/**
  //   E-Jeep Charging
  //
  //   Copyright (C) 2023, Sephalias.
*/

#include <LiquidCrystal_I2C.h>
#include <Keypad.h>
#include <ctype.h>
#include <EEPROM.h>
// #include "ACS712.h"

// ACS712 sensor(ACS712_30A, A0);

/* Display setup */
LiquidCrystal_I2C lcd(0x27, 20, 4);

/* Keypad setup */
const byte KEYPAD_ROWS = 4;
const byte KEYPAD_COLS = 4;
byte rowPins[KEYPAD_ROWS] = {2, 3, 4, 5};
byte colPins[KEYPAD_COLS] = {6, 7, 8, 9};
char keys[KEYPAD_ROWS][KEYPAD_COLS] = {
    {'1', '2', '3', 'A'},
    {'4', '5', '6', 'B'},
    {'7', '8', '9', 'C'},
    {'.', '0', '#', 'D'}};

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, KEYPAD_ROWS, KEYPAD_COLS);

unsigned int mode = 0;
unsigned int settingsMode = 0;

// System States
bool confirm = false;
bool charging = false;
bool cancelled = false;
bool completed = false;

String input = "";

// VARIABLES: Amount Mode
float amount = 0.00f;

// VARIABLES: Time Mode
int seconds = 0;

// Sensor values
int adc_voltage = 0;
float voltage = 0.00;
float current = 0.00;

double energy;
float total_energy;

// VARIABLES: Rate
float rate = 0.0000f;
float price = 0.00;

unsigned long charging_time = 0;

unsigned long lastExecutedMillis = 0;

unsigned long lastMillisAbout = 0;
int aboutInterval = 3000;
bool aboutFirstPage = true;

bool cancelLED = false;
int interval = 2000;

unsigned int address = 0;
unsigned int length = EEPROM.length();

void setup()
{
  Serial.begin(115200);

  lcd.begin(20, 4);
  lcd.init();
  lcd.backlight();
  lcd.noBlink();

  pinMode(11, OUTPUT); // Relay
  pinMode(12, OUTPUT); // LED G
  pinMode(13, OUTPUT); // LED R

  pinMode(A0, INPUT); // Current Sensor
  pinMode(A1, INPUT); // Voltage Sensor

  digitalWrite(11, HIGH); // Set default state of relay

  Serial.println("Calibrating... Ensure that no current flows through the sensor at this moment");
  // int zero = sensor.calibrate();
  Serial.println("Done!");
  Serial.print("Zero point for this sensor = ");
  // Serial.println(zero);

  // ======== EEPROM ===========
  Serial.println("Initialize EEPROM...");
  Serial.print("EEPROM Length: ");
  Serial.println(length);

  // Read from EEPROM
  EEPROM.get(address, rate);

  if (isnan(rate))
  {
    Serial.println("EEPROM: EMPTY. Adding default values.");
    EEPROM.write(address, 0.00f); // Set value
    EEPROM.get(address, rate);    // Read again
    Serial.print("EEPROM data added: ");
    Serial.println(rate);
  }
  else
  {
    Serial.println("EEPROM: Has value.");
    Serial.print("EEPROM data: ");
    Serial.println(rate);
  }

  showSplashScreen();
  showMenuScreen();
}

unsigned long lastMillisEnergy = 0;

void loop()
{
  unsigned long currentMillis = millis();

  voltage = map(analogRead(A0), 0, 1023, 0, 70.0);

  current = map(analogRead(A1), 0, 1023, 0, 10.0);

  // adc_voltage = analogRead(A1);
  // voltage = (adc_voltage * 5.0) / 1023.0;
  // voltage = (voltage / 0.09090909091);

  // current = sensor.getCurrentDC();

  // if (current < 0.01)
  // {
  //   current = 0;
  // }

  float power = voltage * current;

  if (charging)
  {

    if (currentMillis - lastMillisEnergy >= 1000)
    {
      lastMillisEnergy = currentMillis;
      energy += (power / 3600); // in Wh
      Serial.print(energy);
      Serial.println(" Wh");
    }

    if (mode == 1)
      showChargingScreenAmount();
    if (mode == 2)
      showChargingScreenTime();
  }

  if (completed)
  {
    if (mode == 1)
      showChargeCompleteAmount();
    if (mode == 2)
      showChargeCompleteTime();
    charging = false;
  }

  char key = keypad.getKey();
  if (key)
  {
    processInput(key);
  }

  if (charging)
  {
    digitalWrite(11, LOW);
    digitalWrite(12, HIGH);
    digitalWrite(13, LOW);
  }
  else
  {
    digitalWrite(11, HIGH);
    if (cancelled)
    {
      if (currentMillis - lastExecutedMillis >= interval)
      {
        lastExecutedMillis = currentMillis;
        digitalWrite(12, cancelLED);
        cancelLED = !cancelLED;
      }
      showCancelledScreen();
    }
    else
    {
      digitalWrite(12, LOW);
      digitalWrite(13, HIGH);
    }
  }

  if (mode == 3 && settingsMode == 2)
  {
    if (currentMillis - lastMillisAbout >= aboutInterval)
    {
      lastMillisAbout = currentMillis;
      if (aboutFirstPage)
      {
        lcd.setCursor(0, 1);
        lcd.print("                    ");
        lcd.setCursor(0, 2);
        lcd.print("                    ");
        lcd.setCursor(0, 1);
        lcd.print("* Alemania, Ronn");
        lcd.setCursor(0, 2);
        lcd.print("* Carmona, Andrea");
      }
      else
      {
        lcd.setCursor(0, 1);
        lcd.print("                    ");
        lcd.setCursor(0, 2);
        lcd.print("                    ");
        lcd.setCursor(0, 1);
        lcd.print("* Ngalatan, Francis");
        lcd.setCursor(0, 2);
        lcd.print("* Quizon, John Lloyd");
      }
      aboutFirstPage = !aboutFirstPage;
    }
  }
}

String getTimeFromSeconds(int seconds) {
  unsigned int sec = seconds;
  unsigned int mins = seconds / 60;
  unsigned int hour = seconds / 3600;
  String timeString = String(hour) + "h " + String(mins % 60) + "m " + String(sec % 60) + "s";
  return timeString;
}


void writeRate(float newRate)
{
  Serial.print("EEPROM: Writing new rate ");
  Serial.println(newRate, 4);
  Serial.print("EEPROM: Previous data: ");
  Serial.println(rate, 4);
  EEPROM.put(address, newRate);
  EEPROM.get(address, rate);
  Serial.print("EEPROM: Data updated: ");
  Serial.println(rate);
}

void showSplashScreen()
{
  lcd.clear();
  lcd.setCursor(2, 1);
  lcd.print("E-Jeep Prepaid");
  lcd.setCursor(2, 2);
  String message = "Charging Station";
  for (byte i = 0; i < message.length(); i++)
  {
    lcd.print(message[i]);
    delay(50);
  }
  delay(2000);
}

void showMenuScreen()
{
  energy = 0.0;
  lcd.clear();
  lcd.noBlink();
  lcd.setCursor(0, 0);
  lcd.print("E-Jeep Charging");
  lcd.setCursor(0, 1);
  lcd.print("[A] Amount Mode");
  lcd.setCursor(0, 2);
  lcd.print("[B] Time Mode");
  lcd.setCursor(0, 3);
  lcd.print("[C] Set Mode");
  lcd.setCursor(17, 0);
  lcd.write(255);
  lcd.print(" M");
  lcd.setCursor(17, 1);
  lcd.write(255);
  lcd.print(" E");
  lcd.setCursor(17, 2);
  lcd.write(255);
  lcd.print(" N");
  lcd.setCursor(17, 3);
  lcd.write(255);
  lcd.print(" U");
}

unsigned long lastMillisUpdateAmount = 0;
bool updateAmount = true;

// Charging Screens

void showChargingScreenAmount()
{
  float target_energy = ((float)((float)amount * (float)((float)1 / (float)rate))*1000)/1000;
  if (energy >= target_energy)
  {
    charging = 0;
    completed = 1;
    updateAmount = true;
  }

  unsigned long currentMillis = millis();

  if (currentMillis - lastMillisUpdateAmount >= 1000)
  {
    lastMillisUpdateAmount = currentMillis;
    updateAmount = true;
  }

  lcd.noBlink();
  lcd.setCursor(0, 0);
  lcd.print("CHARGING: AMOUNT  D>");
  if (updateAmount)
  {
    lcd.setCursor(0, 1);
    lcd.print("                    ");
    lcd.setCursor(0, 1);
    lcd.print("PHP ");
    lcd.print(amount);

    lcd.setCursor(0, 2);
    lcd.print("                    ");
    lcd.setCursor(0, 2);
    lcd.print(energy);
    lcd.print("/");
    lcd.print(target_energy);
    lcd.print(" Wh");

    lcd.setCursor(0, 3);
    lcd.print("                    ");
    lcd.setCursor(0, 3);
    lcd.print("V: ");
    lcd.print(voltage);
    lcd.setCursor(9, 3);
    lcd.print(" A: ");
    lcd.print(current);

    updateAmount = false;
  }
}

unsigned long lastMillisUpdateTime = 0;
bool updateTime = true;

void showChargingScreenTime()
{
  if (seconds == 0)
  {
    charging = 0;
    completed = 1;
    updateTime = true;
  }

  unsigned long currentMillis = millis();

  if (currentMillis - lastMillisUpdateTime >= 1000)
  {
    lastMillisUpdateTime = currentMillis;
    seconds -= 1;
    updateTime = true;
  }

  lcd.noBlink();
  lcd.setCursor(0, 0);
  lcd.print("CHARGING: TIME    D>");
  if (updateTime)
  {
    lcd.setCursor(0, 1);
    lcd.print("                    ");
    lcd.setCursor(0, 1);
    lcd.print("Time ");
    lcd.print(getTimeFromSeconds(seconds));

    lcd.setCursor(0, 2);
    lcd.print("                    ");
    lcd.setCursor(0, 2);
    lcd.print(energy);
    lcd.print(" Wh");

    lcd.setCursor(0, 3);
    lcd.print("                    ");
    lcd.setCursor(0, 3);
    lcd.print("V: ");
    lcd.print(voltage);
    lcd.setCursor(9, 3);
    lcd.print(" A: ");
    lcd.print(current);

    updateTime = false;
  }
}

// Charging Complete Screens

bool chargeCompleteAmountClear = true;
void showChargeCompleteAmount()
{
  lcd.noBlink();
  if (chargeCompleteAmountClear)
  {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print(" CHARGING COMPLETE");
    lcd.setCursor(0, 1);
    lcd.print("Amount : PHP ");
    lcd.print(amount);
    lcd.setCursor(0, 2);
    lcd.print("Wh : ");
    lcd.print(energy);
    lcd.setCursor(0, 3);
    lcd.setCursor(14, 3);
    lcd.print("[D] OK");
    chargeCompleteAmountClear = false;
  }
}

bool chargeCompleteTimeClear = true;
void showChargeCompleteTime()
{
  lcd.noBlink();
  if (chargeCompleteTimeClear)
  {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("CHARGING COMPLETE");
    lcd.setCursor(0, 1);
    lcd.print("Time: ");
    lcd.print(getTimeFromSeconds(input.toInt() * 60));
    lcd.setCursor(0, 2);
    lcd.print("Pay : PHP ");
    lcd.print((rate * energy)/1000);
    lcd.setCursor(0, 3);
    lcd.print("Wh : ");
    lcd.print(energy);
    lcd.setCursor(14, 3);
    lcd.print("[D] OK");
    chargeCompleteTimeClear = false;
  }
}

// Charging Cancelled Screens

bool cancelledScreenClear = true;
void showCancelledScreen()
{
  if (cancelledScreenClear)
  {
    lcd.clear();
    lcd.noBlink();
    lcd.setCursor(0, 0);
    lcd.print("CHARGING CANCELLED");
    if (mode == 1)
    {
      lcd.setCursor(0, 1);
      lcd.print("Amount: ");
      lcd.print (amount);
      lcd.setCursor(0, 2);
      lcd.setCursor(0, 3);
      lcd.print("Wh : ");
      lcd.print (energy);
      lcd.setCursor(14, 3);
      lcd.print("[D] OK");
    }
    if (mode == 2)
    {
      lcd.setCursor(0, 1);
      lcd.print("Time: ");
      lcd.print(getTimeFromSeconds(input.toInt() * 60 - seconds));
      lcd.setCursor(0, 2);
      lcd.print("Pay : PHP ");
      lcd.print("amount");
      lcd.setCursor(0, 3);
      lcd.print("Wh : ");
      lcd.print("energy");
      lcd.setCursor(14, 3);
      lcd.print("[D] OK");
    }
    cancelledScreenClear = false;
  }
}

// Charging Configuration Screens

void enterAmountMode()
{
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("--- Enter Amount ---");
  lcd.setCursor(0, 2);
  lcd.print("          [#] ENTER");
  lcd.setCursor(0, 3);
  lcd.print("[C] DEL   [D] CANCEL");
  lcd.setCursor(0, 1);
  lcd.print("PHP ");
  lcd.setCursor(4, 1);
  lcd.print(input);
  lcd.blink();
}

void showAmountComfirmScreen()
{
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Confirm Amount");
  lcd.setCursor(0, 1);
  lcd.print("PHP ");
  lcd.print(input);
  lcd.setCursor(0, 2);
  lcd.print("Rate: ");
  lcd.print(rate);
  lcd.print("/kWh");
  lcd.setCursor(0, 3);
  lcd.print("    [D]CANCEL  [#]OK");
  lcd.noBlink();
}

void enterTimeMode()
{
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("--- Enter Time ---");
  lcd.setCursor(0, 2);
  lcd.print("          [#] ENTER");
  lcd.setCursor(0, 3);
  lcd.print("[C] DEL   [D] CANCEL");
  lcd.setCursor(0, 1);
  lcd.print("Min ");
  lcd.setCursor(4, 1);
  lcd.print(input);
  lcd.blink();
}

void showTimeComfirmScreen()
{
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Confirm Time");
  lcd.setCursor(0, 1);
  lcd.print("Time ");
  lcd.print(getTimeFromSeconds(input.toInt() * 60));
  lcd.setCursor(0, 2);
  lcd.print("Rate: PHP ");
  lcd.print(rate);
  lcd.print("/Ah");
  lcd.setCursor(0, 3);
  lcd.print("    [D]CANCEL  [#]OK");
  lcd.noBlink();
}

void showSettingsSetRate()
{
  input = rate;
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("----- Set Rate -----");
  lcd.setCursor(0, 2);
  lcd.print("    /kWh  [#] ENTER");
  lcd.setCursor(0, 3);
  lcd.print("[C] DEL   [D] CANCEL");
  lcd.setCursor(0, 1);
  lcd.print("PHP ");
  lcd.setCursor(4, 1);
  lcd.print(input.toFloat());
  lcd.blink();
}

void showSettingsAbout()
{
  lcd.clear();
  lcd.noBlink();
  lcd.setCursor(0, 0);
  lcd.print("       MEMBERS      ");
  lcd.setCursor(0, 3);
  lcd.print("            [D] Back");
}

void showSettingsSaved()
{
  lcd.clear();
  lcd.noBlink();
  lcd.setCursor(0, 0);
  lcd.print("------ SAVED! ------");
  lcd.setCursor(0, 1);
  lcd.write(255);
  lcd.print(" Rate: ");
  lcd.print(rate, 4);
  lcd.setCursor(0, 2);
  lcd.write(255);
  lcd.setCursor(8, 2);
  lcd.print("PHP/Ah");
  lcd.setCursor(0, 3);
  lcd.write(255);
  lcd.print("           [#] OK ");
  lcd.setCursor(19, 1);
  lcd.write(255);
  lcd.setCursor(19, 2);
  lcd.write(255);
  lcd.setCursor(19, 3);
  lcd.write(255);
}

void enterSetMode()
{
  lcd.clear();
  lcd.noBlink();
  lcd.setCursor(0, 0);
  lcd.print("      SETTINGS      ");
  lcd.setCursor(0, 1);
  lcd.print("[A] Set Rate");
  lcd.setCursor(0, 2);
  lcd.print("[B] About");
  lcd.setCursor(0, 3);
  lcd.print("            [D] Back");
}

void keyInput(char key)
{
  // Limit input to 4 charcaters for time, 12 characters for amount.
  if (mode == 2)
  {
    if (input.length() > 3)
    {
      return;
    }
  }
  if (mode == 1) {
  if (input.length() > 12)
  {
    return;
  }
}

  // Check if input is digit.
  if (key >= '0' && key <= '9')
  {
    // Check if input has decimal and limit decimal to 2 places.
    if (mode != 3)
    {
      if (input.indexOf(".") != -1 && input.substring(input.indexOf(".") + 1, input.length()).length() == 2)
      {
        return;
      }
    }
    else
    {
      if (input.indexOf(".") != -1 && input.substring(input.indexOf(".") + 1, input.length()).length() == 4)
      {
        return;
      }
    }

    input += key;
    lcd.print(key);
  }
  else if (key == '.')
  {
    if (mode == 2 || mode == 3)
    {
      // Restrict input to only one decimal.
      if (input.indexOf('.') < 0)
      {
        input += key;
        lcd.print(key);
      }
    }
  }
}

void processInput(char key)
{
  switch (mode)
  {
  case 0:
    switch (key)
    {
    case 'A':
      mode = 1;
      enterAmountMode();
      break;
    case 'B':
      mode = 2;
      enterTimeMode();
      break;
    case 'C':
      mode = 3;
      enterSetMode();
      break;
    default:
      break;
    }
    break;
  case 1:
    if (charging)
    {
      if (key == 'D')
      {
        charging = false;
        cancelled = true;
        break;
      }
      else
      {
        return;
      }
    }

    if (cancelled)
    {
      if (key == 'D')
      {
        showMenuScreen();
        input = "";
        mode = 0;
        cancelled = false;
        break;
      }
    }

    if (completed)
    {
      if (key == 'D')
      {
        showMenuScreen();
        input = "";
        mode = 0;
        completed = false;
        break;
      }
    }

    if (confirm)
    {
      if (key == '#')
      {
        if (input.length() <= 0)
          return;
        charging = true;
        confirm = false;
        amount = input.toFloat();
        lcd.clear();
        break;
      }
      if (key == 'D')
      {
        confirm = false;
        enterAmountMode();
        break;
      }
    }

    if (!confirm && key == 'C')
    {
      input.remove(input.length() - 1);
      lcd.setCursor(4 + input.length(), 1);
      lcd.print(" ");
      lcd.setCursor(4, 1);
      lcd.print(input);
      break;
    }

    if (key == '#')
    {
      confirm = true;
      showAmountComfirmScreen();
      break;
    }

    if (key == 'D')
    {
      showMenuScreen();
      input = "";
      mode = 0;
      break;
    }

    keyInput(key);

    break;
  case 2:
    if (charging)
    {
      if (key == 'D')
      {
        charging = false;
        cancelled = true;
        break;
      }
      else
      {
        return;
      }
    }

    if (cancelled)
    {
      if (key == 'D')
      {
        showMenuScreen();
        input = "";
        mode = 0;
        cancelled = false;
        cancelledScreenClear = true;
        break;
      }
    }

    if (completed)
    {
      if (key == 'D')
      {
        showMenuScreen();
        input = "";
        completed = false;
        chargeCompleteTimeClear = true;
        mode = 0;
        break;
      }
    }

    if (confirm)
    {
      if (key == '#')
      {
        if (input.length() <= 0)
          return;
        charging = true;
        confirm = false;
        seconds = input.toInt() * 60;
        lcd.clear();
        break;
      }
      if (key == 'D')
      {
        confirm = false;
        enterTimeMode();
        break;
      }
    }

    if (!confirm && key == 'C')
    {
      input.remove(input.length() - 1);
      lcd.setCursor(4 + input.length(), 1);
      lcd.print(" ");
      lcd.setCursor(4, 1);
      lcd.print(input);
      break;
    }

    if (key == '#')
    {
      if (input.toInt() == 0)
        return;
      confirm = true;
      showTimeComfirmScreen();
      break;
    }

    if (key == 'D')
    {
      showMenuScreen();
      input = "";
      mode = 0;
      break;
    }

    keyInput(key);

    break;
  case 3:
    switch (settingsMode)
    {
    case 0:
      if (key == 'A')
      {
        showSettingsSetRate();
        settingsMode = 1;
        break;
      }
      if (key == 'B')
      {
        showSettingsAbout();
        settingsMode = 2;
        break;
      }
      if (key == 'D')
      {
        showMenuScreen();
        mode = 0;
        break;
      }
      break;
    case 1:
      if (key == 'C')
      {
        input.remove(input.length() - 1);
        lcd.setCursor(4 + input.length(), 1);
        lcd.print(" ");
        lcd.setCursor(4, 1);
        lcd.print(input);
        break;
      }
      if (key == 'D')
      {
        enterSetMode();
        settingsMode = 0;
        input = "";
        break;
      }
      if (key == '#')
      {
        writeRate(input.toFloat());
        showSettingsSaved();
        settingsMode = 3;
        input = "";
        break;
      }
      keyInput(key);
      break;
    case 2:
      if (key == 'D')
      {
        enterSetMode();
        settingsMode = 0;
        break;
      }
      break;
    case 3:
      if (key == '#')
      {
        enterSetMode();
        settingsMode = 0;
        break;
      }
      break;
    }
    break;
  }

  Serial.println("mode " + String(mode));
  Serial.println("settings " + String(settingsMode));
  Serial.println("input " + String(input));
  Serial.println("confirm " + String(confirm));
  Serial.println("cancelled " + String(cancelled));
  Serial.println("charging " + String(charging));
  Serial.println("complete " + String(completed));
  Serial.println();
}