Re-implement syncLinks and processLinks via WikiLinkResolver

syncLinks parses the default-locale content; processLinks resolves
each [[link]] against the current locale at render time. Link labels
preserve original spelling; destination resolves to the same document
in the current locale (with fallback).

src/app/Models/Document.php

@@ -184,10 +184,66 @@ public function scopeInDirectory(Builder $query, string $directory): Builder
     }
 
     /**
-     * Sync wiki-links for this document. Implementation in Task 7.
+     * Extract [[wiki-links]] from the default-locale translation's content
+     * and persist them via DocumentLink.
      */
     public function syncLinks(): void
     {
-        // Replaced in Task 7
+        $this->outgoingLinks()->delete();
+
+        $translation = $this->translationFor($this->default_locale, fallback: false);
+        if (!$translation || !$translation->content) {
+            return;
+        }
+
+        preg_match_all('/\[\[([^\]]+)\]\]/', $translation->content, $matches);
+        if (empty($matches[1])) {
+            return;
+        }
+
+        $resolver = new \App\Services\WikiLinkResolver();
+        $position = 0;
+        foreach ($matches[1] as $linkTitle) {
+            $linkTitle = trim($linkTitle);
+            $target = $resolver->resolve($linkTitle, $this->default_locale);
+
+            DocumentLink::create([
+                'source_document_id' => $this->id,
+                'target_document_id' => $target?->id,
+                'target_title' => $linkTitle,
+                'position' => $position++,
+            ]);
+        }
+    }
+
+    /**
+     * Convert [[wiki-links]] in the current-locale rendered_html to anchor tags.
+     * Link labels stay in the original language; the destination document is
+     * resolved against the current locale (with fallback).
+     */
+    public function processLinks(): string
+    {
+        $html = $this->rendered_html ?? '';
+        if ($html === '') {
+            return '';
+        }
+
+        $resolver = new \App\Services\WikiLinkResolver();
+        $currentLocale = App::getLocale();
+
+        return preg_replace_callback(
+            '/\[\[([^\]]+)\]\]/',
+            function ($matches) use ($resolver, $currentLocale) {
+                $linkText = trim($matches[1]);
+                $target = $resolver->resolve($linkText, $currentLocale);
+
+                if ($target) {
+                    return '<a href="' . route('documents.show', $target->slug) . '" class="wiki-link">' . e($linkText) . '</a>';
+                }
+
+                return '<a href="' . route('documents.create') . '?title=' . urlencode($linkText) . '" class="wiki-link wiki-link-new">' . e($linkText) . '</a>';
+            },
+            $html
+        );
     }
 }

src/tests/Unit/Models/DocumentTest.php

@@ -76,4 +76,70 @@ public function test_available_locales_lists_existing_translations(): void
         sort($locales);
         $this->assertSame(['en', 'fr', 'ja'], $locales);
     }
+
+    public function test_sync_links_creates_outgoing_links_with_resolved_targets(): void
+    {
+        $target = Document::factory()->create(['default_locale' => 'en']);
+        $target->translations()->where('locale', 'en')->update(['title' => 'Target']);
+
+        $source = Document::factory()->create(['default_locale' => 'en']);
+        $source->translations()->where('locale', 'en')->update([
+            'content' => 'See [[Target]] for details.',
+        ]);
+
+        $source->fresh('translations')->syncLinks();
+
+        $links = $source->fresh()->outgoingLinks;
+        $this->assertCount(1, $links);
+        $this->assertSame($target->id, $links->first()->target_document_id);
+        $this->assertSame('Target', $links->first()->target_title);
+    }
+
+    public function test_sync_links_records_unresolved_links_with_null_target(): void
+    {
+        $source = Document::factory()->create();
+        $source->translations()->first()->update([
+            'content' => 'Goes to [[NoSuchPage]].',
+        ]);
+
+        $source->fresh('translations')->syncLinks();
+
+        $links = $source->fresh()->outgoingLinks;
+        $this->assertCount(1, $links);
+        $this->assertNull($links->first()->target_document_id);
+    }
+
+    public function test_process_links_replaces_wiki_link_with_anchor_keeping_label(): void
+    {
+        $target = Document::factory()->create(['default_locale' => 'en', 'slug' => 'target-doc']);
+        $target->translations()->where('locale', 'en')->update(['title' => 'Target']);
+        \Illuminate\Support\Facades\App::setLocale('ja');
+        \App\Models\DocumentTranslation::factory()->create([
+            'document_id' => $target->id,
+            'locale' => 'ja',
+            'title' => 'ターゲット',
+        ]);
+
+        $source = Document::factory()->create();
+        $source->translations()->first()->update([
+            'rendered_html' => '<p>See [[Target]].</p>',
+        ]);
+
+        $html = $source->fresh()->processLinks();
+
+        $this->assertStringContainsString('href="' . route('documents.show', 'target-doc') . '"', $html);
+        $this->assertStringContainsString('>Target<', $html); // label preserved
+        $this->assertStringContainsString('class="wiki-link"', $html);
+    }
+
+    public function test_process_links_marks_unresolved_links_as_new(): void
+    {
+        $source = Document::factory()->create();
+        $source->translations()->first()->update([
+            'rendered_html' => '<p>Click [[Ghost]].</p>',
+        ]);
+
+        $html = $source->fresh()->processLinks();
+        $this->assertStringContainsString('wiki-link-new', $html);
+    }
 }