request);
-    }
-    else {
-      $response = $this->handleRequest($request);
-    }
-
-    return \json_encode($response);
-  }
-
-  protected function handleRequest($request): array {
-    try {
-      if ($request === NULL) {
-        throw new \InvalidArgumentException('Parse error', -32700);
-      }
-      if (($request['jsonrpc'] ?? '') !== '2.0') {
-        throw new \InvalidArgumentException('Invalid Request', -32600);
-      }
-
-      $method = str_replace('.', '_', mb_strtolower($request['method']));
-      if (!is_string($method) || !preg_match(self::METHOD_REGEX, $method)) {
-        throw new \InvalidArgumentException('Invalid Request', -32600);
+    return JsonRpc::run($requestLine, function($method, $params) {
+      $method = str_replace('.', '_', $method);
+      if (!preg_match(self::METHOD_REGEX, $method)) {
+        throw new \InvalidArgumentException('Method not found', -32601);
       }
 
       if (!is_callable([$this->methods, $method])) {
         throw new \InvalidArgumentException('Method not found', -32601);
       }
 
-      $result = call_user_func([$this->methods, $method], $this, $request['params'] ?? []);
-      $id = array_key_exists('id', $request) ? ['id' => $request['id']] : [];
-      return [
-        'jsonrpc' => '2.0',
-        'result' => $result,
-      ] + $id;
-    }
-    catch (\Throwable $t) {
-      return $this->createJsonError($request, $t);
-    }
+      return call_user_func([$this->methods, $method], $this, $params);
+    });
   }
 
   /**
    * @inheritDoc
    */
   protected function onException(string $requestLine, \Throwable $t): ?string {
-    return \json_encode($this->createJsonError(['jsonrpc' => '2.0'], $t));
-  }
-
-  protected function createJsonError(array $request, \Throwable $t): array {
-    $isJsonErrorCode = $t->getCode() >= -32999 && $t->getCode() <= -32000;
-    $errorData = \CRM_Core_Config::singleton()->debug
-      ? ['class' => get_class($t), 'trace' => $t->getTraceAsString()]
-      : NULL;
-    return \CRM_Utils_Array::subset($request, ['jsonrpc', 'id']) + [
-      'error' => [
-        'code' => $isJsonErrorCode ? $t->getCode() : -32099,
-        'message' => $t->getMessage(),
-        'data' => $errorData,
-      ],
-    ];
+    $error = JsonRpc::createResponseError([], $t);
+    return \json_encode($error);
   }
 
 }
-- 
2.25.1