<?php
/**
 * Player stamina storage and recovery.
 */

namespace common\services;

use common\models\User;
use common\utils\RedisKeyUtil;
use RedisLock\RedisLock;
use Yii;
use yii\base\Object;

class StaminaService extends Object
{
    const MAX_STAMINA = 20;
    const STEAL_COST = 10;
    const RECOVER_AMOUNT = 2;
    const RECOVER_INTERVAL = 3600;

    public static function getClientData($userID)
    {
        $userDbData = User::findById($userID, false);
        if (!$userDbData) {
            return self::defaultClientData();
        }

        self::recover($userDbData, time());
        self::save($userDbData);
        return self::formatClientData($userDbData);
    }

    public static function consumeSteal($userID)
    {
        return self::withStaminaLock($userID, function ($userID) {
            return self::consumeStealUnlocked($userID);
        });
    }

    public static function withStaminaLock($userID, callable $callback)
    {
        $lock = new RedisLock(Yii::$app->redis, RedisKeyUtil::lockUserStamina($userID), RedisLock::FLAG_CATCH_EXCEPTIONS);
        if (!$lock->acquire(10)) {
            $userDbData = User::findById($userID, false);
            return [
                'ok' => false,
                'status' => ResultStatusServices::RS_SAME_TIME_OPERATION,
                'data' => $userDbData ? self::formatClientData($userDbData) : self::defaultClientData(),
            ];
        }

        try {
            return call_user_func($callback, $userID);
        } finally {
            $lock->release();
        }
    }

    public static function consumeStealUnlocked($userID)
    {
        $check = self::checkStealUnlocked($userID);
        if (empty($check['ok'])) {
            return $check;
        }

        $userDbData = User::findById($userID, false);
        $now = time();
        $wasFull = (int)$userDbData->stamina >= (int)$userDbData->stamina_max;
        $userDbData->stamina -= self::STEAL_COST;
        if ($wasFull) {
            $userDbData->stamina_recover_time = $now;
        }
        self::save($userDbData);

        return [
            'ok' => true,
            'status' => ResultStatusServices::RS_OPERATION_SUCCESS,
            'data' => self::formatClientData($userDbData),
        ];
    }

    public static function checkStealUnlocked($userID)
    {
        $userDbData = User::findById($userID, false);
        if (!$userDbData) {
            return [
                'ok' => false,
                'status' => ResultStatusServices::RS_NOT_FIND_USER,
                'data' => self::defaultClientData(),
            ];
        }

        $now = time();
        self::recover($userDbData, $now);
        if ((int)$userDbData->stamina < self::STEAL_COST) {
            self::save($userDbData);
            return [
                'ok' => false,
                'status' => ResultStatusServices::RS_STAMINA_NOT_ENOUGH,
                'data' => self::formatClientData($userDbData),
            ];
        }

        self::save($userDbData);

        return [
            'ok' => true,
            'status' => ResultStatusServices::RS_OPERATION_SUCCESS,
            'data' => self::formatClientData($userDbData),
        ];
    }

    public static function increaseMax($userID, $amount, $fillAddedCapacity = true)
    {
        if ($amount <= 0) {
            return [
                'ok' => false,
                'status' => ResultStatusServices::RS_PARAM_ERROR,
                'data' => self::getClientData($userID),
            ];
        }
        return self::setMax($userID, self::currentMax($userID) + (int)$amount, $fillAddedCapacity);
    }

    public static function setMax($userID, $maxStamina, $fillAddedCapacity = true)
    {
        $lock = new RedisLock(Yii::$app->redis, RedisKeyUtil::lockUserStamina($userID), RedisLock::FLAG_CATCH_EXCEPTIONS);
        if (!$lock->acquire(10)) {
            return [
                'ok' => false,
                'status' => ResultStatusServices::RS_SAME_TIME_OPERATION,
                'data' => self::getClientData($userID),
            ];
        }

        try {
            $userDbData = User::findById($userID, false);
            if (!$userDbData) {
                return [
                    'ok' => false,
                    'status' => ResultStatusServices::RS_NOT_FIND_USER,
                    'data' => self::defaultClientData(),
                ];
            }

            self::recover($userDbData, time());
            $oldMax = self::normalizeMax((int)$userDbData->stamina_max);
            $newMax = self::normalizeMax((int)$maxStamina);
            $userDbData->stamina_max = $newMax;
            if ($fillAddedCapacity && $newMax > $oldMax) {
                $userDbData->stamina = min($newMax, (int)$userDbData->stamina + ($newMax - $oldMax));
            } else {
                $userDbData->stamina = min((int)$userDbData->stamina, $newMax);
            }
            if ((int)$userDbData->stamina >= $newMax) {
                $userDbData->stamina_recover_time = time();
            }
            self::save($userDbData);

            return [
                'ok' => true,
                'status' => ResultStatusServices::RS_OPERATION_SUCCESS,
                'data' => self::formatClientData($userDbData),
            ];
        } finally {
            $lock->release();
        }
    }

    private static function currentMax($userID)
    {
        $userDbData = User::findById($userID, false);
        if (!$userDbData) {
            return self::MAX_STAMINA;
        }
        return self::normalizeMax((int)$userDbData->stamina_max);
    }

    private static function recover(User $userDbData, $now)
    {
        $maxStamina = self::normalizeMax((int)$userDbData->stamina_max);
        $userDbData->stamina_max = $maxStamina;
        $userDbData->stamina = max(0, min($maxStamina, (int)$userDbData->stamina));

        if ((int)$userDbData->stamina >= $maxStamina) {
            $userDbData->stamina = $maxStamina;
            $userDbData->stamina_recover_time = $now;
            return;
        }

        if ((int)$userDbData->stamina_recover_time <= 0) {
            $userDbData->stamina_recover_time = $now;
            return;
        }

        $elapsed = $now - (int)$userDbData->stamina_recover_time;
        if ($elapsed < self::RECOVER_INTERVAL) {
            return;
        }

        $recoverTimes = (int)floor($elapsed / self::RECOVER_INTERVAL);
        $userDbData->stamina = min($maxStamina, (int)$userDbData->stamina + $recoverTimes * self::RECOVER_AMOUNT);
        if ((int)$userDbData->stamina >= $maxStamina) {
            $userDbData->stamina_recover_time = $now;
        } else {
            $userDbData->stamina_recover_time += $recoverTimes * self::RECOVER_INTERVAL;
        }
    }

    private static function save(User $userDbData)
    {
        return $userDbData->save(true, ['stamina', 'stamina_max', 'stamina_recover_time']);
    }

    private static function formatClientData(User $userDbData)
    {
        $maxStamina = self::normalizeMax((int)$userDbData->stamina_max);
        $stamina = max(0, min($maxStamina, (int)$userDbData->stamina));
        $nextRecoverTime = 0;
        if ($stamina < $maxStamina) {
            $nextRecoverTime = (int)$userDbData->stamina_recover_time + self::RECOVER_INTERVAL;
        }

        return [
            'stamina' => $stamina,
            'stamina_max' => $maxStamina,
            'stamina_next_recover_time' => $nextRecoverTime,
            'stamina_recover_amount' => self::RECOVER_AMOUNT,
            'stamina_recover_interval' => self::RECOVER_INTERVAL,
            'stamina_cost_steal' => self::STEAL_COST,
        ];
    }

    private static function defaultClientData()
    {
        return [
            'stamina' => self::MAX_STAMINA,
            'stamina_max' => self::MAX_STAMINA,
            'stamina_next_recover_time' => 0,
            'stamina_recover_amount' => self::RECOVER_AMOUNT,
            'stamina_recover_interval' => self::RECOVER_INTERVAL,
            'stamina_cost_steal' => self::STEAL_COST,
        ];
    }

    private static function normalizeMax($maxStamina)
    {
        return max(1, (int)$maxStamina);
    }
}