#include <LiquidCrystal_I2C.h>
#include <DHTesp.h>
#include <WiFi.h>
#include <HTTPClient.h>
#include <ArduinoJson.h>

#define LED_PIN 32
#define PIR_PIN 26
#define DHT_PIN 18

String serverURL = "https://postman-echo.com/post";

DHTesp dhtSensor;

LiquidCrystal_I2C lcd(0x27, 20, 4);

void setup() {
  Serial.begin(115200);
  Serial.println("Sensor is collecting data...");

  // config LED and PIR Sensor output
  pinMode(LED_PIN, OUTPUT);
  pinMode(PIR_PIN, OUTPUT);
  // setup sensor
  dhtSensor.setup(DHT_PIN, DHTesp::DHT22);
  // setup lcd screen
  lcd.init();
  lcd.backlight();

  // config wifi
  Serial.println(("Connecting to WiFi..."));
  WiFi.begin("Wokwi-GUEST", "", 6);
  if (WiFi.status() != WL_CONNECTED) {
    Serial.println(".");
    delay(100);
  }
  Serial.println("Connected!");
}

unsigned long sensor_timer = 0;
unsigned long get_timer = 0;

void loop() {
  float dtemp, dhum;
  String shum, stemp;

  // millis() instead of delay() for non-blocking
  if (millis() > sensor_timer + 2000) {
    sensor_timer = millis(); // set new update interval
    TempAndHumidity data = dhtSensor.getTempAndHumidity();
    dtemp = data.temperature;
    dhum = data.humidity;
    stemp = String(dtemp);
    shum = String(dhum);

    // print and log temperature
    lcd.setCursor(0, 0);
    lcd.print("TEMP: " + stemp + "C");
    Serial.println("Temperature: " + stemp);
    // print and log humidity
    lcd.setCursor(0, 1);
    lcd.print("HUM: " + shum + "%");
    Serial.println("Humidity: " + shum);
    Serial.println("---");

    // packing json object
    DynamicJsonDocument doc(1024);
    String jsonstr;
    JsonObject root = doc.to<JsonObject>();
    root["temperature"] = stemp;
    root["humidity"] = shum;
    serializeJson(doc, jsonstr);
    String serverRequest = jsonstr;
    if (millis() > get_timer + 10000) { // send request every 10 seconds
      get_timer = millis();
      if (WiFi.status() == WL_CONNECTED) {
        HTTPClient http;
        http.begin(serverURL); // Send HTTP POST request
        http.addHeader("Content-Type", "application/form-json");
        int httpResponseCode = http.POST(serverRequest);
        if (httpResponseCode > 0) {
          Serial.print("HTTP Response code: ");
          Serial.println(httpResponseCode);
          String payload = http.getString();
          Serial.println(payload);
        } else {
          Serial.print("Error code: ");
          Serial.println(httpResponseCode);
        }
        http.end();
      } else {
        Serial.println("WiFi Disconnected");
      }
    }
  }

  // motion sensor
  int pir_val = digitalRead(PIR_PIN);
  if (pir_val == 1) {
    // log if detect motion
    Serial.println("Motion Detected");
    digitalWrite(LED_PIN, HIGH);
    delay(50);
    digitalWrite(LED_PIN, LOW);
  }
}