<?php

namespace BenTools\GuzzleHttp\Middleware\Storage;

class Counter implements \Serializable, \JsonSerializable, \Countable
{
    /**
     * @var bool
     */
    private $useMicroseconds;

    /**
     * @var float
     */
    private $expiresIn;

    /**
     * @var float
     */
    private $expiresAt;

    /**
     * @var int
     */
    private $counter;

    /**
     * Counter constructor.
     * @param float $expiresIn
     */
    public function __construct(float $expiresIn)
    {
        $this->useMicroseconds = intval($expiresIn) != $expiresIn;
        $this->expiresIn = $this->useMicroseconds ? $expiresIn : intval($expiresIn);
        $this->reset();
    }

    private function now()
    {
        return $this->useMicroseconds ? microtime(true) : time();
    }

    public function reset()
    {
        $this->counter = 0;
        $this->expiresAt = null;
    }

    /**
     * Increment counter.
     */
    public function increment()
    {
        $this->counter++;
        if (1 === $this->counter) {
            $this->expiresAt = $this->now() + $this->expiresIn;
        }
    }

    /**
     * @return int
     */
    public function count(): int
    {
        if ($this->isExpired()) {
            $this->reset();
        }
        return $this->counter;
    }

    /**
     * @return int|float
     */
    public function getRemainingTime()
    {
        $remainingTime = (float) max(0, $this->expiresAt - $this->now());
        if (false === $this->useMicroseconds) {
            $remainingTime = ceil($remainingTime);
        }
        return $remainingTime;
    }

    /**
     * @return bool
     */
    public function isExpired()
    {
        return null !== $this->expiresAt && 0.0 === $this->getRemainingTime();
    }

    /**
     * @inheritDoc
     */
    public function serialize()
    {
        return json_encode($this);
    }

    /**
     * @inheritDoc
     */
    public function unserialize($serialized)
    {
        $data = json_decode($serialized, true);
        $this->expiresAt = $data['e'];
        $this->expiresIn = $data['i'];
        $this->counter = $data['n'];
        $this->useMicroseconds = $data['m'];
    }

    /**
     * @inheritDoc
     */
    public function jsonSerialize()
    {
        return [
            'm' => $this->useMicroseconds,
            'i' => $this->expiresIn,
            'e' => $this->expiresAt,
            'n' => $this->counter,
        ];
    }

    public function __debugInfo()
    {
        return [
            'counter' => $this->counter,
            'microseconds' => $this->useMicroseconds,
            'expiresIn' => $this->expiresIn,
            'expiresAt' => $this->expiresAt,
            'now' => $this->now(),
            'remaining' => $this->useMicroseconds ? $this->getRemainingTime() : round($this->getRemainingTime()),
            'expired' => $this->isExpired(),
        ];
    }
}