Enhance Alert component with elevation validation and preprocessing

src/Components/Alert.php

@@ -1,15 +1,31 @@
 <?php
 
+declare(strict_types=1);
+
 namespace MaterialBlade\Components;
 
 use Illuminate\View\Component;
 use Illuminate\View\ComponentAttributeBag;
+use InvalidArgumentException;
 use MaterialBlade\Components\Alert\Properties\Severity;
 use MaterialBlade\Components\Alert\Properties\Variant;
 use MaterialBlade\Helper;
 
 /**
+ * Alert Component
+ *
+ * Displays an alert message with optional icon, title, and customizable styling.
+ * Supports different severity levels, variants, and Material Design elevation.
+ *
+ * @property Severity $severity The severity level of the alert (success, info, warning, error)
+ * @property Variant $variant The visual variant (standard, filled, outlined)
+ * @property string $cssColor The computed CSS color value
+ * @property string|array|null $icon Custom icon or auto-selected based on severity
+ * @property string|null $title Optional title text
+ * @property int $elevation Material Design elevation level (0-24)
+ *
  * @see https://mui.com/material-ui/react-alert/
+ * @see https://m2.material.io/design/components/elevation.html
  */
 class Alert extends Component
 {
@@ -22,7 +38,15 @@ class Alert extends Component
     /**
      * Create a new component instance.
      *
+     * @param  string|null  $severity  The severity level: 'success', 'info', 'warning', or 'error'
+     * @param  string|null  $color  Custom color (theme color or CSS color value)
+     * @param  string|null  $variant  Display variant: 'standard', 'filled', or 'outlined'
+     * @param  string|array|null  $icon  Custom icon name or [name, variant] array
+     * @param  string|null  $title  Optional title text displayed above the message
+     * @param  int  $elevation  Material Design elevation level (0-24)
      * @return void
+     *
+     * @throws InvalidArgumentException If elevation is out of range
      */
     public function __construct(
         ?string $severity = null,
@@ -31,7 +55,16 @@ public function __construct(
 
         private string|array|null $icon = null,
         public ?string $title = null,
+        private int $elevation = 0,
     ) {
+        // Validate elevation range
+        if ($this->elevation < 0 || $this->elevation > 24) {
+            throw new InvalidArgumentException(
+                "Elevation must be between 0 and 24, got {$this->elevation}. ".
+                'See Material Design elevation specification: https://m2.material.io/design/environment/elevation.html'
+            );
+        }
+
         if ($variant) {
             $this->variant = Variant::fromString($variant);
         }
@@ -53,8 +86,21 @@ public function render()
         return 'mbv::alert';
     }
 
+    /**
+     * Preprocess component attributes to apply styling and classes.
+     *
+     * Applies appropriate styling based on variant (standard, filled, outlined),
+     * adds Material Design elevation classes, and sets typography.
+     *
+     * @param  ComponentAttributeBag  $attributes  Component attributes
+     * @return ComponentAttributeBag Processed attributes with classes and styles
+     */
     public function attributesPreprocess(ComponentAttributeBag $attributes): ComponentAttributeBag
     {
+        $attributes = $attributes->class([
+            "mdc-elevation--z{$this->elevation}" => $this->elevation > 0 && $this->elevation <= 24,
+        ]);
+
         if ($this->variant === Variant::FILLED) {
             return $attributes->style([
                 "background-color: {$this->cssColor}",
@@ -78,6 +124,14 @@ public function attributesPreprocess(ComponentAttributeBag $attributes): Compone
         ])->class('mdc-typography--body1');
     }
 
+    /**
+     * Get the icon to display in the alert.
+     *
+     * Returns custom icon if provided, otherwise returns default icon
+     * based on severity level with 'outlined' variant.
+     *
+     * @return string|array Icon name as string or [name, variant] array
+     */
     public function getIcon(): string|array
     {
         return $this->icon ?? match ($this->severity) {