#include <Arduino.h>
#include <SPI.h>
#include <U8x8lib.h>
#include <FastLED.h>
#include <EncButton.h>
#define NUM_LEDS 8
#define COUNT_STR 8


CRGB leds[NUM_LEDS];
EncButton eb(2, 3, 4); // 4 - key, 3, 2 - turn
U8X8_SSD1306_128X64_NONAME_HW_I2C u8x8 = U8X8_SSD1306_128X64_NONAME_HW_I2C();
unsigned long lastTime = millis();

void handleAction();

void setup() {
    Serial.begin(9600);
    u8x8.begin();


    // показаны значения по умолчанию
    eb.setBtnLevel(LOW);
    eb.setClickTimeout(500);
    eb.setDebTimeout(50);
    eb.setHoldTimeout(600);
    eb.setStepTimeout(200);

    eb.setEncReverse(0);
    eb.setEncType(EB_STEP4_LOW);
    eb.setFastTimeout(30);

    // сбросить счётчик энкодера
    eb.counter = 0;

    FastLED.addLeds<NEOPIXEL, 6>(leds, NUM_LEDS); // 6 - led

    eb.attach(handleAction);

    display();
}

char nameMode[3][7] {
  "Static",
  "LGBT",
  "Blink"
};

char name[3][COUNT_STR][13] {
  {
    "Menu (^.^)",
    "",
    "Mode: ", 
    "R: ", // 0-255
    "G: ",
    "B: ",
    "Brigthness: ", // 0-255
    "",
  },
  {
    "Menu (^.^)",
    "",
    "Mode: ", 
    "DeltaHue: ",
    "Brightness: ",
    "Delay: ",
    "",
    "",
  },
  {
    "Menu (^.^)",
    "",
    "Mode: ", 
    "R: ",
    "G: ",
    "B: ",
    "Brigthness: ",
    "Delay: ",
  },
  
};


typedef enum Mode {
  staticMode = 0,
  dynamicMode = 1,
  blinkMode = 2,
}Mode;

typedef struct State {  

    // menu
    int cursor = 2;
    bool onClick = false;

    // led
    Mode mode = Mode::dynamicMode;
    CRGB color = CRGB(0, 255, 3);
    uint8_t brightness = 158;
    uint8_t delayl = 30;
    uint8_t hue = 50;
    uint8_t dhue = 3;
    
      
    bool hasChanged = true;

} State;
State state;

int inc(int shift, int base, int num, int dt) {
  return (num - shift + dt) % base + shift;
}

int dec(int shift, int base, int num, int dt) {
  return ((num - shift - dt) % base  + base) % base + shift;
}

void handleAction() {
    if (!eb.action())
      return;
      
    switch (eb.action()) {
      case EB_PRESS:
        state.onClick = !state.onClick;
        state.hasChanged = true;
        break;
      case EB_TURN:
        if (state.mode == Mode::staticMode) {
          if (!state.onClick) {
            if (eb.left()) {
               state.cursor = inc(2, 5, state.cursor, 1);
            } else if (eb.right()) {
              state.cursor = dec(2, 5, state.cursor, 1);
            }
            state.hasChanged = true;
          }

          if (state.onClick) {
            switch (state.cursor) {
              case 2:
                if (eb.left()) {
                  state.mode = inc(0, 3, state.mode, 1);
                } else if (eb.right()) {
                  state.mode  = dec(0, 3, state.mode, 1);
                }
                break;
              case 3:
                if (eb.left()) {
                  state.color[0] = inc(0, 255, state.color[0], 5);
                } else if (eb.right()) {
                  state.color[0] = dec(0, 255, state.color[0], 5);
                }
                break;
              case 4:
                if (eb.left()) {
                  state.color[1] = inc(0, 255, state.color[1], 5);
                } else if (eb.right()) {
                  state.color[1] = dec(0, 255, state.color[1], 5);
                }
                break;
              case 5:
                if (eb.left()) {
                  state.color[2] = inc(0, 255, state.color[2], 5);
                } else if (eb.right()) {
                  state.color[2] = dec(0, 255, state.color[2], 5);
                }
                break;
              case 6:
                if (eb.left()) {
                  state.brightness = inc(0, 255, state.brightness, 5);
                } else if (eb.right()) {
                  state.brightness = dec(0, 255, state.brightness, 5);
                }
                break;    
            }
            state.hasChanged = true;
          }
        } else if (state.mode == Mode::dynamicMode) {
          if (!state.onClick) {
            if (eb.left()) {
               state.cursor = inc(2, 4, state.cursor, 1);
            } else if (eb.right()) {
              state.cursor = dec(2, 4, state.cursor, 1);
            }
            state.hasChanged = true;
          }

          if (state.onClick) {
            switch (state.cursor) {
              case 2:
                if (eb.left()) {
                  state.mode = inc(0, 3, state.mode, 1);
                } else if (eb.right()) {
                  state.mode  = dec(0, 3, state.mode, 1);
                }
                break;
              case 3:
                if (eb.left()) {
                  state.dhue = inc(0, 255, state.dhue, 1);
                } else if (eb.right()) {
                  state.dhue = dec(0, 255, state.dhue, 1);
                }
                break;
              case 4:
                if (eb.left()) {
                  state.brightness = inc(0, 255, state.brightness, 5);
                } else if (eb.right()) {
                  state.brightness = dec(0, 255, state.brightness, 5);
                }
                break;
              case 5:
                if (eb.left()) {
                  state.delayl = inc(5, 200, state.delayl, 1);
                } else if (eb.right()) {
                  state.color[2] = dec(5, 200, state.delayl, 1);
                }
                break; 
            }
            state.hasChanged = true;
          }
        } else if (state.mode == Mode::blinkMode) {
          if (!state.onClick) {
            if (eb.left()) {
               state.cursor = inc(2, 6, state.cursor, 1);
            } else if (eb.right()) {
              state.cursor = dec(2, 6, state.cursor, 1);
            }
            state.hasChanged = true;
          }

          if (state.onClick) {
            switch (state.cursor) {
              case 2:
                if (eb.left()) {
                  state.mode = inc(0, 3, state.mode, 1);
                } else if (eb.right()) {
                  state.mode  = dec(0, 3, state.mode, 1);
                }
                break;
              case 3:
                if (eb.left()) {
                  state.color[0] = inc(0, 255, state.color[0], 5);
                } else if (eb.right()) {
                  state.color[0] = dec(0, 255, state.color[0], 5);
                }
                break;
              case 4:
                if (eb.left()) {
                  state.color[1] = inc(0, 255, state.color[1], 5);
                } else if (eb.right()) {
                  state.color[1] = dec(0, 255, state.color[1], 5);
                }
                break;
              case 5:
                if (eb.left()) {
                  state.color[2] = inc(0, 255, state.color[2], 5);
                } else if (eb.right()) {
                  state.color[2] = dec(0, 255, state.color[2], 5);
                }
                break;
              case 6:
                if (eb.left()) {
                  state.brightness = inc(0, 255, state.brightness, 5);
                } else if (eb.right()) {
                  state.brightness = dec(0, 255, state.brightness, 5);
                }
                break;
              case 7:
                if (eb.left()) {
                  state.delayl = inc(5, 200, state.delayl, 5);
                } else if (eb.right()) {
                  state.delayl = dec(5, 200, state.delayl, 5);
                }
                break;  
            }
            state.hasChanged = true;
          }
        }

        break;
    }

  // где-то внутри функции мы будем знать, что изменили состояние
  // либо же, будем знать что любое событие изменяет состояние  
}

char strTmp[16] = {0};
void displayMain() {
  for (int i = 0; i < COUNT_STR; i++) {
    sprintf(strTmp, "%s%s", i == state.cursor ? "-" : "", name[state.mode][i]/*i == 5 ? nameMode[state.mode] : ""*/);

    if (i == 2)
      sprintf(strTmp, "%s%s", strTmp, nameMode[0]);
    if (i == 3)
      sprintf(strTmp, "%s%d", strTmp, state.color[0]);
    if (i == 4)
      sprintf(strTmp, "%s%d", strTmp, state.color[1]);
    if (i == 5)
      sprintf(strTmp, "%s%d", strTmp, state.color[2]);
    if (i == 6)
      sprintf(strTmp, "%s%d", strTmp, state.brightness);

    u8x8.setFont(u8x8_font_chroma48medium8_r);
    u8x8.setInverseFont(i == state.cursor && state.onClick);
    u8x8.drawString(0, i, strTmp);
  }
}

void displayBlink() {
  for (int i = 0; i < COUNT_STR; i++) {
    sprintf(strTmp, "%s%s", i == state.cursor ? "-" : "", name[state.mode][i]/*i == 5 ? nameMode[state.mode] : ""*/);

    if (i == 2)
      sprintf(strTmp, "%s%s", strTmp, nameMode[2]);
    if (i == 3)
      sprintf(strTmp, "%s%d", strTmp, state.color[0]);
    if (i == 4)
      sprintf(strTmp, "%s%d", strTmp, state.color[1]);
    if (i == 5)
      sprintf(strTmp, "%s%d", strTmp, state.color[2]);
    if (i == 6)
      sprintf(strTmp, "%s%d", strTmp, state.brightness);
    if (i == 7)
      sprintf(strTmp, "%s%d", strTmp, state.delayl);


    u8x8.setFont(u8x8_font_chroma48medium8_r);
    u8x8.setInverseFont(i == state.cursor && state.onClick);
    u8x8.drawString(0, i, strTmp);
  }
}

void displayLgbt() {
  for (int i = 0; i < COUNT_STR; i++) {
    sprintf(strTmp, "%s%s", i == state.cursor ? "-" : "", name[state.mode][i]/*i == 5 ? nameMode[state.mode] : ""*/);

    if (i == 2)
      sprintf(strTmp, "%s%s", strTmp, nameMode[1]);
    if (i == 3)
      sprintf(strTmp, "%s%d", strTmp, state.dhue);
    if (i == 4)
      sprintf(strTmp, "%s%d", strTmp, state.brightness);
    if (i == 5)
      sprintf(strTmp, "%s%d", strTmp, state.delayl);

    u8x8.setFont(u8x8_font_chroma48medium8_r);
    u8x8.setInverseFont(i == state.cursor && state.onClick);
    u8x8.drawString(0, i, strTmp);
  }
}

void display() {
  // в простейшем случае, функция каждый раз перерисовывает содержание дисплея исходя из состояния.
  // конечно, это можно оптимизировать, храня копию предыдущего состояния и перерисовывать только измененные элементы UI
  u8x8.clear();
  switch(state.mode) {
    case Mode::staticMode:
      displayMain();
      break;
    case Mode::dynamicMode:
      displayLgbt();
      break;
    case Mode::blinkMode:
      displayBlink();
      break;
  }
}

void ledStatic() {
  FastLED.setBrightness(state.brightness);
  for (int i = 0; i < NUM_LEDS; i++) {
    leds[i] = state.color;
  }
  FastLED.show();
}

void ledLgbt() {
  if ((millis() - lastTime) < state.delayl)
    return;
  fill_rainbow(leds, NUM_LEDS, state.hue, state.dhue);
  FastLED.show();
  state.hue = (state.hue + 1) % 255;
  FastLED.delay(state.delayl);
  lastTime = millis();
}

void ledBlink() {
  if ((millis() - lastTime) < state.delayl)
    return;
  FastLED.setBrightness(state.brightness);

  for (int i = 0; i < NUM_LEDS; i++) {
    leds[i] = state.color;
  }
  FastLED.show();

  for (int i = 0; i < NUM_LEDS; i++) {
    leds[i] = CRGB::White;
  }
  FastLED.show();
}

void led() {
  switch (state.mode) {
    case Mode::staticMode:
      ledStatic();
      break;
    case Mode::dynamicMode:
      ledLgbt();
      break;
    case Mode::blinkMode:
      ledBlink();
      break;
  }
}


void loop(void) {
    eb.tick();

    // не стоит каждый раз перерисовывать дисплей. 
    // Только если состояние изменилось
    if (state.hasChanged) {
        display();  
        state.hasChanged = false;  
    } 
    
    // как часто стоит обновлять ленту уже зависит от режима
    led();
}