#include <Arduino.h>
#include <U8g2lib.h>
#include <Wire.h>
#include <Preferences.h>

// --- PINOUT ---
const int swPins[6] = {35, 36, 37, 38, 40, 39}; 
const int tapPin = 41;                          
const int ledPins[4] = {15, 16, 17, 18};   
#define MIDI_TX_PIN 43

U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE, /* clock=*/ 2, /* data=*/ 1);
Preferences prefs;

// --- STATE MANAGEMENT ---
int currentBank = 1, activeBank = 1, activePreset = 0, deviceMode = 0;
bool inMenu = false, isBlinking = false, blinkState = true;
unsigned long lastBlinkTime = 0;
bool lastSwState[6] = {HIGH, HIGH, HIGH, HIGH, HIGH, HIGH};
bool lastTapState = HIGH;

// Tap Tempo Logic
unsigned long lastTapTime = 0, lastTapActivity = 0;
int currentBPM = 120;
bool isTapModeActive = false;
const int tapTimeout = 1200; 

const char* deviceNames[] = {"NUX MG-300", "VALETON GP", "BOSS GT-1"};
const int maxBanks[] = {9, 32, 50}; 

// --- MIDI ENGINE ---
void sendMIDI(byte status, byte data1, byte data2) {
  Serial1.write(status); 
  Serial1.write(data1);
  if ((status & 0xF0) != 0xC0) Serial1.write(data2);
}

void executeMIDI(int bank, int preset) {
  int pcNum = ((bank - 1) * 4) + preset;
  if (deviceMode == 1) { 
    sendMIDI(0xB0, 0, (pcNum > 127) ? 1 : 0);
    sendMIDI(0xC0, pcNum % 128, 0);
  } else { 
    sendMIDI(0xC0, pcNum, 0);
  }
}

// --- DISPLAY ENGINE ---
void refreshDisplay() {
  u8g2.clearBuffer();
  if (isTapModeActive) {
    u8g2.setFont(u8g2_font_7x14_tr);
    u8g2.drawStr(22, 15, "BON-BON TAP");
    u8g2.drawLine(0, 18, 128, 18);
    u8g2.setFont(u8g2_font_logisoso32_tf);
    char bpmStr[5]; sprintf(bpmStr, "%d", currentBPM);
    u8g2.drawStr((128 - u8g2.getStrWidth(bpmStr)) / 2, 55, bpmStr);
  } else if (inMenu) {
    u8g2.setFont(u8g2_font_7x14_tr);
    u8g2.drawStr(25, 18, "DEVICE SET");
    u8g2.drawFrame(5, 25, 118, 25);
    u8g2.drawStr(15, 42, deviceNames[deviceMode]);
    u8g2.setFont(u8g2_font_5x7_tr);
    u8g2.drawStr(10, 60, "P3:CHANGE  P4:SAVE");
  } else {
    u8g2.setDrawColor(1);
    u8g2.drawRBox(0, 0, 128, 15, 2);
    u8g2.setDrawColor(0);
    u8g2.setFont(u8g2_font_haxrcorp4089_tr);
    u8g2.drawStr((128 - u8g2.getStrWidth(deviceNames[deviceMode])) / 2, 12, deviceNames[deviceMode]);
    u8g2.setDrawColor(1);
    u8g2.drawLine(64, 18, 64, 62); 
    u8g2.setFont(u8g2_font_6x12_tr);
    u8g2.drawStr(20, 26, "BANK"); u8g2.drawStr(80, 26, "PRESET"); 
    u8g2.setFont(u8g2_font_logisoso32_tf);
    if (!isBlinking || blinkState) {
      char bStr[3]; sprintf(bStr, "%02d", currentBank);
      u8g2.drawStr((64 - u8g2.getStrWidth(bStr)) / 2, 60, bStr); 
    }
    if (!isBlinking) {
      char pStr[2] = {(char)('A' + activePreset), '\0'};
      u8g2.drawStr(64 + (64 - u8g2.getStrWidth(pStr)) / 2, 60, pStr); 
    }
  }
  u8g2.sendBuffer();
}

void commitPreset(int p) {
  activePreset = p; 
  activeBank = currentBank;
  executeMIDI(activeBank, activePreset);
  for(int i=0; i<4; i++) digitalWrite(ledPins[i], (i == p) ? HIGH : LOW);
  isBlinking = false;
  isTapModeActive = false; 
  refreshDisplay();
}

// --- SETUP ---
void setup() {
  Serial1.begin(31250, SERIAL_8N1, -1, MIDI_TX_PIN);
  u8g2.begin();
  u8g2.clearBuffer();
  u8g2.setFont(u8g2_font_ncenB14_tr);
  u8g2.drawStr(25, 40, "BON-BON");
  u8g2.sendBuffer();
  delay(500);
  
  for(int i=0; i<6; i++) pinMode(swPins[i], INPUT_PULLUP);
  pinMode(tapPin, INPUT_PULLUP);
  for(int i=0; i<4; i++) { pinMode(ledPins[i], OUTPUT); digitalWrite(ledPins[i], LOW); }
  
  prefs.begin("midi-cfg", true);
  deviceMode = prefs.getInt("devMode", 0);
  prefs.end();
  commitPreset(0); 
}

void loop() {
  unsigned long now = millis();

  // 1. Blink Handling
  if (isBlinking && (now - lastBlinkTime > 200)) {
    blinkState = !blinkState; lastBlinkTime = now;
    if (!isTapModeActive && !inMenu) refreshDisplay();
  }

  // 2. Tap Timeout
  if (isTapModeActive && (now - lastTapActivity > tapTimeout)) {
    isTapModeActive = false; refreshDisplay();
  }

  // 3. Tap Logic
  bool tapRead = digitalRead(tapPin);
  if (tapRead == LOW && lastTapState == HIGH) {
    unsigned long diff = now - lastTapTime;
    if (diff < 2000 && diff > 150) currentBPM = 60000 / diff;
    lastTapTime = now; lastTapActivity = now;
    isTapModeActive = true;
    sendMIDI(0xB0, 64, 127);
    refreshDisplay();
  }
  lastTapState = tapRead;

  // --- LOGIKA ANTI-GLITCH TOMBOL ---
  if (!inMenu) {
    // Cek Menu dulu sebelum proses Preset A
    if (digitalRead(swPins[0]) == LOW && digitalRead(swPins[1]) == LOW) {
      inMenu = true; 
      delay(300); // Tunggu sampai tangan lepas
      refreshDisplay();
      return; 
    }

    for (int i = 0; i < 6; i++) {
      bool swRead = digitalRead(swPins[i]);
      if (swRead == LOW && lastSwState[i] == HIGH) {
        // Jika P1 ditekan, tunggu 20ms sebentar untuk pastikan bukan mau tekan P2 (Menu)
        if (i == 0) {
          delay(20); 
          if (digitalRead(swPins[1]) == LOW) { lastSwState[i] = LOW; continue; }
        }

        if (i < 4) {
          commitPreset(i);
        } else if (i == 4) {
          if (currentBank > 1) { currentBank--; isBlinking = true; refreshDisplay(); }
        } else if (i == 5) {
          if (currentBank < maxBanks[deviceMode]) { currentBank++; isBlinking = true; refreshDisplay(); }
        }
      }
      lastSwState[i] = swRead;
    }
  } else {
    // Logika Menu
    if (digitalRead(swPins[2]) == LOW) { deviceMode = (deviceMode + 1) % 3; refreshDisplay(); delay(250); }
    if (digitalRead(swPins[3]) == LOW) { 
      prefs.begin("midi-cfg", false); prefs.putInt("devMode", deviceMode); prefs.end(); 
      inMenu = false; commitPreset(0); 
    }
  }
}