#include <TinyGPSPlus.h>
#include <U8g2lib.h>

#define GPS_BAUD 9600

#define ROTARY_PIN_A 33
#define ROTARY_PIN_B 32
#define ROTARY_PIN_BTN 34

#define BUZZER_PIN 9
#define BUZZER_PWM_CHANNEL 0
#define BUZZER_PWM_FREQUENCY 1000
#define BUZZER_PWM_RESOLUTION 8

#define MAX_DISTANCE_FT 2000 // maximum allowable distance




TinyGPSPlus gps;
U8G2_SSD1306_128X64_NONAME_F_SW_I2C u8g2(U8G2_R0, /*clock=*/ 22, /*data=*/ 21, /*reset=*/ U8X8_PIN_NONE);
// ClickEncoder encoder(ROTARY_PIN_A, ROTARY_PIN_B, ROTARY_PIN_BTN);

double anchor_lat, anchor_lng;
bool is_armed = false;
uint16_t alarm_range = 0; // in feet

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

    u8g2.begin();
    u8g2.setFont(u8g2_font_ncenB08_tr);

    // encoder.setAccelerationEnabled(true);
    // buzzer stuff
    ledcSetup(BUZZER_PWM_CHANNEL, BUZZER_PWM_FREQUENCY, BUZZER_PWM_RESOLUTION);
    ledcAttachPin(BUZZER_PIN, BUZZER_PWM_CHANNEL);

}

void loop() {
  while (Serial.available() > 0) {
    if (gps.encode(Serial.read())) {
      if (!gps.location.isValid()) {
          u8g2.clearBuffer();
          u8g2.drawStr(0, 10, "GPS Lock: No");
      } else {
        // if (encoder.getButton() == ClickEncoder::Clicked) {
        //   if (is_armed) {
        //     is_armed = false;
        //   } else {
        //     is_armed = true;
        //     anchor_lat = gps.location.lat();
        //     anchor_lng = gps.location.lng();
        //   }
        // }
        // setRange();
        displayGPS();
        checkDistance();
      }
    } else {
        u8g2.clearBuffer();
        u8g2.drawStr(0, 10, "GPS Error");
    }
  }
}

// void setRange() {
//   int16_t encoder_value = encoder.getValue();
//   if (encoder_value != 0) {
//     // Update the alarm range
//     alarm_range += encoder_value;
//     if (alarm_range > MAX_DISTANCE_FT) {
//       alarm_range = MAX_DISTANCE_FT;
//     } else if (alarm_range < 0) {
//       alarm_range = 0;
//     }
//   }
// }

void displayGPS() {
  u8g2.clearBuffer();
  u8g2.drawStr(0, 10, "GPS Lock: Yes");
  u8g2.drawStr(0, 20, ("Max Range: " + String(alarm_range) + "ft").c_str());
  u8g2.drawStr(0, 30, String("Alarm: " + String(is_armed ? "Armed" : "Disarmed")).c_str());

  if (is_armed) {
    double current_distance = TinyGPSPlus::distanceBetween(gps.location.lat(), gps.location.lng(), anchor_lat, anchor_lng);
    current_distance *= 3.281; // convert to feet
    u8g2.drawStr(0, 40, ("Distance: " + String(current_distance, 2) + "ft").c_str());
  }

  u8g2.sendBuffer();
}

void checkDistance() {
  if (is_armed) {
    double current_distance = TinyGPSPlus::distanceBetween(gps.location.lat(), gps.location.lng(), anchor_lat, anchor_lng);
    current_distance *= 3.281; // convert to feet
       if (current_distance > alarm_range) {
      alarm(true);
    } else {
      alarm(false);
    }
  } else {
    alarm(false);
  }
}

void alarm(bool isOn){
    ledcWrite(BUZZER_PWM_CHANNEL, isOn ? 127 : 0); // 1.65 V
}