//renamed some vars from really old english..
//i understood it though.. :)
const int BTN_RETRACT = 5; //retract button
const int BTN_EXTEND = 6;// extend button
const int SEN_MIDDLE = 7;//middle sensor

const int LIN_ACT = 3;//linear activator
const int CTL_DIRECTION = 12;//was sens

#define STATE_RET 1
#define STATE_EXT 2
#define STATE_MID 3
#define STATE_STOP 4

//vars to track samples
bool Retract = false;
bool Extend = false;
bool InMiddle = false;

//0=before 1=at 2=after
byte MidPosition = 0;

int lastState = 0;
//millis from last sample
unsigned long lastSample = 0;
//sampling rate in millis
int SampleRate = 100;


void setup() {
 // Serial.begin(115200);
  pinMode (BTN_RETRACT, INPUT);
  pinMode (BTN_EXTEND, INPUT);
  pinMode (SEN_MIDDLE, INPUT);
  pinMode (LIN_ACT, OUTPUT);
  pinMode (CTL_DIRECTION, OUTPUT);
  lastState = 3 ;//start in middle
 // Serial.println("Ready..");
 
}

void SampleInputs()
{

   unsigned long currMilli = millis();
   if (currMilli-lastSample>=SampleRate)
   {
     lastSample = currMilli;
     Retract = digitalRead(BTN_RETRACT);
     Extend = digitalRead(BTN_EXTEND);
     InMiddle = digitalRead(SEN_MIDDLE);

     if (InMiddle){
       MidPosition = 1;
     }else {
          switch (lastState){
            case STATE_RET: MidPosition = 0;break;
            case STATE_EXT: MidPosition = 2;break;
          }

     }


   }

}

void loop() {

     SampleInputs();

     int newState;
     if ((Retract&&Extend)||(!Retract&&!Extend)){
       newState = STATE_MID;
     }else
     if (Retract){
       newState = STATE_RET;
     } else
     if (Extend){
       newState = STATE_EXT;
     }
      //if we're moving to mid and we're there, STOP
      if (newState==STATE_MID && InMiddle) newState = STATE_STOP; 

       lastState = newState;

    switch (lastState) {
      case STATE_RET: //retract
       // Serial.println("Retracting");
        digitalWrite(CTL_DIRECTION, LOW);
        analogWrite(LIN_ACT, 255);
        break;

      case STATE_EXT: //extend
       // Serial.println("Extending");
        digitalWrite(CTL_DIRECTION, HIGH);
        analogWrite(LIN_ACT, 255);
        break;

      case  STATE_MID: //go middle
     //  Serial.println("Middle");
      if (MidPosition==0)
       {digitalWrite(CTL_DIRECTION, HIGH);}
       else
       {digitalWrite(CTL_DIRECTION, HIGH);}
       analogWrite(LIN_ACT, 255);
        break;
      case  STATE_STOP: //stop
      //  Serial.println("Stop");
       digitalWrite(CTL_DIRECTION, LOW);
       analogWrite(LIN_ACT, 0);
        break;
    }
     // delay(1000); used for debuging slows the serial prints down..

    }