#include <Arduino.h>

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

// Wi-Fi Credentials
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// ThingSpeak
unsigned long myChannelNumber = 2943053;
const char* WriteAPIKey = "0AUA67RCJVZ3KAF3";
WiFiClient client;

// Pin Configuration
#define TRIG_PIN 19
#define ECHO_PIN 18
#define DHT_PIN 17
#define RED_LED 5
#define GREEN_LED 4
#define BUZZER 15

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

DHTesp dhtSensor;

// Bitmaps (16x16)
const unsigned char temp_icon [] PROGMEM = {
  0x18, 0x00, 0x24, 0x00, 0x42, 0x00, 0x81, 0x00,
  0x81, 0x00, 0x81, 0x00, 0x42, 0x00, 0x24, 0x00,
  0x18, 0x00, 0x18, 0x00, 0x24, 0x00, 0x42, 0x00,
  0x81, 0x00, 0x81, 0x00, 0xff, 0x00, 0x7e, 0x00
};

const unsigned char humid_icon [] PROGMEM = {
  0x18, 0x00, 0x3c, 0x00, 0x3c, 0x00, 0x66, 0x00,
  0x42, 0x00, 0x81, 0x00, 0x81, 0x00, 0x81, 0x00,
  0x42, 0x00, 0x66, 0x00, 0x3c, 0x00, 0x3c, 0x00,
  0x18, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};

const unsigned char alert_icon [] PROGMEM = {
  0x10, 0x00, 0x38, 0x00, 0x38, 0x00, 0x7c, 0x00,
  0x7c, 0x00, 0xfe, 0x00, 0xfe, 0x00, 0xfe, 0x00,
  0xfe, 0x00, 0x7c, 0x00, 0x7c, 0x00, 0x38, 0x00,
  0x38, 0x00, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00
};

float distance_cm, distance_m;

void setup() {
  Serial.begin(9600);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(RED_LED, OUTPUT);
  pinMode(GREEN_LED, OUTPUT);
  pinMode(BUZZER, OUTPUT);
  dhtSensor.setup(DHT_PIN, DHTesp::DHT22);

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("OLED failed"));
    while (true);
  }

  display.clearDisplay();
  display.setTextColor(SSD1306_WHITE);
  display.setTextSize(1);

  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("\nWiFi connected");
  ThingSpeak.begin(client);
}

void loop() {
  // Distance
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  long duration = pulseIn(ECHO_PIN, HIGH);
  distance_cm = 0.017 * duration;
  distance_m = distance_cm / 100.0;

  // DHT22 Sensor
  TempAndHumidity data = dhtSensor.getTempAndHumidity();
  float temperature = data.temperature;
  float humidity = data.humidity;

  // OLED Display
  display.clearDisplay();

  // Temperature
  display.drawBitmap(0, 0, temp_icon, 16, 16, SSD1306_WHITE);
  display.setCursor(20, 4);
  display.print("Temp: ");
  display.print(temperature, 1);
  display.print(" C");

  // Humidity
  display.drawBitmap(0, 18, humid_icon, 16, 16, SSD1306_WHITE);
  display.setCursor(20, 22);
  display.print("Hum: ");
  display.print(humidity, 1);
  display.print(" %");

  // Distance
  display.setCursor(0, 40);
  display.print("Dist: ");
  display.print(distance_cm, 1);
  display.print(" cm");

  // Alert System
  if (temperature > 50 || humidity > 55) {
    display.drawBitmap(100, 0, alert_icon, 16, 16, SSD1306_WHITE);
    display.setCursor(0, 55);
    display.print("🚨 ALERT: High T/H");
    digitalWrite(RED_LED, HIGH);
    digitalWrite(GREEN_LED, LOW);
    tone(BUZZER, 1000);
  } else {
    display.setCursor(0, 55);
    display.print("✅ Normal");
    digitalWrite(RED_LED, LOW);
    digitalWrite(GREEN_LED, HIGH);
    noTone(BUZZER);
  }

  display.display();

  // ThingSpeak update
  ThingSpeak.setField(1, distance_cm);
  ThingSpeak.setField(2, distance_m);
  ThingSpeak.setField(3, temperature);
  ThingSpeak.setField(4, humidity);
  int status = ThingSpeak.writeFields(myChannelNumber, WriteAPIKey);
  if (status == 200) {
    Serial.println("✅ ThingSpeak Updated");
  } else {
    Serial.println("❌ ThingSpeak Error: " + String(status));
  }

  delay(15000); // Wait 15s
}