// ═══════════════════════════════════════════════════════════
// SMART LOCK SYSTEM — ESP32-S3
// Unlock methods: NFC tap | QIACHIP remote buttons
// 
// HOW QIACHIP WORKS:
// The receiver decodes the EV1527 signal itself.
// When you press a button, the matching CH pin goes HIGH.
// No RF library needed — just read GPIO like a button.
// ═══════════════════════════════════════════════════════════

#include <Wire.h>
#include <Adafruit_PN532.h>

// ── PIN DEFINITIONS ─────────────────────────────────────────
#define RELAY_PIN     5    // Relay → lock motor
#define SDA_PIN       21   // PN532 SDA
#define SCL_PIN       22   // PN532 SCL

// QIACHIP receiver channel output pins
// Each pin goes HIGH when that button is pressed
#define QIACHIP_CH1   4    // Button A → unlock 5 seconds
#define QIACHIP_CH2   13   // Button B → unlock 30 seconds
#define QIACHIP_CH3   14   // Button C → future use
#define QIACHIP_CH4   27   // Button D → future use

// ── UNLOCK DURATIONS ────────────────────────────────────────
#define UNLOCK_SHORT  5000  // Button A — 5 sec (single visitor)
#define UNLOCK_LONG   30000 // Button B — 30 sec (group/delivery)

// ── YOUR AUTHORIZED NFC CARD UIDs ───────────────────────────
// Run uid_reader.ino first, tap your phone sticker,
// copy the hex values from Serial Monitor and paste here.
uint8_t authorizedCards[][7] = {
  {0xAB, 0xCD, 0xEF, 0x12},   // 📱 Your phone sticker
  {0x34, 0x56, 0x78, 0x90},   // 🔵 Spare card
};
uint8_t cardLengths[] = {4, 4};
int numCards = 2;

// ── OBJECTS ──────────────────────────────────────────────────
Adafruit_PN532 nfc(SDA_PIN, SCL_PIN);

// ── STATE ────────────────────────────────────────────────────
bool isUnlocked = false;
unsigned long unlockTime = 0;
unsigned long unlockDuration = 0;

// Track last button state to detect rising edge (press, not hold)
bool lastCH1 = false;
bool lastCH2 = false;

// ════════════════════════════════════════════════════════════
void setup() {
  Serial.begin(115200);
  Serial.println("\n\n══ SMART LOCK BOOTING ══");

  // Relay — LOW = locked
  pinMode(RELAY_PIN, OUTPUT);
  digitalWrite(RELAY_PIN, LOW);

  // QIACHIP channel pins — INPUT, reads HIGH when button pressed
  pinMode(QIACHIP_CH1, INPUT);
  pinMode(QIACHIP_CH2, INPUT);
  pinMode(QIACHIP_CH3, INPUT);
  pinMode(QIACHIP_CH4, INPUT);
  Serial.println("✓ QIACHIP receiver ready");

  // NFC setup
  Wire.begin(SDA_PIN, SCL_PIN);
  nfc.begin();
  uint32_t versiondata = nfc.getFirmwareVersion();
  if (!versiondata) {
    Serial.println("❌ PN532 not found — check wiring");
    while (1);
  }
  nfc.SAMConfig();
  Serial.println("✓ NFC reader ready");
  Serial.println("══ SYSTEM READY ══\n");
}

// ════════════════════════════════════════════════════════════
void loop() {
  checkNFC();
  checkQIACHIP();
  checkLockTimeout();
}

// ── NFC CHECK ────────────────────────────────────────────────
void checkNFC() {
  uint8_t uid[7];
  uint8_t uidLength;

  bool cardFound = nfc.readPassiveTargetID(
    PN532_MIFARE_ISO14443A, uid, &uidLength, 100
  );

  if (cardFound) {
    Serial.print("📡 NFC UID: ");
    for (int i = 0; i < uidLength; i++) {
      Serial.print(uid[i], HEX); Serial.print(" ");
    }
    Serial.println();

    if (isAuthorizedNFC(uid, uidLength)) {
      Serial.println("✓ NFC ACCESS GRANTED");
      unlock(UNLOCK_SHORT);
    } else {
      Serial.println("✗ NFC ACCESS DENIED");
    }
    delay(1000);
  }
}

// ── QIACHIP BUTTON CHECK ─────────────────────────────────────
// Reads HIGH/LOW from receiver output pins.
// Uses edge detection so holding the button doesnt
// repeatedly unlock — only the initial press counts.
void checkQIACHIP() {
  bool ch1 = digitalRead(QIACHIP_CH1);
  bool ch2 = digitalRead(QIACHIP_CH2);

  // Button A pressed (rising edge)
  if (ch1 && !lastCH1) {
    Serial.println("🔲 QIACHIP Button A — unlock 5 sec");
    unlock(UNLOCK_SHORT);
  }

  // Button B pressed (rising edge) — longer for groups
  if (ch2 && !lastCH2) {
    Serial.println("🔲 QIACHIP Button B — unlock 30 sec");
    unlock(UNLOCK_LONG);
  }

  lastCH1 = ch1;
  lastCH2 = ch2;
}

// ── UNLOCK ───────────────────────────────────────────────────
void unlock(unsigned long duration) {
  digitalWrite(RELAY_PIN, HIGH);
  isUnlocked = true;
  unlockTime = millis();
  unlockDuration = duration;
  Serial.print("🔓 UNLOCKED for ");
  Serial.print(duration / 1000);
  Serial.println("s");
}

// ── AUTO RELOCK ───────────────────────────────────────────────
void checkLockTimeout() {
  if (isUnlocked && (millis() - unlockTime >= unlockDuration)) {
    digitalWrite(RELAY_PIN, LOW);
    isUnlocked = false;
    Serial.println("🔒 RELOCKED");
  }
}

// ── NFC AUTH ─────────────────────────────────────────────────
bool isAuthorizedNFC(uint8_t *uid, uint8_t uidLength) {
  for (int i = 0; i < numCards; i++) {
    if (uidLength == cardLengths[i] &&
        memcmp(uid, authorizedCards[i], uidLength) == 0) {
      return true;
    }
  }
  return false;
}

#include <Wire.h>
#include <Adafruit_PN532.h>

Adafruit_PN532 nfc(21, 22);

void setup() {
  Serial.begin(115200);
  Wire.begin(21, 22);
  nfc.begin();
  nfc.SAMConfig();
  Serial.println("Tap your NFC card or phone sticker...");
}

void loop() {
  uint8_t uid[7]; uint8_t uidLen;
  if (nfc.readPassiveTargetID(PN532_MIFARE_ISO14443A, uid, &uidLen, 500)) {
    Serial.print("UID (copy into main sketch): {");
    for (int i = 0; i < uidLen; i++) {
      Serial.print("0x"); Serial.print(uid[i], HEX);
      if (i < uidLen - 1) Serial.print(", ");
    }
    Serial.println("}");
    delay(2000);
  }
}