/* 
  Millis() clock with timed event intervals.
  Version 1/25/25

  Set all values in seconds.
  - Set event duration time, max is 999
  - Set event repeat time, max is 9999, 3600 = 1 hour

  Replace led with DC motor. Have motor run a small animation.
  Make a 'peanut' man and have him sawing wood.

*/


#include <TinyWireM.h>
#include <Tiny4kOLED.h>

#define led PB3
#define navButton PB1 // Navigation/Increment button
#define selButton PB4 // Confirm/Select button

const uint8_t width = 128;
const uint8_t height = 64;

// Time variables
uint8_t second, minute, hour;

int eventCountdown = 0; // Time to next event countdown
int eventDurationCount = 0; // Event duration countdown
int eventDuration = 0; // User-adjustable
int eventRepeatInterval = 0; // User-adjustable

int navButtonRead;
int selButtonRead;
uint8_t oldNavButtonRead = 0;
uint8_t oldSelButtonRead = 0;
const uint8_t debounceTime = 10;

int menuState = 0;  // 0: Viewing eventDuration, 1: Editing eventDuration, 2: Viewing eventRepeatInterval, 3: Editing eventRepeatInterval

void setup() {
  pinMode(navButton, INPUT_PULLUP);
  pinMode(selButton, INPUT_PULLUP);
  pinMode(led, OUTPUT);

  oled.begin(width, height, sizeof(tiny4koled_init_128x64br), tiny4koled_init_128x64br);
  oled.setInternalIref(true); // Provides brighter display using internal voltage reference
  oled.setFont(FONT8X16);

  oled.clear(); // Clear the memory before turning on the display
  oled.on(); // Turn on the display

  digitalWrite(led, LOW);
}

// - - - - - START FUNCTIONS - - - - -

void displayTime() {
  oled.setCursor(0, 0);
  oled.print("Time");
  oled.setCursor(63, 0);
  if (hour < 10) oled.print("0");
  oled.print(hour); oled.print(":");
  if (minute < 10) oled.print("0");
  oled.print(minute); oled.print(":");
  if (second < 10) oled.print("0");
  oled.print(second);
}

void displayEventCountdown() {
  oled.setCursor(0, 2);
  oled.print("Next Event");
  oled.setCursor(95, 2);
  if (eventCountdown < 10) oled.print("000");
  else if (eventCountdown < 100) oled.print("00");
  else if (eventCountdown < 1000) oled.print("0");
  oled.print(eventCountdown);
}

void displayEventDuration() {
  oled.setCursor(0, 4);
  oled.print("Event On");
  oled.setCursor(103, 4);
  if (eventDurationCount < 10) oled.print("00");
  else if (eventDurationCount < 100) oled.print("0");
  oled.print(eventDurationCount);
}

void displayMenu() {
  if (menuState == 0 || menuState == 1) {
    oled.setCursor(0, 6);
    oled.print("Duration:");
    oled.setCursor(95, 6);
    if (eventDuration < 10) oled.print("000");
    else if (eventDuration < 100) oled.print("00");
    else if (eventDuration < 1000) oled.print("0");
    oled.print(eventDuration);
    if (menuState == 1) {
      oled.setCursor(80, 6);
      oled.print("*"); // Editing indicator
      oled.clear();
    }
  } 
  else if (menuState == 2 || menuState == 3) {
    oled.setCursor(0, 6);
    oled.print("Interval:");
    oled.setCursor(95, 6);
    if (eventRepeatInterval < 10) oled.print("000");
    else if (eventRepeatInterval < 100) oled.print("00");
    else if (eventRepeatInterval < 1000) oled.print("0");
    oled.print(eventRepeatInterval);
    if (menuState == 3) {
      oled.setCursor(80, 6);
      oled.print("*"); // Editing indicator
      oled.clear();
    }
  }
}

void handleNavButton() {
  navButtonRead = digitalRead(navButton); // reads 1 with pull-up

  if (navButtonRead != oldNavButtonRead) { // debounce routine
    oldNavButtonRead = navButtonRead;
    delay (debounceTime);

    if (navButtonRead == LOW) {
      if (menuState % 2 == 0) {
        menuState = (menuState + 2) % 4; // Cycle between viewing options
      } else {
        if (menuState == 1) eventDuration += 10; // Increment during editing, 10 sec
        if (menuState == 3) eventRepeatInterval += 60; // Increment during editing, 60 sec
      }
    }
  }
}

void handleSelButton() {
  selButtonRead = digitalRead(selButton); // reads 1 with pull-up

  if (selButtonRead != oldSelButtonRead) { // debounce routine
    oldSelButtonRead = selButtonRead;
    delay (debounceTime);

    if (selButtonRead == LOW) {
      if (menuState % 2 == 0) {
        menuState++; // Enter edit mode
      } else {
        menuState--; // Exit edit mode
      }
    }
  }
}

// - - - - - END FUNCTIONS - - - - -

void loop() {
  handleNavButton();
  handleSelButton();
  displayMenu();

  unsigned long currentMillis = millis();
  unsigned long elapsedSeconds = currentMillis / 1000;

  // Convert current time to hours, minutes, and seconds
  hour = (elapsedSeconds / 3600) % 12;  // 12-hour format
  minute = (elapsedSeconds / 60) % 60;
  second = elapsedSeconds % 60;

  // Calculate time to the next event
  eventCountdown = (eventRepeatInterval - (elapsedSeconds % eventRepeatInterval)) % eventRepeatInterval;

  // Check if the current second is within the event duration
  if ((elapsedSeconds % eventRepeatInterval) >= 0 &&
      (elapsedSeconds % eventRepeatInterval) < (eventDuration)) {
    eventDurationCount = eventDuration - (elapsedSeconds % eventRepeatInterval);
    digitalWrite(led, HIGH);
  } else {
    eventDurationCount = 0;
    digitalWrite(led, LOW);
  }

  displayTime();
  displayEventCountdown();
  displayEventDuration();

  delay(10);
}