<?php

namespace App\Services;

use App\Models\BlogPost;
use App\Models\Recipe;
use App\Models\User;
use Carbon\Carbon;
use Illuminate\Support\Facades\DB;

class FeedService
{
    public static function showActualFeed()
    {
        $days = 5;
        $dateMax = Recipe::max('created_at');
        $dateMin = Carbon::parse($dateMax)->subDays(10);

        $sql = <<<'EOF'
        SELECT
            p.id,
            p.title,
            (
                (p.likes_count + p.comments_count) /
                ((UNIX_TIMESTAMP(GREATEST(p.created_at,
                    COALESCE((SELECT MAX(l.created_at) FROM blog_post_likes l WHERE l.blog_post_id = p.id), p.created_at),
                    COALESCE((SELECT MAX(c.created_at) FROM blog_post_comments c WHERE c.blog_post_id = p.id), p.created_at)
                    )) - UNIX_TIMESTAMP(p.created_at))/60 + 1
                ) ^ 1.8
            ) AS popularity
        FROM
            (SELECT
                `blog_posts`.id,
                    blog_posts.title,
                    blog_posts.created_at,
                    COUNT(blog_post_comments.id) AS comments_count,
                    COUNT(blog_post_likes.id) AS likes_count
            FROM
                `blog_posts`
            LEFT JOIN blog_post_comments ON blog_post_comments.blog_post_id = blog_posts.id
            LEFT JOIN blog_post_likes ON blog_post_likes.blog_post_id = blog_posts.id
            GROUP BY blog_posts.id) p
        ORDER BY popularity DESC;
EOF;

        $hotBlogPosts = collect(
            DB::select(DB::raw($sql))
        )->map(fn ($post) => BlogPost::find($post->id))
            ->take(16)->chunk(4);

        $newbiesBlogPosts = User::orderBy('created_at', 'desc')
            ->withCount('author_of_blog_post')
            ->get()
            ->filter(fn ($u) => $u->author_of_blog_post_count > 0)->take(4)
            ->pluck('id')
            ->map(fn ($id) => User::find($id)->author_of_blog_post()->limit(2)->get())
            ->flatten()
            ->random();

        $randomRecipe = Recipe::where('created_at', '>=', $dateMin)
            ->where('created_at', '<=', $dateMax)
            ->inRandomOrder()
            ->limit(2)
            ->get();

        $firstCollection = $hotBlogPosts->first()->push($newbiesBlogPosts->first())->push($randomRecipe->first());
        $secondCollection = $hotBlogPosts->skip(1)->first()->push($newbiesBlogPosts->skip(1)->first())->push($randomRecipe->skip(1)->first());

        return $firstCollection->concat($secondCollection)->filter(fn ($el) => ! is_null($el) && $el->id);
    }
}