#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

// OLED дисплей 128x64, I2C адрес по умолчанию — 0x3C
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET     -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// Кнопки
#define BTN_UP_PIN     32
#define BTN_DOWN_PIN   33
#define BTN_OK_PIN     25   // #
#define BTN_BACK_PIN   26   // *

extern uint16_t startAddr;
extern void writeStringToEEPROM(const char* str, uint16_t addr);
extern void readVersionFromEEPROM();
extern char versionStr[32];
char moduleStr[32] = {0};  // буфер для считанного модуля
extern uint8_t eepromReadByte(uint8_t addr);
extern uint16_t startAddr;

enum MenuState {
  MENU_MAIN,
  MENU_SELECT_MODULE,
  MENU_SELECT_VERSION,
  MENU_SHOW_EEPROM
};


const char* moduleOptions[] = {
  "DPO4COMP", "DPO2EMBD", "DPO4EMBD", "DPO4AUTO", "DPO4AUTOMAX", "DPO4PWR",
  "DPO4USB", "DPO4ENET", "DPO4LMT", "DPO4AUDIO", "MSO5204B 5RL", "MDO4MSO", "MDO4EMBD",
  "MDO4AERO", "MDO4AUTO", "MDO4COMP", "MDO4FLEX", "MDO4LMT", "MDO4SA", "MDO4SA3",
  "MDO4SA6", "MDO4AFG", "MDO4PWR", "MDO4BND", "MDO4SEC", "MDO4AUDIO"
};
const uint8_t moduleCount = sizeof(moduleOptions) / sizeof(moduleOptions[0]);

MenuState currentMenu = MENU_MAIN;
uint8_t cursorPos = 0;

extern char versionStr[32]; // Используется из основного кода

void readModuleFromEEPROM() {
  memset(moduleStr, 0, sizeof(moduleStr));
  for (size_t i = 0; i < sizeof(moduleStr) - 1; i++) {
    uint8_t b = eepromReadByte(startAddr + i);
    if (b == 0 || b == 0xFF) {
      moduleStr[i] = 0;
      break;
    }
    moduleStr[i] = (char)b;
  }
  moduleStr[sizeof(moduleStr)-1] = 0;
}


void setupUI() {
  pinMode(BTN_UP_PIN, INPUT_PULLUP);
  pinMode(BTN_DOWN_PIN, INPUT_PULLUP);
  pinMode(BTN_OK_PIN, INPUT_PULLUP);
  pinMode(BTN_BACK_PIN, INPUT_PULLUP);

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 not found"));
    while (true);
  }
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.display();

  showMainMenu();
}

void loopUI() {
  static uint32_t lastPress = 0;
  if (millis() - lastPress < 200) return;

  if (!digitalRead(BTN_UP_PIN)) {
    if (cursorPos > 0) cursorPos--;
    updateMenuDisplay();
    lastPress = millis();
  } else if (!digitalRead(BTN_DOWN_PIN)) {
    cursorPos++;
    updateMenuDisplay();
    lastPress = millis();
  } else if (!digitalRead(BTN_OK_PIN)) {
    handleOk();
    lastPress = millis();
  } else if (!digitalRead(BTN_BACK_PIN)) {
    handleBack();
    lastPress = millis();
  }
}

void showMainMenu() {
  currentMenu = MENU_MAIN;
  cursorPos = 0;
  updateMenuDisplay();
}

void updateMenuDisplay() {
  display.clearDisplay();
  display.setCursor(0, 0);

  if (currentMenu == MENU_MAIN) {
    display.setCursor(0, 0);
    display.print(cursorPos == 0 ? "> Module" : "  Module");

    display.setCursor(0, 10);
    display.print(cursorPos == 1 ? "> Version" : "  Version");

    display.setCursor(0, 20);
    display.print(cursorPos == 2 ? "> Read" : "  Read");
  } else if (currentMenu == MENU_SELECT_MODULE) {
    display.print("Module:");
    display.setCursor(0, 10);
    display.print(">");
    display.print(moduleOptions[cursorPos % moduleCount]);
  } else if (currentMenu == MENU_SELECT_VERSION) {
    display.print("Set version via UART:");
    display.setCursor(0, 10);
    display.print("VER=1.23");
  } else if (currentMenu == MENU_SHOW_EEPROM) {
  display.setCursor(0, 0);
  display.print("Module: ");
  display.println(moduleStr);

  display.setCursor(0, 20);
  display.print("Version: ");
  display.println(versionStr);
}
  display.display();
}

void handleOk() {
  if (currentMenu == MENU_MAIN) {
    if (cursorPos == 0) {
      currentMenu = MENU_SELECT_MODULE;
      cursorPos = 0;
    } else if (cursorPos == 1) {
      currentMenu = MENU_SELECT_VERSION;
    } else if (cursorPos == 2) {
      // Считать из EEPROM
      readVersionFromEEPROM();    // версия из 0x00
      readModuleFromEEPROM();     // модуль из startAddr
      currentMenu = MENU_SHOW_EEPROM;
    }
  } 
  else if (currentMenu == MENU_SELECT_MODULE) {
    const char* sel = moduleOptions[cursorPos % moduleCount];
    writeStringToEEPROM(sel, startAddr);
    readAndDumpEEPROM();
    strncpy(versionStr, sel, sizeof(versionStr) - 1);
    versionStr[sizeof(versionStr) - 1] = 0;
    Serial.print("[UI] Module written to EEPROM: ");
    Serial.println(sel);
    showMainMenu();
  } 
  else if (currentMenu == MENU_SELECT_VERSION) {
    writeStringToEEPROM("v1.23", 0);
    readAndDumpEEPROM();
    strncpy(versionStr, "v1.23", sizeof(versionStr) - 1);
    versionStr[sizeof(versionStr) - 1] = 0;
    Serial.print("[UI] Version written to EEPROM: ");
    Serial.println(versionStr);
    showMainMenu();
  }

  updateMenuDisplay();
}



void handleBack() {
  showMainMenu();
}