#include <TM1637.h>
#include <dht.h>

/* ================== PIN MAP ================== */
const uint8_t PIN_LED_Y = 7;
const uint8_t PIN_LED_B = 6;
const uint8_t PIN_LED_G = 5;
const uint8_t PIN_LED_R = 4;
const uint8_t PIN_BUZZ  = 3;

const uint8_t PIN_TM_CLK = 10;
const uint8_t PIN_TM_DIO = 11;

const uint8_t PIN_BTN_K1 = 9;   // Disarm (NO -> GND, INPUT_PULLUP)
const uint8_t PIN_BTN_K2 = 8;   // Panic  (NO -> GND, INPUT_PULLUP)

const uint8_t PIN_LDR    = A2;
const uint8_t PIN_POT    = A0;
const uint8_t PIN_DHT    = 12;

/* =============== DEVICES/OBJECTS ============== */
TM1637 tm;
dht    DHT;

/* ================== CONSTANTS ================= */
const float    TEMP_LIMIT_C        = 35.0;
const uint16_t DISARM_MIN          = 500;
const uint16_t DISARM_MAX          = 520;
const uint32_t DISARM_HOLD_MS      = 2000;
const uint16_t LDR_DELTA_TRIP      = 180;
const uint32_t LDR_MIN_HOLD_MS     = 100;    // <<< NEW: LDR ต้องเกิน threshold ต่อเนื่อง >=100ms
const uint32_t LDR_CAL_TIME_MS     = 1500;
const uint32_t SIREN_TOGGLE_MS     = 250;
const uint32_t BLINK_MS            = 200;
const uint32_t DHT_MIN_INTERVAL_MS = 2200;
const uint32_t PRINT_INTERVAL_MS   = 1000;

/* ==================== STATE =================== */
enum SysState { ARMED_SECURE=0, ALARM_TRIGGERED, DISARM_MODE };
SysState state = ARMED_SECURE, lastState = (SysState)255;

/* =================== RUNTIME ================== */
uint32_t tLastDHTRead=0, tLastPrint=0, tLastBlink=0, tLastSiren=0, tDisarmStart=0, tStart=0;
uint32_t ignoreButtonsUntil = 0;
bool     sirenHigh=false, blinkFlag=false;

float    lastTempC = NAN;
float    lastOkTempC = 0;
int      ldrBaseline = 0;
int      lastLDRRaw  = -1;
uint32_t ldrOverStart = 0;       // <<< NEW

/* ================== HELPERS =================== */
// ดีบาวซ์ + ต้องกดค้าง >= hold_ms ถึงจะนับว่า "กด"
bool readButtonHeld(uint8_t pin, uint16_t hold_ms = 80) {   // <<< NEW
  if (millis() < ignoreButtonsUntil) return false;
  static uint32_t tPressStart[32] = {0};
  bool pressed = (digitalRead(pin) == LOW); // INPUT_PULLUP: LOW = กด
  if (pressed) {
    if (tPressStart[pin] == 0) tPressStart[pin] = millis();
    return (millis() - tPressStart[pin]) >= hold_ms;
  } else {
    tPressStart[pin] = 0;
    return false;
  }
}

// (เดิม) แสดงผล TM1637
void showALRT()   { char s[5]="ALrt"; tm.displayPChar(s); }
void showDashes() { char s[5]="----"; tm.displayPChar(s); }
void showTempC_int(int tC){
  char b[5]="   ";
  if (tC>=100){ snprintf(b,sizeof(b),"%03d",tC); b[3]='C'; }
  else if (tC>=10){ snprintf(b,sizeof(b)," %2d",tC); b[3]='C'; }
  else if (tC>=0){ snprintf(b,sizeof(b),"  %d",tC); b[3]='C'; }
  else { int v=-tC, d=v%10; b[0]='-'; b[1]='0'+d; b[2]=' '; b[3]='C'; }
  tm.displayPChar(b);
}

const char* dhtStatusText(int rc){
  if (rc==DHTLIB_OK) return "OK";
#ifdef DHTLIB_ERROR_CHECKSUM
  if (rc==DHTLIB_ERROR_CHECKSUM) return "CHECKSUM";
#endif
#ifdef DHTLIB_ERROR_TIMEOUT
  if (rc==DHTLIB_ERROR_TIMEOUT) return "TIMEOUT";
#endif
  static char buf[16]; snprintf(buf,sizeof(buf),"ERR(%d)",rc); return buf;
}

bool readDHTIfDue(){
  uint32_t now=millis();
  if (now - tLastDHTRead < DHT_MIN_INTERVAL_MS) return false;
  tLastDHTRead = now;
  int rc = DHT.read22(PIN_DHT);
  if (rc==DHTLIB_OK){
    lastTempC = DHT.temperature;
    if (!isnan(lastTempC) && lastTempC>-10 && lastTempC<80) lastOkTempC=lastTempC;
  } else {
    Serial.print(F("[DHT] status: ")); Serial.println(dhtStatusText(rc));
  }
  return true;
}

/* ---- Intrusion from LDR (with hold-time) ---- */
bool intrusionAlarmNow(){
  lastLDRRaw = analogRead(PIN_LDR);
  bool over = (abs(lastLDRRaw - ldrBaseline) >= LDR_DELTA_TRIP);

  if (over) {
    if (ldrOverStart == 0) ldrOverStart = millis();
    return (millis() - ldrOverStart) >= LDR_MIN_HOLD_MS;
  } else {
    ldrOverStart = 0;
    return false;
  }
}

void sirenUpdate(bool on){
  uint32_t now=millis();
  if (!on){ noTone(PIN_BUZZ); return; }
  if (now - tLastSiren >= SIREN_TOGGLE_MS){
    tLastSiren = now; sirenHigh=!sirenHigh; tone(PIN_BUZZ, sirenHigh?1200:700);
  }
}

void setSecureLights(){ 
  digitalWrite(PIN_LED_G,HIGH); 
  digitalWrite(PIN_LED_R,LOW); 
  digitalWrite(PIN_LED_Y,LOW); 
  digitalWrite(PIN_LED_B,LOW); 
}

void alarmBlinkLights(){
  uint32_t now=millis();
  if (now - tLastBlink >= BLINK_MS){
    tLastBlink=now; blinkFlag=!blinkFlag;
    digitalWrite(PIN_LED_Y, blinkFlag?HIGH:LOW);
    digitalWrite(PIN_LED_R, blinkFlag?LOW:HIGH);
  }
  digitalWrite(PIN_LED_G,LOW); digitalWrite(PIN_LED_B,LOW);
}
void disarmLights(){ digitalWrite(PIN_LED_B,HIGH); }

bool potInDisarmWindow(){ int v=analogRead(PIN_POT); return (v>=DISARM_MIN && v<=DISARM_MAX); }

/* =================== SETUP =================== */
void setup(){
  pinMode(PIN_LED_Y,OUTPUT); pinMode(PIN_LED_B,OUTPUT);
  pinMode(PIN_LED_G,OUTPUT); pinMode(PIN_LED_R,OUTPUT);
  pinMode(PIN_BUZZ,OUTPUT);
  pinMode(PIN_BTN_K1,INPUT_PULLUP); pinMode(PIN_BTN_K2,INPUT_PULLUP);

  tm.begin(PIN_TM_CLK, PIN_TM_DIO, 4);
  tm.setBrightness(7); tm.displayClear(); showDashes();

  Serial.begin(9600);
  Serial.println("Security Box Started");

  // คาลิเบรต LDR baseline ตอนบูต (มีเซ็นเซอร์จริง)
  tStart=millis(); long acc=0; uint16_t n=0;
  while (millis()-tStart < LDR_CAL_TIME_MS) { acc+=analogRead(PIN_LDR); n++; delay(5); }
  if (n==0) n=1; ldrBaseline = acc/(int)n;
  Serial.print(F("[LDR] baseline: ")); Serial.println(ldrBaseline);

  delay(1500); readDHTIfDue();
  Serial.print(F("[DHT] first temperature: ")); Serial.println(lastOkTempC,1);

  setSecureLights(); // Green LED
  ignoreButtonsUntil = millis() + 2000;  // กันกลิตช์ช่วงบูต
}

/* ==================== LOOP ==================== */
void loop(){
  // 0) PANIC (ต้องกดค้าง >=80ms)
  if (readButtonHeld(PIN_BTN_K2, 80)) {            // <<< NEW
    Serial.println(F("[CAUSE] PANIC_K2"));         // <<< NEW
    state = ALARM_TRIGGERED;
  }

  // 1) Update sensors
  readDHTIfDue();
  bool tempAlarmActive      = (lastOkTempC > TEMP_LIMIT_C);
  bool intrusionAlarmActive = intrusionAlarmNow();

  // 2) Telemetry ทุก 1 วิ (รวมสถานะปุ่มดิบ)
  if (millis() - tLastPrint >= PRINT_INTERVAL_MS){
    tLastPrint = millis();
    int pot = analogRead(PIN_POT);
    int k1Raw = digitalRead(PIN_BTN_K1);
    int k2Raw = digitalRead(PIN_BTN_K2);

    Serial.print(F("Temperature (C): ")); Serial.print(lastOkTempC,1);
    Serial.print(F(" | Pot: ")); Serial.print(pot);
    Serial.print(F(" | LDR: ")); Serial.print(lastLDRRaw);
    Serial.print(F(" (base=")); Serial.print(ldrBaseline);
    Serial.print(F(", Δ=")); Serial.print(abs(lastLDRRaw - ldrBaseline)); Serial.print(F(")"));
    Serial.print(F(" | TEMP_ALARM=")); Serial.print(tempAlarmActive?"1":"0");
    Serial.print(F(" | INTRUSION_ALARM=")); Serial.print(intrusionAlarmActive?"1":"0");
    Serial.print(F(" | PANIC_ALARM=")); Serial.print(k2Raw==LOW?1:0);     // raw
    Serial.print(F(" | DISARM_BTN=")); Serial.println(k1Raw==LOW?1:0);    // raw
  }

  // 3) Log mode change
  if (state != lastState){
    switch(state){
      case ARMED_SECURE:    Serial.println("===ARMED_SECURE==="); break;
      case ALARM_TRIGGERED: Serial.println("===ALARM_TRIGGERED==="); break;
      case DISARM_MODE:     Serial.println("===DISARM_MODE==="); break;
    }
    lastState = state;
  }

  // 4) เข้าสู่ ALARM จากเซ็นเซอร์ (และพิมพ์เหตุ)
  if (state == ARMED_SECURE && (tempAlarmActive || intrusionAlarmActive)){
    if (tempAlarmActive) {
      Serial.print(F("[CAUSE] TEMP ")); Serial.println(lastOkTempC,1);
    }
    if (intrusionAlarmActive) {
      Serial.print(F("[CAUSE] LDR Δ=")); Serial.println(abs(lastLDRRaw - ldrBaseline));
    }
    Serial.println(">>> ALARM TRIGGERED <<<");
    state = ALARM_TRIGGERED;
  }

  // 5) Per-mode behavior
  switch(state){
    case ARMED_SECURE: {
      sirenUpdate(false);
      setSecureLights();
      showTempC_int((int)(lastOkTempC + 0.5f));
      break;
    }
    case ALARM_TRIGGERED: {
      alarmBlinkLights();
      showALRT();
      sirenUpdate(true);
      if (readButtonHeld(PIN_BTN_K1, 80)) {        // <<< NEW: Disarm ต้องกดจริง
        state = DISARM_MODE;
        tDisarmStart = 0;
        showDashes();
      }
      break;
    }
    case DISARM_MODE: {
      sirenUpdate(true);
      disarmLights();
      alarmBlinkLights();
      showDashes();
      if (potInDisarmWindow()){
        if (tDisarmStart == 0) tDisarmStart = millis();
        else if (millis() - tDisarmStart >= DISARM_HOLD_MS){
          noTone(PIN_BUZZ);
          state = ARMED_SECURE;
          setSecureLights();
        }
      } else {
        tDisarmStart = 0;
      }
      break;
    }
  }
}