'use strict';
/**
 * H102 recovery script.
 * Sends RFM_SET_GET_READMODE to switch back to RFID mode.
 * Also tries factory-reset (RFM_REBOOT) if needed.
 * Run: node recover.js
 */

const { SerialPort } = require('serialport');

const PORT = process.env.RFID_PORT || '/dev/cu.usbserial-4130';
const BAUDS = [115200, 9600, 19200, 38400, 57600];

function crc16(buf) {
  let crc = 0xFFFF;
  for (const b of buf) {
    crc ^= b;
    for (let i = 0; i < 8; i++) crc = (crc & 1) ? ((crc >> 1) ^ 0x8408) : (crc >> 1);
  }
  return crc;
}

function frame(cmd, data = Buffer.alloc(0), addr = 0xFF) {
  const hdr  = Buffer.from([0xCF, addr, cmd[0], cmd[1], data.length]);
  const body = Buffer.concat([hdr, data]);
  const chk  = crc16(body);
  return Buffer.concat([body, Buffer.from([(chk >> 8) & 0xFF, chk & 0xFF])]);
}

const hex = b => Buffer.from(b).toString('hex').replace(/../g, '$& ').trim().toUpperCase();

// Commands
const CMD_GET_PARAM  = [0x00, 0x72];
const CMD_REBOOT     = [0x00, 0x52];
const CMD_READMODE   = [0x00, 0x8E];

// RFM_SET_GET_READMODE: set RFID mode (0x00 = RFID, 0x01 = barcode/QR)
// SET format: OPTION(0x01=set) + READMODE(1) + RECEV(7 reserved zeros)
const SET_RFID_MODE  = frame(CMD_READMODE, Buffer.from([0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]));
const GET_READMODE   = frame(CMD_READMODE, Buffer.from([0x02])); // OPTION=0x02 = read

const FACTORY_RESET  = frame(CMD_REBOOT, Buffer.alloc(0));
const GET_PARAM      = frame(CMD_GET_PARAM, Buffer.alloc(0));

function tryAtBaud(baud, targetPort) {
  return new Promise(resolve => {
    console.log(`\n── Trying ${baud} baud on ${targetPort} ──`);
    const port = new SerialPort({ path: targetPort, baudRate: baud, autoOpen: false });
    let resolved = false;

    port.open(err => {
      if (err) {
        console.log(`  open failed: ${err.message}`);
        return resolve(false);
      }

      let rxBuf = Buffer.alloc(0);

      port.on('data', chunk => {
        rxBuf = Buffer.concat([rxBuf, chunk]);
        console.log(`  RX: ${hex(chunk)}`);
      });

      const done = ok => {
        if (resolved) return;
        resolved = true;
        setTimeout(() => port.close(() => resolve(ok)), 200);
      };

      // Step 1: GET_ALL_PARAM — checks if device responds to serial at all
      console.log(`  TX GET_PARAM: ${hex(GET_PARAM)}`);
      port.write(GET_PARAM);

      setTimeout(() => {
        if (rxBuf.length === 0) {
          console.log(`  No response at ${baud} baud — trying next`);
          return done(false);
        }

        console.log(`\n  ✓ Device responding at ${baud} baud!`);
        console.log(`  Full RX so far: ${hex(rxBuf)}`);

        rxBuf = Buffer.alloc(0);

        // Step 2: GET current READMODE
        console.log(`\n  TX GET_READMODE: ${hex(GET_READMODE)}`);
        port.write(GET_READMODE);

        setTimeout(() => {
          console.log(`  READMODE response: ${hex(rxBuf)}`);
          // rxBuf[5]=STATUS, rxBuf[6]=Option, rxBuf[7]=READMODE value
          const readModeVal = rxBuf[7];
          if (readModeVal === 0x01) {
            console.log('\n  !! Device is in BARCODE/QR mode (READMODE=0x01).');
            console.log('     Switching back to RFID mode...');
          } else {
            console.log(`\n  READMODE = 0x${(readModeVal||0).toString(16)} — may already be RFID mode, sending SET anyway`);
          }

          rxBuf = Buffer.alloc(0);

          // Step 3: SET RFID mode
          console.log(`\n  TX SET_RFID_MODE: ${hex(SET_RFID_MODE)}`);
          port.write(SET_RFID_MODE);

          setTimeout(() => {
            console.log(`  SET_RFID_MODE response: ${hex(rxBuf)}`);
            const setStatus = rxBuf[5];
            if (setStatus === 0x00) {
              console.log('\n  ✓ RFID mode restored! Unplug and replug the H102, then restart the daemon.');
            } else {
              console.log(`\n  SET_RFID_MODE returned status 0x${(setStatus||0).toString(16)}`);
              console.log('  Trying factory reset...');
              rxBuf = Buffer.alloc(0);

              console.log(`\n  TX FACTORY_RESET: ${hex(FACTORY_RESET)}`);
              port.write(FACTORY_RESET);

              setTimeout(() => {
                console.log(`  FACTORY_RESET response: ${hex(rxBuf)}`);
                console.log('\n  Factory reset sent. Unplug and replug the H102.');
                done(true);
              }, 2000);
              return;
            }
            done(true);
          }, 2000);
        }, 1500);
      }, 2000);
    });

    port.on('error', err => {
      console.log(`  port error: ${err.message}`);
      if (!resolved) done(false);
    });
  });
}

async function main() {
  // Check if port exists
  const ports = await SerialPort.list();
  console.log('Available ports:');
  ports.forEach(p => console.log(`  ${p.path} (${p.manufacturer || 'unknown'})`));

  const usbPort = ports.find(p => /usbserial|usbmodem|ttyUSB|ttyACM/i.test(p.path));
  const targetPort = process.env.RFID_PORT || (usbPort ? usbPort.path.replace('/dev/tty.', '/dev/cu.') : PORT);
  console.log(`\nTargeting: ${targetPort}`);

  for (const baud of BAUDS) {
    const ok = await tryAtBaud(baud, targetPort);
    if (ok) return;
  }

  console.log('\n━━━ No serial response at any baud rate ━━━');
  console.log('The device may have switched to USB-HID keyboard mode entirely.');
  console.log('\nHardware factory reset options for H102:');
  console.log('  1. Hold the scan TRIGGER button for 8-10 seconds while powered on');
  console.log('  2. Hold POWER + TRIGGER simultaneously for 5 seconds');
  console.log('  3. Check the back/bottom for a reset pinhole (use a paperclip)');
  console.log('  4. Connect via BLE: power cycle the device, then within 30 seconds');
  console.log('     open the CfTech app → "BLE" → scan — the device only advertises');
  console.log('     for ~30 seconds after power-on');
}

main().catch(console.error);