// Librarys
#include <LiquidCrystal.h>
#include <IRremote.h>
#include <EEPROM.h>

// Const Variable
#define TRIGGER_PIN 4
#define ECHO_PIN 3
#define BUTTON_PIN 2
#define LED_1_PIN 12
#define LED_2_PIN 11
#define LED_3_PIN 10
#define PHOTORESISTOR_PIN A0
#define IRRECEIVER_PIN 5

#define MAX_PAGE 3
#define ULTRASONIC_UNIT_ROW 10
#define ULTRASONIC_DEFAULT_UNIT 1
#define DEFAULT_PAGE 1

// Variables
int LCDPIN[6] = { 168, 144, 224, 176, 162 };
// Play, Up, Down, EQ, Power
constexpr int IRRemoteCode[5] = { 5, 10, 8, 13, 0 };
unsigned long ultrasonicTimeToSub = millis();
unsigned long ultrasonicDelayTime = 60;
volatile unsigned long ultrasonicTimeBegin;
volatile unsigned long ultrasonicTimeEnd;
volatile bool isDistanceAvialable = false;
double UltrasonicDistance;
double perviousDistance = 400.0;
double maxDistance1 = 10;
bool lockApplication = false;
unsigned long buttonTimeToSub = millis();
unsigned long buttonDelay = 50;
byte buttonState = LOW;
unsigned long LED1TimeToSub = millis();
unsigned long LED1DelayTime = 300;
byte LED1State = LOW;
unsigned long LED2TimeToSub = millis();
unsigned long LED2DelayTime;
byte LED2State = LOW;
int ultrasonicUnit = 1;
int LCDPage = 1;
int LCDPage1 = 1;
double maxDistance2 = 10;

// Functions
void triggerUltrasonic() {
  digitalWrite(TRIGGER_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIGGER_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIGGER_PIN, LOW);
}

void interruptsUltrasonic() {
  if (digitalRead(ECHO_PIN) == HIGH) {
    ultrasonicTimeBegin = micros();
  } else {
    ultrasonicTimeEnd = micros();
    isDistanceAvialable = true;
  }
}

double getUltrasonicDistance() {
  long durationMicro = ultrasonicTimeEnd - ultrasonicTimeBegin;
  double distance = durationMicro / 58.0;
  if (distance > 401.0) {
    return perviousDistance;
  }
  distance = distance * 0.9 + perviousDistance * 0.1;
  perviousDistance = distance;
  return distance;
}

// OUTSIDE SETUP
LiquidCrystal lcd(LCDPIN[0], LCDPIN[1], LCDPIN[2], LCDPIN[3], LCDPIN[4], LCDPIN[5]);

// Main Setup
void setup() {
  // put your setup code here, to run once:
  pinMode(TRIGGER_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(BUTTON_PIN, INPUT);
  pinMode(LED_1_PIN, OUTPUT);
  pinMode(LED_2_PIN, OUTPUT);
  pinMode(LED_3_PIN, OUTPUT);
  lcd.begin(16, 2);
  lcd.setCursor(0, 0);
  lcd.print("Initializing... ");
  lcd.setCursor(0, 1);
  lcd.print("                ");
  Serial.begin(115200);
  IrReceiver.begin(IRRECEIVER_PIN);
  UltrasonicDistance = 400.0;
  delay(1000);
  lcd.setCursor(0, 0);
  lcd.print("Loading...      ");
  lcd.setCursor(0, 1);
  lcd.print("                ");
  if (EEPROM.read(ULTRASONIC_UNIT_ROW) > 2 || EEPROM.read(ULTRASONIC_UNIT_ROW) <= 0) {
    EEPROM.write(ULTRASONIC_UNIT_ROW, ULTRASONIC_DEFAULT_UNIT);
  }
  ultrasonicUnit = EEPROM.read(ULTRASONIC_UNIT_ROW);
  LCDPage = DEFAULT_PAGE;
  delay(500);
  attachInterrupt(digitalPinToInterrupt(ECHO_PIN), interruptsUltrasonic, CHANGE);
}

// Main Loop
void loop() {
  // put your main code here, to run repeatedly:
  unsigned long timeNow = millis();

  if (timeNow - ultrasonicTimeToSub > ultrasonicDelayTime) {
    ultrasonicTimeToSub += ultrasonicDelayTime;
    triggerUltrasonic();
  }

  if (isDistanceAvialable) {
    isDistanceAvialable = false;
    UltrasonicDistance = getUltrasonicDistance();
  }

  double luminosity = analogRead(PHOTORESISTOR_PIN);
  double brightness = 255 - luminosity / 4;
  analogWrite(LED_3_PIN, brightness);

  if (luminosity < maxDistance2) {
    lockApplication = true;
  }

  if (UltrasonicDistance < maxDistance1) {
    lockApplication = true;
  }

  if (timeNow - buttonTimeToSub > buttonDelay) {
    byte newButtonState = digitalRead(BUTTON_PIN);
    if (buttonState != newButtonState) {
      buttonTimeToSub = timeNow;
      buttonState = newButtonState;
      if (buttonState == LOW) {
        lockApplication = false;
      }
    }
  }

  if (lockApplication) {
    lcd.setCursor(0, 0);
    lcd.print("    !Locked!    ");
    lcd.setCursor(0, 1);
    lcd.print("Press to Unlock.");
    if (timeNow - LED1TimeToSub > LED1DelayTime) {
      LED1TimeToSub += LED1DelayTime;
      if (LED1State == HIGH) {
        LED1State = LOW;
      } else {
        LED1State = HIGH;
      }
    }
    LED2State = LED1State;
  } else {
    if (LCDPage1 == 1) {
      lcd.setCursor(0, 0);
      lcd.print("Dist: ");
      if (ultrasonicUnit == 1) {
        lcd.print(UltrasonicDistance);
        lcd.print(" cm       ");
      } else {
        lcd.print((UltrasonicDistance * 58.0) / 148.0);
        lcd.print(" in        ");
      }
      lcd.setCursor(0, 1);
      if (UltrasonicDistance > 10 && UltrasonicDistance < 50) {
        lcd.print("   !Warning!    ");
      } else {
        lcd.print("  No Obstacle.  ");
      }
    } else if (LCDPage1 == 2) {
      lcd.setCursor(0, 0);
      lcd.print("Press on OFF to ");
      lcd.setCursor(0, 1);
      lcd.print("reset settings. ");
    } else if (LCDPage1 == 3) {
      lcd.setCursor(0, 0);
      lcd.print("Luminosity: ");
      lcd.print(luminosity);
      lcd.print("                ");
      lcd.setCursor(0, 1);
      lcd.print("                ");
    } else if (LCDPage1 == 4) {
      lcd.setCursor(0, 0);
      lcd.print("Settings have   ");
      lcd.setCursor(0, 1);
      lcd.print("been reset.     ");
    }

    LED1State = LOW;

    if (timeNow - LED2TimeToSub > LED2DelayTime) {
      LED2TimeToSub += LED2DelayTime;
      if (LED2State == HIGH) {
        LED2State = LOW;
      } else {
        LED2State = HIGH;
      }
    }
  }

  LED2DelayTime = UltrasonicDistance * 4;
  digitalWrite(LED_2_PIN, LED2State);
  digitalWrite(LED_1_PIN, LED1State);

  if (IrReceiver.decode()) {
    int command = IrReceiver.decodedIRData.command;
    Serial.println(command);
    switch (command) {
      case IRRemoteCode[0]:  // Play
        lockApplication = false;
        break;
      case IRRemoteCode[1]:  // UP
        if (!lockApplication) {
          LCDPage++;
          if (LCDPage > MAX_PAGE) {
            LCDPage = 1;
          }
          if (LCDPage1 == 4) {
            LCDPage = 1;
          }
          LCDPage1 = LCDPage;
        }
        break;
      case IRRemoteCode[2]:  // Down
        if (!lockApplication) {
          LCDPage--;
          if (LCDPage == 0) {
            LCDPage = MAX_PAGE;
          }
          if (LCDPage1 == 4) {
            LCDPage = 1;
          }
          LCDPage1 = LCDPage;
        }
        break;
      case IRRemoteCode[3]:  // EQ
        if (!lockApplication) {
          if (LCDPage == 1) {
            if (ultrasonicUnit == 1) {
              ultrasonicUnit = 2;
            } else {
              ultrasonicUnit = 1;
            }
            EEPROM.write(ULTRASONIC_UNIT_ROW, ultrasonicUnit);
          }
        }
        break;
      case IRRemoteCode[4]:  // POWER
        if (!lockApplication) {
          if (LCDPage == 2) {
            ultrasonicUnit = ULTRASONIC_DEFAULT_UNIT;
            EEPROM.write(ULTRASONIC_UNIT_ROW, ULTRASONIC_DEFAULT_UNIT);
            LCDPage1 = 4;
          }
        }
        break;
    }
    IrReceiver.resume();
  }
}