#include "AD9833.h"       
#include <Wire.h>         
#include <Adafruit_GFX.h> 
#include <Adafruit_SSD1306.h> 
#include <math.h>         

#define SCREEN_WIDATA_PINH 128 
#define SCREEN_HEIGHT 64       

#define SET_FREQUENCY_HZ A2    
#define SET_FREQUENCY_KHZ A3   
#define SET_FREQUENCY_MHZ A6   
#define ENABLE_DISABLE_OUTPUT_PIN A7 
#define FNC_PIN 4              
#define CLK_PIN 7              
#define DATA_PIN 8             
#define BTN_PIN 9              
#define OUT_SIGNAL_PIN 5       

long counter = 1; 
int clockPin;
int clockPinState;
long debounce = 220; 

unsigned long time_delay_enc = 0; 
unsigned long time_delay_hz = 0;
unsigned long time_delay_khz = 0;
unsigned long time_delay_mhz = 0;
unsigned long time_delay_out = 0;

unsigned long moduleFrequency = 1000; 

bool btn_state = false;
bool set_frequency_hz = 1; 
bool set_frequency_khz = 0;
bool set_frequency_mhz = 0;
String waveSelect = "SIN"; 
int encoder_btn_count = 0; 

const byte sineTable[64] = {
  128, 140, 153, 165, 178, 190, 201, 212, 
  222, 230, 238, 244, 249, 252, 254, 255, 
  254, 252, 249, 244, 238, 230, 222, 212, 
  201, 190, 178, 165, 153, 140, 128, 115, 
  102, 90, 77, 65, 54, 43, 33, 25, 
  17, 11, 6, 3, 1, 0, 1, 3, 
  6, 11, 17, 25, 33, 43, 54, 65, 
  77, 90, 102, 115, 128
};

const byte triangleTable[64] = {
  0, 8, 16, 24, 32, 40, 48, 56, 
  64, 72, 80, 88, 96, 104, 112, 120, 
  128, 136, 144, 152, 160, 168, 176, 184, 
  192, 200, 208, 216, 224, 232, 240, 248, 
  255, 247, 239, 231, 223, 215, 207, 199, 
  191, 183, 175, 167, 159, 151, 143, 135, 
  127, 119, 111, 103, 95, 87, 79, 71, 
  63, 55, 47, 39, 31, 23, 15, 7
};

Adafruit_SSD1306 display(SCREEN_WIDATA_PINH, SCREEN_HEIGHT, &Wire, -1);
AD9833 gen(FNC_PIN);

void setup() {
  Serial.begin(115200); 
  gen.Begin(); 
  
  pinMode(CLK_PIN, INPUT_PULLUP);
  pinMode(DATA_PIN, INPUT_PULLUP);
  pinMode(BTN_PIN, INPUT_PULLUP);
  clockPinState = digitalRead(CLK_PIN);
  
  pinMode(SET_FREQUENCY_HZ, INPUT);
  pinMode(SET_FREQUENCY_KHZ, INPUT);
  pinMode(SET_FREQUENCY_MHZ, INPUT);
  pinMode(ENABLE_DISABLE_OUTPUT_PIN, INPUT);
  
  pinMode(OUT_SIGNAL_PIN, OUTPUT);
  
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { 
    Serial.println(F("SSD1306 allocation failed"));
    while (true); // حلقه بی‌نهایت در صورت خطای نمایشگر
  }
  
  display.clearDisplay(); 
  display.setTextSize(2); 
  display.setTextColor(WHITE); 
  display.setCursor(30, 0); 
  display.println("AD9833"); 
  display.setCursor(17, 20);  
  display.println("Function"); 
  display.setCursor(13, 40); 
  display.println("Generator"); 
  display.display(); 
  delay(2000); 
  update_display(); 
}

void loop() {
  // ۱. دریافت لاگ از اپلیکیشن اندروید یا پایتون
  if (Serial.available() > 0) {
    String logCommand = Serial.readStringUntil('\n');
    logCommand.trim();
    
    if (logCommand == "MODE:SIN") {
      waveSelect = "SIN";
      encoder_btn_count = 0;
      update_display();
    } 
    else if (logCommand == "MODE:SQR") {
      waveSelect = "SQR";
      encoder_btn_count = 1;
      update_display();
    } 
    else if (logCommand == "MODE:TRI") {
      waveSelect = "TRI";
      encoder_btn_count = 2;
      update_display();
    } 
    else if (logCommand == "OUT:ON") {
      btn_state = true;
      gen.EnableOutput(btn_state);
      update_display();
    } 
    else if (logCommand == "OUT:OFF") {
      btn_state = false;
      gen.EnableOutput(btn_state);
      update_display();
    } 
    else if (logCommand.startsWith("FREQ:")) {
      long targetFreq = logCommand.substring(5).toInt();
      if (targetFreq > 0 && targetFreq <= 12000000) {
        counter = targetFreq;
        set_frequency_hz = 1;
        set_frequency_khz = 0;
        set_frequency_mhz = 0;
        update_display();
      }
    }
    // پاسخ به درخواست وضعیت گوشی
    else if (logCommand == "GET:STATUS") {
      send_status_to_app();
    }
  }

  // ۲. سخت‌افزار: کنترل چرخش انکودر
  clockPin = digitalRead(CLK_PIN);
  if (clockPin != clockPinState && clockPin == 1) {
    if (digitalRead(DATA_PIN) != clockPin) {
      counter--;
    } else {
      counter++;
    }
    if (counter < 1) counter = 1;
    update_display();
  }
  clockPinState = clockPin;

  // ۳. سخت‌افزار: کنترل دکمه فشاری انکودر (تغییر موج)
  if (digitalRead(BTN_PIN) == LOW && millis() - time_delay_enc > debounce) {
    encoder_btn_count++;
    if (encoder_btn_count > 2) encoder_btn_count = 0;
    
    if (encoder_btn_count == 0) waveSelect = "SIN";
    if (encoder_btn_count == 1) waveSelect = "SQR";
    if (encoder_btn_count == 2) waveSelect = "TRI";
    
    update_display();
    time_delay_enc = millis();
  }

  // ۴. سخت‌افزار: کنترل دکمه‌های تنظیم فرکانس
  if (analogRead(SET_FREQUENCY_HZ) < 100 && millis() - time_delay_hz > debounce) {
    set_frequency_hz = 1; set_frequency_khz = 0; set_frequency_mhz = 0;
    update_display();
    time_delay_hz = millis();
  }
  
  if (analogRead(SET_FREQUENCY_KHZ) < 100 && millis() - time_delay_khz > debounce) {
    set_frequency_hz = 0; set_frequency_khz = 1; set_frequency_mhz = 0;
    update_display();
    time_delay_khz = millis();
  }
  
  if (analogRead(SET_FREQUENCY_MHZ) < 100 && millis() - time_delay_mhz > debounce) {
    set_frequency_hz = 0; set_frequency_khz = 0; set_frequency_mhz = 1;
    update_display();
    time_delay_mhz = millis();
  }
  
  if (analogRead(ENABLE_DISABLE_OUTPUT_PIN) < 100 && millis() - time_delay_out > debounce) {
    btn_state = !btn_state; // تغییر وضعیت روشن/خاموش
    gen.EnableOutput(btn_state);
    update_display();
    time_delay_out = millis();
  }

  // ۵. تولید خروجی آنالوگ نرم‌افزاری و رسم نمودار زنده در پلاتر
  if (btn_state && moduleFrequency <= 5000) {
    if (waveSelect == "SQR") {
      tone(OUT_SIGNAL_PIN, moduleFrequency);
      int sqrValue = (millis() % (1000 / moduleFrequency) < (500 / moduleFrequency)) ? 255 : 0;
      Serial.println(sqrValue);
    } 
    else {
      static byte index = 0;
      int waveValue = 0;

      if (waveSelect == "SIN") {
        waveValue = sineTable[index];
        analogWrite(OUT_SIGNAL_PIN, waveValue);
      } else if (waveSelect == "TRI") {
        waveValue = triangleTable[index];
        analogWrite(OUT_SIGNAL_PIN, waveValue);
      }
      
      Serial.println(waveValue); 

      index = (index + 1) % 64;
      delayMicroseconds(1000000 / (moduleFrequency * 64));
    }
  } else if (!btn_state || moduleFrequency > 5000) {
    noTone(OUT_SIGNAL_PIN);
    if (!btn_state) analogWrite(OUT_SIGNAL_PIN, 0);
  }
}

// تابع ارسال لاگ وضعیت به اندروید (فیدبک سیستم)
void send_status_to_app() {
  String outState = btn_state ? "ON" : "OFF";
  String statusLog = "UPDATE:" + waveSelect + "," + String(moduleFrequency) + "," + outState;
  // این لاگ به اپلیکیشن می‌گوید که الان مدار روی چه تنظیمی قرار دارد
  // Serial.println(statusLog); // در زمان اتصال واقعی به ماژول بلوتوث این خط از کامنت خارج می‌شود
}

void update_display() {
  display.clearDisplay(); 
  display.setTextSize(1); 
  display.setCursor(10, 0); 
  display.println("Function Generator"); 
  display.setTextSize(2);
  display.setCursor(0, 20);
  
  if (set_frequency_hz == 1) moduleFrequency = counter;
  if (set_frequency_khz == 1) moduleFrequency = counter * 1000;
  if (set_frequency_mhz == 1) moduleFrequency = counter * 1000000;
  
  if (moduleFrequency > 12000000) {
    moduleFrequency = 12000000;
    counter = 12; 
  }

  if (waveSelect == "SIN") {
    display.println("SIN");
    gen.ApplySignal(SINE_WAVE, REG0, moduleFrequency);
  }
  if (waveSelect == "SQR") {
    display.println("SQR");
    gen.ApplySignal(SQUARE_WAVE, REG0, moduleFrequency);
  }
  if (waveSelect == "TRI") {
    display.println("TRI");
    gen.ApplySignal(TRIANGLE_WAVE, REG0, moduleFrequency);
  }
  
  display.setCursor(45, 20);
  display.println(counter); 
  
  display.setCursor(90, 20);
  if (set_frequency_hz == 1) display.println("Hz");
  if (set_frequency_khz == 1) display.println("Khz");
  if (set_frequency_mhz == 1) display.println("Mhz");

  display.setTextSize(1);
  display.setCursor(65, 45);
  if (btn_state) { 
    display.print("Output ON"); 
  } else {
    display.print("Output OFF"); 
  }
  
  display.display(); 
  
  // ارسال خودکار فیدبک به اپلیکیشن موبایل با هر بار تغییر سخت‌افزاری
  send_status_to_app();
}