feat: implement dynamic rule discovery and incremental level filtering

src/Rules/AbstractRule.php

@@ -14,6 +14,11 @@ abstract class AbstractRule implements RuleInterface
     abstract public function getStandard(): WCAGStandard;
     abstract public function getSeverity(): Severity;
 
+    public function getLevel(): int
+    {
+        return 4;
+    }
+
     protected function createViolation(DOMElement $element, string $message, ?string $suggestion = null): Violation
     {
         $doc = $element->ownerDocument;

src/Rules/AriaFocusable.php

@@ -0,0 +1,55 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class AriaFocusable extends AbstractRule
+{
+    /** @var array<int, string> */
+    private static array $interactiveRoles = [
+        'button', 'link', 'checkbox', 'menuitem', 'radio', 'textbox',
+        'searchbox', 'slider', 'spinbutton', 'switch', 'tab'
+    ];
+
+    /** @var array<int, string> */
+    private static array $nativeFocusable = [
+        'a', 'button', 'input', 'select', 'textarea', 'iframe'
+    ];
+
+    public function getId(): string { return 'WCAG_2_1_1_ARIA_FOCUSABLE'; }
+    public function getDescription(): string { return 'Elements with interactive ARIA roles must be focusable (e.g. have a tabindex attribute).'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::A; }
+    public function getSeverity(): Severity { return Severity::WARNING; }
+    public function getLevel(): int { return 3; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        if (!$element->hasAttribute('role')) {
+            return null;
+        }
+
+        $role = strtolower(trim($element->getAttribute('role')));
+        if (!in_array($role, self::$interactiveRoles, true)) {
+            return null;
+        }
+
+        $tagName = strtolower($element->tagName);
+        if (in_array($tagName, self::$nativeFocusable, true)) {
+            return null;
+        }
+
+        if (!$element->hasAttribute('tabindex')) {
+            return $this->createViolation(
+                $element,
+                $this->getDescription(),
+                'Add tabindex="0" to make the element focusable via keyboard navigation.'
+            );
+        }
+
+        return null;
+    }
+}

src/Rules/AriaHiddenFocusable.php

@@ -13,6 +13,7 @@ class AriaHiddenFocusable extends AbstractRule
     public function getDescription(): string { return 'Focusable elements must not be hidden with aria-hidden="true".'; }
     public function getStandard(): WCAGStandard { return WCAGStandard::A; }
     public function getSeverity(): Severity { return Severity::ERROR; }
+    public function getLevel(): int { return 5; }
 
     public function check(DOMElement $element): ?Violation
     {

src/Rules/AriaRole.php

@@ -78,4 +78,5 @@ class AriaRole extends AbstractRule
 
     public function getStandard(): WCAGStandard { return WCAGStandard::A; }
     public function getSeverity(): Severity { return Severity::ERROR; }
+    public function getLevel(): int { return 3; }
 }

src/Rules/ButtonName.php

@@ -13,6 +13,7 @@ class ButtonName extends AbstractRule
     public function getDescription(): string { return 'Buttons must have discernible text.'; }
     public function getStandard(): WCAGStandard { return WCAGStandard::A; }
     public function getSeverity(): Severity { return Severity::ERROR; }
+    public function getLevel(): int { return 1; }
 
     public function check(DOMElement $element): ?Violation
     {

src/Rules/ColorContrast.php

@@ -13,6 +13,7 @@ class ColorContrast extends AbstractRule
     public function getDescription(): string { return 'Text must have sufficient contrast against the background (4.5:1 minimum).'; }
     public function getStandard(): WCAGStandard { return WCAGStandard::AA; }
     public function getSeverity(): Severity { return Severity::WARNING; }
+    public function getLevel(): int { return 5; }
 
     public function check(DOMElement $element): ?Violation
     {

src/Rules/DuplicateId.php

@@ -48,4 +48,5 @@ class DuplicateId extends AbstractRule
 
     public function getStandard(): WCAGStandard { return WCAGStandard::A; }
     public function getSeverity(): Severity { return Severity::ERROR; }
+    public function getLevel(): int { return 3; }
 }

src/Rules/EmptyHeading.php

@@ -0,0 +1,35 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class EmptyHeading extends AbstractRule
+{
+    public function getId(): string { return 'WCAG_1_3_1_EMPTY_HEADING'; }
+    public function getDescription(): string { return 'Heading elements (h1-h6) must have discernible text content.'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::A; }
+    public function getSeverity(): Severity { return Severity::ERROR; }
+    public function getLevel(): int { return 2; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        if (!preg_match('/^h([1-6])$/i', $element->tagName)) {
+            return null;
+        }
+
+        $text = trim($element->textContent);
+        if ($text === '' && !$element->hasAttribute('aria-label') && !$element->hasAttribute('title')) {
+            return $this->createViolation(
+                $element,
+                $this->getDescription(),
+                'Add descriptive text or an aria-label to the heading element.'
+            );
+        }
+
+        return null;
+    }
+}

src/Rules/EmptyLabel.php

@@ -0,0 +1,35 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class EmptyLabel extends AbstractRule
+{
+    public function getId(): string { return 'WCAG_1_3_1_EMPTY_LABEL'; }
+    public function getDescription(): string { return 'Label elements must have discernible text content.'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::A; }
+    public function getSeverity(): Severity { return Severity::ERROR; }
+    public function getLevel(): int { return 2; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        if (strtolower($element->tagName) !== 'label') {
+            return null;
+        }
+
+        $text = trim($element->textContent);
+        if ($text === '') {
+            return $this->createViolation(
+                $element,
+                $this->getDescription(),
+                'Add text content to the label element to describe its associated input.'
+            );
+        }
+
+        return null;
+    }
+}

src/Rules/EmptyLink.php

@@ -13,6 +13,7 @@ class EmptyLink extends AbstractRule
     public function getDescription(): string { return 'Links must have discernible text.'; }
     public function getStandard(): WCAGStandard { return WCAGStandard::A; }
     public function getSeverity(): Severity { return Severity::ERROR; }
+    public function getLevel(): int { return 1; }
 
     public function check(DOMElement $element): ?Violation
     {

src/Rules/FieldsetLegend.php

@@ -13,6 +13,7 @@ class FieldsetLegend extends AbstractRule
     public function getDescription(): string { return 'Fieldsets should have a legend.'; }
     public function getStandard(): WCAGStandard { return WCAGStandard::A; }
     public function getSeverity(): Severity { return Severity::WARNING; }
+    public function getLevel(): int { return 2; }
 
     public function check(DOMElement $element): ?Violation
     {

src/Rules/FormLabel.php

@@ -13,6 +13,7 @@ class FormLabel extends AbstractRule
     public function getDescription(): string { return 'Form inputs must have an associated label.'; }
     public function getStandard(): WCAGStandard { return WCAGStandard::A; }
     public function getSeverity(): Severity { return Severity::ERROR; }
+    public function getLevel(): int { return 2; }
 
     public function check(DOMElement $element): ?Violation
     {

src/Rules/HeadingOrder.php

@@ -15,6 +15,7 @@ class HeadingOrder extends AbstractRule
     public function getDescription(): string { return 'Headings should follow a logical nesting order.'; }
     public function getStandard(): WCAGStandard { return WCAGStandard::A; }
     public function getSeverity(): Severity { return Severity::WARNING; }
+    public function getLevel(): int { return 2; }
 
     public function check(DOMElement $element): ?Violation
     {

src/Rules/HtmlHasLang.php

@@ -13,6 +13,7 @@ class HtmlHasLang extends AbstractRule
     public function getDescription(): string { return 'The html element must have a lang attribute.'; }
     public function getStandard(): WCAGStandard { return WCAGStandard::A; }
     public function getSeverity(): Severity { return Severity::ERROR; }
+    public function getLevel(): int { return 1; }
 
     public function check(DOMElement $element): ?Violation
     {

src/Rules/IframeTitle.php

@@ -13,6 +13,7 @@ class IframeTitle extends AbstractRule
     public function getDescription(): string { return 'Iframe elements must have a non-empty title attribute to describe their content.'; }
     public function getStandard(): WCAGStandard { return WCAGStandard::A; }
     public function getSeverity(): Severity { return Severity::ERROR; }
+    public function getLevel(): int { return 2; }
 
     public function check(DOMElement $element): ?Violation
     {

src/Rules/ImgAltText.php

@@ -13,6 +13,7 @@ class ImgAltText extends AbstractRule
     public function getDescription(): string { return 'Images must have an alt attribute.'; }
     public function getStandard(): WCAGStandard { return WCAGStandard::A; }
     public function getSeverity(): Severity { return Severity::ERROR; }
+    public function getLevel(): int { return 1; }
 
     public function check(DOMElement $element): ?Violation
     {

src/Rules/PageTitle.php

@@ -13,6 +13,7 @@ class PageTitle extends AbstractRule
     public function getDescription(): string { return 'Web pages must have a non-empty title element in the head.'; }
     public function getStandard(): WCAGStandard { return WCAGStandard::A; }
     public function getSeverity(): Severity { return Severity::ERROR; }
+    public function getLevel(): int { return 1; }
 
     public function check(DOMElement $element): ?Violation
     {

src/Rules/RuleLevels.php

@@ -0,0 +1,70 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+class RuleLevels
+{
+    /**
+     * Get rule instances for the specified level.
+     * Levels are incremental: Level 5 includes all rules from Levels 1, 2, 3, and 4.
+     *
+     * @param int $level
+     * @return array<int, \YakNet\AccessibilityConsole\Rules\RuleInterface|\YakNet\AccessibilityConsole\Core\AbstractRule>
+     */
+    public static function getRulesForLevel(int $level): array
+    {
+        $rules = [];
+        $files = glob(__DIR__ . '/*.php');
+        if ($files === false) {
+            return [];
+        }
+
+        foreach ($files as $file) {
+            $className = pathinfo($file, PATHINFO_FILENAME);
+            $fqcn = 'YakNet\AccessibilityConsole\Rules\\' . $className;
+
+            if (class_exists($fqcn)) {
+                $reflection = new \ReflectionClass($fqcn);
+
+                if ($reflection->isAbstract() || $reflection->isInterface() || $reflection->isTrait()) {
+                    continue;
+                }
+
+                // Check if it is a concrete rule
+                $isRule = $reflection->isSubclassOf(\YakNet\AccessibilityConsole\Core\AbstractRule::class) || 
+                          $reflection->implementsInterface(\YakNet\AccessibilityConsole\Rules\RuleInterface::class);
+
+                if ($isRule) {
+                    // Exclude Turkish custom rules to match standard behavior
+                    if (in_array($className, ['EmptyLinkRule', 'HeadingOrderRule', 'ImageAltRule'], true)) {
+                        continue;
+                    }
+
+                    $instance = $reflection->newInstance();
+
+                    // Check level
+                    $ruleLevel = 4; // default
+                    if (method_exists($instance, 'getLevel')) {
+                        /** @var mixed $levelVal */
+                        $levelVal = $instance->getLevel();
+                        if (is_int($levelVal)) {
+                            $ruleLevel = $levelVal;
+                        }
+                    }
+
+                    if ($ruleLevel <= $level) {
+                        /** @var \YakNet\AccessibilityConsole\Rules\RuleInterface|\YakNet\AccessibilityConsole\Core\AbstractRule $instance */
+                        $rules[] = $instance;
+                    }
+                }
+            }
+        }
+
+        // Sort rules by class name to ensure deterministic order
+        usort($rules, function ($a, $b) {
+            return strcmp(get_class($a), get_class($b));
+        });
+
+        return $rules;
+    }
+}

src/Rules/StandardRuleSet.php

@@ -5,31 +5,10 @@ namespace YakNet\AccessibilityConsole\Rules;
 class StandardRuleSet
 {
     /**
-     * @return RuleInterface[]
+     * @return array<int, \YakNet\AccessibilityConsole\Rules\RuleInterface|\YakNet\AccessibilityConsole\Core\AbstractRule>
      */
     public static function all(): array
     {
-        /** @var RuleInterface[] $rules */
-        $rules = [
-            new HtmlHasLang(),
-            new ImgAltText(),
-            new EmptyLink(),
-            new ButtonName(),
-            new FormLabel(),
-            new FieldsetLegend(),
-            new HeadingOrder(),
-            new MetaViewport(),
-            new TabindexOrder(),
-            new ColorContrast(),
-            new DuplicateId(),
-            new AriaRole(),
-            new IframeTitle(),
-            new LinkTextGeneric(),
-            new PlaceholderAsLabel(),
-            new ImageAltRedundant(),
-            new AriaHiddenFocusable(),
-            new PageTitle(),
-        ];
-        return $rules;
+        return RuleLevels::getRulesForLevel(5);
     }
 }

src/Rules/TabindexOrder.php

@@ -13,6 +13,7 @@ class TabindexOrder extends AbstractRule
     public function getDescription(): string { return 'Avoid positive tabindex values to maintain natural keyboard focus order.'; }
     public function getStandard(): WCAGStandard { return WCAGStandard::A; }
     public function getSeverity(): Severity { return Severity::WARNING; }
+    public function getLevel(): int { return 3; }
 
     public function check(DOMElement $element): ?Violation
     {

src/Rules/VideoTrack.php

@@ -0,0 +1,36 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class VideoTrack extends AbstractRule
+{
+    public function getId(): string { return 'WCAG_1_2_2_VIDEO_TRACK'; }
+    public function getDescription(): string { return 'Video elements must contain at least one track element for captions or subtitles.'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::A; }
+    public function getSeverity(): Severity { return Severity::WARNING; }
+    public function getLevel(): int { return 2; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        if (strtolower($element->tagName) !== 'video') {
+            return null;
+        }
+
+        // Check if there is a track element inside
+        $tracks = $element->getElementsByTagName('track');
+        if ($tracks->length === 0) {
+            return $this->createViolation(
+                $element,
+                $this->getDescription(),
+                'Add a <track kind="captions"> or <track kind="subtitles"> element inside the video element.'
+            );
+        }
+
+        return null;
+    }
+}