<?php

declare(strict_types=1);

namespace App\Controllers\Admin;

/**
 * SEO quality dashboard: automated audit of the whole indexable surface.
 *
 * Critical checks (block publishing in ToolsAdmin too):
 *   unique titles / descriptions, length ranges, H1 present, canonical
 *   slug hygiene, FAQ presence for content tools, duplicate detection.
 */
final class SeoAdmin extends AdminBase
{
    public function index(): string
    {
        $tools  = service('finder')->all();
        $guides = model(\App\Models\GuideModel::class)->published(1000);

        $issues = [];
        $seenTitles = [];
        $seenDescs  = [];

        foreach ($tools as $tool) {
            $slug = $tool['slug'];
            $title = (string) $tool['seo_title'];
            $desc  = (string) $tool['seo_description'];

            if (trim($title) === '') {
                $issues[] = ['severity' => 'critical', 'page' => '/' . $slug, 'check' => 'Missing SEO title'];
            } elseif (mb_strlen($title) > 65) {
                $issues[] = ['severity' => 'warning', 'page' => '/' . $slug, 'check' => 'Title longer than 65 chars (' . mb_strlen($title) . ')'];
            }
            if (trim($desc) === '') {
                $issues[] = ['severity' => 'critical', 'page' => '/' . $slug, 'check' => 'Missing meta description'];
            } elseif (mb_strlen($desc) < 70 || mb_strlen($desc) > 320) {
                $issues[] = ['severity' => 'warning', 'page' => '/' . $slug, 'check' => 'Description outside 70–320 chars (' . mb_strlen($desc) . ')'];
            }
            if (trim((string) $tool['h1']) === '') {
                $issues[] = ['severity' => 'critical', 'page' => '/' . $slug, 'check' => 'Missing H1'];
            }
            if ($tool['faqs'] === [] && ! in_array($tool['kind'], ['text'], true)) {
                $issues[] = ['severity' => 'warning', 'page' => '/' . $slug, 'check' => 'No FAQ content'];
            }
            if ($tool['related_slugs'] === [] && count(service('relatedTools')->forTool($tool, 4)) < 3) {
                $issues[] = ['severity' => 'warning', 'page' => '/' . $slug, 'check' => 'Thin internal linking (<3 related tools)'];
            }
            if (! preg_match('/^[a-z0-9]+$/', (string) ($tool['primary_input_format'] ?? '')) && $tool['operation'] === 'convert') {
                $issues[] = ['severity' => 'warning', 'page' => '/' . $slug, 'check' => 'Converter without primary format pair'];
            }

            $tKey = mb_strtolower($title);
            if ($tKey !== '' && isset($seenTitles[$tKey])) {
                $issues[] = ['severity' => 'critical', 'page' => '/' . $slug, 'check' => 'Duplicate title with /' . $seenTitles[$tKey]];
            }
            $seenTitles[$tKey] = $slug;

            $dKey = mb_substr(mb_strtolower($desc), 0, 120);
            if ($dKey !== '' && isset($seenDescs[$dKey])) {
                // near-duplicate short descriptions are common across generated converters — flag only exact dupes
                if (mb_strtolower((string) $tool['short_description']) === mb_strtolower((string) $desc)) {
                    $issues[] = ['severity' => 'warning', 'page' => '/' . $slug, 'check' => 'Description identical to /' . $seenDescs[$dKey]];
                }
            }
            $seenDescs[$dKey] = $slug;
        }

        foreach ($guides as $g) {
            if ((string) $g['excerpt'] === '' || (string) $g['body_md'] === '') {
                $issues[] = ['severity' => 'critical', 'page' => '/blog/' . $g['slug'], 'check' => 'Guide missing excerpt/body'];
            }
        }

        usort($issues, static fn ($a, $b) => [$b['severity'], $a['page']] <=> [$a['severity'], $b['page']]);
        $criticalCount = count(array_filter($issues, static fn ($i) => $i['severity'] === 'critical'));

        return $this->render('seo_index', [
            'issues'        => $issues,
            'criticalCount' => $criticalCount,
            'toolCount'     => count($tools),
            'guideCount'    => count($guides),
            'sitemapUrl'    => base_url('/sitemap.xml'),
        ]);
    }
}