<?php

namespace App\Http\Services;

use App\Models\Post;
use App\Models\PostCategory;
use App\Support\GeneratesUniqueSlug;
use Illuminate\Support\Carbon;
use Illuminate\Support\Arr;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Str;

class DocsWordpressSyncService
{
    /**
     * @return array{created:int,updated:int,skipped:int,total:int}
     */
    public function sync(?string $sourceUrl = null, int $perPage = 20, ?int $maxPages = null): array
    {
        $url = $sourceUrl ?: config('services.docs.wordpress_posts_url');

        if (!$url) {
            throw new \RuntimeException('Chưa cấu hình nguồn đồng bộ WordPress.');
        }

        $created = 0;
        $updated = 0;
        $skipped = 0;
        $total = 0;

        $page = 1;

        while (true) {
            if ($maxPages !== null && $page > max(1, $maxPages)) {
                break;
            }

            $response = Http::timeout(20)
                ->retry(2, 300)
                ->acceptJson()
                ->get($url, [
                    'per_page' => min(max($perPage, 1), 100),
                    'page' => $page,
                    '_embed' => 1,
                    'status' => 'publish',
                ]);

            $response->throw();

            /** @var array<int, array<string, mixed>> $items */
            $items = $response->json() ?? [];

            if (empty($items)) {
                break;
            }

            foreach ($items as $item) {
                $total++;
                $result = $this->syncItem($item);

                match ($result) {
                    'created' => $created++,
                    'updated' => $updated++,
                    default => $skipped++,
                };
            }

            if (count($items) < $perPage) {
                break;
            }

            $page++;
        }

        return compact('created', 'updated', 'skipped', 'total');
    }

    private function syncItem(array $item): string
    {
        $title = trim((string) data_get($item, 'title.rendered', ''));
        $content = (string) data_get($item, 'content.rendered', '');
        $slug = trim((string) data_get($item, 'slug', ''));

        if ($title === '' || $content === '') {
            return 'skipped';
        }

        $category = $this->resolveCategory($item);
        $existing = Post::withTrashed()->where('slug', $slug)->first();
        $thumbnail = $this->resolveFeaturedImage($item);
        $excerpt = trim(strip_tags((string) data_get($item, 'excerpt.rendered', '')));
        $publishedAt = data_get($item, 'date_gmt') ?: data_get($item, 'date');

        $payload = [
            'post_category_id' => $category->id,
            'title' => html_entity_decode(strip_tags($title), ENT_QUOTES | ENT_HTML5, 'UTF-8'),
            'excerpt' => $excerpt !== '' ? html_entity_decode($excerpt, ENT_QUOTES | ENT_HTML5, 'UTF-8') : null,
            'content' => $content,
            'thumbnail' => $thumbnail,
            'status' => 'published',
            'is_featured' => false,
            'reading_time' => $this->estimateReadingTime($content),
            'meta_title' => html_entity_decode(strip_tags($title), ENT_QUOTES | ENT_HTML5, 'UTF-8'),
            'meta_description' => $excerpt !== '' ? html_entity_decode($excerpt, ENT_QUOTES | ENT_HTML5, 'UTF-8') : null,
            'published_at' => $publishedAt ? Carbon::parse($publishedAt) : now(),
        ];

        if ($existing) {
            $existing->restore();
            $existing->update($payload);
            return 'updated';
        }

        Post::create($payload + [
            'slug' => GeneratesUniqueSlug::forModel(Post::class, $slug !== '' ? $slug : $title),
            'view_count' => 0,
        ]);

        return 'created';
    }

    private function resolveCategory(array $item): PostCategory
    {
        $termGroups = (array) data_get($item, '_embedded.wp:term', []);
        $terms = is_array($termGroups[0] ?? null) ? $termGroups[0] : [];
        $firstTerm = Arr::first($terms);
        $categoryName = trim((string) data_get($firstTerm, 'name', 'Imported Docs'));
        $categorySlug = trim((string) data_get($firstTerm, 'slug', 'imported-docs'));

        return PostCategory::firstOrCreate(
            ['slug' => $categorySlug !== '' ? $categorySlug : 'imported-docs'],
            [
                'name' => $categoryName !== '' ? $categoryName : 'Imported Docs',
                'description' => 'Danh mục đồng bộ từ WordPress Docs.',
                'status' => 'active',
                'sort_order' => 999,
            ]
        );
    }

    private function resolveFeaturedImage(array $item): ?string
    {
        return data_get($item, '_embedded.wp:featuredmedia.0.source_url')
            ?: data_get($item, '_embedded.wp:featuredmedia.0.media_details.sizes.full.source_url')
            ?: null;
    }

    private function estimateReadingTime(string $html): int
    {
        $wordCount = str_word_count(Str::of(strip_tags($html))->squish()->value());

        return max(1, (int) ceil($wordCount / 200));
    }
}