<?php

namespace App\Services;

use App\HashtagFollow;
use Illuminate\Support\Facades\Redis;

class HashtagFollowService
{
    const FOLLOW_KEY = 'pf:services:hashtag-follows:v1:';

    const CACHE_KEY = 'pf:services:hfs:byHid:';

    const CACHE_WARMED = 'pf:services:hfs:wc:byHid';

    public static function getPidByHid($hid)
    {
        if (! self::isWarm($hid)) {
            return self::warmCache($hid);
        }

        return self::get($hid);
    }

    public static function unfollow($hid, $pid)
    {
        return Redis::zrem(self::CACHE_KEY.$hid, $pid);
    }

    public static function add($hid, $pid)
    {
        return Redis::zadd(self::CACHE_KEY.$hid, $pid, $pid);
    }

    public static function rem($hid, $pid)
    {
        return Redis::zrem(self::CACHE_KEY.$hid, $pid);
    }

    public static function get($hid)
    {
        return Redis::zrange(self::CACHE_KEY.$hid, 0, -1);
    }

    public static function count($hid)
    {
        return Redis::zcard(self::CACHE_KEY.$hid);
    }

    public static function warmCache($hid)
    {
        foreach (HashtagFollow::whereHashtagId($hid)->lazyById(20, 'id') as $h) {
            if ($h) {
                self::add($h->hashtag_id, $h->profile_id);
            }
        }

        self::setWarm($hid);

        return self::get($hid);
    }

    public static function isWarm($hid)
    {
        return Redis::zcard(self::CACHE_KEY.$hid) > 0 || Redis::zscore(self::CACHE_WARMED, $hid) !== null;
    }

    public static function setWarm($hid)
    {
        return Redis::zadd(self::CACHE_WARMED, $hid, $hid);
    }
}