From f165bd059e82ffc2c748a6b54b97b30b1c4053ee Mon Sep 17 00:00:00 2001
From: Ahmed Darrazi <ahmeddarrazi@adsmac.local>
Date: Thu, 1 Jan 2026 21:33:19 +0100
Subject: [PATCH] feat: highlight changed lines in script diffs

---
 .../entries/normalized-diff.blade.php         | 127 +++++++++++++++---
 .../ScriptPoliciesNormalizedDisplayTest.php   |   5 +-
 2 files changed, 115 insertions(+), 17 deletions(-)

diff --git a/resources/views/filament/infolists/entries/normalized-diff.blade.php b/resources/views/filament/infolists/entries/normalized-diff.blade.php
index 4d9a154..844df9d 100644
--- a/resources/views/filament/infolists/entries/normalized-diff.blade.php
+++ b/resources/views/filament/infolists/entries/normalized-diff.blade.php
@@ -104,6 +104,94 @@
             return null;
         }
     };
+
+    $splitLines = static function (string $text): array {
+        $text = str_replace(["\r\n", "\r"], "\n", $text);
+
+        return $text === '' ? [] : explode("\n", $text);
+    };
+
+    $myersLineDiff = static function (array $a, array $b): array {
+        $n = count($a);
+        $m = count($b);
+        $max = $n + $m;
+
+        $v = [1 => 0];
+        $trace = [];
+
+        for ($d = 0; $d <= $max; $d++) {
+            $trace[$d] = $v;
+
+            for ($k = -$d; $k <= $d; $k += 2) {
+                $kPlus = $v[$k + 1] ?? 0;
+                $kMinus = $v[$k - 1] ?? 0;
+
+                if ($k === -$d || ($k !== $d && $kMinus < $kPlus)) {
+                    $x = $kPlus;
+                } else {
+                    $x = $kMinus + 1;
+                }
+
+                $y = $x - $k;
+
+                while ($x < $n && $y < $m && $a[$x] === $b[$y]) {
+                    $x++;
+                    $y++;
+                }
+
+                $v[$k] = $x;
+
+                if ($x >= $n && $y >= $m) {
+                    break 2;
+                }
+            }
+        }
+
+        $ops = [];
+        $x = $n;
+        $y = $m;
+
+        for ($d = count($trace) - 1; $d >= 0; $d--) {
+            $v = $trace[$d];
+            $k = $x - $y;
+
+            $kPlus = $v[$k + 1] ?? 0;
+            $kMinus = $v[$k - 1] ?? 0;
+
+            if ($k === -$d || ($k !== $d && $kMinus < $kPlus)) {
+                $prevK = $k + 1;
+            } else {
+                $prevK = $k - 1;
+            }
+
+            $prevX = $v[$prevK] ?? 0;
+            $prevY = $prevX - $prevK;
+
+            while ($x > $prevX && $y > $prevY) {
+                $ops[] = ['type' => 'equal', 'line' => $a[$x - 1]];
+                $x--;
+                $y--;
+            }
+
+            if ($d === 0) {
+                break;
+            }
+
+            if ($x === $prevX) {
+                $ops[] = ['type' => 'insert', 'line' => $b[$y - 1] ?? ''];
+                $y--;
+            } else {
+                $ops[] = ['type' => 'delete', 'line' => $a[$x - 1] ?? ''];
+                $x--;
+            }
+        }
+
+        return array_reverse($ops);
+    };
+
+    $scriptLineDiff = static function (string $fromText, string $toText) use ($splitLines, $myersLineDiff): array {
+        return $myersLineDiff($splitLines($fromText), $splitLines($toText));
+    };
 @endphp
 
 <div class="space-y-4">
@@ -159,8 +247,7 @@
                                                 $toText = $stringify($to);
 
                                                 $isScriptContent = $canHighlightScripts($policyType) && $isScriptKey($name);
-                                                $fromHighlight = $isScriptContent ? $highlight($policyType, (string) $fromText) : null;
-                                                $toHighlight = $isScriptContent ? $highlight($policyType, (string) $toText) : null;
+                                                $ops = $isScriptContent ? $scriptLineDiff((string) $fromText, (string) $toText) : [];
                                             @endphp
                                             <div class="grid grid-cols-1 gap-2 sm:grid-cols-3">
                                                 <div class="text-sm font-medium text-gray-900 dark:text-white">
@@ -168,17 +255,21 @@
                                                 </div>
                                                 <div class="text-sm text-gray-600 dark:text-gray-300">
                                                     <span class="text-xs font-semibold uppercase tracking-wide text-gray-500 dark:text-gray-400">From</span>
-                                                    @if ($isExpandable($from))
+                                                    @if ($isScriptContent || $isExpandable($from))
                                                         <details class="mt-1">
                                                             <summary class="cursor-pointer text-sm text-gray-700 dark:text-gray-200">
                                                                 View
                                                             </summary>
-                                                            @if (is_string($fromHighlight) && $fromHighlight !== '')
-                                                                @once
-                                                                    @include('filament.partials.torchlight-dark-overrides')
-                                                                @endonce
-
-                                                                <div class="mt-2 overflow-x-auto">{!! $fromHighlight !!}</div>
+                                                            @if ($isScriptContent)
+                                                                <pre class="mt-2 overflow-x-auto text-xs text-gray-800 dark:text-gray-200 whitespace-pre">
+@foreach ($ops as $op)
+@if ($op['type'] === 'equal')
+{{ $op['line'] }}
+@elseif ($op['type'] === 'delete')
+<span class="block bg-danger-50 text-danger-700 dark:bg-danger-950/40 dark:text-danger-200">- {{ $op['line'] }}</span>
+@endif
+@endforeach
+                                                                </pre>
                                                             @else
                                                                 <pre class="mt-2 overflow-x-auto text-xs text-gray-800 dark:text-gray-200">{{ $fromText }}</pre>
                                                             @endif
@@ -189,17 +280,21 @@
                                                 </div>
                                                 <div class="text-sm text-gray-600 dark:text-gray-300">
                                                     <span class="text-xs font-semibold uppercase tracking-wide text-gray-500 dark:text-gray-400">To</span>
-                                                    @if ($isExpandable($to))
+                                                    @if ($isScriptContent || $isExpandable($to))
                                                         <details class="mt-1">
                                                             <summary class="cursor-pointer text-sm text-gray-700 dark:text-gray-200">
                                                                 View
                                                             </summary>
-                                                            @if (is_string($toHighlight) && $toHighlight !== '')
-                                                                @once
-                                                                    @include('filament.partials.torchlight-dark-overrides')
-                                                                @endonce
-
-                                                                <div class="mt-2 overflow-x-auto">{!! $toHighlight !!}</div>
+                                                            @if ($isScriptContent)
+                                                                <pre class="mt-2 overflow-x-auto text-xs text-gray-800 dark:text-gray-200 whitespace-pre">
+@foreach ($ops as $op)
+@if ($op['type'] === 'equal')
+{{ $op['line'] }}
+@elseif ($op['type'] === 'insert')
+<span class="block bg-success-50 text-success-700 dark:bg-success-950/40 dark:text-success-200">+ {{ $op['line'] }}</span>
+@endif
+@endforeach
+                                                                </pre>
                                                             @else
                                                                 <pre class="mt-2 overflow-x-auto text-xs text-gray-800 dark:text-gray-200">{{ $toText }}</pre>
                                                             @endif
diff --git a/tests/Feature/Filament/ScriptPoliciesNormalizedDisplayTest.php b/tests/Feature/Filament/ScriptPoliciesNormalizedDisplayTest.php
index 092ec9e..f2f9f78 100644
--- a/tests/Feature/Filament/ScriptPoliciesNormalizedDisplayTest.php
+++ b/tests/Feature/Filament/ScriptPoliciesNormalizedDisplayTest.php
@@ -116,7 +116,10 @@
 
     $this->get($url.'?tab=diff')
         ->assertSuccessful()
-        ->assertSee('torchlight', false);
+        ->assertSeeText("- Write-Host 'one'")
+        ->assertSeeText("+ Write-Host 'two'")
+        ->assertSee('bg-danger-50', false)
+        ->assertSee('bg-success-50', false);
 
     $originalEnv !== false
         ? putenv("INTUNE_TENANT_ID={$originalEnv}")