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

namespace A11yMate\Rules\Server;

use A11yMate\Rules\Registry;
use A11yMate\Support\Html;

defined( 'ABSPATH' ) || exit;

/**
 * Alt text and friends.
 */
class Images {

	/**
	 * Run the checks.
	 *
	 * @param Context $c Context.
	 * @return void
	 */
	public function run( Context $c ) {
		$phrases = Registry::phrases();
		foreach ( $c->q( '//img' ) as $img ) {
			$role = strtolower( $img->getAttribute( 'role' ) );
			if ( 'presentation' === $role || 'none' === $role || 'true' === $img->getAttribute( 'aria-hidden' ) ) {
				continue;
			}
			if ( Html::is_hidden( $img ) ) {
				continue;
			}
			$w = $img->getAttribute( 'width' );
			$h = $img->getAttribute( 'height' );
			if ( '1' === $w && '1' === $h ) {
				continue; // Tracking pixel.
			}
			$has_alt = $img->hasAttribute( 'alt' );
			$alt     = trim( $img->getAttribute( 'alt' ) );
			$named   = '' !== trim( $img->getAttribute( 'aria-label' ) ) || '' !== trim( $img->getAttribute( 'aria-labelledby' ) );
			$link    = $this->sole_link( $img );

			if ( $link && '' === $alt && ! $named ) {
				$c->add( 'img-link-no-name', $link, array( 'message' => __( 'The link contains only an image with no alt text.', 'a11ymate' ) ) );
				continue;
			}
			if ( ! $has_alt && ! $named && '' === trim( $img->getAttribute( 'title' ) ) ) {
				$c->add( 'img-alt-missing', $img );
				continue;
			}
			if ( '' === $alt ) {
				continue;
			}
			$base = strtolower( pathinfo( wp_parse_url( $img->getAttribute( 'src' ), PHP_URL_PATH ) ? wp_parse_url( $img->getAttribute( 'src' ), PHP_URL_PATH ) : '', PATHINFO_FILENAME ) );
			if (
				preg_match( '/\.(jpe?g|png|gif|webp|svg|avif|bmp|tiff?)$/i', $alt )
				|| preg_match( '/^(img|dsc|dscn|image|photo|pic|screenshot|screen shot|untitled|wp|capture)[-_ ]?\d+/i', $alt )
				|| ( strlen( $base ) > 4 && strtolower( $alt ) === $base && preg_match( '/[\d_]/', $base ) )
			) {
				$c->add( 'img-alt-filename', $img, array( 'alt' => $alt ) );
				continue;
			}
			$lower = strtolower( $alt );
			foreach ( $phrases['redundantAlt'] as $p ) {
				if ( 0 === strpos( $lower, $p ) ) {
					$c->add( 'img-alt-redundant', $img, array( 'alt' => $alt ) );
					break;
				}
			}
			if ( strlen( $alt ) > 150 ) {
				$c->add( 'img-alt-long', $img, array( 'length' => strlen( $alt ) ) );
			}
		}

		foreach ( $c->q( "//svg[@role='img']" ) as $svg ) {
			if ( 'true' === $svg->getAttribute( 'aria-hidden' ) ) {
				continue;
			}
			if ( '' === Html::svg_name( $svg ) && '' === trim( $svg->getAttribute( 'aria-labelledby' ) ) ) {
				$c->add( 'svg-role-img-no-name', $svg );
			}
		}

		foreach ( $c->q( "//input[translate(@type,'IMAGE','image')='image']" ) as $in ) {
			if ( '' === trim( $in->getAttribute( 'alt' ) ) && '' === trim( $in->getAttribute( 'aria-label' ) ) && '' === trim( $in->getAttribute( 'title' ) ) && '' === trim( $in->getAttribute( 'aria-labelledby' ) ) ) {
				$c->add( 'input-image-alt', $in );
			}
		}

		foreach ( $c->q( '//area[@href]' ) as $area ) {
			if ( '' === trim( $area->getAttribute( 'alt' ) ) && '' === trim( $area->getAttribute( 'aria-label' ) ) ) {
				$c->add( 'area-alt', $area );
			}
		}
	}

	/**
	 * If the image is the only content of a link, return the link.
	 *
	 * @param \DOMElement $img Image.
	 * @return \DOMElement|null
	 */
	private function sole_link( \DOMElement $img ) {
		$node = $img->parentNode;
		while ( $node instanceof \DOMElement && in_array( strtolower( $node->tagName ), array( 'span', 'figure', 'picture', 'div' ), true ) ) {
			$node = $node->parentNode;
		}
		if ( ! $node instanceof \DOMElement || 'a' !== strtolower( $node->tagName ) || ! $node->hasAttribute( 'href' ) ) {
			return null;
		}
		if ( '' !== Html::clean( Html::text_of( $node ) ) && '' !== trim( Html::clean( Html::text_of( $node ) ) ) ) {
			return null;
		}
		if ( '' !== trim( $node->getAttribute( 'aria-label' ) ) || '' !== trim( $node->getAttribute( 'aria-labelledby' ) ) || '' !== trim( $node->getAttribute( 'title' ) ) ) {
			return null;
		}
		return $node;
	}
}