<?php

declare(strict_types=1);

namespace App\Blog\Controllers;

use App\Models\Post;
use Illuminate\Support\Str;
use League\HTMLToMarkdown\HtmlConverter;

class LlmsController extends Controller
{
    /**
     * /llms.txt — live index for agents. Not a static file.
     */
    public function index()
    {
        $siteName = (string) blog_setting('site_name', config('blog.name'));
        $siteDescription = (string) blog_setting('site_description', config('blog.description'));

        $posts = Post::query()
            ->published()
            ->latest('published_at')
            ->limit(200)
            ->get();

        $lines = [
            '# '.$siteName,
            '',
            '> '.$siteDescription,
            '',
            '## Feeds',
            '',
            '- [RSS]('.route('feed.rss').')',
            '- [Sitemap]('.route('feed.sitemap').')',
            '- [llms.txt]('.route('feed.llms').')',
            '',
            '## Articles',
            '',
        ];

        foreach ($posts as $post) {
            if ($this->isRestricted($post)) {
                continue;
            }

            $summary = Str::limit(trim(preg_replace('/\s+/', ' ', strip_tags($post->excerpt_or_fallback)) ?? ''), 120);
            $markdownUrl = $this->markdownUrl($post);
            $htmlUrl = $post->url;
            $title = $post->title;

            $lines[] = $markdownUrl
                ? '- ['.$title.']('.$markdownUrl.') — '.$summary.' ([html]('.$htmlUrl.'))'
                : '- ['.$title.']('.$htmlUrl.') — '.$summary;
        }

        return response(implode("\n", $lines)."\n", 200, [
            'Content-Type' => 'text/plain; charset=utf-8',
            'Cache-Control' => 'no-store',
        ]);
    }

    /**
     * /posts/{slug}.md — full markdown for a published public post.
     */
    public function postMarkdown(string $slug)
    {
        $post = Post::query()
            ->where('slug', $slug)
            ->orWhere('id', (int) $slug)
            ->first();

        abort_unless($post && $post->status === 'published' && ! $this->isRestricted($post), 404);

        $body = $post->content_format === 'markdown'
            ? (string) $post->content
            : $this->htmlToMarkdown((string) $post->content);

        $out = '# '.$post->title."\n\n";
        if ($post->excerpt) {
            $out .= '> '.$post->excerpt."\n\n";
        }
        $out .= $body."\n";

        return response($out, 200, [
            'Content-Type' => 'text/markdown; charset=utf-8',
            'Cache-Control' => 'no-store',
        ]);
    }

    private function isRestricted(Post $post): bool
    {
        if (filled($post->read_password)) {
            return true;
        }

        return ! empty(($post->meta ?? [])['members_only']);
    }

    private function markdownUrl(Post $post): ?string
    {
        $slug = trim((string) $post->slug);

        if ($slug === '') {
            return route('geo.post.markdown', ['slug' => (string) $post->id]);
        }

        return route('geo.post.markdown', ['slug' => $slug]);
    }

    private function htmlToMarkdown(string $html): string
    {
        $converter = new HtmlConverter([
            'strip_tags' => false,
            'hard_break' => true,
        ]);

        return $converter->convert($html);
    }
}