コンテンツ情報取得の実装をapi.phpから剥がした

app/MetadataResolver/Metadata.php

@@ -0,0 +1,10 @@
+<?php
+
+namespace App\MetadataResolver;
+
+class Metadata
+{
+    public $title = '';
+    public $description = '';
+    public $image = '';
+}

app/MetadataResolver/MetadataResolver.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace App\MetadataResolver;
+
+class MetadataResolver implements Resolver
+{
+    public $rules = [
+        '~(((sp\.)?seiga\.nicovideo\.jp/seiga(/#!)?|nico\.ms))/im~' => NicoSeigaResolver::class,
+        '~nijie\.info/view\.php~' => NijieResolver::class,
+        '/.*/' => OGPResolver::class
+    ];
+
+    public function resolve(string $url): Metadata
+    {
+        foreach ($this->rules as $pattern => $class) {
+            if (preg_match($pattern, $url) === 1) {
+                $resolver = new $class;
+                return $resolver->resolve($url);
+            }
+        }
+
+        throw new \UnexpectedValueException('URL not matched.');
+    }
+}

app/MetadataResolver/NicoSeigaResolver.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace App\MetadataResolver;
+
+class NicoSeigaResolver implements Resolver
+{
+    public function resolve(string $url): Metadata
+    {
+        $client = new \GuzzleHttp\Client();
+        $res = $client->get($url);
+        if ($res->getStatusCode() === 200) {
+            $ogpResolver = new OGPResolver();
+            $metadata = $ogpResolver->parse($res->getBody());
+
+            // ページURLからサムネイルURLに変換
+            preg_match('~http://(?:(?:sp\\.)?seiga\\.nicovideo\\.jp/seiga(?:/#!)?|nico\\.ms)/im(\\d+)~', $url, $matches);
+            $metadata->image = "http://lohas.nicoseiga.jp/thumb/${matches[1]}l?";
+
+            return $metadata;
+        } else {
+            throw new \RuntimeException("{$res->getStatusCode()}: $url");
+        }
+    }
+}

app/MetadataResolver/NijieResolver.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace App\MetadataResolver;
+
+class NijieResolver implements Resolver
+{
+    public function resolve(string $url): Metadata
+    {
+        $client = new \GuzzleHttp\Client();
+        $res = $client->get($url);
+        if ($res->getStatusCode() === 200) {
+            $ogpResolver = new OGPResolver();
+            $metadata = $ogpResolver->parse($res->getBody());
+
+            $dom = new \DOMDocument();
+            @$dom->loadHTML(mb_convert_encoding($res->getBody(), 'HTML-ENTITIES', 'UTF-8'));
+            $xpath = new \DOMXPath($dom);
+            $dataNode = $xpath->query('//script[substring(@type, string-length(@type) - 3, 4) = "json"]');
+            foreach ($dataNode as $node) {
+                // 改行がそのまま入っていることがあるのでデコード前にエスケープが必要
+                $imageData = json_decode(preg_replace('/\r?\n/', '\n', $node->nodeValue), true);
+                if (isset($imageData['thumbnailUrl'])) {
+                    $metadata->image = preg_replace('~nijie\\.info/.*/nijie_picture/~', 'nijie.info/nijie_picture/', $imageData['thumbnailUrl']);
+                    break;
+                }
+            }
+
+            return $metadata;
+        } else {
+            throw new \RuntimeException("{$res->getStatusCode()}: $url");
+        }
+    }
+}

app/MetadataResolver/OGPResolver.php

@@ -0,0 +1,52 @@
+<?php
+
+namespace App\MetadataResolver;
+
+class OGPResolver implements Resolver
+{
+    public function resolve(string $url): Metadata
+    {
+        $client = new \GuzzleHttp\Client();
+        $res = $client->get($url);
+        if ($res->getStatusCode() === 200) {
+            return $this->parse($res->getBody());
+        } else {
+            throw new \RuntimeException("{$res->getStatusCode()}: $url");
+        }
+    }
+
+    public function parse(string $html): Metadata
+    {
+        $dom = new \DOMDocument();
+        @$dom->loadHTML(mb_convert_encoding($html, 'HTML-ENTITIES', 'UTF-8'));
+        $xpath = new \DOMXPath($dom);
+
+        $metadata = new Metadata();
+
+        $titleNode = $xpath->query('//meta[@*="og:title"]');
+        foreach ($titleNode as $node) {
+            if (!empty($node->getAttribute('content'))) {
+                $metadata->title = $node->getAttribute('content');
+                break;
+            }
+        }
+
+        $descriptionNode = $xpath->query('//meta[@*="og:description"]');
+        foreach ($descriptionNode as $node) {
+            if (!empty($node->getAttribute('content'))) {
+                $metadata->description = $node->getAttribute('content');
+                break;
+            }
+        }
+
+        $imageNode = $xpath->query('//meta[@*="og:image"]');
+        foreach ($imageNode as $node) {
+            if (!empty($node->getAttribute('content'))) {
+                $metadata->image = $node->getAttribute('content');
+                break;
+            }
+        }
+
+        return $metadata;
+    }
+}

app/MetadataResolver/Resolver.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace App\MetadataResolver;
+
+interface Resolver
+{
+    public function resolve(string $url): Metadata;
+}

app/Providers/AppServiceProvider.php

@@ -2,6 +2,7 @@
 
 namespace App\Providers;
 
+use App\MetadataResolver\MetadataResolver;
 use Illuminate\Support\ServiceProvider;
 
 class AppServiceProvider extends ServiceProvider
@@ -23,6 +24,8 @@ class AppServiceProvider extends ServiceProvider
      */
     public function register()
     {
-        //
+        $this->app->singleton(MetadataResolver::class, function ($app) {
+            return new MetadataResolver();
+        });
     }
 }