Adom Desktop - KiCad Bridge

"""adom-desktop loader for KiCad embedded Python.

This file is a tiny shim that fires at every KiCad-bundled Python init
(see PLAN.md Phase 4 v4 architectural notes for the discovery story).

It does TWO things:

1. Writes a process-discovery breadcrumb to %TEMP%\\adom-kicad-process-<exe>.json
   so adom-desktop can confirm which KiCad executables exposed Python.
   This is the same diagnostic file the original Phase 4 probe wrote;
   adom-desktop's kicad-detect code uses it for the `embeddedPython`
   field of `kicad_list_versions`.

2. Calls `adom_bridge.start()` to spin up the per-process WebSocket
   server (Phase 2 reverse bridge). If `adom_bridge` import fails
   (e.g. plugin not deployed yet, or websockets lib unavailable in an
   older KiCad), we just log the error and the discovery breadcrumb
   still gets written so the orchestrator sees this process at all.

Both steps are wrapped in try/except so a bug here never crashes KiCad.
Honors ADOM_KICAD_BRIDGE_DISABLE=1 (skip the bridge but still write
discovery) and ADOM_KICAD_PROBE_DISABLE=1 (skip everything).
"""

try:
    import json
    import os
    import sys
    import traceback
    from datetime import datetime
    from pathlib import Path

    if os.environ.get("ADOM_KICAD_PROBE_DISABLE") == "1":
        raise SystemExit

    _OUT_DIR = Path(os.environ.get("TEMP") or os.environ.get("TMP") or "/tmp")
    _EXE_NAME = (Path(sys.executable).stem or "unknown").lower()
    _PROCESS_PATH = _OUT_DIR / f"adom-kicad-process-{_EXE_NAME}.json"
    _ERR_PATH = _OUT_DIR / f"adom-kicad-loader-{_EXE_NAME}.error.log"

    # -- Step 1: discovery breadcrumb (lightweight, always written) --
    try:
        _PROCESS_PATH.write_text(json.dumps({
            "stage": "usercustomize-fired",
            "firedAt": datetime.utcnow().isoformat() + "Z",
            "exeName": _EXE_NAME,
            "executable": sys.executable,
            "argv": sys.argv,
            "cwd": os.getcwd(),
            "pythonVersion": sys.version,
            "pid": os.getpid(),
        }, indent=2, default=str), encoding="utf-8")
    except OSError:
        pass

    # -- Step 2: start the reverse bridge (Phase 2 MVP) --
    try:
        import adom_bridge  # type: ignore[import-not-found]
        port = adom_bridge.start()
        # Stash the port back into the discovery file so consumers can
        # find it without parsing both files.
        if port is not None:
            try:
                payload = json.loads(_PROCESS_PATH.read_text(encoding="utf-8"))
                payload["bridgePort"] = port
                payload["bridgeVersion"] = adom_bridge.__version__
                _PROCESS_PATH.write_text(json.dumps(payload, indent=2, default=str), encoding="utf-8")
            except (OSError, ValueError):
                pass
    except Exception:
        # adom_bridge missing or its start() raised. Log but don't fail.
        try:
            _ERR_PATH.write_text(traceback.format_exc(), encoding="utf-8")
        except OSError:
            pass

except SystemExit:
    pass
except Exception:
    # Last-resort safety net.
    try:
        import os as _os
        import traceback as _tb
        _tmp = _os.environ.get("TEMP") or _os.environ.get("TMP") or "/tmp"
        with open(_os.path.join(_tmp, "adom-kicad-usercustomize-fatal.log"), "w", encoding="utf-8") as _f:
            _f.write(_tb.format_exc())
    except Exception:
        pass