#include <Arduino.h>
#include <SPI.h>      //for screen
#include <U8g2lib.h>  //for screen
#include <stdlib.h>
#include <Wire.h>                                       //for RTC
#include <DS3231.h>                                     //for RTC
#include "SparkFun_Ublox_Arduino_Library_Series_6_7.h"  //for gps
#include <TimeLib.h>                                    //https://github.com/PaulStoffregen/Time
//#include <Chronos.h>                                    //for easy date calc https://inductive-kickback.com/projects/chronos/
#include <SolarCalculator.h>  //https://github.com/jpb10/SolarCalculator
#include "I2C_eeprom.h"       //for EEPROM https://github.com/RobTillaart/I2C_EEPROM
#include "helperFunctions.h"
#include "images.h"
#include "pico/stdlib.h"

#define GPS_POWER_PIN 2
#define INTERRUPT_PIN 3

unsigned long timer = 0UL;
enum sunriseORSunset {
  SHOW_SUNRISE,
  SHOW_SUNSET
};
enum sunriseORSunset showSunriseOrSunset = SHOW_SUNSET;
//setup screen
U8G2_SH1106_128X64_NONAME_F_4W_HW_SPI u8g2(U8G2_R2, 17, 21, 20);
uint8_t *buf;
char outString[99];

//RTC setup
DS3231 rtc;
bool h12;
bool pmt;
bool setRtcDateAndTime = true;
bool setDate = true;
bool RTCsetTime = true;

//GPS setup
SFE_UBLOX_GPS myGPS;
double lat = 0;
double lng = 0;
bool isGPSOn = true;
bool doSunsetCalcs = true;
bool locationDataSet = false;

//sunset setup
int tzOff = 13;                                        //local TZ offset
bool centuryBit;                                       //needed to get month from RTC
double az, elev;                                       //for sun location in the sky
double transit, sunrise, sunset;                       //sun related times
double civilTransit, civilRiise, civilSet;             //astro related times
double nextDayTransit, nextDaySunrise, nextDaySunset;  // vars to be used for the following day cals
double nextDayCivilTransit, nextDayCivilRise, nextDayCivilSet;
char str[6];  //needed to convert hours to string

//setup EEPROM
//I2C_eeprom store(0x50, I2C_DEVICESIZE_24LC256);

struct locationData {
  double lat = 0;
  double lng = 0;
} location;

void gpsOff() {
  digitalWrite(GPS_POWER_PIN, LOW);
  isGPSOn = false;
}

void gpsOn() {
  digitalWrite(GPS_POWER_PIN, HIGH);
  isGPSOn = true;
}

void setLowCPUSpeed() {
  set_sys_clock_pll(900000000, 6, 6);  //set cpu to 15 MHZ
}

void setHighCPUSpeed() {
  set_sys_clock_pll(1596000000, 6, 2);  //set cpu to 133MHZ
}
/*
void wakeGPS() {
  setHighCPUSpeed();
  gpsOn();
  connectGPS();
  doSunsetCalcs = true;
}*/

void connectGPS() {  //need to do this everytime the GPS turns back on
  do {               //set gps to 115200 baudrate code comes from sparkfun examples
    Serial.println("GNSS: trying 115200 baud");
    Serial1.begin(115200);
    if (myGPS.begin(Serial1) == true) break;
    delay(100);
    Serial.println("GNSS: trying 9600 baud");
    Serial1.begin(9600);
    if (myGPS.begin(Serial1) == true) {
      Serial.println("GNSS: connected at 9600 baud, switching to 115200");
      myGPS.setSerialRate(115200);
      delay(100);
    } else {
      delay(2000);  //Wait a bit before trying again to limit the Serial output
    }
  } while (1);
  myGPS.setUART1Output(COM_TYPE_UBX);  //Set the UART1 port to output UBX only (turn off NMEA noise)
  myGPS.setNavigationFrequency(1);
  myGPS.setDynamicModel(DYN_MODEL_PORTABLE);
}

void setup() {
  //Screen setup
  u8g2.begin();
  u8g2.clearDisplay();
  u8g2.setPowerSave(0);
  u8g2.setFont(u8g2_font_ncenB14_tr);

  u8g2.clearBuffer();
  sprintf(outString, "SUNCLOCK");  //show start up text
  u8g2.drawStr(7, 35, outString);
  u8g2.sendBuffer();

  //interrupt pin
  // pinMode(INTERRUPT_PIN, INPUT_PULLUP);
  //attachInterrupt(digitalPinToInterrupt(INTERRUPT_PIN), wakeGPS, FALLING);

  //RTC setup
  Wire.begin();
  rtc.setClockMode(false);

  //GPS setup
  Serial1.setRX(1);
  Serial1.setTX(0);
  pinMode(GPS_POWER_PIN, OUTPUT_2MA);
  gpsOn();
  connectGPS();

  //RTC time set
  if (isGPSOn && myGPS.getPVT()) {  //myGPS.getPVT() will return true if data is available
    rtc.setYear(myGPS.getYear());
    rtc.setMonth(myGPS.getMonth());
    rtc.setDate(myGPS.getDay());
    rtc.setHour(myGPS.getHour());
    rtc.setMinute(myGPS.getMinute());
    rtc.setSecond(myGPS.getSecond());
  }

  if (isGPSOn && myGPS.getPVT()) {  //gps has to be on to set lat and long, once gps chords are set the gps is turned off so no need to set gps chords.
    lat = myGPS.getLatitude();
    lng = myGPS.getLongitude();
    lat = lat / 10000000;
    lng = lng / 10000000;
    locationDataSet = true;
    gpsOff();
  }
  timer = millis();  //get time so we only set the clock once per second
}

void loop() {

  if (isGPSOn && myGPS.getPVT()) {  //myGPS.getPVT() will return true if data is available
    rtc.setYear(myGPS.getYear());
    rtc.setMonth(myGPS.getMonth());
    rtc.setDate(myGPS.getDay());
    rtc.setHour(myGPS.getHour());
    rtc.setMinute(myGPS.getMinute());
    rtc.setSecond(myGPS.getSecond());
  }

  if (isGPSOn && myGPS.getPVT()) {  //gps has to be on to set lat and long, once gps chords are set the gps is turned off so no need to set gps chords.
    lat = myGPS.getLatitude();
    lng = myGPS.getLongitude();
    lat = lat / 10000000;
    lng = lng / 10000000;
    locationDataSet = true;
  }

  if (isGPSOn && lat != 0 && lng != 0) {
    gpsOff();
  }

  if (millis() > timer + 1000) {

    DateTime tm(rtc.getYear(), (int)rtc.getMonth(centuryBit), (int)rtc.getDate(), (int)rtc.getHour(h12, pmt), rtc.getMinute(), (int)rtc.getSecond());  //set date and time to use for the rest of the loop

    if (doSunsetCalcs) {
      //get sunset time
      calcSunriseSunset(tm.year(), tm.month(), tm.day(), lat, lng, transit, sunrise, sunset);
      //get civilSet time
      calcCivilDawnDusk(tm.year(), tm.month(), tm.day(), lat, lng, civilTransit, civilRiise, civilSet);

      //calcs for sunrise times
      uint16_t year = tm.year();
      uint16_t month = tm.month();
      uint16_t day = tm.day();

      if (((tm.hour() + tzOff) % 24) > 6) {  //only increment day if it is before midnight
        //detect when day is at the end of the month and increment month and set day to 1 otherwise increment day by 1
        if (month == 1 || month == 3 || month == 5 || month == 7 || month == 8 || month == 10 || month == 12) {
          if (day == 31) {
            if (month == 12) {
              year++;
              month = 1;
              day = 1;
            } else {
              month++;
              day = 1;
            }
          } else {
            day++;
          }
        } else if (month == 4 || month == 6 || month == 9 || month == 11) {
          if (day == 30) {
            month++;
            day = 1;
          } else {
            day++;
          }
        } else {
          if (month == 2) {
            if (year % 400 == 0 || year % 4 == 0) {  //special case for leap year
              if (day == 29) {
                month++;
                day = 1;
              } else {
                if (day == 28) {
                  month++;
                  day = 1;
                }
              }
            } else {
              day++;
            }
          }
        }
      }
      //calc sunrise times
      //calcSunriseSunset(tm.year(), tm.month(), tm.day(), lat, lng, nextDaySunrise, nextDaySunrise, nextDaySunset);
      calcSunriseSunset(year, month, day, lat, lng, nextDayTransit, nextDaySunrise, nextDaySunset);
      calcCivilDawnDusk(year, month, day, lat, lng, nextDayCivilTransit, nextDayCivilRise, nextDayCivilSet);
    }


    //get current time
    double dhour = tm.hour();
    double dmin = tm.minute();
    double dsec = tm.second();

    //calc time to sunset time
    double currentTimeInHours = dhour + (dmin / 60) + (dsec / 60 / 60);
    double TimeToSunset = sunset - currentTimeInHours;
    double timeTocivilSet = civilSet - currentTimeInHours;
    //calc time to sunrise time
    double timeToSunrise = nextDaySunrise + tzOff - currentTimeInHours + tzOff;  //+tzoff is a work around as library gives incorrect time
    double timeToCivilRise = nextDayCivilRise + tzOff - currentTimeInHours + tzOff;

    if (TimeToSunset < 0) {
      TimeToSunset = 0;
    }

    if (timeTocivilSet < 0) {
      timeTocivilSet = 0;
      showSunriseOrSunset = SHOW_SUNRISE;
    }

    if (timeToSunrise < 0) {
      timeToSunrise = 0;
      showSunriseOrSunset = SHOW_SUNSET;
    }
    if (timeToCivilRise < 0) {
      timeToCivilRise = 0;
    }

    u8g2.clearBuffer();
    sprintf(outString, "%.2f:%.2f", lat, lng);  //show location chords
    u8g2.drawStr(0, 35, outString);
    sprintf(outString, "%s", hoursToString(currentTimeInHours + tzOff, str));  //show current time
    u8g2.drawStr(0, 55, outString);
    if (showSunriseOrSunset == SHOW_SUNSET) {

      sprintf(outString, "%s", hoursToString(TimeToSunset, str));  //show time to sunset
      u8g2.drawStr(0, 15, outString);
      sprintf(outString, "%s", hoursToString(timeTocivilSet, str));  //show civilSet time
      u8g2.drawStr(75, 15, outString);
    }
    if (showSunriseOrSunset == SHOW_SUNRISE) {
      sprintf(outString, "%s", hoursToString(timeToSunrise, str));  //show time to sunrise
                                                                    // sprintf(outString, "%f", timeToSunrise);
      u8g2.drawStr(0, 15, outString);
      sprintf(outString, "%s", hoursToString(timeToCivilRise, str));  //show civilRise time
      u8g2.drawStr(75, 15, outString);
    }

    u8g2.sendBuffer();


    if (locationDataSet == true) {  //set to low power mode
      doSunsetCalcs = false;        //stop doing sunset calcs once we have the gps data.
      locationDataSet = false;      //this this to false because location data will need to be reset once GPS turns back on
      setLowCPUSpeed();
    }
    timer = millis();
  }

  if (BOOTSEL) {
    rp2040.rebootToBootloader();
  }
}