/*
 * @Title: Slot & Play: ESP32-Driven Cloud Integrated Charging Hub
 * @Author: Princetoniño B. Piscos
 * Course: BCA188 | Internet of Things
 * Members: Enlawan, Piscos
 * @Date: 10/31/23 15:40:36 GMT +08:00
 *
 */

//#define HTTPC_ERROR_CONNECTION_REFUSED (-1)
//#define HTTPC_ERROR_SEND_HEADER_FAILED (-2)
//#define HTTPC_ERROR_SEND_PAYLOAD_FAILED (-3)
//#define HTTPC_ERROR_NOT_CONNECTED (-4)
//#define HTTPC_ERROR_CONNECTION_LOST (-5)
//#define HTTPC_ERROR_NO_STREAM (-6)
//#define HTTPC_ERROR_NO_HTTP_SERVER (-7)
//#define HTTPC_ERROR_TOO_LESS_RAM (-8)
//#define HTTPC_ERROR_ENCODING (-9)
//#define HTTPC_ERROR_STREAM_WRITE (-10)
//#define HTTPC_ERROR_READ_TIMEOUT (-11)

#define ChannelID 53986900473679872
#define TINAPA_API "http://api.olympusworld.online:1336/api/esp/"

// 4-DIGIT CONF
#define CLK 19
#define DIO 14

// Other Elec. Components
#define BTN_PIN 36
#define RELAY_PIN 10

// Button
#define DEBOUNCE_DELAY 100

//WiFi
#define _SSID "Wokwi-GUEST"
#define _PASS ""


#include <WiFi.h>
#include <WiFiClient.h>
#include <HTTPClient.h>
#include <TM1637.h>
#include <queue>
#include <Ticker.h>

// SLOT BOX CONFIG
const int coinValuePer = 120; // 3 mins per coin (180 seconds)
unsigned int remainingSec = 0;
const long interval = 1000; // 1 second
unsigned int accumulated = 0;
unsigned long lastTime = 0;

// BUTTON AS COIN SENSOR MUNA NGEKNGOK
int prevBtnState = LOW;
unsigned long lastDebounceTime = 0;

const String urlEp = String(TINAPA_API) + String(ChannelID);

TM1637 tm(CLK, DIO);
WiFiClient client;
HTTPClient http;
Ticker push2Tinapa;
Ticker releaserTinapa;

struct HttpRequest
{
  String ep;
  String data;
};

std::queue<HttpRequest> requestQueue;


void setup()
{
	Serial.begin(115200);
	pinMode(BTN_PIN, INPUT);
	pinMode(RELAY_PIN, OUTPUT);

	tm.init();
	tm.set(BRIGHT_TYPICAL);

	WiFi.mode(WIFI_STA);
	WiFi.begin(_SSID, _PASS);

	while (WiFi.status() != WL_CONNECTED)
	{
		delay(1000);
		Serial.println("Connecting to WiFi...");
	}
	Serial.print("Connected to Wi-Fi network with IP Address: ");
	Serial.println(WiFi.localIP());

  http.addHeader("Connection", "Keep-Alive");
  http.addHeader("Content-Type", "application/json");
  http.setReuse(true); // reuse ang connection for ease post

  //send heartbeat pra online status
  http.begin("http://api.olympusworld.online:1336/api/tinapa_ping/" + String(ChannelID));
  int httpResponseCode = http.GET();
	if (httpResponseCode > 0)
  {
		Serial.println("Successfully sent heartbeat");
    http.end(); // end heartbeat, proceed to tinapa data
    http.begin(client, urlEp);

    updateDisplay(0); // init display 0000
    Serial.println("Tinapa is ready na");

    push2Tinapa.attach_ms(5000, pushToTinapa); // push data to Tinapa  every 5 sec.
    releaserTinapa.attach_ms(15000, releaseTinapa); // release connection every 20 sec.
  } else Serial.println("Failed to connect to tinapa.");
}

void loop()
{
  unsigned long currTime = millis();
  if ((currTime - lastTime) >= interval)
  {
    lastTime = currTime;
    if (remainingSec > 0)
    {
      remainingSec--;

      // update 4dig disp
      updateDisplay(remainingSec);
      digitalWrite(RELAY_PIN, HIGH);
    } else digitalWrite(RELAY_PIN, LOW);
  }

  int btnRead = digitalRead(BTN_PIN);
  if (btnRead == HIGH && prevBtnState == LOW)
  {
    if ((currTime - lastDebounceTime) >= DEBOUNCE_DELAY)
    {
      remainingSec += (coinValuePer + 1); // add time sa timer
      String data = "{\"accumulated\":" + String(++accumulated) + "}";
      pushTinapa(urlEp, data); // queue ang mga nahulog sa user, then fire after sometime
    }
    lastDebounceTime = currTime;
  }
  prevBtnState = btnRead;

  delayMicroseconds(10);
}

void pushTinapa(String ep, String data)
{
  HttpRequest newRequest;
  newRequest.ep = ep;
  newRequest.data = data;

  requestQueue.push(newRequest);
  Serial.println("Tinapa pushed to queue");
}

void pushToTinapa()
{
  while (!requestQueue.empty())
  {
    HttpRequest nextRequest = requestQueue.front();
    if (!http.connected())
    {
      http.addHeader("Connection", "Keep-Alive");
      http.addHeader("Content-Type", "application/json");
      http.setReuse(true); // reuse ang connection for ease post

      // reinitialize HTTP client if wla nka connect
      http.begin(client, nextRequest.ep);
      Serial.println("Connection to Tinapa has been established");
    }

    int httpResponseCode = http.POST(nextRequest.data);
    if (httpResponseCode > 0)
      Serial.println("Successfully sent data to Tinapa");
    else {
      Serial.print("Error code: ");
      Serial.println(httpResponseCode);
      if (httpResponseCode == -1 || httpResponseCode == -5)
        pushTinapa(nextRequest.ep, nextRequest.data); // requeue kung fail
    }

    requestQueue.pop();
  }
}

void releaseTinapa()
{
  if (requestQueue.empty())
  {
    http.end(); // release resources after sometime
    Serial.println("Released tinapa");
  }
}

void updateDisplay(unsigned int seconds)
{
  unsigned int mins = seconds / 60;
  if (seconds >= 3600)
  {
    tm.point(false);
    // 4100 = 0065
    unsigned int hundredsOfMins = mins / 100;
    unsigned int remainingMins = mins % 100;

    tm.display(0, hundredsOfMins / 10); // 9
    tm.display(1, hundredsOfMins % 10); // 9
    tm.display(2, remainingMins / 10); // 9
    tm.display(3, remainingMins % 10); // 9
  } else {

    tm.point(true);
    unsigned int remainingSecs = seconds % 60;
    tm.display(0, mins / 10); // 5
    tm.display(1, mins % 10); // 9:
    tm.display(2, remainingSecs / 10); // 5
    tm.display(3, remainingSecs % 10); // 9
  }
}