#include <SPI.h>
#include <Wire.h> // I2C
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <math.h> // for sine drawing
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
#define OLED_RESET -1 // OLED Reset pin or -1 if sharing Arduino reset pin
#define SCREEN_ADDRESS 0x3C // See datasheet for OLED Address; 0x3C for 128x32 and 128x64
#define OLED_RESET     4 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
/* Adafruit_SSD1306 display(OLED_RESET); */
/* Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET); */
/* #include <Fonts/FreeSans12pt7b.h> */


uint16_t screen_redraw; // track screen redraws
// Encoder state structure
struct EncoderState {
  int16_t value;
  uint8_t increment;                // stores fator of increment for wheel
  int8_t delta;                     // stores last change in wheel value
  uint8_t button; // gets clicked or double clicked
  uint8_t click_cycle;              // increases with button presses
  uint8_t click_cycle_count;        // count of states for button presses
  uint8_t d_click_cycle;            // increases with double button presses
  uint8_t d_click_cycle_count;      // count of states for double button presses
};
EncoderState encoder_state = {0, 1, 0, -1, 0, 0};

// 'sq2', 8x6px
const unsigned char sq2_bmp [] PROGMEM = {
	0x06, 0x09, 0x09, 0x90, 0x90, 0x60, // 'sine, 8x6px
	0x18, 0x18, 0x24, 0x24, 0x42, 0xc3, // 'tr, 8x6px
	0x77, 0x55, 0x55, 0x55, 0x55, 0xdd, // 'sq1, 8x6px
	0x3c, 0x24, 0x24, 0x24, 0x24, 0xe7// 'sq2, 8x6px
};
const unsigned char wave_bmp [] PROGMEM = {
// '1', 12x12px
0x00, 0xc0, 0x01, 0x20, 0x01, 0x20, 0x02, 0x10, 0x02, 0x10, 0x02, 0x10, 0x84, 0x00, 0x84, 0x00, 
0x84, 0x00, 0x48, 0x00, 0x48, 0x00, 0x30, 0x00, 
// '2', 12x12px
0x3c, 0xf0, 0x24, 0x90, 0x24, 0x90, 0x24, 0x90, 0x24, 0x90, 0x24, 0x90, 0x24, 0x90, 0x24, 0x90, 
0x24, 0x90, 0x24, 0x90, 0x24, 0x90, 0xe7, 0x90, 
// '3', 12x12px
0x1f, 0x80, 0x10, 0x80, 0x10, 0x80, 0x10, 0x80, 0x10, 0x80, 0x10, 0x80, 0x10, 0x80, 0x10, 0x80, 
0x10, 0x80, 0x10, 0x80, 0x10, 0x80, 0xf0, 0xf0, 
// '4', 12x12px
0x06, 0x00, 0x09, 0x00, 0x09, 0x00, 0x09, 0x00, 0x09, 0x00, 0x10, 0x80, 0x10, 0x80, 0x10, 0x80, 
0x10, 0x80, 0x20, 0x40, 0x20, 0x40, 0xe0, 0x70
};

void setup() {

  // Display init
  if (!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;); // Don't proceed, loop forever
  }
  // Display config
  //display.setFont(&FreeSans12pt7b);  // Set custom font
  display.setTextSize(1); // Normal 1:1 pixel scale
  display.setTextColor(SSD1306_WHITE); // Draw white text
  display.cp437(true); // Use full 256 char 'Code Page 437' font

  Serial.begin(9600);
  Serial.println("Setup complete");

  //showSplash();
  showStatic(); // start showing the initial wave
  Serial.println("Back");
  display.clearDisplay();
//   textNormal("setup end");
  display.display();
}

void showSplash() {
  // Display welcome message for 2 seconds
  display.clearDisplay();
  display.setCursor(20, 5);
  display.print("Signal Generator");

  // Calculate the center and radius of the circle
  int center_x = SCREEN_WIDTH / 2;
  int center_y = SCREEN_HEIGHT / 2;
  int radius = 12; // Half of the wave height

  // Draw the circle (optional, for visualization)
  display.drawCircle(center_x, center_y, radius+4, SSD1306_WHITE);

  float step_size = 2.0 * PI / (2 * radius);

  // Draw the sinusoidal wave
  for (int x = center_x - radius; x <= center_x + radius; x++) {
    int y = center_y + (int)(radius * sin((x - (center_x - radius)) * step_size));
    display.drawPixel(x, y, SSD1306_WHITE);
  }

  display.display();
  delay(500);
  display.clearDisplay();
  display.display();
}

// when changing freq, click changes increment ammount
// double click enters menu
void showStatic() {
  encoder_state.value = 0;
  showStaticInfo();
  encoder_state.click_cycle = 0; // reset click
  encoder_state.click_cycle_count = 2; // click has 3 states
  encoder_state.d_click_cycle = 0; // reset d_click
  encoder_state.d_click_cycle_count = 2; // d_click has 3 states

  // stay here until goto menu is selected
  while (1) { //encoder_state.button != CheapClickEncoder::DoubleClicked) {

    // do a first info redraw when double clicked to show
    // the selected menu
/*     if (encoder_state.button != CheapClickEncoder::DoubleClicked) {
      showStaticInfo();
    }
 */
    // handle the menu switching from the encoder?
    // the wheel value should be blocked from menu to
    // menu

    // menu
    switch (encoder_state.d_click_cycle) {
      case 0: // frequency, change using wheel
        // check encoder multiplier
        switch (1) {
          case 0:
            encoder_state.increment = 1;
            break;
          case 1:
            encoder_state.increment = 10;
            break;
          case 2:
            encoder_state.increment = 100;
            break;
        }
        // if encoder changes refresh screen and set new freq
        if (0) {
          showStaticInfo();
        }
//         Serial.println("asdkljkl");
        break;
      case 1: // channel, change using wheel
        // should disable the button cycle count
        // if encoder changes toggle channel and refresh screen
        if (encoder_state.delta != 0) {

          showStaticInfo();
        }
        break;
      case 2: // wave form, change using wheel
        if (encoder_state.delta != 0) {

          showStaticInfo();
        }
//       case 3:
//         break;

    }



  }

  Serial.print("screen_redraw ");Serial.println(screen_redraw);
  return;
}
// show the static wave screen
void showStaticInfo() {
  ++screen_redraw; // track screen redraws

  display.clearDisplay();
  display.setTextSize(1);
  // display wave info
  
  display.setCursor(0, 0);
  display.print("ch ");
  display.print(0);  
//   display.print(ad.getChannelTxt());
  //invertIfSelectedAndPrint(0, 1);

/*   display.setCursor(86, 0);
  display.print("f+ ");
  display.print(100);
 */

  invertIconIfSelectedAndDraw(114, 0, wave_bmp, 12, 12);

  display.setTextSize(2);
  display.setTextSize(2);
  display.setCursor(35, 16);
  display.print(1440);
  display.setCursor(50, 40);
  display.print("Hz");
  

  display.setCursor(80, 40);
  display.write(0x12); // up down
//  display.write(0x17); // up
//  display.write(0x17); // down
  
  display.setTextSize(1);
  display.setCursor(110, 54);
  display.print("100");

  // return to menu
  display.setCursor(0, 54);
  display.write(0x1B);


  display.display();    
}

// Template function to display "selected" text
template <typename T>
void invertIfSelectedAndPrint(T text, uint8_t menu_id) {
  if (encoder_state.d_click_cycle == menu_id) {
    display.setTextColor(SSD1306_BLACK, SSD1306_WHITE); // Draw inverted text
  }
  display.print(text);
  display.setTextColor(SSD1306_WHITE); // Draw white text
}

void invertIconIfSelectedAndDraw(
  uint8_t x, uint8_t y, const unsigned char* bmp, uint8_t w, uint8_t h) {
  bool isSelected = (encoder_state.d_click_cycle == 1);

  // Set background and icon colors based on selection state
  uint16_t bgColor = isSelected ? SSD1306_WHITE : SSD1306_BLACK;
  uint16_t iconColor = isSelected ? SSD1306_BLACK : SSD1306_WHITE;

  // Draw background rectangle
  display.fillRect(x - 1, y - 1, w + 1, h + 1, bgColor);

  // Draw the icon bitmap
  display.drawBitmap(x, y, bmp, w, h, iconColor);
}

void loop() {


}