#include <Arduino.h>

// ------------------ Pins ------------------
const int trig = PA9;
const int echo = PA10;

#define LED_GREEN PA5
#define LED_ORANGE PB7
#define LED_RED PB0
#define BUZZER PA12
#define SWITCH_PIN PB6

// 74HC595 (Interface Mikro-Bus)
#define DS PA6
#define SH_CP PA7
#define ST_CP PA4

// ------------------ Variables ------------------
long duration;
float distance;

// ------------------ Table ANODE COMMUNE ------------------
const byte SEG[10] = {
  0b11000000, // 0
  0b11111001, // 1
  0b10100100, // 2
  0b10110000, // 3
  0b10011001, // 4
  0b10010010, // 5
  0b10000010, // 6
  0b11111000, // 7
  0b10000000, // 8
  0b10010000  // 9
};

void setup() {
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);
  pinMode(LED_GREEN, OUTPUT);
  pinMode(LED_ORANGE, OUTPUT);
  pinMode(LED_RED, OUTPUT);
  pinMode(BUZZER, OUTPUT);
  pinMode(SWITCH_PIN, INPUT_PULLUP);
  pinMode(DS, OUTPUT);
  pinMode(SH_CP, OUTPUT);
  pinMode(ST_CP, OUTPUT);
  Serial.begin(115200);
}

void displayTwoDigits(int meters, int decimeters) {
  // Point décimal activé sur le premier digit (Mètres)
  byte metersData = SEG[meters] & 0b01111111; 
  byte decimetersData = SEG[decimeters];

  digitalWrite(ST_CP, LOW);
  shiftOut(DS, SH_CP, MSBFIRST, decimetersData);
  shiftOut(DS, SH_CP, MSBFIRST, metersData);
  digitalWrite(ST_CP, HIGH);
}

void loop() {
  // Le système ne s'active que si l'interrupteur est actionné (appui = LOW)
  if (digitalRead(SWITCH_PIN) == HIGH) {
    digitalWrite(LED_GREEN, LOW);
    digitalWrite(LED_ORANGE, LOW);
    digitalWrite(LED_RED, LOW);
    noTone(BUZZER);
    // On peut laisser les afficheurs éteints ou à 0.0
    return;
  }

  // --- Mesure distance ---
  digitalWrite(trig, LOW);
  delayMicroseconds(2);
  digitalWrite(trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(trig, LOW);

  duration = pulseIn(echo, HIGH, 30000);
  distance = (duration * 0.0343) / 2; // cm

  // --- Préparation Affichage (ex: 70cm -> 0.7) ---
  float distMetres = distance / 100.0;
  if (distMetres > 9.9) distMetres = 9.9;
  if (distMetres < 0) distMetres = 0;

  int metersPart = (int)distMetres;
  int deciPart = (int)(distMetres * 10) % 10;
  displayTwoDigits(metersPart, deciPart);

  // --- Terminal PC (Phase 1) ---
  Serial.print("Distance: ");
  Serial.print(distMetres, 1);
  Serial.println(" m");

  // --- Logique Alertes (Cahier des charges) ---
  if (distance > 120) {
    // Diode Verte uniquement
    digitalWrite(LED_GREEN, HIGH);
    digitalWrite(LED_ORANGE, LOW);
    digitalWrite(LED_RED, LOW);
    noTone(BUZZER);
  } 
  else if (distance >= 30) {
    // Diode Orangée + Bips variables
    digitalWrite(LED_GREEN, LOW);
    digitalWrite(LED_ORANGE, HIGH);
    digitalWrite(LED_RED, LOW);
    
    // Intervalle linéaire : 1s (1000ms) à 1.2m, 0s à 30cm
    int interval = map(distance, 30, 120, 0, 1000);
    tone(BUZZER, 440, 50); 
    delay(interval + 50); // Ajustement pour la fluidité
  } 
  else {
    // Diode Rouge + Bip continu
    digitalWrite(LED_GREEN, LOW);
    digitalWrite(LED_ORANGE, LOW);
    digitalWrite(LED_RED, HIGH);
    tone(BUZZER, 440);
  }
  
  delay(50);
}