<?php

namespace Modules\Stylist\Services;

use Illuminate\Filesystem\Filesystem;
use Modules\Stylist\Theme\Theme;

final class ThemeAccessibilityValidator
{
    public function __construct(private readonly Filesystem $files) {}

    /** @return array<int, array{severity:string,message:string,file:string}> */
    public function validate(Theme $theme): array
    {
        $issues = [];

        foreach ($this->files->allFiles($theme->path().'/views') as $file) {
            $content = $file->getContents();
            $relative = $file->getRelativePathname();

            $missingAlt = 0;
            if (preg_match_all('/<img\\b(?:(?:"[^"]*")|(?:\'[^\']*\')|[^\'">])*>/is', $content, $images)) {
                foreach ($images[0] as $image) {
                    if (! preg_match('/\\balt\\s*=\\s*(?:"[^"]*"|\'[^\']*\')/is', $image)) {
                        $missingAlt++;
                    }
                }
            }

            if ($missingAlt > 0) {
                $issues[] = [
                    'severity' => 'error',
                    'message' => $missingAlt.' image(s) missing alt text.',
                    'file' => $relative,
                ];
            }

            if (preg_match('/<html\\b(?![^>]*\\blang=)/i', $content)) {
                $issues[] = [
                    'severity' => 'warning',
                    'message' => 'HTML element is missing a lang attribute.',
                    'file' => $relative,
                ];
            }

            $unnamedButtons = 0;
            if (preg_match_all('/<button\\b((?:(?:"[^"]*")|(?:\'[^\']*\')|[^\'">])*)>(.*?)<\\/button>/is', $content, $buttons, PREG_SET_ORDER)) {
                foreach ($buttons as $button) {
                    $attributes = $button[1];
                    $body = $button[2];

                    $hasAccessibleAttribute = preg_match('/\\b(?:aria-label|aria-labelledby|title)\\s*=\\s*(?:"[^"]+"|\'[^\']+\')/is', $attributes) === 1;
                    $visibleText = trim(html_entity_decode(strip_tags($body), ENT_QUOTES | ENT_HTML5));

                    if (! $hasAccessibleAttribute && $visibleText === '') {
                        $unnamedButtons++;
                    }
                }
            }

            if ($unnamedButtons > 0) {
                $issues[] = [
                    'severity' => 'warning',
                    'message' => $unnamedButtons.' button(s) may lack an accessible name.',
                    'file' => $relative,
                ];
            }
        }

        return $issues;
    }
}