// =====================================================
//  NEOPIXEL RING CLOCK — Arduino MEGA
//  MakeMindz Summer Course · Module 4
//  Pins: DIN→6 | TRIG→10 | ECHO→11 | BTN_A→2 | BTN_B→3
// =====================================================

#include <Adafruit_NeoPixel.h>

#define LED_PIN   6    // NeoPixel data pin
#define NUM_LEDS  60   // 60 pixels in the ring
#define TRIG_PIN  10   // HC-SR04 trigger
#define ECHO_PIN  11   // HC-SR04 echo
#define BTN_A     2    // Mode switch button (blue)
#define BTN_B     3    // Minute advance button (green)

Adafruit_NeoPixel ring(NUM_LEDS, LED_PIN, NEO_GRB + NEO_KHZ800);

int hh = 10, mm = 9, sc = 0;   // start at 10:09:00
unsigned long prevMs = 0;
uint8_t dispMode = 0;            // 0=Clock 1=EQ 2=Radar 3=Rainbow
bool prevA = HIGH, prevB = HIGH;
unsigned long dbA = 0, dbB = 0;
// ── Ultrasonic ping — returns distance in cm ──
long ping() {
  digitalWrite(TRIG_PIN, LOW);  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH); delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  long t = pulseIn(ECHO_PIN, HIGH, 23000);
  return t ? t * 17L / 1000 : 60;
}

// ── Colour wheel: maps 0-255 to smooth colour ─
uint32_t wheel(uint8_t p) {
  p = 255 - p;
  if (p < 85)  return ring.Color(255-p*3, 0,       p*3);
  if (p < 170) { p-=85;  return ring.Color(0, p*3, 255-p*3); }
                 p-=170; return ring.Color(p*3, 255-p*3, 0);
}

uint32_t scalec(uint32_t c, uint8_t f) {
  return ring.Color(
    ((c>>16)&0xFF)*f/255,
    ((c>>8) &0xFF)*f/255,
    ( c      &0xFF)*f/255);
}
// ── MODE 0: Classic Clock ─────────────────────
void modeClock() {
  ring.clear();
  for (int i=0;i<60;i+=5) ring.setPixelColor(i,ring.Color(14,14,14));
  int hc=(int)round(((hh%12)*60.0f+mm)/720.0f*60.0f)%60;
  for (int d=-2;d<=2;d++){
    int px=(hc+d+60)%60;
    uint8_t b=(d==0)?230:(abs(d)==1?100:35);
    ring.setPixelColor(px,ring.Color(b,0,0));
  }
  int mc=(int)round((mm*60.0f+sc)/3600.0f*60.0f)%60;
  ring.setPixelColor((mc-1+60)%60,scalec(ring.Color(0,255,80),70));
  ring.setPixelColor(mc,ring.Color(0,255,80));
  ring.setPixelColor((mc+1)%60,scalec(ring.Color(0,255,80),70));
  ring.setPixelColor(sc%60,ring.Color(0,210,255));
  ring.show();
}

// ── MODE 1: Equalizer ─────────────────────────
uint8_t eqH[8]={20,42,16,52,34,28,46,22};
int8_t  eqV[8]={ 1,-1, 1,-1, 1,-1, 1,-1};
unsigned long eqMs=0;
void modeEQ() {
  if(millis()-eqMs>65){
    for(int i=0;i<8;i++){
      eqH[i]+=eqV[i]*(int8_t)random(2,7);
      if(eqH[i]>=58||eqH[i]<=4){eqV[i]=-eqV[i];eqH[i]=constrain(eqH[i],4,58);}
    } eqMs=millis();
  }
  ring.clear();
  for(int b=0;b<8;b++){
    int ctr=b*7+3;
    uint32_t c=wheel(map(eqH[b],4,58,0,185));
    uint8_t br=map(eqH[b],4,58,40,255);
    for(int d=-2;d<=2;d++) ring.setPixelColor((ctr+d+60)%60,scalec(c,(uint16_t)br*(d==0?255:abs(d)==1?130:45)/255));
  }
  ring.show();
}

// ── MODE 2: Radar + Proximity ─────────────────
int radarHead=0; unsigned long radarMs=0;
void modeRadar() {
  if(millis()-radarMs>22){radarHead=(radarHead+1)%60;radarMs=millis();}
  ring.clear();
  for(int i=0;i<18;i++) ring.setPixelColor((radarHead-i+60)%60,ring.Color(0,map(i,0,17,210,4),0));
  long cm=ping();
  if(cm<40){
    int obj=map(cm,2,40,0,59);
    ring.setPixelColor(obj,ring.Color(255,80,0));
    ring.setPixelColor((obj+1)%60,ring.Color(80,20,0));
    ring.setPixelColor((obj-1+60)%60,ring.Color(80,20,0));
  }
  ring.show();
}

// ── MODE 3: Rainbow (speed = hand distance) ───
uint16_t rbPos=0; unsigned long rbMs=0;
void modeRainbow() {
  long cm=constrain(ping(),2,40);
  uint8_t spd=map(cm,2,40,14,1);
  if(millis()-rbMs>spd){rbPos=(rbPos+1)%256;rbMs=millis();}
  for(int i=0;i<NUM_LEDS;i++) ring.setPixelColor(i,wheel((i*4+rbPos)&0xFF));
  ring.show();
}
void checkButtons() {
  unsigned long now=millis();
  bool a=digitalRead(BTN_A), b=digitalRead(BTN_B);
  if(prevA==HIGH&&a==LOW&&now-dbA>200){
    dispMode=(dispMode+1)%4; dbA=now;
    ring.fill(ring.Color(25,25,25)); ring.show(); delay(55); ring.clear();
  }
  if(prevB==HIGH&&b==LOW&&now-dbB>200){ mm=(mm+5)%60; sc=0; dbB=now; }
  prevA=a; prevB=b;
}

void setup() {
  ring.begin(); ring.setBrightness(75); ring.show();
  pinMode(TRIG_PIN,OUTPUT); pinMode(ECHO_PIN,INPUT);
  pinMode(BTN_A,INPUT_PULLUP); pinMode(BTN_B,INPUT_PULLUP);
  // Boot spiral animation
  for(int i=0;i<NUM_LEDS;i++){ring.setPixelColor(i,wheel(i*4));ring.show();delay(16);}
  delay(250);
  for(int i=NUM_LEDS-1;i>=0;i--){ring.setPixelColor(i,0);ring.show();delay(9);}
  prevMs=millis(); randomSeed(42);
}

void loop() {
  checkButtons();
  if(millis()-prevMs>=1000){
    prevMs+=1000;
    if(++sc>=60){sc=0;if(++mm>=60){mm=0;if(++hh>=24)hh=0;}}
  }
  switch(dispMode){
    case 0: modeClock();   break;
    case 1: modeEQ();     break;
    case 2: modeRadar();  break;
    case 3: modeRainbow(); break;
  }
  delay(8);
}