#include <EEPROM.h>

/*
TO DO
 - Check 24VDC status
 - Proper .csv logging format w/ toggle
*/

#define ERROR_STATE 99
#define FINISHED_STATE 50




//Pins
const int PUMPS_PIN = 10;                     //Pump control PWM signal goes to DIN rail mounted Crydom MOSFET-ish
const int FAN_PIN = 11;                       //Fanc control PWM signal goes to DIN rail mounted Crydom MOSFET-ish




/////////////////// FUNCTION INITS ///////////////////
void serialReciever();
void printInstructions();
bool isValidPwmNumber(char input[32]);
bool isValidPwmCommand(char input[32]);
void printEndMarker();
void runPumps(uint8_t _pwm);
void runFan(uint8_t _pwm);


// TaskScheduler Callback methods:
void logTaskCallback();
void readFlowTaskCallback();




/////////////////// VARIABLES ///////////////////
uint8_t state = 0;
uint32_t stateTimer = 0;
uint32_t currentMillis, lastMillis;

uint8_t fanPwm = 0;
uint8_t fanMaxPwm = 100;
uint8_t pumpsPwm = 0;
char pwmCommandPrefix[] = {'p', 'f'};
const int eeAddress1 = 4;
uint32_t cycleNumber;
uint32_t numberToBeReached = 10000;
uint32_t lastSave;
uint32_t saveNumber;
String errorMessage;
uint32_t f = 0; //EEPROM storage bullshit


bool runProgram = false;
bool log1 = false;
bool log2 = false;       //second pressure sensor
bool csvLogFlag = false;
bool fastLog = false;      //log flag for fast logging during pressure rise




//Serial reading
const byte numChars = 32;
char receivedChars[numChars];
bool newData = false;
bool sendEcho = false;
char endMarker = '\n';



/////////////////// SETUP ///////////////////
void setup() {
  pinMode(FAN_PIN, OUTPUT);
  pinMode(PUMPS_PIN, OUTPUT);
  //PINMODE FOR FLOW INTERRUPTS??

  Serial.begin(115200);

  //Boot sequence
  Serial.println(' ');
  Serial.println("...booting");
  printEndMarker();
  printInstructions();


}//end setup



/////////////////// LOOP ///////////////////
void loop() {
  currentMillis = millis();  

  
  if (runProgram == true) {
    
    switch (state) {
      case 0://START STATE RUNS ONCE
        Serial.println("---------------");
        Serial.println("no program");

        stateTimer = currentMillis;
        state++;
        break;
      
      case 1://WAIT STATE     
        if( currentMillis >= stateTimer + 1000){
          state == FINISHED_STATE;
        }
        break;
      

      case FINISHED_STATE:
       
        Serial.println("Program finished!");
        runProgram = false;
        csvLogFlag = false;
        break;

      case ERROR_STATE://ERROR STATE, REQUIRES MANUAL RESET TO GET OUT OF
        Serial.println(errorMessage);
        runProgram = false;

        break;
          
    
    }//end program switch

    
    
    
  }//end of program
  

  if(fanPwm > 125 ) {fanPwm = 0; } //turn off fan if accidentally try and feed it more than 12V
  serialReciever();
}//end loop


void runPumps(uint8_t _pwm){
  pumpsPwm = _pwm;
  analogWrite(PUMPS_PIN, pumpsPwm);
}

void runFan(uint8_t _pwm){
  fanPwm = _pwm;
  analogWrite(FAN_PIN, fanPwm);
}





/////////////////// SERIAL COMMUNICATION ///////////////////


void printEndMarker(){
  if( endMarker == '\n' ){ Serial.println("New Line must be used as end marker"); }
  if (endMarker == '\r' ){ Serial.println("Carriage Return must be used as end marker"); } 
}

bool isValidPwmNumber(char input[32]){ 

  for( int i=0 ; i<32 ; i++){
    if( !isdigit(input[i]) && input[i] != '\0' ){
      //Serial.print("Char at index ");
      //Serial.print(i);
      //Serial.println(" was not a digit");
      return false;
      break;
    } 
  }

  if( atoi(input) > 255 ){ 
    Serial.println("255 is max value for PWM");
    return false; 
  }
  else { return true; }
  
}


bool isValidPwmCommand(char firstChar, String inputSub){
  int numberOfCommands = 2;
  int a = 1;
  /*
  Serial.print("firstChar = ");
  Serial.println(firstChar);
  Serial.print("inputSub.toInt() = ");
  Serial.println(inputSub.toInt() );
  */

  switch (a){
    case 1:       //check if first char is in pwmCommandPrefix arry, if yes move on
      bool continueFlag = false;
      for(int i=0 ; i<numberOfCommands ; i++ ){
        if( firstChar == pwmCommandPrefix[i] ){
          continueFlag = true;     
        }
      }
      if(continueFlag){ a++; }
      else{
        //Serial.println("case 1 goto");
        goto bailout;
      }

      case 2:     //check if rest of input is digits
        if( inputSub.toInt() || inputSub.charAt(0) == '0' ){
          //Serial.println("inside case 2 if");  
          a++;
        }
        else{
          //Serial.println("case 2 goto");
          goto bailout;
        }
        
      
      case 3:     //check if input is <= 255
        if( inputSub.toInt() <= 255){
          return true;
        }
        else{
          Serial.println("Max PWM value is 255");  
          goto bailout;
        }
 
      
  }
  bailout:
  return false;
}



void serialReciever(){
  //Recieve data over serial
  static byte ndx = 0;
  char rc;

  //Recieve stuff with end marker
  while (Serial.available() > 0 && newData == false) {
    rc = Serial.read();
  
    if (rc != endMarker) {
      receivedChars[ndx] = rc;
      ndx++;
      if (ndx >= numChars) {
        ndx = numChars - 1;
      }
    }
   else {
    receivedChars[ndx] = '\0'; // terminate the string
    ndx = 0;
    newData = true;
    }
  }
 
  //Do stuff with data
  if (newData == true) {
    String receivedString = receivedChars;
    String receivedSubString = receivedString.substring(1);
    

    if(sendEcho){ 
      Serial.print("ECHO: ");
      Serial.println(receivedChars); 
    }

    /////////////////// Start of the might command-handler if/else-if 
    if( isValidPwmCommand(receivedChars[0], receivedSubString) ){
     
      if( receivedChars[0] == 'p' ){
        runPumps( receivedSubString.toInt() );
      }
      else if( receivedChars[0] == 'f' && receivedSubString.toInt() <= fanMaxPwm ){
        runFan(receivedSubString.toInt());
      }
      else if(receivedChars[0] == 'f' && receivedSubString.toInt() > fanMaxPwm){
        Serial.print("Max PWM for fan is ");
        Serial.println(fanMaxPwm);
      }
    }
  
   else if(strcmp(receivedChars, "beep") == 0) {
      Serial.println("boop");
    }

    else if(strcmp(receivedChars, "echo") == 0){
      sendEcho = !sendEcho;
      if(sendEcho){ Serial.println("Serial echo tured ON"); }
      else { Serial.println("Serial echo turned OFF"); }
    }

    else if(strcmp(receivedChars, "help") == 0){
      printInstructions();
    }
    
    else if(strcmp(receivedChars, "eeprom") == 0) {
    
      EEPROM.get(eeAddress1, f);
      Serial.print("Saved number in EEPROM: ");
      Serial.println(f);
    }

    else if(strcmp(receivedChars, "eepromclear") == 0) {
      Serial.println("Clearing EEPROM...");
      for (int i = 0 ; i < EEPROM.length() ; i++) {
        EEPROM.write(i, 0);
      }
      Serial.println("EEPROM cleared");
    }
    
    else if(strcmp(receivedChars, "start") == 0) {
      EEPROM.get(eeAddress1, f);
      if( cycleNumber == 0  && f > 0){
        cycleNumber = f;
      }
    
      log1 = false;
      runProgram = true;
    }
    
    else if(strcmp(receivedChars, "stop") == 0) {
      runProgram = false;
    }

    else if(strcmp(receivedChars, "reset") == 0) {
      runProgram = false;
      state = 0;
      fanPwm = 0;
      cycleNumber = 0;
      lastSave = 0;
    }
 
    else if(strcmp(receivedChars, "off") == 0) {
      runPumps(0);
      runFan(0);
      Serial.println("Pump & fan pwm set to 0");
    }
    

    else if(strcmp(receivedChars, "cycle") == 0) {
      Serial.println(cycleNumber);
    }

    else{
      Serial.println("Command not recognized");
    }

    //Set char array to null for safety
    for( int i=0 ; i<32 ; i++){
      receivedChars[i] = '\0';
    }
  
    newData = false;
  }


}

void printInstructions(){
  Serial.println("---------------------------------------------------------");
  Serial.println("Available commands are as follows:");
  Serial.println(' ');
  Serial.println("help = prints list of commands");
  Serial.println("echo = turns on/off serial echo (off by def)");
  Serial.println("log = enables logTask");
  Serial.println("eeprom = prints number saved in eeprim");
  Serial.println("eepromclear = clears eeprom DO AT YOUR OWN RISK");
  Serial.println("start = Starts the test cycle");
  Serial.println("stop = Stops the test cycle");
  Serial.println("reset = Resets state machine");
  Serial.println("[Any number between 0 and 255]p = Sets the pwm for the pump");
  Serial.print("[Any number between 0 and ");
  Serial.print(fanMaxPwm);
  Serial.println("]f = Sets the pwm for the pump");
  Serial.println("off = turns OFF fan & both pumps");
  
  //Serial.println("cycle = Prints current cycle number");
  Serial.println("---------------------------------------------------------");
}