#include <Arduino.h>
#include <WiFi.h>
#include <Firebase_ESP_Client.h>
#include <Wire.h>
#include "time.h"

// Provide the token generation process info.
#include "addons/TokenHelper.h"
// Provide the RTDB payload printing info and other helper functions.
#include "addons/RTDBHelper.h"

// Insert your network credentials
#define WIFI_SSID "MAKERSPACE"
#define WIFI_PASSWORD "12345678"

// Insert Firebase project API Key
#define API_KEY "AIzaSyBGuoAUVZFy2OD0HiAvGkKj6ORqWfMpqZM"

// Insert Authorized Email and Corresponding Password
#define USER_EMAIL "Dsolomon@college.harvard.edu"
#define USER_PASSWORD "Sololebow1"

// Insert RTDB URLefine the RTDB URL
#define DATABASE_URL "https://esp32-senordisplay-default-rtdb.firebaseio.com/"

// Settings
#define SAMPLING_FREQ_HZ    4                         // Sampling frequency (Hz)
#define SAMPLING_PERIOD_MS  1000 / SAMPLING_FREQ_HZ   // Sampling period (ms)
#define NUM_SAMPLES         8                         // 8 samples at 4 Hz is 2 seconds

// Define Firebase objects
FirebaseData fbdo;
FirebaseAuth auth;
FirebaseConfig config;

// Variable to save USER UID
String uid;

// Database main path (to be updated in setup with the user UID)
String databasePath;
// Database child nodes
String sen0Path = "/Sensor0";
String sen1Path = "/Sensor1";
String sen2Path = "/Sensor2";
String sen3Path = "/Sensor3";
String sen4Path = "/Sensor4";
String sen5Path = "/Sensor5";
String timePath = "/timestamp";

// Parent Node (to be updated in every loop)
String parentPath;
String chartrangePath; 

int timestamp;
FirebaseJson json;

const char* ntpServer = "pool.ntp.org";

int sensor0 = 25;
int sensor1 = 26;
int sensor2 = 13;
int sensor3 = 15;
int sensor4 = 18;
int sensor5 = 19;

unsigned int sensorValue0;
unsigned int sensorValue1;
unsigned int sensorValue2;
unsigned int sensorValue3;
unsigned int sensorValue4;
unsigned int sensorValue5;

// Timer variables (send new readings every three minutes)
unsigned long sendDataPrevMillis = 0;
unsigned long timerDelay = 180000/12;


// Initialize WiFi
void initWiFi() {
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  Serial.print("Connecting to WiFi ..");
  while (WiFi.status() != WL_CONNECTED) {
    Serial.print('.');
    delay(1000);
  }
  Serial.println(WiFi.localIP());
  Serial.println();
}

// Function that gets current epoch time
unsigned long getTime() {
  time_t now;
  struct tm timeinfo;
  if (!getLocalTime(&timeinfo)) {
    //Serial.println("Failed to obtain time");
    return(0);
  }
  time(&now);
  return now;
}

void setup(){
  Serial.begin(115200);

  // Initialize BME280 sensor
  initWiFi();
  configTime(0, 0, ntpServer);

  // Assign the api key (required)
  config.api_key = API_KEY;

  // Assign the user sign in credentials
  auth.user.email = USER_EMAIL;
  auth.user.password = USER_PASSWORD;

  // Assign the RTDB URL (required)
  config.database_url = DATABASE_URL;

  Firebase.reconnectWiFi(true);
  fbdo.setResponseSize(4096);

  // Assign the callback function for the long running token generation task */
  config.token_status_callback = tokenStatusCallback; //see addons/TokenHelper.h

  // Assign the maximum retry of token generation
  config.max_token_generation_retry = 5;

  // Initialize the library with the Firebase authen and config
  Firebase.begin(&config, &auth);

  // Getting the user UID might take a few seconds
  Serial.println("Getting User UID");
  while ((auth.token.uid) == "") {
    Serial.print('.');
    delay(1000);
  }
  // Print user UID
  uid = auth.token.uid.c_str();
  Serial.print("User UID: ");
  Serial.println(uid);

  // Update database path
  databasePath = "/UsersData/" + uid + "/readings";
  chartrangePath = "/UsersData/" + uid + "/charts/ranges";
}

void loop(){
  if (Firebase.ready()){
    for (int i = 0; i < NUM_SAMPLES; i++) { 
      sendDataPrevMillis = millis();
      sensorValue0 = analogRead(sensor0);
      sensorValue1 = analogRead(sensor1);
      sensorValue2 = analogRead(sensor2);
      sensorValue3 = analogRead(sensor3);
      sensorValue4 = analogRead(sensor4);
      sensorValue5 = analogRead(sensor5);

      //Get current timestamp
      timestamp = getTime();

      // Print CSV data with timestamp
      Serial.print(timestamp);
      Serial.print(",");
      Serial.print(sensorValue0);
      Serial.print(",");
      Serial.print(sensorValue1);
      Serial.print(",");
      Serial.print(sensorValue2);
      Serial.print(",");
      Serial.print(sensorValue3);
      Serial.print(",");
      Serial.print(sensorValue4);
      Serial.print(",");
      Serial.print(sensorValue5);
      Serial.println();

      parentPath= databasePath + "/" + String(timestamp);

      json.set(sen0Path.c_str(), String(sensorValue0));
      json.set(sen1Path.c_str(), String(sensorValue1));
      json.set(sen2Path.c_str(), String(sensorValue2));
      json.set(sen3Path.c_str(), String(sensorValue3));
      json.set(sen4Path.c_str(), String(sensorValue4));
      json.set(sen5Path.c_str(), String(sensorValue5));
      json.set(timePath, String(timestamp));
      Firebase.RTDB.setJSON(&fbdo, parentPath.c_str(), &json);
      // Serial.printf("Set json... %s\n", Firebase.RTDB.setJSON(&fbdo, parentPath.c_str(), &json) ? "ok" : fbdo.errorReason().c_str());
      Firebase.RTDB.setInt(&fbdo, chartrangePath, 25);

      // Wait just long enough for our sampling period
      while (millis() < sendDataPrevMillis + SAMPLING_PERIOD_MS);
    }
    // Print empty line to transmit termination of recording
    Serial.println();
  }
}