#include <LiquidCrystal.h>

#define BTN_UP 2
#define BTN_LEFT 3
#define BTN_OK 4
#define BTN_RIGHT 13
#define BTN_DOWN 6
#define PHOTOR A0
#define LED 5

LiquidCrystal lcd(12, 11, 10, 9, 8, 7);


int state = 0;  

String names[4] = {"Led", "Photo", "Brightness", "Progress Bar"};
String photoModes[2] = {"Manual", "Auto"};

boolean UpWasUp = true;
boolean DownWasUp = true;
boolean LeftWasUp = true;
boolean RightWasUp = true;
boolean OkWasUp = true;

int index = 0;

int photoMode = 0;

int manualBright = 150;

unsigned long timeBlink = 0;

void setup() {
  lcd.begin(16, 2);
  lcd.print("Start...");
  delay(1000);
  lcd.clear();

  for (int i = 2; i < 7; i++) {
    pinMode(i == 5 ? 13 : i, INPUT_PULLUP);
  }
  pinMode(LED, OUTPUT);
}

void loop() {

  if (state == 0) menuScreen();
  else if (state == 1) ledScreen();
  else if (state == 2) photoScreen();
  else if (state == 3) brightnessScreen();
  else if (state == 4) progressBarScreen();

  boolean Ok = digitalRead(BTN_OK);
  if (Ok != OkWasUp) {
    delay(20);
    Ok = digitalRead(BTN_OK);

    if (!Ok) {
      lcd.clear();

      if (state == 0) {
        if (index == 0) state = 1;
        if (index == 1) state = 2;
        if (index == 2) state = 3;
        if (index == 3) state = 4;
      } else {
        state = 0;
      }
    }
  }
  OkWasUp = Ok;
}

void menuScreen() {
  lcd.setCursor(0, 0);
  lcd.print("Menu");
  lcd.setCursor(0, 1);
  printLine(names[index]);

  boolean Up = digitalRead(BTN_UP);
  if (Up != UpWasUp) {
    delay(10);
    Up = digitalRead(BTN_UP);
    if (!Up) index = (index + 1) % 4;
  }
  UpWasUp = Up;

  boolean Down = digitalRead(BTN_DOWN);
  if (Down != DownWasUp) {
    delay(10);
    Down = digitalRead(BTN_DOWN);
    if (!Down) index = (index - 1 < 0 ? 3 : index - 1);
  }
  DownWasUp = Down;
}

void ledScreen() {
  lcd.setCursor(0, 0);
  lcd.print("LED Mode");

  lcd.setCursor(0, 1);
  printLine("Photo:" + photoModes[photoMode]);

  int value = analogRead(PHOTOR);
  value = constrain(value, 0, 1023);

  if (photoMode == 1) {
    int bright = map(value, 0, 1023, 255, 0);
    analogWrite(LED, bright);
  }
  else {
    analogWrite(LED, manualBright);
  }

  boolean Right = digitalRead(BTN_RIGHT);
  if (Right != RightWasUp) {
    delay(10);
    Right = digitalRead(BTN_RIGHT);
    if (!Right) photoMode = (photoMode + 1) % 2;
  }
  RightWasUp = Right;

  boolean Left = digitalRead(BTN_LEFT);
  if (Left != LeftWasUp) {
    delay(10);
    Left = digitalRead(BTN_LEFT);
    if (!Left) photoMode = (photoMode == 0 ? 1 : 0);
  }
  LeftWasUp = Left;
}

void photoScreen() {

  int value = analogRead(PHOTOR);
  value = constrain(value, 0, 1023);
  int percent = map(value, 0, 1023, 0, 100);

  lcd.setCursor(0, 0);
  lcd.print("Photo:");
  lcd.setCursor(7, 0);
  lcd.print(photoModes[photoMode]);

  lcd.setCursor(0, 1);
  lcd.print("Light:");
  lcd.print(percent);
  lcd.print("% ");

  if (photoMode == 1) {
    int bright = map(value, 0, 1023, 255, 0);
    analogWrite(LED, bright);
  }

  boolean Right = digitalRead(BTN_RIGHT);
  if (Right != RightWasUp) {
    delay(10);
    Right = digitalRead(BTN_RIGHT);
    if (!Right) photoMode = (photoMode + 1) % 2;
  }
  RightWasUp = Right;

  boolean Left = digitalRead(BTN_LEFT);
  if (Left != LeftWasUp) {
    delay(10);
    Left = digitalRead(BTN_LEFT);
    if (!Left) photoMode = (photoMode == 0 ? 1 : 0);
  }
  LeftWasUp = Left;
}

void brightnessScreen() {

  lcd.setCursor(0, 0);
  lcd.print("Brightness");

  int percent = map(manualBright, 0, 255, 0, 100);
  lcd.setCursor(0, 1);
  lcd.print(percent);
  lcd.print("%     ");

  if (photoMode == 0)
    analogWrite(LED, manualBright);

  boolean Right = digitalRead(BTN_RIGHT);
  if (Right != RightWasUp) {
    delay(10);
    Right = digitalRead(BTN_RIGHT);
    if (!Right) {
      manualBright += 5;
      if (manualBright > 255) manualBright = 255;
    }
  }
  RightWasUp = Right;

  boolean Left = digitalRead(BTN_LEFT);
  if (Left != LeftWasUp) {
    delay(10);
    Left = digitalRead(BTN_LEFT);
    if (!Left) {
      manualBright -= 5;
      if (manualBright < 0) manualBright = 0;
    }
  }
  LeftWasUp = Left;
}

void progressBarScreen() {

  int value = analogRead(PHOTOR);
  int percent = map(value, 0, 1023, 0, 100);
  int bars = percent / 10;

  lcd.setCursor(0, 0);
  lcd.print("Progress Bar");

  lcd.setCursor(0, 1);
  for (int i = 0; i < 10; i++) {
    if (i < bars) lcd.write(255);
    else lcd.print(" ");
  }

  lcd.setCursor(12, 1);
  lcd.print(percent);
  lcd.print("% ");
}

void printLine(String s) {
  for (int i = 0; i < 16; i++) {
    if (i < s.length()) lcd.print(s[i]);
    else lcd.print(" ");
  }
}