added youtube tag (#16)

* added youtube tag

composer.json

@@ -4,7 +4,8 @@
 	"description": "php parser for bb code",
     "license": "MIT",
 	"require": {
-        "php": ">=7.0"
+        "php": ">=7.0",
+        "tekstove/url-video-parser": "^1.0.1"
 	},
     "require-dev": {
         "phpUnit/phpUnit": "5.6.*"

src/Potaka/BbCode/Factory.php

@@ -9,6 +9,8 @@ use Potaka\BbCode\Tag\Italic;
 use Potaka\BbCode\Tag\Link;
 use Potaka\BbCode\Tag\ImgTag;
 
+use Potaka\BbCode\Tag\YoutubeTag;
+
 /**
  * Create different BbCode configurations
  *
@@ -43,6 +45,9 @@ class Factory
         $unknownTag = new Tag\UnknownSimpleType();
         $bbcode->addTag($unknownTag);
 
+        $youtubeTag = new YoutubeTag();
+        $bbcode->addTag($youtubeTag);
+
         $tags = [
             $bold,
             $underline,
@@ -50,6 +55,7 @@ class Factory
             $link,
             $unknownTag,
             $img,
+            $youtubeTag,
         ];
 
         // link allowed

src/Potaka/BbCode/Tag/YoutubeTag.php

@@ -0,0 +1,40 @@
+<?php
+
+namespace Potaka\BbCode\Tag;
+
+use Potaka\BbCode\Tokenizer\Tag as TokenTag;
+use Tekstove\UrlVideoParser\Youtube\YoutubeParser;
+use Tekstove\UrlVideoParser\Youtube\YoutubeException;
+
+/**
+ * Tag for youtube videos
+ *
+ * @author po_taka <angel.koilov@gmail.com>
+ */
+class YoutubeTag implements TagInterface
+{
+    public function format(TokenTag $tokenTag): string
+    {
+        $link = $tokenTag->getText();
+
+        try {
+            $parser = new YoutubeParser();
+            $videoId = $parser->getId($link);
+        } catch (YoutubeException $e) {
+            $unknownTag = new UnknownSimpleType();
+            return $unknownTag->format($tokenTag);
+        }
+
+        return '<iframe src="https://www.youtube.com/embed/' . $videoId . '" frameborder="0" allowfullscreen></iframe>';
+    }
+
+    public function getName(): string
+    {
+        return 'youtube';
+    }
+
+    public function getOriginalText(TokenTag $tokenTag): string
+    {
+        return "[{$this->getName()}]{$tokenTag->getText()}[/{$this->getName()}";
+    }
+}

tests/phpUnit/Test/Potaka/BbCode/Tag/YoutubeTest.php

@@ -0,0 +1,58 @@
+<?php
+
+use PHPUnit\Framework\TestCase;
+
+use Potaka\BbCode\Tokenizer\Tag as TokenTag;
+use Potaka\BbCode\Tag\YoutubeTag;
+
+/**
+ * Description of YoutubeTest
+ *
+ * @author po_taka <angel.koilov@gmail.com>
+ */
+class YoutubeTest extends TestCase
+{
+    public function testFormat()
+    {
+        $cases = [
+            [
+                'link' =>  'https://www.youtube.com/watch?v=zur_B7kw9uM',
+                'id' => 'zur_B7kw9uM',
+            ],
+            [
+                'link' => 'https://www.youtube.com/watch?v=zur_B7kw9uM&feature=youtu.be&t=8259',
+                'id' => 'zur_B7kw9uM',
+            ],
+        ];
+
+        foreach ($cases as $testData) {
+            $tokenTag = new TokenTag('youtube');
+            $tokenTag->setText($testData['link']);
+            $youtubeTag = new YoutubeTag();
+            $html = $youtubeTag->format($tokenTag);
+            $this->assertSame('<iframe src="https://www.youtube.com/embed/' . $testData['id'] . '" frameborder="0" allowfullscreen></iframe>', $html);
+        }
+    }
+
+    public function testInvalidFormat()
+    {
+        $cases = [
+            'ftp://lorempixel.com/output/abstract-q-c-640-480-2.jpg', // ftp
+            'https://www.youtube.com/watch?v=zur_^B7kw9uM', // ^
+        ];
+
+        foreach ($cases as $testData) {
+            $tokenTag = new TokenTag('youtube');
+            $tokenTag->setText($testData);
+            $youtubeTag = new YoutubeTag();
+            $html = $youtubeTag->format($tokenTag);
+            $this->assertSame('[youtube]' . $testData . '[/youtube]', $html);
+        }
+    }
+
+    public function testGetName()
+    {
+        $youtube = new YoutubeTag();
+        $this->assertSame('youtube', $youtube->getName());
+    }
+}