# NFC Network Client, Global Input Capture and Smart Connect

**Date:** 2025-12-24
**Project:** moonlight-drive-in
**Status:** resolved
**Tags:** nfc, network-client, tkinter, pynput, threading, launcher, windows

## Context
NFC readers act as keyboards, so scanning only worked when the player window had focus, and it tied the reader to the player PC. Jess wanted a remote NFC client that can run on another machine, send scans to the player over the network, and "just connect" when launched. Work ran 2025-12-22 to 2025-12-24: a GUI client (v1.1.0 bug-fix release), a CLI client, launchers, then global input capture and a smart-connect launcher.

## Key Decisions
- **Network client instead of local keyboard input** — the reader can live anywhere on the LAN/VPN and send IDs to the player's web API.
- **Global input capture with `pynput`** — scans are captured regardless of which window has focus.
- **Thread-safe Tkinter updates** — background threads schedule UI changes with `root.after(0, ...)`; direct updates caused "main thread is not in main loop" errors.
- **Smart connect with verification** — try multiple resolution methods (DNS, Tailscale MagicDNS, mDNS) and verify the player's HTTP server responds before connecting; fall back to the fixed LAN IP `10.0.0.134`.
- **Simplify to a CLI auto-start with a 5-second timer** — the final launcher starts the interactive CLI client automatically after 5 s unless the user intervenes, which proved more reliable than the GUI auto-connect.
- **ASCII-safe console output** (`[WEB]`, `[CTRL]`, `[VIDEO]`) instead of emoji — emoji corrupted the Windows console.
- **Keep compatibility with `NFCNetworkClient` v1.1.0** — the launcher passes the Tk `root` correctly rather than changing the client API.

## Technical Details
- Player web UI/API on port 8547 (LAN `10.0.0.134`, Tailscale `<redacted>`).
- `clients/nfc_network_client.py` — GUI remote control; `clients/nfc_autoconnect.py` — fixed auto-connect client; `clients/nfc_cli_client.py` — CLI client; `clients/network_test.py` — connectivity diagnostics.
- Launchers: `START_DRIVEIN.bat`, `START_CLIENT.bat`, `start_nfc_client.bat`, `connect_drivein_simple.bat`, `test_network.bat`.
- `clients/client_requirements.txt` — includes `pynput`.

## Code Changes
- `clients/` — new client system (GUI, CLI, auto-connect, diagnostics, launchers, docs: README, QUICKSTART, CHANGELOG, UPDATE_GUIDE, SMART_CONNECT_FIX, IMPLEMENTATION_SUMMARY).
- Global input capture fix — NFC scans work regardless of focus (`40f23b0`).
- Smart connect v2.2.0 — HTTP verification + fallback IP (`ca36215`).
- `connect_drivein_simple.bat` — 5-second auto-start of the CLI client (`5ad870e`).

## Open Questions / Next Steps
- LEGO Dimensions portal is the planned replacement for the single-tag ACR122 reader (see `lego-dimensions-reader`).

## Artifacts
- `5ad870e` — Simplify to auto-start Interactive CLI with 5-second timer
- `ca36215` — Fix smart connect v2.2.0
- `40f23b0` — Fix global input capture
- `e90b8da` — FIXED auto-connect client - resolves GUI initialization error