#include <SPI.h>
#include <Adafruit_GFX.h>
#include <Adafruit_ILI9341.h>
#include <DHT.h>

// DHT sensor settings
#define DHTPIN 12    // let's move to GPIO12 to avoid conflicts
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

// TFT display settings
#define TFT_CS    15
#define TFT_DC    2
#define TFT_RST   4

Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_RST);

// Graph settings
#define GRAPH_WIDTH  250
#define GRAPH_HEIGHT 150
#define GRAPH_X      20
#define GRAPH_Y      50
#define MAX_POINTS   100

float temperatureData[MAX_POINTS];
float humidityData[MAX_POINTS];
int dataIndex = 0;

void setup() {
  Serial.begin(115200);

  // Important: Initialize SPI manually
  SPI.begin(18, 19, 23, 15);

  tft.begin();
  tft.setRotation(1); // Landscape
  tft.fillScreen(ILI9341_BLACK);

  dht.begin();

  // Labels
  tft.setTextColor(ILI9341_WHITE);
  tft.setTextSize(2);
  tft.setCursor(10, 10);
  tft.print("Temp. & Humidity");

  // Draw graph box
  tft.drawRect(GRAPH_X - 1, GRAPH_Y - 1, GRAPH_WIDTH + 2, GRAPH_HEIGHT + 2, ILI9341_WHITE);
}

void loop() {
  float h = dht.readHumidity();
  float t = dht.readTemperature();

  if (isnan(h) || isnan(t)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  Serial.print("Temp: ");
  Serial.print(t);
  Serial.print(" C, Humidity: ");
  Serial.println(h);

  if (dataIndex >= MAX_POINTS) {
    shiftData();
    dataIndex = MAX_POINTS - 1;
  }

  temperatureData[dataIndex] = t;
  humidityData[dataIndex] = h;
  dataIndex++;

  drawGraph();
  delay(1000); // Update every second
}

void shiftData() {
  for (int i = 1; i < MAX_POINTS; i++) {
    temperatureData[i - 1] = temperatureData[i];
    humidityData[i - 1] = humidityData[i];
  }
}

void drawGraph() {
  tft.fillRect(GRAPH_X, GRAPH_Y, GRAPH_WIDTH, GRAPH_HEIGHT, ILI9341_BLACK);

  for (int i = 1; i < dataIndex; i++) {
    int x0 = GRAPH_X + (i - 1) * (GRAPH_WIDTH / MAX_POINTS);
    int y0_t = GRAPH_Y + GRAPH_HEIGHT - map(temperatureData[i - 1], 0, 50, 0, GRAPH_HEIGHT);
    int y0_h = GRAPH_Y + GRAPH_HEIGHT - map(humidityData[i - 1], 0, 100, 0, GRAPH_HEIGHT);
    int x1 = GRAPH_X + i * (GRAPH_WIDTH / MAX_POINTS);
    int y1_t = GRAPH_Y + GRAPH_HEIGHT - map(temperatureData[i], 0, 50, 0, GRAPH_HEIGHT);
    int y1_h = GRAPH_Y + GRAPH_HEIGHT - map(humidityData[i], 0, 100, 0, GRAPH_HEIGHT);

    tft.drawLine(x0, y0_t, x1, y1_t, ILI9341_RED);
    tft.drawLine(x0, y0_h, x1, y1_h, ILI9341_CYAN);
  }
}