// Include the required Arduino libraries:
#include <LedControl.h>
#include <EEPROM.h>

//define pin outputs for LedMatrix
int DIN = 11; //data input
int CS = 12; //control system input
int CLK = 13; //clock input

//byte map for checkmark display
byte checkmark [8] = {
  B10000000,B01000000,B00100000,B00010000,B00001000,B00000101,B00000010,B00000000
};

//byte map for cross display
byte cross [8] = {
  B10000001,B01000010,B00100100,B00011000,B00011000,B00100100,B01000010,B10000001
};

//byte map for circle display
byte circle [8] = {
  B00111100,B01000010,B10000001,B10000001,B10000001,B10000001,B01000010,B00111100
};

//byte map for square display
byte sqr [8] = {
  B00000000,B01111110,B01000010,B01000010,B01000010,B01000010,B01111110,B00000000
};

//byte map for target display
byte target [8] = {
  B00111100,B01000010,B10011001,B10100101,B10100101,B10011001,B01000010,B00111100
};

//define pins used for LedMatrix as well as number of devices in chain
LedControl lc=LedControl(DIN, CLK, CS,0); // 0 means 1 device in chain

const int numRows = 4;        //number of keypad rows
const int numCols = 4;        //number of keypad columns
const int debounceTime = 20;  //number of ms for debounce
const int maxChars = 9;       //maximum characters for passcodes

//list of access codes
const String defaultPassCodes[4] = {"EEE20003","100997445","103182927","101957275"};

// keymap defines character returned when corresponding key is pressed
const char keymap[numRows][numCols] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};

//determining pins for rows and columns
const int rowPins[numRows] = {9,8,7,6};
const int colPins[numCols] = {5,4,3,2};

/*-----------------------SETUP-----------------------*/
void setup() {

  Serial.begin(9600); //start up serial monitor
  
  lc.shutdown(0,false); //turn on ledcontrol system
  lc.setIntensity(0,15); // set led intensity
  lc.clearDisplay(0); //clear led display

  for (int row = 0; row < numRows; row++){
    pinMode(rowPins[row],INPUT);        //set row pins as input
    digitalWrite(rowPins[row], HIGH);   //turn on Pull-ups
  }
  for (int column = 0; column < numCols; column++){
    pinMode(colPins[column],OUTPUT);        //set column pins as output for writing
    digitalWrite(colPins[column], HIGH);   //deactivate columns
  }

}

/*-----------------------LOOP-----------------------*/
void loop() {

  delay(500);
  Serial.println("\n-------- Welcome to the Access Control System -------\n");

  /*---Keypad Entry---*/
  delay(500);
  Serial.println("------------ Keypad Online -----------");
  keypad();
  
  /*---Menu Options---*/
  Serial.println("\n--------Welcome to the Access Control System-------\n");
  Serial.println("Menu Options: ");
  Serial.println("  1 : Change Passcodes");
  Serial.println("  2 : Retrieve Temperature Data");
  Serial.println("  3 : Access Keypad");
  while(Serial.available() > 0) Serial.read();
  
  int select = menuSelect();

  switch (select) {
    case 1: 
      /*---Passcode Change---*/
      Serial.println("--------Passcode Change Placeholder-------");
      break;
    case 2:
      /*---Sensor Data---*/
      Serial.println("--------Retrieve Temperature Data-------");
      Serial.println(getTemperature());
      break;
    case 3:
      /*---Keypad Entry---*/
      Serial.println("------------Keypad-----------");
      keypad();
  }
  delay(500);
}

//function to access system via default passcode in serial monitor
bool serialPass() {

  String input = "";
  Serial.println("Enter passcode in Serial Monitor to unlock Keypad: ");
  Serial.println("Hint: it's EEE20003");

  while (true) {

    delay(100);
    if (Serial.available() > 0) {
      input = Serial.readString();
      input.trim();
    }
    while(Serial.available() > 0) {Serial.read();}

    if (input != "") {
      Serial.println(input);
      if (input == readFromEEPROM(0)){
        Serial.println("\nKeypad Unlocked.\n");
        return true;
      }
      else { 
        Serial.println("Invalid passcode. Try again :");
        input = "";
      }
        
    }   
  } 
}

//function to display main menu
int menuSelect(){

  while (true){
    if (Serial.available() > 0) {
      char input = Serial.read();

      if (input == '1'){
        Serial.println("\n1");
        return 1;
      }
      else if (input == '2'){
        Serial.println("\n2");
        return 2;
      }
      else if (input == '3') {
        Serial.println("\n3");
        return 3;
      }
      else {
        Serial.println("\nUnknown Input");
      }
    }
    while(Serial.available() > 0) Serial.read();
    delay(500);
  }
}

//function to use keypad
void keypad() {
  String passEnter = "";
  int count = 0;
  String passCheck = "";

  Serial.println("Select User");
  if (Serial.available() > 0){
    
    int UserCheck = Serial.read();
    passCheck = defaultPassCodes[UserCheck];

  }


  while (true) {
    Serial.println("Enter passcode on Keypad: ");
    while (count < 9){
      char key = getKey();
      if (key != 0){                             //checks for not 0
        Serial.print(key);
        if (key == passCheck.charAt(count)){
          passEnter = passEnter + key;
          count += 1;
        }
      else if (key != passCheck.charAt(count)){
        ledDisplay(cross,5000);
        break;
      }
      }
    }
    /*---Check Keypad Entry---*/
    if (checkPasscode(passEnter)) { 
      break; 
    }
    else { 
      passEnter = ""; 
      count = 0;
    }
  }
}

//function to return the pressed key, or '0' if no key is pressed
char getKey() {
  char key = 0;                                      //sets 0 as no key pressed

  for (int column = 0; column < numCols; column++){
    digitalWrite(colPins[column], LOW);              //activates current column
    for (int row = 0; row < numRows; row++){         //scan rows for key press
      if(digitalRead(rowPins[row]) == LOW){          
        delay(debounceTime);        
        while (digitalRead(rowPins[row]) == LOW)
          ;                                          //wait for key to be released
        key = keymap[row][column];
      }
    }
    digitalWrite(colPins[column], HIGH);             //deactivate current column
  }
  return key;                                        //returns character of key press, or 0
}

//function to read temperature from sensor
String getTemperature() {

  float BETA = 3950;
  bool metricCelsius;
  String temp;

  Serial.println("Choose metric to read temperature: ");
  Serial.println("1 : Celsius");
  Serial.println("2 : Fahrenheit");
  Serial.println();

  while (true){

    if (Serial.available() > 0) {
        
      char selection = Serial.read();

      if (selection == '1'){
        metricCelsius = true;
        break;
      }
      else if (selection == '2'){
        metricCelsius = false;
        break;
      }
      else {
        Serial.println("Please enter value '1' (Celsius) or '2' (Fahrenheit).\n");
      }
    }

    while(Serial.available() > 0) {Serial.read();}
    delay(500);
  }

  int analogValue = analogRead(A0);
  float celsius = 1 / (log(1 / (1023. / analogValue - 1)) / BETA + 1.0 / 298.15) - 273.15;
  float fahren = celsius * 1.8 + 32;

  if (metricCelsius) {
    temp = "Temperature: "+String(celsius)+" C";
  }
  else {
    temp = "Temperature "+String(fahren)+" F";
  }
  return temp;
}

//function to write passcode to EEPROM
void writeToEEPROM(String passcode, int passIndex) {

  char passcodeArray[maxChars];

  passcode.toCharArray(passcodeArray,maxChars+1);

  for (int i = 0; i < maxChars+1; i++){
        EEPROM.write((passIndex*(maxChars+1))+i, passcodeArray[i]);
      }
}

//function to read passcode from EEPROM
String readFromEEPROM(int passIndex) {

  String passRead = "";

  for (int i = 0; i < maxChars; i++){
    char digit = EEPROM.read((10*passIndex)+i);
    if (isAlphaNumeric(digit)) {
      passRead = passRead + digit;
    }
  }

  return passRead;
}

//function to compare keypad entry to list of stored passcodes
bool checkPasscode(String passEnter) {

  bool access = false;

  for (int codeNum = 0; codeNum < sizeof(defaultPassCodes)/sizeof(defaultPassCodes[0]); codeNum++){
    if (passEnter == defaultPassCodes[codeNum]){
      access = true;
      break;
    }
  }
  if (access == true){
    Serial.println("\n\n**** Access Granted. ****");

    //display positive access response
    for (int i=0;i<8;i++){
    lc.setRow(0,i,checkmark[i]);   
    }  
  
    delay(2000);
    lc.clearDisplay(0);

    //series of if statements to identify and display
    //specific bitmap to individual passcodes
    if (passEnter == defaultPassCodes[1]){
      
      for (int i=0;i<8;i++){
      lc.setRow(0,i,circle[i]);   
      }  
  
     delay(3000);
     lc.clearDisplay(0);
    }

    if (passEnter == defaultPassCodes[2]){
      
      for (int i=0;i<8;i++){
      lc.setRow(0,i,sqr[i]);   
      }  
  
     delay(3000);
     lc.clearDisplay(0);
    }

    if (passEnter == defaultPassCodes[3]){
      
      for (int i=0;i<8;i++){
      lc.setRow(0,i,target[i]);   
      }  
  
     delay(3000);
     lc.clearDisplay(0);
    }  
  }
  else { 
    Serial.println("\n\n**** Access Denied. ****");
    
    //display negative access response
    for (int i=0;i<8;i++){
    lc.setRow(0,i,cross[i]);
    }
   
    delay(3000);
    lc.clearDisplay(0);
    }
  return access;


}