#include <TM1637.h>   // TM1637_RT (Rob Tillaart)
#include <dht.h>      // DHTlib (Rob Tillaart)

/* ================== PIN MAP (เดิม) ================== */
const uint8_t PIN_LED_Y = 7;     // LED1 Yellow  : Auto indicator
const uint8_t PIN_LED_B = 6;     // LED2 Blue    : Grow light (LDR)
const uint8_t PIN_LED_G = 5;     // LED3 Green   : Fan (PWM)
const uint8_t PIN_LED_R = 4;     // LED4 Red     : Safety alert
const uint8_t PIN_BUZZ  = 3;     // Buzzer

const uint8_t PIN_TM_CLK = 10;   // TM1637 CLK
const uint8_t PIN_TM_DIO = 11;   // TM1637 DIO

const uint8_t PIN_BTN_K1 = 9;    // Toggle Auto/Manual (INPUT_PULLUP)
const uint8_t PIN_BTN_K2 = 8;    // Cycle Data View (INPUT_PULLUP)

const uint8_t PIN_LDR    = A2;   // LDR
const uint8_t PIN_POT    = A0;   // Potentiometer
const uint8_t PIN_DHT    = 12;   // DHT11

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

/* ================== CONSTANTS ================= */
// --- Greenhouse spec ---
const float    CRIT_TEMP_C         = 30.0;        // Safety limit
const float    CRIT_TEMP_HYST      = 1.0;         // Hysteresis เมื่อปลด safety

// --- DHT & timing ---
const uint32_t DHT_MIN_INTERVAL_MS = 2200;        // DHT11 >= 1s แต่กันชัวร์ๆ 2.2s
const uint32_t PRINT_INTERVAL_MS   = 1000;
const uint32_t DISPLAY_REFRESH_MS  = 250;         // กันจอกระพริบถี่เกิน

// --- LDR ---
const uint32_t LDR_CAL_TIME_MS     = 1500;
const int      LDR_DARK_MARGIN     = 120;         // มืด = >= baseline + margin (ทิศนี้ใช้ได้กับวงจรยอดนิยม)
const uint32_t LDR_MIN_HOLD_MS     = 100;         // ต้องมืดค้าง >= 100 ms

// --- Auto fan (humidity threshold by POT) ---
const int      HUM_THR_MIN         = 30;          // %RH
const int      HUM_THR_MAX         = 90;          // %RH

// --- Beep / Safety pulse ---
const uint32_t BEEP_MS             = 80;
const uint16_t BEEP_FREQ_HZ        = 2500;
const uint32_t SAFETY_ON_MS        = 300;
const uint32_t SAFETY_OFF_MS       = 700;

// --- LEDs blink usedเดิม ---
const uint32_t BLINK_MS            = 200;

/* ==================== STATE =================== */
// โหมดหลัก 2 แบบ + safety override แยกเป็นแฟลก
enum RunMode { MODE_AUTO=0, MODE_MANUAL };
RunMode mode = MODE_AUTO;

enum ViewMode { VIEW_TEMP=0, VIEW_HUM, VIEW_LDR };
ViewMode view = VIEW_TEMP;

bool safetyActive = false;        // true เมื่อ Temp >= CRIT_TEMP_C (มีฮิสเทอรีซิส)
bool growLightOn  = false;        // LED2 สถานะไฟปลูก
int  fanPWM       = 0;            // 0..255 (LED3)
int  humThreshold = 60;           // %RH (อัปเดตจาก POT ใน Auto)

// สำหรับ LDR detection แบบ hold-time
int      ldrBaseline = 0;
int      lastLDRRaw  = -1;
uint32_t ldrOverStart = 0;

/* =================== RUNTIME ================== */
uint32_t tLastDHTRead=0, tLastPrint=0, tLastDisp=0, tLastBlink=0;
uint32_t tBeepEnd=0, tSafetyPulse=0;
uint32_t ignoreButtonsUntil = 0;

float lastTempC = NAN, lastOkTempC = 0;
int   lastRH = 0;  // DHT11 ความชื้นเป็นจำนวนเต็ม

/* ================== HELPERS =================== */
bool readButtonHeld(uint8_t pin, uint16_t hold_ms = 80) {
  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;
  }
}

void beepClick() {                      // beep สั้นยืนยัน K2
  tone(PIN_BUZZ, BEEP_FREQ_HZ);
  tBeepEnd = millis() + BEEP_MS;
}

void beepTask() {                       // ปิด beep เมื่อครบเวลา
  if (tBeepEnd && (int32_t)(millis() - tBeepEnd) >= 0) {
    noTone(PIN_BUZZ);
    tBeepEnd = 0;
  }
}

/* ---- TM1637 helpers (ใช้รูปแบบเดิม) ---- */
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);
}
void showHum_int(int rh){               // แสดง RH เป็นตัวเลข + 'H'
  if (rh<0) rh=0; if (rh>100) rh=100;
  char b[5]="   ";
  if (rh==100) { snprintf(b,sizeof(b),"%03d",rh); b[3]='H'; }
  else if (rh>=10){ snprintf(b,sizeof(b)," %2d",rh); b[3]='H'; }
  else { snprintf(b,sizeof(b),"  %d",rh); b[3]='H'; }
  tm.displayPChar(b);
}
void showLDR_int(int v){                // 0..1023 ตัดที่ 9999
  if (v<0) v=0; if (v>9999) v=9999;
  char b[5]; snprintf(b,sizeof(b), "%4d", v);
  tm.displayPChar(b);
}

/* ---- DHT ---- */
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;
    lastRH    = (int)DHT.humidity;
    if (!isnan(lastTempC) && lastTempC>-10 && lastTempC<80) lastOkTempC=lastTempC;
  } else {
    Serial.print(F("[DHT] status: ")); Serial.println(dhtStatusText(rc));
  }
  return true;
}

/* ---- LDR: มืด = ค่ามากกว่า baseline + margin (พร้อม hold-time) ---- */
bool isDarkNow(){
  lastLDRRaw = analogRead(PIN_LDR);
  bool over = (lastLDRRaw >= (ldrBaseline + LDR_DARK_MARGIN));
  if (over) {
    if (ldrOverStart == 0) ldrOverStart = millis();
    return (millis() - ldrOverStart) >= LDR_MIN_HOLD_MS;
  } else {
    ldrOverStart = 0;
    return false;
  }
}

/* ---- Safety task (override) ---- */
void safetyTask() {
  // อัปเดตแฟลก safety ตามฮิสเทอรีซิส
  if (!safetyActive && lastOkTempC >= CRIT_TEMP_C) safetyActive = true;
  if (safetyActive  && lastOkTempC <= (CRIT_TEMP_C - CRIT_TEMP_HYST)) safetyActive = false;

  if (safetyActive) {
    // LED4 ค้าง / Fan เต็ม / Buzzer pulse ช้า
    digitalWrite(PIN_LED_R, HIGH);
    analogWrite(PIN_LED_G, 255);      // fan full
    // pulse buzzer
    uint32_t now = millis();
    if (tSafetyPulse==0) tSafetyPulse = now;
    uint32_t phase = (now - tSafetyPulse) % (SAFETY_ON_MS + SAFETY_OFF_MS);
    if (phase < SAFETY_ON_MS) tone(PIN_BUZZ, 1200);
    else noTone(PIN_BUZZ);
  } else {
    // ปิดเอาต์พุต safety
    digitalWrite(PIN_LED_R, LOW);
    // buzzer ปล่อยให้ beepTask() จัดการเคสอื่น
    if (tSafetyPulse) { noTone(PIN_BUZZ); tSafetyPulse=0; }
  }
}

/* ---- Display updater ---- */
void updateDisplayIfDue(){
  if (millis() - tLastDisp < DISPLAY_REFRESH_MS) return;
  tLastDisp = millis();

  switch(view){
    case VIEW_TEMP: showTempC_int((int)(lastOkTempC + 0.5f)); break;
    case VIEW_HUM:  showHum_int(lastRH); break;
    case VIEW_LDR:  showLDR_int(lastLDRRaw); break;
  }
}

/* =================== 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();

  Serial.begin(9600);
  Serial.println(F("Dynamic Greenhouse Started"));

  // คาลิเบรต LDR baseline
  uint32_t t0=millis(); long acc=0; uint16_t n=0;
  while (millis()-t0 < 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);

  // อ่าน DHT รอบแรก
  delay(1500); readDHTIfDue();
  Serial.print(F("[DHT] first T=")); Serial.print(lastOkTempC,1);
  Serial.print(F(" C, RH=")); Serial.println(lastRH);

  // เริ่มที่โหมด Auto
  mode = MODE_AUTO;
  digitalWrite(PIN_LED_Y, HIGH);   // Auto indicator on
  view = VIEW_TEMP;

  ignoreButtonsUntil = millis() + 500;  // กันกลิตช์ช่วงบูตเล็กน้อย
}

/* ==================== LOOP ==================== */
void loop(){
  // 1) อ่านเซ็นเซอร์
  readDHTIfDue();
  bool darkNow = isDarkNow();                    // LDR -> grow light
  updateDisplayIfDue();
  beepTask();

  // 2) ปุ่ม K1: toggle Auto/Manual
  if (readButtonHeld(PIN_BTN_K1, 80)) {
    mode = (mode==MODE_AUTO) ? MODE_MANUAL : MODE_AUTO;
    Serial.print(F("[MODE] ")); Serial.println(mode==MODE_AUTO ? F("AUTO") : F("MANUAL"));
    // ปรับไฟบอกโหมด
    digitalWrite(PIN_LED_Y, mode==MODE_AUTO ? HIGH : LOW);
    beepClick();
  }

  // 3) ปุ่ม K2: cycle data view (Temp → Hum → LDR)
  if (readButtonHeld(PIN_BTN_K2, 80)) {
    view = (ViewMode)((view + 1) % 3);
    Serial.print(F("[VIEW] ")); 
    if (view==VIEW_TEMP) Serial.println(F("TEMP"));
    else if (view==VIEW_HUM) Serial.println(F("HUM"));
    else Serial.println(F("LDR"));
    beepClick();
  }

  // 4) ตัดสินใจเอาต์พุตพื้นฐาน (ยังไม่รวม safety override)
  // 4.1 grow light (LED2): มืด -> เปิด
  growLightOn = darkNow;
  digitalWrite(PIN_LED_B, growLightOn ? HIGH : LOW);

  // 4.2 fan (LED3 Green)
  int pot = analogRead(PIN_POT);
  if (mode == MODE_AUTO) {
    // แปลง POT -> humidity threshold
    humThreshold = map(pot, 0, 1023, HUM_THR_MIN, HUM_THR_MAX);
    fanPWM = (lastRH > humThreshold) ? 255 : 0;     // เกิน threshold -> เปิดเต็ม (ตรงโจทย์)
  } else {
    // Manual: POT -> PWM โดยตรง
    fanPWM = map(pot, 0, 1023, 0, 255);
  }
  analogWrite(PIN_LED_G, fanPWM);

  // 5) Safety override (ทำท้ายสุดเพื่อครอบทับเอาต์พุตหากจำเป็น)
  safetyTask();

  // 6) Serial telemetry ทุก 1 วินาที
  if (millis() - tLastPrint >= PRINT_INTERVAL_MS){
    tLastPrint = millis();

    Serial.print(F("MODE=")); Serial.print(mode==MODE_AUTO ? F("AUTO") : F("MANUAL"));
    Serial.print(F(" | VIEW="));
      if (view==VIEW_TEMP) Serial.print(F("TEMP"));
      else if (view==VIEW_HUM) Serial.print(F("HUM"));
      else Serial.print(F("LDR"));
    Serial.print(F(" | Safety=")); Serial.print(safetyActive ? 1 : 0);

    Serial.print(F(" | T=")); Serial.print(lastOkTempC,1); Serial.print(F("C"));
    Serial.print(F(" | RH=")); Serial.print(lastRH); Serial.print(F("%"));

    Serial.print(F(" | LDR=")); Serial.print(lastLDRRaw);
    Serial.print(F(" (thr=")); Serial.print(ldrBaseline + LDR_DARK_MARGIN);
    Serial.print(F(", dark=")); Serial.print(growLightOn?1:0); Serial.print(F(")"));

    if (mode == MODE_AUTO) {
      Serial.print(F(" | POT=")); Serial.print(pot);
      Serial.print(F(" -> HUM_THR=")); Serial.print(humThreshold); Serial.print(F("%"));
      Serial.print(F(" | FAN=")); Serial.print(fanPWM>0?F("ON"):F("OFF"));
    } else {
      Serial.print(F(" | POT=")); Serial.print(pot);
      Serial.print(F(" -> FAN_PWM=")); Serial.print(fanPWM);
    }
    Serial.println();
  }
}