// ============================================================
//  SMART TV SIMULATION — Wokwi + ESP32
// ============================================================
//
//  COMPONENTS:
//    - DHT22        → temperature & humidity sensor  (GPIO 4)
//    - IR Receiver  → reads the remote control       (GPIO 15)
//    - IR Remote    → the TV remote
//    - LCD 16x2 I2C → TV screen display              (SDA=21, SCL=22)
//    - Green LED    → power indicator                (GPIO 2)
//    - Red LED      → temperature warning            (GPIO 13)
//    - Buzzer       → audio feedback                 (GPIO 5)
//
//  HOW TO USE:
//    1. Press Play in Wokwi to start the simulation
//    2. Use the IR Remote to control the TV
//         ON / OFF / MUTE / VOL UP / VOL DOWN / CH UP / CH DOWN
//    4. Click the DHT22 and drag temperature above 35C or below 15C
//       to trigger the temperature warning
//
// ============================================================

// ── SECTION 1: LIBRARIES ────────────────────────────────────
#include <DHT.h>
#include <LiquidCrystal_I2C.h>
#include <IRremoteESP8266.h>
#include <IRrecv.h>
#include <IRutils.h>

// ── SECTION 2: PIN DEFINITIONS ──────────────────────────────
#define DHT_PIN     4     // DHT22 data pin
#define DHT_TYPE    DHT22
#define IR_PIN      15    // IR Receiver output pin
#define BUZZER_PIN  5     // Buzzer
#define LED_POWER   2     // Green LED (power on/off)
#define LED_WARN    13    // Red LED (temperature warning)

// ── SECTION 3: SETTINGS ─────────────────────────────────────
#define TEMP_HIGH   35.0  // Degrees C — triggers high temp warning
#define TEMP_LOW    15.0  // Degrees C — triggers low temp warning

// ── SECTION 4: IR REMOTE BUTTON CODES (NEC Protocol) ────────
// If buttons don't respond, check the Serial Monitor for the
// printed hex code and update the matching line below.
#define IR_POWER     0xFF629D
#define IR_VOL_UP    0xFFA857
#define IR_VOL_DOWN  0xFFE01F
#define IR_CH_UP     0xFF22DD
#define IR_CH_DOWN   0xFF02FD
#define IR_MUTE      0xFF9867

// ── SECTION 5: OBJECTS ──────────────────────────────────────
DHT dht(DHT_PIN, DHT_TYPE);
LiquidCrystal_I2C lcd(0x27, 16, 2);
IRrecv irrecv(IR_PIN);
decode_results irResults;

// ── SECTION 6: TV STATE VARIABLES ───────────────────────────
bool tvOn    = false;  // Is the TV on or off?
int  channel = 1;      // Current channel (1–999)
int  volume  = 50;     // Current volume (0–100)
bool muted   = false;  // Is the TV muted?

float temperature = 0; // Last temperature reading
float humidity    = 0; // Last humidity reading
bool  tempHigh    = false; // Is temperature too high?
bool  tempLow     = false; // Is temperature too low?

unsigned long lastTempRead = 0;
unsigned long lastDisplay  = 0;

// ============================================================
//  SETUP — runs once when the simulation starts
// ============================================================
void setup() {
  Serial.begin(115200);

  // Set pin modes
  pinMode(LED_POWER,  OUTPUT);
  pinMode(LED_WARN,   OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);

  // Start sensors and display
  dht.begin();
  lcd.init();
  lcd.backlight();

  // Welcome screen
  lcd.setCursor(3, 0);
  lcd.print("SMART TV");
  lcd.setCursor(2, 1);
  lcd.print("Booting up..");
  delay(2000);
  lcd.clear();

  // Start IR receiver
  irrecv.enableIRIn();

  // Print instructions to Serial Monitor
  Serial.println("====================================");
  Serial.println("        SMART TV — READY");
  Serial.println("====================================");
  Serial.println("Voice Commands (type in Serial):");
  Serial.println("  ON          — turn TV on");
  Serial.println("  OFF         — turn TV off");
  Serial.println("  MUTE        — toggle mute");
  Serial.println("  VOL UP      — raise volume");
  Serial.println("  VOL DOWN    — lower volume");
  Serial.println("  CH UP       — next channel");
  Serial.println("  CH DOWN     — previous channel");
  Serial.println("====================================");
}

// ============================================================
//  LOOP — runs repeatedly while the simulation is running
// ============================================================
void loop() {

  // 1. Read temperature every 2 seconds
  if (millis() - lastTempRead >= 2000) {
    readTemperature();
    lastTempRead = millis();
  }

  // 2. Check for IR remote button presses
  if (irrecv.decode(&irResults)) {
    uint32_t code = irResults.value;
    if (code != 0xFFFFFFFF) {  // 0xFFFFFFFF = button held down (repeat), ignore it
      handleIR(code);
    }
    irrecv.resume();           // Ready to receive the next signal
  }

  // 3. Check for voice commands typed in Serial Monitor
  if (Serial.available()) {
    String cmd = Serial.readStringUntil('\n');
    cmd.trim();
    cmd.toUpperCase();
    handleVoice(cmd);
  }

  // 4. Refresh the LCD display every 500ms
  if (millis() - lastDisplay >= 500) {
    updateDisplay();
    lastDisplay = millis();
  }
}

// ============================================================
//  TEMPERATURE — reads DHT22 and checks thresholds
// ============================================================
void readTemperature() {
  float t = dht.readTemperature();
  float h = dht.readHumidity();
  if (isnan(t)) return;  // Sensor not ready yet

  temperature = t;
  humidity    = h;

  bool wasHigh = tempHigh;
  bool wasLow  = tempLow;

  tempHigh = (temperature > TEMP_HIGH);
  tempLow  = (temperature < TEMP_LOW);

  if (tempHigh && !wasHigh) {
    // Just crossed above the high threshold
    digitalWrite(LED_WARN, HIGH);
    alertBeep(3);
    Serial.print("WARNING: Temperature too HIGH! ");
    Serial.print(temperature);
    Serial.println("C");
  } else if (tempLow && !wasLow) {
    // Just crossed below the low threshold
    digitalWrite(LED_WARN, HIGH);
    alertBeep(3);
    Serial.print("WARNING: Temperature too LOW! ");
    Serial.print(temperature);
    Serial.println("C");
  } else if (!tempHigh && !tempLow) {
    // Temperature is back to normal
    digitalWrite(LED_WARN, LOW);
  }
}

// ============================================================
//  IR REMOTE — handles button presses from the remote
// ============================================================
void handleIR(uint32_t code) {
  Serial.print("IR Received: 0x");
  Serial.println(code, HEX);  // Prints the code — useful for finding unmapped buttons

  switch (code) {
    case IR_POWER:    togglePower();     break;
    case IR_VOL_UP:   changeVolume(+5);  break;
    case IR_VOL_DOWN: changeVolume(-5);  break;
    case IR_CH_UP:    changeChannel(+1); break;
    case IR_CH_DOWN:  changeChannel(-1); break;
    case IR_MUTE:     toggleMute();      break;
    default:
      Serial.println("  (button not mapped — copy the hex code above into the #define section)");
  }
}

// ============================================================
//  VOICE COMMANDS — handles text typed in Serial Monitor
// ============================================================
void handleVoice(String cmd) {
  Serial.print("Voice Command: \"");
  Serial.print(cmd);
  Serial.println("\"");

  if      (cmd == "ON"         || cmd == "TURN ON")     { if (!tvOn) togglePower(); }
  else if (cmd == "OFF"        || cmd == "TURN OFF")    { if (tvOn)  togglePower(); }
  else if (cmd == "MUTE"       || cmd == "UNMUTE")      toggleMute();
  else if (cmd == "VOL UP"     || cmd == "VOLUME UP")   changeVolume(+10);
  else if (cmd == "VOL DOWN"   || cmd == "VOLUME DOWN") changeVolume(-10);
  else if (cmd == "CH UP"      || cmd == "CHANNEL UP")  changeChannel(+1);
  else if (cmd == "CH DOWN"    || cmd == "CHANNEL DOWN")changeChannel(-1);
  else Serial.println("  Unknown command. Check the list above.");
}

// ============================================================
//  TV CONTROLS
// ============================================================
void togglePower() {
  tvOn = !tvOn;
  digitalWrite(LED_POWER, tvOn ? HIGH : LOW);

  if (tvOn) {
    lcd.backlight();
    beep(200);
    Serial.println("TV → ON");
  } else {
    lcd.noBacklight();
    lcd.clear();
    beep(200);
    delay(100);
    beep(200);
    Serial.println("TV → OFF");
  }
}

void changeVolume(int delta) {
  if (!tvOn) return;
  volume = constrain(volume + delta, 0, 100);
  beep(80);
  Serial.print("Volume: ");
  Serial.println(volume);
}

void changeChannel(int delta) {
  if (!tvOn) return;
  channel += delta;
  if (channel > 999) channel = 1;
  if (channel < 1)   channel = 999;
  beep(80);
  Serial.print("Channel: ");
  Serial.println(channel);
}

void toggleMute() {
  if (!tvOn) return;
  muted = !muted;
  beep(150);
  Serial.print("Mute: ");
  Serial.println(muted ? "ON" : "OFF");
}

// ============================================================
//  DISPLAY — updates the LCD screen
// ============================================================
void updateDisplay() {
  if (!tvOn) return;

  // ── Row 0: Channel and Volume ──
  lcd.setCursor(0, 0);
  lcd.print("CH:");
  if      (channel < 10)  lcd.print("  ");
  else if (channel < 100) lcd.print(" ");
  lcd.print(channel);
  lcd.print(" ");

  if (muted) {
    lcd.print("  [MUTED]");
  } else {
    lcd.print("VOL:");
    if (volume < 10) lcd.print(" ");
    lcd.print(volume);
    lcd.print("%  ");
  }

  // ── Row 1: Temperature status ──
  lcd.setCursor(0, 1);
  if (tempHigh) {
    lcd.print("!HOT ");
    lcd.print((int)temperature);
    lcd.print("C WARN!  ");
  } else if (tempLow) {
    lcd.print("!COLD ");
    lcd.print((int)temperature);
    lcd.print("C WARN! ");
  } else {
    lcd.print("Temp:");
    lcd.print((int)temperature);
    lcd.print("C  OK      ");
  }
}

// ============================================================
//  HELPERS
// ============================================================
void beep(int ms) {
  // Short beep for button feedback
  digitalWrite(BUZZER_PIN, HIGH);
  delay(ms);
  digitalWrite(BUZZER_PIN, LOW);
}

void alertBeep(int times) {
  // Repeated beep for temperature warnings
  for (int i = 0; i < times; i++) {
    beep(250);
    delay(100);
  }
}

// ============================================================
//  END OF FILE
// ============================================================