#include <LiquidCrystal.h>
#include <Keypad.h>
#include <Servo.h>

#define TICKS_PER_SECOND 60

/* Display */
LiquidCrystal lcd(12, 11, 10, 9, 8, 7);

/* Keypad setup */
const byte KEYPAD_ROWS = 4;
const byte KEYPAD_COLS = 4;
byte rowPins[KEYPAD_ROWS] = { 5, 4, 3, 2 };
byte colPins[KEYPAD_COLS] = { A3, A2, A1, A0 };
char keys[KEYPAD_ROWS][KEYPAD_COLS] = {
  { '1', '2', '3', '+' },
  { '4', '5', '6', '-' },
  { '7', '8', '9', '*' },
  { '.', '0', '=', '/' },
};

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

uint64_t value = 0;

void showSpalshScreen(void)
{
     lcd.setCursor(4, 0);
     lcd.print("Welcome!");
     lcd.setCursor(3, 1);
     String message = "Calculator";
     for (byte i = 0; i < message.length(); i++)
     {
          lcd.print(message[i]);
          delay(50);
     }
     delay(500);
}

void updateCursor(void)
{
     if (millis() / 250 % 2 == 0)
     {
          lcd.cursor();
     }
     else
     {
          lcd.noCursor();
     }
}

void setup()
{
     Serial.begin(115200);
     lcd.begin(16, 2);

     showSpalshScreen();
     lcd.clear();
     lcd.cursor();

     lcd.setCursor(1, 0);
}

char operation = 0;
String memory = "";
String current = "";
uint64_t currentDecimal;
bool decimalPoint = false;
char nextKey = '2';
bool secretMode = false;

double calculate(char operation, double left, double right)
{
     switch (operation)
     {
     case '+': return left + right;
     case '-': return left - right;
     case '*': return left * right;
     case '/': return left / right;
     }
}

char gameID = '0';
int jumperObstacle = -1;
int jumperObstacleY = 1;
int jumperJumpTime = 0;
int walkerPosX = 0;
int walkerPosY = 0;

void setClear()
{
     lcd.clear();
     lcd.setCursor(0, 0);
}

void processGameWalker(char key)
{
  lcd.clear();
  if(key == '2')
  {
    walkerPosY -= 1;
  }
  if(key == '5')
  {
    walkerPosY += 1;
  }
  if(key == '4')
  {
    walkerPosX -= 1;
  }
  if(key == '6')
  {
    walkerPosX += 1;
  }

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

  if(walkerPosY > 1)
  {
    walkerPosY = 1;
  }
  
  if(walkerPosX < 0)
  {
    walkerPosX = 0;
  }

  if(walkerPosX > 16)
  {
    walkerPosX = 16;
  }

  lcd.setCursor(walkerPosX, walkerPosY);
}

void processGameJumper(char key)
{
     if(key == '2')
     {
          jumperJumpTime += TICKS_PER_SECOND;
          if(jumperJumpTime > TICKS_PER_SECOND * 2)
          {
               jumperJumpTime = TICKS_PER_SECOND * 2;
          }
     }

     if(key == '5')
     {
          jumperJumpTime = 0;
     }
}

void GameWalkerUpdate(void)
{
  lcd.
}

void GameJumperUpdate(void)
{
     static uint64_t ticks = 0;
     ticks++;
     lcd.clear();
     int y = 1;
     if (jumperJumpTime != 0)
     {
          y = 0;
          jumperJumpTime--;
     }
     if(ticks % (TICKS_PER_SECOND / 2) == 0)
     {
          if(--jumperObstacle <= 0)
          {
               jumperObstacle = 16;
               jumperObstacleY = rand() % 2 == 0 ? 1 : 0;
          }
     }
     
     lcd.setCursor(5, y);
     lcd.print("&");
     lcd.setCursor(jumperObstacle, jumperObstacleY);
     lcd.print("#");

     if(jumperObstacle == 4 && y == jumperObstacleY)
     {
          lcd.clear();
          lcd.setCursor(4, jumperObstacleY);
          lcd.print("YOU LOST");
          gameID = 0;
          jumperObstacle = -1;
          jumperJumpTime = 0;
          jumperObstacleY = 1;
          ticks = 0;
     }
}

void processSecretMode(char key)
{
     Serial.println(key);
     if (key == '=')
     {
          lcd.clear();
          lcd.setCursor(2, 0);
          lcd.print("Secret  mode");
          gameID = '0';
          return;
     }
     if ('.' == key)
     {
          lcd.clear();

          secretMode = false;
          gameID = 0;
          return;
     }

     switch (gameID)
     {
     case '0':
          Serial.println("Setting game...");
          gameID = key;
          break;
     case '1':
          processGameWalker(key);
          break;
     case '2':
          processGameJumper(key);
          break;
     default:
          Serial.println("Unknown game");
     break;
     }
}

void secretModeUpdate(void)
{
     switch (gameID)
     {
     case '1':
          GameWalkerUpdate();
          break;
     case '2':
          GameJumperUpdate();
          break;
     }
}

void processInput(char key)
{
     if (secretMode)
     {
          processSecretMode(key);
     }
     else
     {
          if (nextKey == key)
          {
               switch (nextKey)
               {
               case '2':
                    nextKey = '1';
                    break;
               case '1':
                    nextKey = '3';
                    break;
               case '3':
                    nextKey = '7';
                    break;
               case '7':
                    nextKey = '=';
                    break;
               case '=':
                    secretMode = true;
                    return;
               default:
                    nextKey = '2';
                    return;
               }

          }
          if ('-' == key && current == "")
          {
               current = "-";
               lcd.print("-");
               return;
          }
          else if ('-' == key && current == "-")
          {
               current = "";
               lcd.setCursor(1, 1);
               lcd.print(" ");
               lcd.setCursor(1, 1);
          }

          switch (key)
          {
          case '+':
          case '-':
          case '*':
          case '/':
               if (!operation)
               {
                    memory = current;
                    current = "";
               }
               operation = key;
               lcd.setCursor(0, 1);
               lcd.print(key);
               lcd.setCursor(current.length() + 1, 1);
               return;

          case '=':
               float leftNum = memory.toDouble();
               float rightNum = current.toDouble();
               memory = String(calculate(operation, leftNum, rightNum));
               current = "";
               lcd.clear();
               lcd.setCursor(1, 0);
               lcd.print(memory);
               lcd.setCursor(0, 1);
               lcd.print(operation);
               return;

          }

          if ('.' == key && current.indexOf('.') >= 0)
          {
               return;
          }

          if ('.' != key && current == "0")
          {
               current = String(key);
          }
          else if (key)
          {
               current += String(key);
          }

          lcd.print(key);
     }
}

void loop()
{
     delay(1000 / TICKS_PER_SECOND);
     if (!secretMode)
     {
          updateCursor();
     }

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

     if (secretMode)
     {
          secretModeUpdate();
     }
}