<?php

declare(strict_types=1);

namespace App\Services\Post;

use App\Models\Post;
use App\Models\Tag;
use App\Services\PaginableResource;
use App\Services\QueryRequestModifiers\Post\PostFilter;
use App\Services\QueryRequestModifiers\Post\PostFilterDTO;
use App\Services\QueryRequestModifiers\Post\PostOrder;
use App\Services\QueryRequestModifiers\Post\PostOrderDTO;
use Illuminate\Support\Facades\DB;

class PostService implements PostServiceInterface
{
    public function __construct(
        protected readonly PostFilter $postFilter,
        protected readonly PostOrder $postOrder,
        protected readonly int $paginate = 10,
    ) {
    }

    public function fetchPosts(int $page, ?PostFilterDTO $filters, ?PostOrderDTO $orderDef): PaginableResource
    {
        $posts = $this->postOrder->apply(
            $this->postFilter->apply(Post::with(['category', 'tags', 'comments']), $filters),
            $orderDef
        )->paginate($this->paginate, page: $page);
        return PaginableResource::createFromLengthAwarePaginator($posts);
    }

    public function findPost(int $id): ?Post
    {
        return Post::with(['category', 'tags', 'comments'])->find($id);
    }

    public function storePost(array $data): Post
    {
        DB::beginTransaction();

        $post = Post::create($data);

        if (isset($data['tags'])) {
            $tags = [];

            foreach ($data['tags'] as $tag) {
                $tag = Tag::firstOrCreate(['name' => $tag]);
                $tags[] = $tag;
            }

            $post->tags()->sync($tags);
        }

        $post = $this->findPost($post->id);

        if ($post === null) {
            throw new \InvalidArgumentException('This should never happen - post is null');
        }

        DB::commit();

        return $post;
    }

    public function updatePost(array $data, int $id): ?Post
    {
        DB::beginTransaction();

        $post = Post::find($id);

        if ($post === null) {
            return null;
        }

        if (isset($data['tags'])) {
            $tags = [];

            foreach ($data['tags'] as $tag) {
                $tag = Tag::firstOrCreate(['name' => $tag]);
                $tags[] = $tag;
            }

            $post->tags()->sync($tags);
        }

        $post->update($data);

        DB::commit();

        return $this->findPost($post->id);
    }

    public function deletePost(int $id): bool
    {
        $post = Post::find($id);

        if ($post === null) {
            return false;
        }

        $post->delete();
        return true;
    }
}