From 469d2a72e38e18cab94f5492a897dea7bfc56fa1 Mon Sep 17 00:00:00 2001
From: Awilum <sergey.romanenko@flextype.org>
Date: Fri, 30 Jul 2021 12:56:38 +0300
Subject: [PATCH] feat(handlers): add basic Shutdown and HttpError handlers
 #199

---
 .../Foundation/Handlers/HttpErrorHandler.php  | 76 +++++++++++++++++
 .../Foundation/Handlers/ShutdownHandler.php   | 83 +++++++++++++++++++
 2 files changed, 159 insertions(+)
 create mode 100644 src/flextype/Foundation/Handlers/HttpErrorHandler.php
 create mode 100644 src/flextype/Foundation/Handlers/ShutdownHandler.php

diff --git a/src/flextype/Foundation/Handlers/HttpErrorHandler.php b/src/flextype/Foundation/Handlers/HttpErrorHandler.php
new file mode 100644
index 000000000..2a687e267
--- /dev/null
+++ b/src/flextype/Foundation/Handlers/HttpErrorHandler.php
@@ -0,0 +1,76 @@
+<?php 
+
+namespace Flextype\Foundation\Handlers;
+
+use Psr\Http\Message\ResponseInterface;
+use Slim\Exception\HttpBadRequestException;
+use Slim\Exception\HttpException;
+use Slim\Exception\HttpForbiddenException;
+use Slim\Exception\HttpMethodNotAllowedException;
+use Slim\Exception\HttpNotFoundException;
+use Slim\Exception\HttpNotImplementedException;
+use Slim\Exception\HttpUnauthorizedException;
+use Slim\Handlers\ErrorHandler;
+use Exception;
+use Throwable;
+
+class HttpErrorHandler extends ErrorHandler
+{
+    public const BAD_REQUEST = 'BAD_REQUEST';
+    public const INSUFFICIENT_PRIVILEGES = 'INSUFFICIENT_PRIVILEGES';
+    public const NOT_ALLOWED = 'NOT_ALLOWED';
+    public const NOT_IMPLEMENTED = 'NOT_IMPLEMENTED';
+    public const RESOURCE_NOT_FOUND = 'RESOURCE_NOT_FOUND';
+    public const SERVER_ERROR = 'SERVER_ERROR';
+    public const UNAUTHENTICATED = 'UNAUTHENTICATED';
+    
+    protected function respond(): ResponseInterface
+    {
+        $exception = $this->exception;
+        $statusCode = 500;
+        $type = self::SERVER_ERROR;
+        $description = 'An internal error has occurred while processing your request.';
+
+        if ($exception instanceof HttpException) {
+            $statusCode = $exception->getCode();
+            $description = $exception->getMessage();
+
+            if ($exception instanceof HttpNotFoundException) {
+                $type = self::RESOURCE_NOT_FOUND;
+            } elseif ($exception instanceof HttpMethodNotAllowedException) {
+                $type = self::NOT_ALLOWED;
+            } elseif ($exception instanceof HttpUnauthorizedException) {
+                $type = self::UNAUTHENTICATED;
+            } elseif ($exception instanceof HttpForbiddenException) {
+                $type = self::UNAUTHENTICATED;
+            } elseif ($exception instanceof HttpBadRequestException) {
+                $type = self::BAD_REQUEST;
+            } elseif ($exception instanceof HttpNotImplementedException) {
+                $type = self::NOT_IMPLEMENTED;
+            }
+        }
+
+        if (
+            !($exception instanceof HttpException)
+            && ($exception instanceof Exception || $exception instanceof Throwable)
+            && $this->displayErrorDetails
+        ) {
+            $description = $exception->getMessage();
+        }
+
+        $error = [
+            'statusCode' => $statusCode,
+            'error' => [
+                'type' => $type,
+                'description' => $description,
+            ],
+        ];
+        
+        $payload = json_encode($error, JSON_PRETTY_PRINT);
+        
+        $response = $this->responseFactory->createResponse($statusCode);        
+        $response->getBody()->write($payload);
+        
+        return $response;
+    }
+}
\ No newline at end of file
diff --git a/src/flextype/Foundation/Handlers/ShutdownHandler.php b/src/flextype/Foundation/Handlers/ShutdownHandler.php
new file mode 100644
index 000000000..184f19dbd
--- /dev/null
+++ b/src/flextype/Foundation/Handlers/ShutdownHandler.php
@@ -0,0 +1,83 @@
+<?php
+
+namespace Flextype\Foundation\Handlers;
+
+use Flextype\Foundation\Handlers\HttpErrorHandler;
+use Psr\Http\Message\ServerRequestInterface as Request;
+use Slim\Exception\HttpInternalServerErrorException;
+use Slim\ResponseEmitter;
+
+class ShutdownHandler
+{
+    /**
+     * @var Request
+     */
+    private $request;
+
+    /**
+     * @var HttpErrorHandler
+     */
+    private $errorHandler;
+
+    /**
+     * @var bool
+     */
+    private $displayErrorDetails;
+
+    /**
+     * ShutdownHandler constructor.
+     *
+     * @param Request           $request
+     * @param HttpErrorHandler  $errorHandler
+     * @param bool              $displayErrorDetails
+     */
+    public function __construct(Request $request, HttpErrorHandler $errorHandler, bool $displayErrorDetails) {
+        $this->request = $request;
+        $this->errorHandler = $errorHandler;
+        $this->displayErrorDetails = $displayErrorDetails;
+    }
+
+    public function __invoke()
+    {
+        $error = error_get_last();
+        if ($error) {
+            $errorFile = $error['file'];
+            $errorLine = $error['line'];
+            $errorMessage = $error['message'];
+            $errorType = $error['type'];
+            $message = 'An error while processing your request. Please try again later.';
+
+            if ($this->displayErrorDetails) {
+                switch ($errorType) {
+                    case E_USER_ERROR:
+                        $message = "FATAL ERROR: {$errorMessage}. ";
+                        $message .= " on line {$errorLine} in file {$errorFile}.";
+                        break;
+
+                    case E_USER_WARNING:
+                        $message = "WARNING: {$errorMessage}";
+                        break;
+
+                    case E_USER_NOTICE:
+                        $message = "NOTICE: {$errorMessage}";
+                        break;
+
+                    default:
+                        $message = "ERROR: {$errorMessage}";
+                        $message .= " on line {$errorLine} in file {$errorFile}.";
+                        break;
+                }
+            }
+
+            $exception = new HttpInternalServerErrorException($this->request, $message);
+            $response = $this->errorHandler->__invoke($this->request, $exception, $this->displayErrorDetails, false, false);
+            
+            if (ob_get_length()) {
+              ob_clean();
+            }
+
+            $responseEmitter = new ResponseEmitter();
+            $responseEmitter->emit($response);
+        }
+    }
+}
\ No newline at end of file