#include <Adafruit_GFX.h>
#include <Adafruit_ILI9341.h>
#include <Adafruit_FT6206.h>

// TFT Display Pins
#define TFT_CS    10
#define TFT_RST   4
#define TFT_DC    9  

// Touch Controller
Adafruit_FT6206 touch = Adafruit_FT6206();
Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_RST);

// Screen States
enum ScreenState {
    MAIN_SCREEN
};
ScreenState currentScreen = MAIN_SCREEN;  // Default screen

// CO2, Temp, and Humidity Values
int color, prevColor;
int co2_value;
int temp_value = 28;  
int humidity_value = 68;

// Function prototypes for icons
void drawWifiIcon(int x, int y);
void drawBluetoothIcon(int x, int y);
void drawGpsIcon(int x, int y);

void setup() {
    Serial.begin(115200);
    tft.begin();
    tft.setRotation(3);

    // Initialize Touch Controller
    if (!touch.begin()) {
        Serial.println("Touchscreen not found!");
        while (1);
    }

    prevColor = ILI9341_BLACK;
    color = prevColor;

    drawMainScreen();
}

void loop() {
    detectSwipe();  // Check for swipe gesture

    if (currentScreen == MAIN_SCREEN) {
        updateCO2Value();
        delay(500);  // Simulate sensor update delay
    }
}

void detectSwipe() {
    if (touch.touched()) {
        TS_Point p = touch.getPoint();
        
        static int startY = -1;
        
        if (startY == -1) {
            startY = p.y;  // Store the initial Y position
        } else {
            int deltaY = p.y - startY;
            
            if (deltaY > 50) {  // If swipe-down detected
                switchScreen();
                startY = -1;  // Reset swipe tracking
            }
        }
    }
}

void switchScreen() {
    if (currentScreen == MAIN_SCREEN) {
        currentScreen = MAIN_SCREEN;
        drawMainScreen();
    }
}

// ------------------- SCREEN DRAW FUNCTIONS -------------------

void drawMainScreen() {
    tft.fillScreen(ILI9341_BLACK);  // Clear the screen with black
    drawUI();
    updateCO2Value();  // Draw initial CO2 value
}

void drawUI() {
    // Draw UI elements
    tft.setTextColor(ILI9341_WHITE);
    tft.setTextSize(1);
    tft.setCursor(10, 10);
    tft.print("25/03/2025 Mon");

    // Status Icons
    drawWifiIcon(220, 10);
    drawBluetoothIcon(240, 10);
    drawGpsIcon(260, 10);

    // Battery Icon
    int batteryX = 300, batteryY = 10, batteryWidth = 18, batteryHeight = 8;
    tft.drawRect(batteryX, batteryY, batteryWidth, batteryHeight + 1, ILI9341_WHITE);
    tft.fillRect(batteryX + batteryWidth, batteryY + 2, 3, 4, ILI9341_WHITE);
    tft.fillRect(batteryX + 2, batteryY + 2, 12, 4, ILI9341_WHITE);
    tft.setCursor(280, 10);
    tft.print("85%");  // Dummy battery percentage

    // CO2 Label
    tft.setTextSize(3);
    tft.setCursor(50, 35);
    tft.print("CO2");

    // Temperature & Humidity
    tft.setTextSize(2);
    tft.setCursor(40, 180);
    tft.print(temp_value);
    tft.print("C");

    tft.setCursor(35, 205);
    tft.print("Temp");

    tft.setCursor(250, 180);
    tft.print(humidity_value);
    tft.print("%");

    tft.setCursor(250, 205);
    tft.print("HUM");

    // Larger Rounded Rectangle for CO2 Value
    tft.drawRoundRect(25, 60, 280, 100, 20, ILI9341_WHITE);

    // Smaller Rounded Rectangles for Temp and Humidity
    tft.drawRoundRect(25, 170, 70, 30, 10, ILI9341_WHITE);
    tft.drawRoundRect(235, 170, 70, 30, 10, ILI9341_WHITE);
}

void updateCO2Value() {
    co2_value = random(300, 2500);  // Simulated CO2 sensor value

    // Determine new background color
    if (co2_value <= 500) color = ILI9341_GREEN;
    else if (co2_value > 500 && co2_value <= 2000) color = ILI9341_ORANGE;
    else color = ILI9341_RED;

    // Only update the screen if the color has changed
    if (color != prevColor) {
        tft.fillRoundRect(25, 60, 280, 100, 20, color);
        tft.setTextColor(ILI9341_WHITE, color);
        tft.setTextSize(4);
        tft.setCursor(80, 95);
        tft.print(co2_value);

        tft.setTextSize(2);
        tft.setCursor(200, 110);
        tft.print("ppm");

        prevColor = color;
    }
}

// ------------------- STATUS ICON DRAW FUNCTIONS -------------------
void drawWifiIcon(int x, int y) {
    int centerX = x + 4;
    int centerY = y + 4;
    tft.drawLine(centerX - 3, y + 2, centerX + 3, y + 2, ILI9341_WHITE);
    tft.drawLine(centerX - 2, y + 4, centerX + 2, y + 4, ILI9341_WHITE);
    tft.drawLine(centerX - 1, y + 6, centerX + 1, y + 6, ILI9341_WHITE);
    tft.drawPixel(centerX, y + 8, ILI9341_WHITE);
}

void drawBluetoothIcon(int x, int y) {
    int centerX = x + 4;
    int centerY = y + 4;
    tft.drawLine(centerX, y, centerX, y + 8, ILI9341_WHITE);
    tft.drawLine(centerX, y, centerX + 2, y + 2, ILI9341_WHITE);
    tft.drawLine(centerX + 2, y + 2, centerX - 2, centerY + 2, ILI9341_WHITE);
    tft.drawLine(centerX - 2, centerY - 2, centerX + 2, centerY + 2, ILI9341_WHITE);
    tft.drawLine(centerX + 2, centerY + 2, centerX, centerY + 4, ILI9341_WHITE);
}

void drawGpsIcon(int x, int y) {
    int centerX = x + 4;
    int centerY = y + 4;
    tft.drawCircle(centerX, centerY, 2, ILI9341_WHITE);
    tft.drawPixel(centerX, centerY, ILI9341_WHITE);
    tft.drawLine(centerX - 4, centerY, centerX - 2, centerY, ILI9341_WHITE);
    tft.drawLine(centerX + 2, centerY, centerX + 4, centerY, ILI9341_WHITE);
    tft.drawLine(centerX, centerY - 4, centerX, centerY - 2, ILI9341_WHITE);
    tft.drawLine(centerX, centerY + 2, centerX, centerY + 4, ILI9341_WHITE);
}