use 'command' design pattern

Author: Alexsey-VR

.gitignore

@@ -1 +1,2 @@
 /vendor/
+/sandbox/

composer.json

@@ -15,7 +15,10 @@
         },
         "files": [
             "vendor/docopt/docopt/src/docopt.php",
-            "src/Gendiff.php"
+            "src/Gendiff.php",
+            "src/CommandInterface.php",
+            "src/Command.php",
+            "src/OutputInterface.php"
         ]
     },
     "authors": [

src/Command.php

@@ -0,0 +1,57 @@
+<?php
+
+namespace App;
+
+use App\CommandInterface;
+use App\OutputInterface;
+
+class Command implements CommandInterface
+{
+    protected $output;
+    protected $docopt;
+    protected $cliData;
+    private const MAX_FILE_SIZE = 4096;
+
+    public function __construct(OutputInterface $output, string $doc)
+    {
+        $this->output = $output;
+        $this->docopt = $doc;
+        $this->cliData = $this->output->parseCommandData($this->docopt);
+    }
+
+    private function parseFile(string $filename): array
+    {
+        $handle = fopen($filename, "r");
+        $result = json_decode(fread($handle, self::MAX_FILE_SIZE));
+        fclose($handle);
+        $type = gettype($result);
+        if ($type === 'object') {
+            $keys = (get_object_vars($result));
+        } elseif ($type === 'array') {
+            $keys = array_keys($result);
+        } else {
+            $keys = null;
+        }
+
+        return $keys;
+    }
+
+    public function execute()
+    {
+        if (isset($this->cliData['FILE1']) & isset($this->cliData['FILE2'])) {
+            if (file_exists($this->cliData['FILE1']) & file_exists($this->cliData['FILE2'])) {
+                $file1Content = $this->parseFile($this->cliData['FILE1']);
+                $file2Content = $this->parseFile($this->cliData['FILE2']);
+
+                print_r("File1 content:\n");
+                print_r($file1Content);
+                print_r("File2 content:\n");
+                print_r($file2Content);
+            } else {
+                print_r("File {$this->cliData['FILE2']} not exists\n");
+            }
+        } else {
+            print_r("File {$this->cliData['FILE1']} not exists\n");
+        }
+    }
+}

src/CommandInterface.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace App;
+
+interface CommandInterface
+{
+    public function execute();
+}

src/Gendiff.php

@@ -3,20 +3,14 @@
 namespace App;
 
 use Docopt;
-
-function parseFile(string $filename): array
-{
-    $handle = fopen($filename, "r");
-    $result = json_decode(fread($handle, 4096));
-    fclose($handle);
-
-    $keys = (get_object_vars($result));
-
-    return $keys;
-}
+use App\OutputInterface;
+use App\CommandInterface;
+use App\Invoker;
+use App\Command;
 
 function runGendiff(): void
 {
+
     $doc = <<<'DOCOPT'
     gendiff -h
 
@@ -34,26 +28,16 @@ function runGendiff(): void
 
     DOCOPT;
 
-    $cliData = Docopt::handle($doc, array('version' => '1.0.6'));
-/*
-    foreach ($cliData as $k => $v) {
-        print_r($k . ': ' . json_encode($v) . PHP_EOL);
-    }
-*/
-    if (file_exists($cliData['FILE1'])) {
-        if (file_exists($cliData['FILE2'])) {
-            $file1Content = parseFile($cliData['FILE1']);
-            $file2Content = parseFile($cliData['FILE2']);
-
-            print_r("File1 content:\n");
-            print_r($file1Content);
-            print_r("File2 content:\n");
-            print_r($file2Content);
-        } else {
-            print_r("File {$cliData['FILE2']} not exists");
+    $output = new class implements OutputInterface
+    {
+        public function parseCommandData(string $docopt): object
+        {
+            return Docopt::handle($docopt, array('version' => '1.0.6'));
         }
-    } else {
-        print_r("File {$cliData['FILE1']} not exists\n");
-        runGendiff();
-    }
+    };
+
+    $command = new Command($output, $doc);
+    $invoker = new Invoker();
+    $invoker->setCommand($command);
+    $invoker->run();
 }

src/Invoker.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace App;
+
+use App\CommandInterface;
+
+class Invoker
+{
+    private $command;
+
+    public function setCommand(CommandInterface $command)
+    {
+        $this->command = $command;
+    }
+
+    public function run()
+    {
+        $this->command->execute();
+    }
+}

src/OutputInterface.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace App;
+
+interface OutputInterface
+{
+    public function parseCommandData(string $docopt): object;
+}