/*
 * Title: Basic Example of Encoder Library
 * Description: A basic example using the rotary encoder library
 * Date: Current Date
 *
 * A rotary encoder is a rotational input device that can detect rotation direction and amount.
 * This example uses the Encoder library for Arduino to read the values from a rotary encoder
 * and output them to the serial monitor.
 *
 * Important: The Encoder library internally handles debouncing for rotation signals only.
 * Debouncing for the encoder's switch (button) must be implemented separately.
 *
 * Note: Most rotary encoders generate 4 steps per detent (quadrature signals).
 * In this example, we divide by 4 so the value changes by 1 per detent for more intuitive usage.
 *
 * Required Library: Encoder (by Paul Stoffregen)
 * Library Installation: Sketch > Include Library > Manage Libraries... > Search for "Encoder" > Install
 * Library GitHub: https://github.com/PaulStoffregen/Encoder
 *
 
 english Ver wokwi https://wokwi.com/projects/425622139517030401
 */

#include <Encoder.h>

// Rotary Encoder Pin Definitions
const int ENCODER_PIN_A = 2;  // Rotary Encoder A pin (use pin with interrupt support)
const int ENCODER_PIN_B = 3;  // Rotary Encoder B pin (use pin with interrupt support)
const int ENCODER_SW_PIN = 4; // Rotary Encoder switch pin (optional)

// Create Encoder Object
// Debouncing for rotation is handled internally by the library
Encoder myEncoder(ENCODER_PIN_A, ENCODER_PIN_B);

// Variables
long oldPosition = -999;     // Previous encoder position (raw library value)
int oldNormalizedPos = -999; // Previous normalized value (divided by 4)

// Switch (button) debouncing variables - not handled by the library
int switchState = HIGH;             // Current switch state
int lastSwitchState = HIGH;         // Previous switch state
unsigned long lastDebounceTime = 0; // Timestamp for debouncing
unsigned long debounceDelay = 50;   // Debounce time in milliseconds

void setup()
{
    // Initialize serial communication
    Serial.begin(9600);
    Serial.println("Rotary Encoder Basic Example");
    Serial.println("Value changes by 1 per detent (normalized)");

    // Set switch pin mode (using internal pull-up resistor)
    pinMode(ENCODER_SW_PIN, INPUT_PULLUP);
}

void loop()
{
    // Split functionality into two separate functions for better readability
    handleEncoder();
    handleSwitch();
}

/**
 * Function to handle rotary encoder rotation
 * Detects rotation and outputs normalized values
 */
void handleEncoder()
{
    // Read encoder rotation (debouncing is handled by the library)
    long newPosition = myEncoder.read();

    // Normalize raw encoder value by dividing by 4 to get 1 change per detent
    int normalizedPos = newPosition / 4;

    // Output new value if position has changed
    if (normalizedPos != oldNormalizedPos)
    {
        Serial.print("Encoder position: ");
        Serial.print(normalizedPos);
        Serial.print(" (raw value: ");
        Serial.print(newPosition);
        Serial.println(")");
        oldPosition = newPosition;
        oldNormalizedPos = normalizedPos;
    }
}

/**
 * Function to handle rotary encoder switch (button)
 * Implements debouncing and resets encoder value when pressed
 */
void handleSwitch()
{
    // Read encoder switch state and apply debouncing
    int reading = digitalRead(ENCODER_SW_PIN);

    // Reset debounce timer when button state changes
    if (reading != lastSwitchState)
    {
        lastDebounceTime = millis();
    }

    // Check if button state has stabilized after debounce delay
    if ((millis() - lastDebounceTime) > debounceDelay)
    {
        // Check if button state has actually changed
        if (reading != switchState)
        {
            switchState = reading;

            // LOW means button is pressed (due to pull-up resistor configuration)
            if (switchState == LOW)
            {
                Serial.println("Encoder button pressed - Counter reset");
                myEncoder.write(0); // Reset encoder value to 0
                oldPosition = 0;
                oldNormalizedPos = 0;
            }
        }
    }

    // Save button state for next iteration
    lastSwitchState = reading;
}