<?php
/**
 * ARIA rules.
 *
 * @package A11yMate
 */

namespace A11yMate\Rules\Server;

use A11yMate\Support\Html;

defined( 'ABSPATH' ) || exit;

/**
 * Roles, attributes, focus.
 */
class Aria {

	const ROLES = 'alert alertdialog application article banner blockquote button caption cell checkbox code columnheader combobox complementary contentinfo definition deletion dialog directory document emphasis feed figure form generic grid gridcell group heading img insertion link list listbox listitem log main marquee math menu menubar menuitem menuitemcheckbox menuitemradio meter navigation none note option paragraph presentation progressbar radio radiogroup region row rowgroup rowheader scrollbar search searchbox separator slider spinbutton status strong subscript superscript switch tab table tablist tabpanel term textbox time timer toolbar tooltip tree treegrid treeitem doc-abstract doc-acknowledgments doc-afterword doc-appendix doc-backlink doc-biblioentry doc-bibliography doc-biblioref doc-chapter doc-colophon doc-conclusion doc-cover doc-credit doc-credits doc-dedication doc-endnote doc-endnotes doc-epigraph doc-epilogue doc-errata doc-example doc-footnote doc-foreword doc-glossary doc-glossref doc-index doc-introduction doc-noteref doc-notice doc-pagebreak doc-pagelist doc-part doc-preface doc-prologue doc-pullquote doc-qna doc-subtitle doc-tip doc-toc graphics-document graphics-object graphics-symbol';

	const ATTRS = 'aria-activedescendant aria-atomic aria-autocomplete aria-braillelabel aria-brailleroledescription aria-busy aria-checked aria-colcount aria-colindex aria-colindextext aria-colspan aria-controls aria-current aria-describedby aria-description aria-details aria-disabled aria-dropeffect aria-errormessage aria-expanded aria-flowto aria-grabbed aria-haspopup aria-hidden aria-invalid aria-keyshortcuts aria-label aria-labelledby aria-level aria-live aria-modal aria-multiline aria-multiselectable aria-orientation aria-owns aria-placeholder aria-posinset aria-pressed aria-readonly aria-relevant aria-required aria-roledescription aria-rowcount aria-rowindex aria-rowindextext aria-rowspan aria-selected aria-setsize aria-sort aria-valuemax aria-valuemin aria-valuenow aria-valuetext';

	/**
	 * Run the checks.
	 *
	 * @param Context $c Context.
	 * @return void
	 */
	public function run( Context $c ) {
		$roles = array_flip( explode( ' ', self::ROLES ) );
		$attrs = array_flip( explode( ' ', self::ATTRS ) );

		foreach ( $c->q( '//*[@role]' ) as $el ) {
			$tokens = preg_split( '/\s+/', strtolower( trim( $el->getAttribute( 'role' ) ) ) );
			$valid  = false;
			foreach ( $tokens as $t ) {
				if ( isset( $roles[ $t ] ) ) {
					$valid = true;
					break;
				}
			}
			if ( ! $valid && '' !== trim( $el->getAttribute( 'role' ) ) ) {
				$c->add( 'aria-role-invalid', $el, array( 'role' => $el->getAttribute( 'role' ) ) );
			}
			if ( in_array( $tokens[0], array( 'presentation', 'none' ), true ) && $this->focusable( $el ) ) {
				$c->add( 'presentation-focusable', $el );
			}
		}

		foreach ( $c->q( '//*[@*[starts-with(name(),"aria-")]]' ) as $el ) {
			foreach ( $el->attributes as $attr ) {
				$n = strtolower( $attr->name );
				if ( 0 === strpos( $n, 'aria-' ) && ! isset( $attrs[ $n ] ) ) {
					$c->add( 'aria-attr-invalid', $el, array( 'attribute' => $n ) );
					break;
				}
			}
		}

		foreach ( $c->q( "//*[@aria-hidden='true']" ) as $el ) {
			if ( Html::is_hidden( $el ) ) {
				continue;
			}
			$bad = $this->focusable( $el );
			if ( ! $bad ) {
				foreach ( $c->q( ".//a[@href] | .//button | .//input[not(@type='hidden')] | .//select | .//textarea | .//*[@tabindex]", $el ) as $d ) {
					if ( $this->focusable( $d ) && ! Html::is_hidden( $d ) ) {
						$bad = true;
						break;
					}
				}
			}
			if ( $bad ) {
				$c->add( 'aria-hidden-focusable', $el );
			}
		}

		foreach ( $c->q( '//*[@tabindex]' ) as $el ) {
			if ( (int) $el->getAttribute( 'tabindex' ) > 0 ) {
				$c->add( 'tabindex-positive', $el, array( 'tabindex' => (int) $el->getAttribute( 'tabindex' ) ) );
			}
		}
	}

	/**
	 * Is the element in the tab order?
	 *
	 * @param \DOMElement $el Element.
	 * @return bool
	 */
	private function focusable( \DOMElement $el ) {
		if ( $el->hasAttribute( 'disabled' ) ) {
			return false;
		}
		if ( $el->hasAttribute( 'tabindex' ) ) {
			return (int) $el->getAttribute( 'tabindex' ) >= 0;
		}
		$tag = strtolower( $el->tagName );
		if ( 'a' === $tag || 'area' === $tag ) {
			return $el->hasAttribute( 'href' );
		}
		if ( 'input' === $tag ) {
			return 'hidden' !== strtolower( $el->getAttribute( 'type' ) );
		}
		return in_array( $tag, array( 'button', 'select', 'textarea', 'summary' ), true );
	}
}