#include <SPI.h>
#include <Servo.h>

#define RST_PIN         9
#define SS_PIN          10
#define SERVO_PIN       2
Servo gate;

#define REG_COMMAND     0x01
#define REG_FIFODATA    0x09
#define REG_FIFOLEN     0x0A
#define REG_BITFRAMING  0x0D
#define REG_MODE        0x11
#define REG_TXCONTROL   0x14

#define CMD_TRANSCEIVE  0x0C
#define CMD_SOFTRESET   0x0F
#define CMD_REQALL      0x52
#define CMD_ANTICOLL    0x93

byte authorizedUID[4] = {0x01, 0x02, 0x03, 0x04};
bool isGateOpen = false;
unsigned long gateOpenTime = 0;

void mfrc522_writeReg(byte reg, byte value) {
  digitalWrite(SS_PIN, LOW);
  SPI.transfer((reg << 1) & 0x7E);
  SPI.transfer(value);
  digitalWrite(SS_PIN, HIGH);
}
byte mfrc522_readReg(byte reg) {
  digitalWrite(SS_PIN, LOW);
  SPI.transfer(((reg << 1) & 0x7E) | 0x80);
  byte res = SPI.transfer(0x00);
  digitalWrite(SS_PIN, HIGH);
  return res;
}
void mfrc522_clearFIFO(){
  mfrc522_writeReg(REG_FIFOLEN,0x80);
}
bool mfrc522_init() {
  pinMode(SS_PIN, OUTPUT);pinMode(RST_PIN, OUTPUT);
  digitalWrite(SS_PIN, HIGH);digitalWrite(RST_PIN, HIGH);delay(50);
  mfrc522_writeReg(REG_COMMAND, CMD_SOFTRESET);delay(80);
  mfrc522_writeReg(REG_MODE, 0x3D);
  mfrc522_writeReg(REG_TXCONTROL, 0x40);
  mfrc522_clearFIFO();
  byte ver = mfrc522_readReg(0x37);
  return !(ver==0x00||ver==0xFF);
}
bool mfrc522_request(byte cmd){
  mfrc522_clearFIFO();
  mfrc522_writeReg(REG_BITFRAMING,0x07);
  mfrc522_writeReg(REG_FIFODATA,cmd);
  mfrc522_writeReg(REG_COMMAND,CMD_TRANSCEIVE);
  delay(60);
  byte len = mfrc522_readReg(REG_FIFOLEN);
  return len==2;
}
bool mfrc522_anticoll(byte* uid){
  mfrc522_clearFIFO();
  mfrc522_writeReg(REG_BITFRAMING,0x00);
  mfrc522_writeReg(REG_FIFODATA,CMD_ANTICOLL);
  mfrc522_writeReg(REG_FIFODATA,0x20);
  mfrc522_writeReg(REG_COMMAND,CMD_TRANSCEIVE);
  delay(60);
  byte len=mfrc522_readReg(REG_FIFOLEN);
  if(len!=5)return false;
  for(byte i=0;i<4;i++)uid[i]=mfrc522_readReg(REG_FIFODATA);
  return true;
}
bool compareUID(byte*u1,byte*u2){
  for(byte i=0;i<4;i++)if(u1[i]!=u2[i])return false;
  return true;
}
void openGate(){
  if(isGateOpen)return;
  Serial.println(">>>开闸放行<<<");
  gate.write(0);
  isGateOpen=true;gateOpenTime=millis();
  Serial.println("闸门抬起✅");
}
void closeGate(){
  if(!isGateOpen)return;
  Serial.println(">>>关闸<<<");
  gate.write(90);
  isGateOpen=false;
  Serial.println("闸门落下❌");
}
void readCard(){
  if(!mfrc522_request(CMD_REQALL))return;
  byte uid[4];
  if(!mfrc522_anticoll(uid))return;
  Serial.print("检测卡片UID:");
  for(byte i=0;i<4;i++){
    if(uid[i]<0x10)Serial.print("0");
    Serial.print(uid[i],HEX);Serial.print(" ");
  }
  Serial.println();
  if(compareUID(uid,authorizedUID)){
    Serial.println("✅授权通过，抬杆");
    openGate();
  }else{
    Serial.println("❌未授权，禁止通行");
  }
}
void setup() {
  Serial.begin(115200);
  SPI.begin();
  gate.attach(SERVO_PIN);gate.write(90);
  if(!mfrc522_init()){
    Serial.println("MFRC522初始化失败");while(1);
  }
  Serial.println("====ETC车道就绪====");
  Serial.print("授权卡UID:01 02 03 04\n");
}
void loop() {
  readCard();
  if(isGateOpen && millis()-gateOpenTime>5000)closeGate();
  delay(200);
}