#define START_STATE 0
#define PREHEAT_STATE 1
#define RAMP_UP_STATE 2
#define TAL_FIRST_STATE 3
#define PEAK_STATE 4
#define TAL_SECOND_STATE 5
#define RAMPDOWN_STATE 6
#define END_STATE 7
#define ERROR_STATE 8

// error conditions
#define E_RAMPUP 1 // oven heats up too fast
#define E_RAMPDOWN_TOO_FAST 2 // oven cools down too fast
#define E_RAMPDOWN_TOO_SLOW 3 // oven cools down too slow
#define E_TIME_MAX 4 // reflow process does take too long
#define E_PEAK_TOO_LONG 5 // package was roasted

unsigned int time = 0; // profile seconds
unsigned int temperatur = 25; // actual oven temp
unsigned int last_temperatur = 25;

unsigned int Ts_max = 200; // °C
unsigned int Ts_min = 150; // °C
unsigned int Tp = 260; // 245-260°C
unsigned int rampup_rate = 3; // 3°C/s
unsigned int preheat_duration = 100; // 60-180s
unsigned int tal = 217; // 217°C
unsigned int tal_duration = 100; // 60-150s
unsigned int peak_duration = 30; // 20-40s
unsigned int rampdown_max = 6; // 6°C/s max
unsigned int rampdown_min = 2; // 2°C/s max
unsigned int time_max = 480; // 8*60s max

unsigned int Ts_min_time = 0;
unsigned int Ts_max_time = 0;
unsigned int Tl_time = 0;
unsigned int Tl_time_end = 0;
unsigned int Tp_time = 0;
unsigned int Tp_time_end = 0;
unsigned int Tl_end_time = 0;
unsigned int error_condition = 0;

byte state = START_STATE;

int analogPin = 2;

void setup() {
  Serial.begin(9600);
}

void get_temp() {
  // simulating an +1K/s rampup oven
  last_temperatur = temperatur++;
}

boolean check_rampup_rate() {
  if (temperatur - last_temperatur > rampup_rate) {
    error_condition = E_RAMPUP;
    return false;
  }
  return true;
}

boolean check_rampdown_rate() {
  unsigned int dt = temperatur - last_temperatur;
  if (dt > rampdown_max) {
    error_condition = E_RAMPDOWN_TOO_FAST;
    return false;
  }

  if (dt < rampdown_min) {
    error_condition = E_RAMPDOWN_TOO_SLOW;
    return false;
  }
  return true;
}

boolean time_max_check() {
  if (time > time_max) {
    error_condition = E_TIME_MAX;
    return false;
  }
}

boolean check_tal_duration() {
  if (time > time_max) {
    error_condition = E_TIME_MAX;
    return false;
  }
}


boolean check_peak_duration() {
  if (Tp_time_end - Tp_time > peak_duration) {
    error_condition = E_PEAK_TOO_LONG;
    return false;
  }
}


void loop() {
//   time = millis() / 1000;
//   get_temp();
//   Serial.print(time);
//   Serial.print(" ");
//   Serial.print(temperatur);
//   Serial.print(" ");
//   Serial.println(last_temperatur);

  Serial.println(analogRead(analogPin));

//   switch (state) {
//       case START_STATE:
//           // going from room temp to preheat, nothing to check here
//           if (!check_rampup_rate())
//               goto error;
//           if (temperatur > Ts_min) {
//               Serial.println("Changed state to PREHEAT_STATE");
//               Ts_min_time = time;
//               state++;
//           }
//       case PREHEAT_STATE:
//           if (temperatur > Ts_max) {
//             Serial.println("Changed state to PREHEAT_STATE");
//             Ts_max_time = time;
//             state++;
//           }
//           break;
//       case TAL_FIRST_STATE:
//         break;
//       case PEAK_STATE:
//         break;
//       case TAL_SECOND_STATE:
//         break;
//       case RAMPDOWN_STATE:
//         break;
//       case END_STATE:
//       default:
//         break;
//   }
//
  delay(1000);
//
//   return;
//
// error:
//   state = END_STATE;
//   Serial.println(error_condition);
}