#include "WiFi.h"
#include <HTTPClient.h>
#include "time.h"
#include <WiFi.h>
#include "esp_wpa2.h"
#define EAP_IDENTITY "benedicx@oregonstate.edu"
#define EAP_USERNAME "benedicx@oregonstate.edu"
#define EAP_PASSWORD "qazwsxedcrfvtgb" //password
#include <detaBaseArduinoESP32.h>
#include <WiFiClientSecure.h>

int thePin = 35; //Voltage divider pin(Needs to be an analog pin)
const int interval = 120; //Number of data points per batch sent to the google sheet
const int SERIESRESISTOR = 10000; //Resistor value in series with the temperature sensor (Ohms)
const char* ssid = "eduroam";
int counter = 0; //Used only in the setup function to hault Wi-Fi connection after a certian period of time
String GOOGLE_SCRIPT_ID = "AKfycbyL1knB1gI5g42_nbB0BXLPZvKIvFBGFWGKj4syQkJrTZtKMRn2HlN_cN2Yd2fgijZi";    // the deployment ID of the google apps script
int count = 0; // Used to store the number of number of loop function cylcle but indexes only after "interval" loop cycles
long timer = 0; // Used in conjunction with the millis function to interated the data collection cycle at each second
int x = 0; // This stores the number of loop function cycles total
float totalMax = 0; // Needs to be a lower number than the sensor input will typically be
float totalMin = 10000000; // Needs to be a larger number than the sensor input will ever be
float sum = 0; // Used to caluclate the rolling average of the data
float intervalAve[720]; // Defined outside the loop function because it needs to be accessed when the 'r' command is inputed in the serial monitor

//Function Definitions:

String convertArrayToString(float* array, int size) {
  String result = "";
  
  for (int i = 0; i < size; i++) {
    result += String(array[i]);
    if (i < size - 1) {
      result += ",";
    }
  }

  return result;
} // Function converts the elements of an array into a string separated by commas(important for spliting elements later after sent to the google sheet)

float rollAverage(float total, int n){
 float rollAve;
 rollAve = (total)/n;
 return rollAve;
} // Function takes in the total sum and divides it by the number of elements

float tenAve(float* array, int t){
 float ten = 0;
  for(int q = 0; q < t; q++){
    ten += array[q];
  }
  ten = ten/t;
  return ten;
} // Function adds all the elements of an array and then divides by the number of elements in the array

void max(float* array, float &totalMax){
  for (int y = 0; y < interval; y++){
    if(array[y]>totalMax){
      totalMax = array[y];
    }
  }
} // Function iterates through the values of an array and compares each to a "max" value replacing the "max" value if the element is greater

void min(float* array, float &totalMin){
  for (int z = 0; z < interval; z++){
    if(array[z] < totalMin){
      totalMin = array[z];
    }
  }
} // Function iterates through the values of an array and compares each to a "min" value replacing the "min" value if the element is lesser in value

void setup() {
  Serial.begin(115200); // Sets the rate of communication over the serial port for the devices
  delay(10);
  Serial.println();
  Serial.print("Connecting to network: ");
  Serial.println(ssid);
  WiFi.disconnect(true);  // Disconnects from wifi to set a new wifi connection
  WiFi.mode(WIFI_STA); // Initialized wifi mode
  WiFi.begin(ssid, WPA2_AUTH_PEAP, EAP_IDENTITY, EAP_USERNAME, EAP_PASSWORD); //Begins trying to connect to specified wifi
  
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
    counter++;
      if(counter>=60){ // After 30 seconds timeout - reset board
        ESP.restart();
      }
  }
  Serial.println("");
  Serial.println("WiFi connected");
}

void loop() {
  float batch[interval]; // Array which stores the teperature data and only stores enough data for one upload
  float iteration[interval]; // Array which stores an index of the current cycles of the data collection loop for the current upload cycle
  float average[interval]; // Array which stores the values of the rolling average corresponding to the current data point
  float time[interval]; // Array which stores the time since the program has begun for each data point
  float twoMinute[interval];
  memset(twoMinute, 0, sizeof(average));
  memset(time, 0, sizeof(average));
    for (int r = 0; r < interval + 1; r++){
      iteration[r] = r + count + 1;
    } // This fills the iteration array with the current indexes for the current loop function cycle
  
  memset(batch, 0, sizeof(batch)); // Sets the elements of the array to 0
  memset(average, 0, sizeof(average)); // Sets the elements of the array to 0
  

    for (int x = count; x < (count + interval + 1); x++){ // The loop which implements the batch size of the upload. Allows the program to upload data once is has collected a certian amount

      while(millis() - timer < 1000){}; // Waits until 1 second has passed sincle last data point was colledcted

        if (millis() - timer == 1000){ // This is the data colloection cycle which works to iterate the for loop only after exactly 1 second has passed.
        float realTime = millis(); // Using to attach a time stamp to the data using the time array
      time[x - count - 1] = realTime/1000; // This is where the time array is filled with the millis() value and converted to seconds
          float ADCvalue; // Analog input from pin 35
	        float Voltage; // Stores the voltage at pin 35
	        ADCvalue = analogRead(thePin); // Reads value between 0 and 4096 at pin 35
	        Voltage = (ADCvalue*3.3)/(4096); // Converts analog value to voltage
          float T = log((SERIESRESISTOR*(3.3/Voltage)-SERIESRESISTOR)/28000)/(-0.041); // Converts voltage to temperature and stores in T using the steinhart-hart equation
	        sum += T; // Adds the temp value to sum
          Serial.print("Temperature: ");
          Serial.print(T);
	        Serial.println(" Celcuis");

          batch[x - count - 1] = T; // Fills the batch array with the temperature data every second
          average[x - count - 1] = rollAverage(sum, x); // Fills the average array with the output of the rolling average function every second
          Serial.print("x:");
          Serial.println(x); // Prints the iteration number to the serial monitor
          Serial.print("Rolling Average: "); 
          Serial.println(rollAverage(sum, x)); // Prints the output of the rolling average function to the serial monitor
        }
    timer = millis(); // Resets the timer variable so that 1 second has to pass before the contents of the if statment are run again
    }

  intervalAve[(count/interval)] = tenAve(batch, interval); //Fills the interval average array with the average after the batch of data has be gather.
  twoMinute[1] = intervalAve[(count/interval)];
  count += interval; // increments the count by the interval (120)

  max(batch, totalMax); // Updates the value of the "totalMax" value so that it can be display if asked for over serial
  min(batch, totalMin); // Updates the value of the "totalMin" value so that it can be display if asked for over serial
  
    if(Serial.available() > 0){ // checks if there was data sent over serial
      char message = Serial.read(); // sets the data to a single character called "message"
        if (message == 'r'){
          Serial.print("Maximum Value Recorded: ");
          Serial.print(totalMax);
          Serial.println(" Celcius");
          Serial.print("Minimum Value Recorded: ");
          Serial.print(totalMin);
          Serial.println(" Celcius");
          Serial.println("Ten Minute Averages: ");
            for(int i = 0; i < 721; i++){ // Increments through each two minute average in the array and prints each over the serial monitor as long as it is non-zero
              if(intervalAve[i] != 0){
                Serial.print(intervalAve[i]);
                Serial.println(" Celcius");
              } else { break;}
            }
        }
     }
  String batchString = convertArrayToString(batch, interval); // The following lines use the convert-to-string functions to make each of the data storage arrays into strings 
  String iterationString = convertArrayToString(iteration, interval);
  String averageString = convertArrayToString(average, interval);
  String twoMinuteString = convertArrayToString(twoMinute, interval);
  String timeString = convertArrayToString(time, interval);

  String urlFinal = "https://script.google.com/macros/s/"+GOOGLE_SCRIPT_ID+"/exec?"+"batch=" + batchString + "&count=" + iterationString + "&rollingaverage=" + averageString + "&tenminuteaverage=" + twoMinuteString + "&time=" + timeString;
  Serial.print("POST data to spreadsheet:");
  Serial.println(urlFinal);
  HTTPClient http; // Declares http as type HTTPClient
  http.begin(urlFinal.c_str()); // begins connection and directs to the urlFinal
  http.setFollowRedirects(HTTPC_STRICT_FOLLOW_REDIRECTS);
  int httpCode = http.GET(); // Returns an execution code (should be between 200 and 500 for successful connection and execution)
  Serial.print("HTTP Status Code: ");
  Serial.println(httpCode);
  String payload;
  
    if (httpCode > 0) {
        payload = http.getString(); // Gets the response back from the location of urlFinal and prints the reply before ending
        Serial.println("Payload: "+payload);    
    http.end();
    }
}