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

int incomingByte = 0; 
struct tm *timeinfo;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println();


  WiFi.begin("Wokwi-GUEST", "");
  Serial.print("Connecting to WiFi ");
  
  
  while (WiFi.status() != WL_CONNECTED) {
    delay(100);
    Serial.print(".");
  }
  Serial.println(" Connected!");

  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
 
  setTime ();

  runonce ();
  
} // setup


void setTime () {  
  time_t now; 
  struct tm t_info;  
  
  configTime(28800, 0, "pool.ntp.org");
  
  while ((now = time(nullptr)) < 8 * 3600 * 2) {
    delay(500);
    Serial.print(".");    
  }
  Serial.println ();
  timeinfo = localtime(&now);
    
  Serial.println ("Today is " + String (timeinfo->tm_year + 1900) + "-" + 
  ((timeinfo->tm_mon + 1 < 10) ? "0" : "") + String (timeinfo->tm_mon + 1) + "-" + 
  ((timeinfo->tm_mday < 10) ? "0" : "") + String (timeinfo->tm_mday));
  Serial.println ("Time now is " + String ((timeinfo->tm_hour < 10) ? "0" : "") + String (timeinfo->tm_hour) + ":" +
  ((timeinfo->tm_min < 10) ? "0" : "") + String (timeinfo->tm_min));
  Serial.println ();
} // setTime


void initializeWifi (int ip) {  
  WiFiMulti wifiMulti;
  int i;

  Serial.println (WiFi.macAddress());  
  
  wifiMulti.addAP ("British", "edwin.george");
   
  for (i = 0; wifiMulti.run() != WL_CONNECTED; i++) {
    Serial.print (".");
    if (i == 10) ESP.restart ();
    else delay (1000);    
  }

  Serial.println ("");  
  
  Serial.println ("SSID: " + WiFi.SSID ());
  Serial.println ("IP: " + WiFi.localIP ().toString ());   
} // initializeWifi


String getDateFromEpoch (long epoch) {
  struct tm *t_info; 
  time_t timestamp = (time_t) epoch;
  t_info = localtime (&timestamp);
    
  return String (t_info->tm_year + 1900) + "-" + 
                ((t_info->tm_mon + 1) < 10 ? "0" : "") + String (t_info->tm_mon + 1) + "-" + 
                ((t_info->tm_mday) < 10 ? "0" : "") + String (t_info->tm_mday);
}

long getEpochFromDate (String date) { // date format ="2023-09-01 03:00:01"
  struct tm t_info; 
  time_t timestamp;

  timestamp = 0;
  if (strptime(date.c_str (), "%Y-%m-%d %H:%M:%S", &t_info) != NULL) timestamp = mktime(&t_info);
  return (long) timestamp;
}


int getTokens (String s, String delimiter) {
  int i, count;
  String s1;

  count = 0;
  for (i = 0; i < s.length (); i++) if ((String (s.charAt (i)) == delimiter)) count++;      

  return count;
}


void runonce () {
  String s, s1, date;
  int i, count;
  long epoch;

  epoch = mktime(timeinfo);
  s = curl ("http://chenlim.com/fuel/get_price.php", "action=getByBrand&pric_brand=SPC&dStart=" + getDateFromEpoch (epoch - 604800) + "&dEnd=" + getDateFromEpoch (epoch));
  
  String arr[getTokens (s, "|")];

  count = 0;
  for (i = 0; i < s.length (); i++) 
    if ((String (s.charAt (i)) == "|")) {
      s1 = s.substring (0, i);
      //Serial.println (s1);
      arr[count] = s1;
      count++;
      s = s.substring (i + 1, s.length ());
      i = 0;
    }  

  i = 0;
  date = arr[i].substring (0, arr[i].indexOf (" "));
  s = arr[i].substring (arr[i].indexOf (",") + 1, arr[i].length ());    
  Serial.println (date + " " + s);
  
  for (i = i; i < count; i++) {
    if (arr[i].substring (arr[i].indexOf (",") + 1, arr[i].length ()) != s) {
      s1 = arr[i].substring (arr[i].indexOf (",") + 1, arr[i].length ());
      Serial.println ("Date: " + arr[i].substring (0, arr[i].indexOf (",")) + " === " +
                     "Old Price: " + s + " === "
                     "New Price: " + arr[i].substring (arr[i].indexOf (",") + 1, arr[i].length ()) + " === " +
                     "Difference: " + String (s1.toFloat () - s.toFloat ()));
      s = s1;               


    }
  }
  
}


String curl (String url, String post) {
  HTTPClient http; 
  String s;

  http.begin (url);
  http.addHeader ("Content-Type", "application/x-www-form-urlencoded");      
  http.POST (post);
  s = http.getString ();
  return s.substring (s.indexOf ("LEVO 95||") + String ("LEVO 95||").length (), s.indexOf ("LEVO 92||") - 2);
}


void loop() {
  delay(100); // this speeds up the simulation
}