library StunUnit // initializer Init
{
    private timer   periodicTimer = CreateTimer()    // Can be replaced with main map timer

    private unit    unitsStack[]
    private effect  effectsStack[]  // Stun effect storage
    private float   timeRemaining[] // Time of stun left
    private int     stackCounter = 0

    #define private TICK_PERIOD  = 0.05
    #define private STACK_LIMIT  = 8190
    #define private STUN_EFFECT  = "Abilities\\Spells\\Human\\Thunderclap\\ThunderclapTarget.mdl"
    #define private ORDERID_STOP = 0xD0004


    // Looking for id of specified unit in stack
    private int StackSearch(unit givenUnit) {
        int i = -1;
        while(i++ < stackCounter) {
            if (givenUnit == unitsStack[i]) {
                return i;
            }
        }
        return -1;
    }

    // Add unit to stack with overflow check
    private void StackPush(unit givenUnit, float duration) {
        if(stackCounter < STACK_LIMIT) {
            unitsStack   [stackCounter] = givenUnit;
            effectsStack [stackCounter] = AddSpecialEffectTarget(STUN_EFFECT, givenUnit, "overhead");
            timeRemaining[stackCounter] = duration;
            stackCounter++;
        } else {
            BJDebugMsg("Stunned units stack overflow!");
        }
    }

    // Remove unit from stack
    private void StackPop(int id) {

        DestroyEffect(effectsStack[id]);

        stackCounter--;
        unitsStack   [id] = unitsStack   [stackCounter];
        effectsStack [id] = effectsStack [stackCounter];
        timeRemaining[id] = timeRemaining[stackCounter];

        unitsStack   [stackCounter] = null;
        effectsStack [stackCounter] = null;
        timeRemaining[stackCounter] = 0.0;
    }

    void StunUnit(unit givenUnit, float duration) {

        int stackedUnitId = StackSearch(givenUnit);

        if (stackedUnitId == -1) {
            StackPush(givenUnit, duration);
        } elseif (timeRemaining[stackedUnitId] < duration) {
            timeRemaining[stackedUnitId] = duration;
        }
    }

    private void TimerCallback() {

        int i = -1;

        while(i++ < stackCounter) {

            timeRemaining[i] -= TICK_PERIOD;
            IssueImmediateOrderById(unitsStack[i], ORDERID_STOP);

            if (timeRemaining[i] <= 0.0) {
                StackPop(i);
            }
        }
    }

    private void Init() {
        TimerStart(periodicTimer, TICK_PERIOD, true, function TimerCallback);
    }
}