#include <WiFi.h>
#include <HTTPClient.h>

#define RXD2  16
#define TXD2  17
#define red   4
#define green 2

const char * ssid = "network";
const char * password = "123456789";
String GOOGLE_SCRIPT_ID = "AKfycby3IzdQMFy8UFlQ4n8gAgbjm-4MyGDwE1vxUk_2A_0Syyz8anTTGhFl11ivjLxVpuvRBQ";
const int number_of_students = 3;
String Student_Name[number_of_students] = {"MHD", "New", "MHD2"};
String Student_ID[number_of_students]   = {"1112", "2223", "3334"};
int found_flag[number_of_students]      = {0, 0, 0};
char c;
String dataIn;
int8_t indexOfA;
String data1;

//updated 04.12.2019
const char * root_ca = \
                       "-----BEGIN CERTIFICATE-----\n" \
                       "MIIDujCCAqKgAwIBAgILBAAAAAABD4Ym5g0wDQYJKoZIhvcNAQEFBQAwTDEgMB4G\n" \
                       "A1UECxMXR2xvYmFsU2lnbiBSb290IENBIC0gUjIxEzARBgNVBAoTCkdsb2JhbFNp\n" \
                       "Z24xEzARBgNVBAMTCkdsb2JhbFNpZ24wHhcNMDYxMjE1MDgwMDAwWhcNMjExMjE1\n" \
                       "MDgwMDAwWjBMMSAwHgYDVQQLExdHbG9iYWxTaWduIFJvb3QgQ0EgLSBSMjETMBEG\n" \
                       "A1UEChMKR2xvYmFsU2lnbjETMBEGA1UEAxMKR2xvYmFsU2lnbjCCASIwDQYJKoZI\n" \
                       "hvcNAQEBBQADggEPADCCAQoCggEBAKbPJA6+Lm8omUVCxKs+IVSbC9N/hHD6ErPL\n" \
                       "v4dfxn+G07IwXNb9rfF73OX4YJYJkhD10FPe+3t+c4isUoh7SqbKSaZeqKeMWhG8\n" \
                       "eoLrvozps6yWJQeXSpkqBy+0Hne/ig+1AnwblrjFuTosvNYSuetZfeLQBoZfXklq\n" \
                       "tTleiDTsvHgMCJiEbKjNS7SgfQx5TfC4LcshytVsW33hoCmEofnTlEnLJGKRILzd\n" \
                       "C9XZzPnqJworc5HGnRusyMvo4KD0L5CLTfuwNhv2GXqF4G3yYROIXJ/gkwpRl4pa\n" \
                       "zq+r1feqCapgvdzZX99yqWATXgAByUr6P6TqBwMhAo6CygPCm48CAwEAAaOBnDCB\n" \
                       "mTAOBgNVHQ8BAf8EBAMCAQYwDwYDVR0TAQH/BAUwAwEB/zAdBgNVHQ4EFgQUm+IH\n" \
                       "V2ccHsBqBt5ZtJot39wZhi4wNgYDVR0fBC8wLTAroCmgJ4YlaHR0cDovL2NybC5n\n" \
                       "bG9iYWxzaWduLm5ldC9yb290LXIyLmNybDAfBgNVHSMEGDAWgBSb4gdXZxwewGoG\n" \
                       "3lm0mi3f3BmGLjANBgkqhkiG9w0BAQUFAAOCAQEAmYFThxxol4aR7OBKuEQLq4Gs\n" \
                       "J0/WwbgcQ3izDJr86iw8bmEbTUsp9Z8FHSbBuOmDAGJFtqkIk7mpM0sYmsL4h4hO\n" \
                       "291xNBrBVNpGP+DTKqttVCL1OmLNIG+6KYnX3ZHu01yiPqFbQfXf5WRDLenVOavS\n" \
                       "ot+3i9DAgBkcRcAtjOj4LaR0VknFBbVPFd5uRHg5h6h+u/N5GJG79G+dwfCMNYxd\n" \
                       "AfvDbbnvRG15RjF+Cv6pgsH/76tuIMRQyV+dTZsXjAzlAcmgQWpzU/qlULRuJQ/7\n" \
                       "TBj0/VLZjmmx6BEP3ojY+x1J96relc8geMJgEtslQIxq/H5COEBkEveegeGTLg==\n" \
                       "-----END CERTIFICATE-----\n";

WiFiClientSecure client;

void setup() {
  for (int j = 0; j < number_of_students; j++) {
    found_flag[j] = 0;
  }
  Serial.begin(115200);
  Serial2.begin(9600, SERIAL_8N1, RXD2, TXD2);
  pinMode(red, OUTPUT);
  pinMode(green, OUTPUT);
  digitalWrite(red, HIGH);
  digitalWrite(green, LOW);
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);

  Serial.println("Started");
  Serial.print("Connecting");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("Ready to go");
}

void loop() {
  while (Serial2.available() > 0) {
    c = Serial2.read();
    if (c == '\n') {
      break;
    }
    else       {
      dataIn += c;
    }
  }
  if (c == '\n') {
    parseData();
    ShowRxData();
    SendDataToGoogleSheets();
    resetData();
  }
}

void parseData() {
  indexOfA = dataIn.indexOf("A");
  data1 = dataIn.substring(0, indexOfA);
}

void ShowRxData() {
  Serial.println("Received ID: " + data1);
}

void SendDataToGoogleSheets() {
  for (int i = 0; i < number_of_students; i++) {
    if (data1 == Student_ID[i] && found_flag[i] == 0) {
      sendData("tag=" + Student_ID[i] + "&value=" + Student_Name[i]);
      Serial.print("Student [" + Student_ID[i] + "] Found !");
      found_flag[i] = 1;
      digitalWrite(red, LOW);
      digitalWrite(green, HIGH);
    }
    else {
      digitalWrite(red, HIGH);
      digitalWrite(green, LOW);
    }
  }
}

void sendData(String params) {
  HTTPClient http;
  String url = "https://script.google.com/macros/s/" + GOOGLE_SCRIPT_ID + "/exec?" + params;
  //Serial.print(url);
  Serial.print("Making a request");
  http.begin(url, root_ca); //Specify the URL and certificate
  int httpCode = http.GET();
  http.end();
  //Serial.println(": done " + httpCode);
}

void resetData() {
  c = 0;
  dataIn = "";
}