#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>
#include <EEPROM.h>

const char* ssid = "nazwasieciwifi";
const char* password = "haslo";


ESP8266WebServer server(80);

const int ledPIN = 0;
const int counterPIN = 2;
unsigned long counter = 0;
unsigned long actTime = 0;
unsigned long delayTime = 0;
unsigned long ledTime = 0;

const int EEPROM_COUNTER = 0;

void f_counter(void)
{
  actTime = millis();
  if (actTime > delayTime)
  {
    delayTime = actTime + 95;
    counter++;
    EEPROMWritelong(EEPROM_COUNTER, counter);
    digitalWrite(ledPIN, HIGH);
    ledTime = actTime;
  }
}

void setup()
{
  Serial.begin(9600);
  Serial.println("Start programu...");

  EEPROM.begin(4);
  counter = EEPROMReadlong(EEPROM_COUNTER);

  pinMode(ledPIN, OUTPUT);
  digitalWrite(ledPIN, LOW);

  attachInterrupt(counterPIN, f_counter, FALLING);

  WiFi.begin(ssid, password);

  server.on("/", []()
  {
    server.send(200, "text/plain", "Stan licznika: " + String(counter, DEC) + " Wh");
  });

  server.on("/getcounter", []()
  {
    server.send(200, "text/plain", String(counter, DEC));
  });

  server.on("/set", []()
  {
    String str = server.arg("counter");
    counter = str.toInt();
    EEPROMWritelong(EEPROM_COUNTER, counter);
    server.send(200, "text/plain", String(counter, DEC));
  });

  server.begin();
}

void loop()
{
  server.handleClient();
  if(ledTime)
  {
    actTime = millis();
    if(actTime > (ledTime + 1000))
    {
      digitalWrite(ledPIN, LOW);
      ledTime = 0;
    }
  }
}

void EEPROMWritelong(int address, unsigned long value)
{
  //Decomposition from a long to 4 bytes by using bitshift.
  //One = Most significant -> Four = Least significant byte
  byte four = (value & 0xFF);
  byte three = ((value >> 8) & 0xFF);
  byte two = ((value >> 16) & 0xFF);
  byte one = ((value >> 24) & 0xFF);

  //Write the 4 bytes into the eeprom memory.
  EEPROM.write(address, four);
  EEPROM.write(address + 1, three);
  EEPROM.write(address + 2, two);
  EEPROM.write(address + 3, one);
  EEPROM.commit();
}

unsigned long EEPROMReadlong(int address)
{
  //Read the 4 bytes from the eeprom memory.
  long four = EEPROM.read(address);
  long three = EEPROM.read(address + 1);
  long two = EEPROM.read(address + 2);
  long one = EEPROM.read(address + 3);

  //Return the recomposed long by using bitshift.
  return ((four << 0) & 0xFF) + ((three << 8) & 0xFFFF) + ((two << 16) & 0xFFFFFF) + ((one << 24) & 0xFFFFFFFF);
}