#include <Adafruit_NeoPixel.h>


// ----- Pin definitions -----
#define Hold0 18// changed to 18 for demo 
#define Hold1 1
#define Hold2 2
#define Hold3 21
#define Hold4 22
#define Hold5 23

#define Battery_LED 0  //change to 0 for demo
#define NeoPixelPin 19
#define ButtonPin 3   // start button (active LOW)

// ----- NeoPixel setup -----
#define NUMPIXELS 8
Adafruit_NeoPixel strip(NUMPIXELS, NeoPixelPin, NEO_GRB + NEO_KHZ800);

// ----- Holds & workout configuration -----
#define NUM_HOLDS 6
#define MAX_STEPS 16   // max number of workout steps you want to support

// Array of hold pins for easier mapping
const uint8_t holdPins[NUM_HOLDS] = {Hold0, Hold1, Hold2, Hold3, Hold4, Hold5};

// Workout data (modifiable via serial)
unsigned long workTimes[MAX_STEPS];   // ms
unsigned long restTimes[MAX_STEPS];   // ms
uint8_t holdOrder[MAX_STEPS];         // index into holdPins[]
uint8_t stepCount = 0;                // number of valid steps

// Extra rest after button press, in ms (configurable via PRE: command)
unsigned long preStartRest = 10000;   // default 10s

// ----- Helper functions -----
void allHoldsLow() {
  for (int i = 0; i < NUM_HOLDS; i++) {
    digitalWrite(holdPins[i], LOW);
  }
}

void clearStrip() {
  for (int i = 0; i < NUMPIXELS; i++) {
    strip.setPixelColor(i, 0, 0, 0);  // off
  }
  strip.show();
}

void workPhase(unsigned long workTimeMs) {
  clearStrip();

  if (workTimeMs < NUMPIXELS) workTimeMs = NUMPIXELS; // avoid 0 delays
  unsigned long stepDelay = workTimeMs / NUMPIXELS;

  // Fill bar one pixel at a time (green)
  for (int i = 0; i < NUMPIXELS; i++) {
    strip.setPixelColor(i, 0, 255, 0); // green
    strip.show();
    delay(stepDelay);
  }

  // If any leftover time due to integer division, wait it out
  unsigned long usedTime = stepDelay * NUMPIXELS;
  if (workTimeMs > usedTime) {
    delay(workTimeMs - usedTime);
  }
}

void restPhase(unsigned long restTimeMs) {
  // All pixels red at start of rest
  for (int i = 0; i < NUMPIXELS; i++) {
    strip.setPixelColor(i, 255, 0, 0); // red
  }
  strip.show();

  if (restTimeMs < NUMPIXELS) restTimeMs = NUMPIXELS; // avoid 0 delays
  unsigned long stepDelay = restTimeMs / NUMPIXELS;

  // Decrease bar one pixel at a time (turn off from the end)
  for (int i = NUMPIXELS - 1; i >= 0; i--) {
    strip.setPixelColor(i, 0, 0, 0); // off
    strip.show();
    delay(stepDelay);
    if (i == 0) break; // avoid underflow
  }

  // Leftover time if any
  unsigned long usedTime = stepDelay * NUMPIXELS;
  if (restTimeMs > usedTime) {
    delay(restTimeMs - usedTime);
  }
}

// ----- Serial parsing helpers -----
void resetWorkoutToDefaults() {
  // Optional: some default 6-step workout if nothing has been sent yet
  stepCount = 6;
  for (uint8_t i = 0; i < stepCount; i++) {
    holdOrder[i] = i % NUM_HOLDS;        // Hold 0..5 in order
    workTimes[i] = 10000UL;              // 10s
    restTimes[i] = 5000UL;               // 5s
  }
  preStartRest = 10000UL;                // 10s
}

void parseLine(String line) {
  line.trim();
  if (line.length() == 0) return;

  // PRE:<seconds>
  if (line.startsWith("PRE:")) {
    String val = line.substring(4);
    unsigned long seconds = val.toInt();
    if (seconds > 0) {
      preStartRest = seconds * 1000UL;
    }
    return;
  }

  // H<hold>,<workSec>,<restSec>
  if (line.charAt(0) == 'H') {
    if (stepCount >= MAX_STEPS) {
      // Ignore extra steps beyond MAX_STEPS
      return;
    }

    int firstComma = line.indexOf(',');
    int secondComma = line.indexOf(',', firstComma + 1);

    if (firstComma == -1 || secondComma == -1) {
      // Bad format, ignore
      return;
    }

    String holdStr = line.substring(1, firstComma);
    String workStr = line.substring(firstComma + 1, secondComma);
    String restStr = line.substring(secondComma + 1);

    int holdIdx = holdStr.toInt();
    unsigned long workSec = workStr.toInt();
    unsigned long restSec = restStr.toInt();

    if (holdIdx < 0 || holdIdx >= NUM_HOLDS) {
      // Invalid hold index
      return;
    }

    holdOrder[stepCount] = (uint8_t)holdIdx;
    workTimes[stepCount] = workSec * 1000UL;
    restTimes[stepCount] = restSec * 1000UL;
    stepCount++;

    return;
  }

  // Anything else: ignore for now
}

void readSerialConfig() {
  // Read all available lines from serial and parse them
  while (Serial.available()) {
    String line = Serial.readStringUntil('\n');
    parseLine(line);
  }
}

void setup() {

  // Serial for config
  Serial.begin(9600);

  // Hold pins
  pinMode(Hold0, OUTPUT);
  pinMode(Hold1, OUTPUT);
  pinMode(Hold2, OUTPUT);
  pinMode(Hold3, OUTPUT);
  pinMode(Hold4, OUTPUT);
  pinMode(Hold5, OUTPUT);
  

  // Battery LED always on
  pinMode(Battery_LED, OUTPUT);
  digitalWrite(Battery_LED, HIGH);

  // Button input (using internal pull-up, active LOW)
  pinMode(ButtonPin, INPUT_PULLUP);

  // NeoPixel init
  strip.begin();
  strip.setBrightness(80); // adjust 0–255 if you want brighter/dimmer
  clearStrip();

  // Make sure holds are off at start
  allHoldsLow();

  // Default workout in case nothing has been sent yet
  resetWorkoutToDefaults();
}

void loop() {
  // Continuously listen for new configuration data
  readSerialConfig();

  // Idle state: all holds off, LEDs off except battery LED
  allHoldsLow();
  clearStrip();

  // Wait until button is pressed (active LOW)
  while (digitalRead(ButtonPin) == HIGH) {
   readSerialConfig();   // allow updating workout while waiting
    delay(10);
  }

  // Simple debounce
  delay(50);
  // Wait for button release
  while (digitalRead(ButtonPin) == LOW) {
    readSerialConfig();
    delay(10);
  }

  // Pre-start rest phase (if configured > 0)
 if (preStartRest > 0) {
   restPhase(preStartRest);
 

  // ----- RUN FULL HOLD SEQUENCE ONCE -----
  for (uint8_t s = 0; s < stepCount; s++) {
    allHoldsLow();

    uint8_t holdIdx = holdOrder[s];
    if (holdIdx < NUM_HOLDS) {
      digitalWrite(holdPins[holdIdx], HIGH); // activate current hold
    }

    // Work phase: bar fills up
    workPhase(workTimes[s]);

   // Turn this hold off before moving to next
    allHoldsLow();

    // Rest phase: bar red then decreases
    restPhase(restTimes[s]);

 
  }

  // After this, loop() restarts, goes back to waiting for the button
}