#include <WiFi.h>
#include <HTTPClient.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include "DHTesp.h"

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

const char* ssid = "Wokwi-GUEST";
const char* password = "";
String writeApiKey = "80H5QKAO3MYMQAID";
String serverUrl = "https://api.thingspeak.com/update";

DHTesp dht;
const int DHT_PIN = 15;
const int LED_PIN = 2;

unsigned long lastSend = 0;
const unsigned long SEND_INTERVAL_MS = 2000;

void updateOLED(float t, float h, String wifiStatus, String sendStatus) {
    display.clearDisplay();
    display.setTextSize(1);
    display.setTextColor(SSD1306_WHITE);
    
    display.setCursor(0, 0);
    display.println("--- MONITORING ---");
    
    display.setCursor(0, 15);
    display.printf("Temp: %.1f C", t);
    
    display.setCursor(0, 25);
    display.printf("Hum : %.1f %%", h);
    
    display.setCursor(0, 40);
    display.print("WiFi: "); display.println(wifiStatus);
    
    display.setCursor(0, 50);
    display.print("TS  : "); display.println(sendStatus);
    
    display.display();
}

void setup() {
    Serial.begin(115200);
    pinMode(LED_PIN, OUTPUT);
    
    if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
        Serial.println(F("SSD1306 allocation failed"));
        for(;;);
    }
    display.clearDisplay();
    display.println("Starting...");
    display.display();

    dht.setup(DHT_PIN, DHTesp::DHT22);

    Serial.print("Menghubungkan WiFi");
    WiFi.begin(ssid, password);

    while (WiFi.status() != WL_CONNECTED) {
        delay(300);
        Serial.print(".");
        updateOLED(0, 0, "Connecting...", "Wait");
    }
    Serial.println("\n✅ WiFi terkoneksi");
}

void loop() {
    if (millis() - lastSend < SEND_INTERVAL_MS) return;
    lastSend = millis();

    TempAndHumidity data = dht.getTempAndHumidity();
    String wifiStatus = (WiFi.status() == WL_CONNECTED) ? "Connected" : "Disconnected";
    String sendStatus = "...";

    if (isnan(data.temperature) || isnan(data.humidity)) {
        Serial.println("❌ Gagal baca DHT22");
        updateOLED(0, 0, wifiStatus, "Sensor Error");
        return;
    }

    if (WiFi.status() == WL_CONNECTED) {
        String url = serverUrl + "?api_key=" + writeApiKey +
                     "&field1=" + String(data.temperature, 2) +
                     "&field2=" + String(data.humidity, 2);

        HTTPClient http;
        http.begin(url);
        int code = http.GET();
        String payload = http.getString();
        
        Serial.print("HTTP Code: "); Serial.println(code);

        if (code > 0) {
            if (payload.toInt() > 0) {
                sendStatus = "Success";
                Serial.println("✅ Berhasil dikirim");
                digitalWrite(LED_PIN, HIGH);
                delay(200);
                digitalWrite(LED_PIN, LOW);
            } else {
                sendStatus = "Error (RateLmt)";
                Serial.println("⚠ Gagal (Response 0) - Rate Limit");
                digitalWrite(LED_PIN, LOW);
            }
        } else {
            sendStatus = "HTTP Fail";
            Serial.printf("❌ Error: %s\n", http.errorToString(code).c_str());
            digitalWrite(LED_PIN, LOW);
        }
        http.end();
    } else {
        sendStatus = "No WiFi";
        digitalWrite(LED_PIN, LOW);
    }

    updateOLED(data.temperature, data.humidity, wifiStatus, sendStatus);
    
    Serial.printf("T=%.2f C | H=%.2f %% | Stat=%s\n", data.temperature, data.humidity, sendStatus.c_str());
}