#!/usr/bin/env python3
"""
mm_client_check.py — exercise the Micromate read client against a real unit.

**Read-only.**  It sends POLL, SERIAL, state, monitor status, the setup walk and
(optionally) one event download.  It never writes, never erases, never starts or
stops monitoring.

Why it exists
-------------
`micromate/{framing,protocol,client}.py` are verified against captures taken
**over USB**, on **one firmware line** (`11.0CB`).  Two things that cannot be
verified that way:

  * **the modem path.**  An RX55/RV55 bridges serial to TCP transparently, but
    it buffers up to ~1 s before forwarding, so a single logical response can
    arrive as many small reads.  The client reads to frame completion rather
    than using idle-gap detection, which should be strictly more robust — but
    "should be" is the point of this script.
  * **the other firmware line.**  `11.0BD` reports `flags = 0x03`, a shorter
    model string, and a `SUB 0x1C` block 4 bytes longer.  Everything about that
    is currently inference from one 2026-09-23 sweep whose captures never
    landed in the repo.

Run it over both paths and diff the two reports.  Anything that differs beyond
timings is a finding.

Usage
-----
    # over the modem
    python3 bridges/mm_client_check.py 63.45.161.30:9034

    # over USB / direct serial
    python3 bridges/mm_client_check.py /dev/ttyACM0 --baud 115200

    # include one event download (still read-only)
    python3 bridges/mm_client_check.py <target> --download

⚠ These modems bridge ONE TCP session to serial at a time.  If THOR holds the
unit, this will connect and then see nothing — that is contention, not a fault.
`bridges/mm_probe.py` explains that case; disconnect THOR first.
"""

from __future__ import annotations

import argparse
import errno
import os
import select
import sys
import termios
import time
from pathlib import Path

sys.path.insert(0, str(Path(__file__).resolve().parent.parent))

from micromate.client import MicromateClient, _content  # noqa: E402
from micromate.protocol import ProtocolError  # noqa: E402
from minimateplus.transport import TcpTransport  # noqa: E402


class StdlibSerial:
    """Raw serial on stdlib `termios` — no pyserial.

    `minimateplus.SerialTransport` needs pyserial, and a bench host is whatever
    is to hand.  On a PEP 668 distro (Mint 22, Ubuntu 24.04, Debian 12) a plain
    `pip install pyserial` is refused outright, so a diagnostic that depends on
    it is one you cannot run at the moment you need it.  `bridges/mm_link.py`
    and `scratch/fake_unit.py` already take this approach; this is the same
    ~30 lines, and it means the tool runs on a stock Python 3 anywhere.

    Not a general replacement for SerialTransport — no flow control, no
    parity options, Linux/macOS only.  Enough for a Micromate, which is 8N1
    with no handshaking.
    """

    _BAUD = {9600: termios.B9600, 19200: termios.B19200, 38400: termios.B38400,
             57600: termios.B57600, 115200: termios.B115200}

    def __init__(self, path: str, baud: int = 115200) -> None:
        if baud not in self._BAUD:
            raise ValueError(f"unsupported baud {baud}; pick from {sorted(self._BAUD)}")
        self.path, self.baud, self.fd = path, baud, None

    def connect(self) -> None:
        if self.fd is not None:
            return
        self.fd = os.open(self.path, os.O_RDWR | os.O_NOCTTY | os.O_NONBLOCK)
        a = termios.tcgetattr(self.fd)
        a[0] = a[1] = a[3] = 0                               # raw in/out, non-canonical
        a[2] = termios.CS8 | termios.CREAD | termios.CLOCAL  # 8N1, ignore modem lines
        a[4] = a[5] = self._BAUD[self.baud]
        a[6] = list(a[6])
        a[6][termios.VMIN] = 0
        a[6][termios.VTIME] = 0
        termios.tcsetattr(self.fd, termios.TCSANOW, a)
        termios.tcflush(self.fd, termios.TCIOFLUSH)

    def disconnect(self) -> None:
        if self.fd is not None:
            os.close(self.fd)
            self.fd = None

    def is_connected(self) -> bool:
        return self.fd is not None

    def read(self, n: int) -> bytes:
        if self.fd is None:
            return b""
        r, _, _ = select.select([self.fd], [], [], 0.05)
        if not r:
            return b""
        try:
            return os.read(self.fd, n)
        except OSError as e:
            if e.errno in (errno.EAGAIN, errno.EWOULDBLOCK):
                return b""
            raise

    def write(self, data: bytes) -> None:
        if self.fd is None:
            raise OSError("port is not open")
        while data:
            data = data[os.write(self.fd, data):]


class _Timed:
    """Count bytes and time each read, so the two transports can be compared."""

    def __init__(self, inner) -> None:
        self._inner = inner
        self.reads = 0
        self.bytes_in = 0
        self.bytes_out = 0

    def connect(self):
        return self._inner.connect()

    def disconnect(self):
        return self._inner.disconnect()

    def is_connected(self):
        return self._inner.is_connected()

    def write(self, data: bytes):
        self.bytes_out += len(data)
        return self._inner.write(data)

    def read(self, n: int) -> bytes:
        chunk = self._inner.read(n)
        if chunk:
            self.reads += 1
            self.bytes_in += len(chunk)
        return chunk


def step(label: str, fn):
    """Run one read, report how long it took and what it returned."""
    t0 = time.monotonic()
    try:
        value = fn()
    except Exception as e:
        print(f"  {label:.<26} FAILED  {type(e).__name__}: {e}")
        return None
    ms = 1000 * (time.monotonic() - t0)
    shown = value if isinstance(value, str) else repr(value)
    if isinstance(value, list):
        shown = f"{len(value)} entries"
    print(f"  {label:.<26} {ms:7.0f} ms   {shown}")
    return value


def main() -> int:
    ap = argparse.ArgumentParser(
        description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter
    )
    ap.add_argument("target", help="host:port for TCP, or a serial device path")
    ap.add_argument("--baud", type=int, default=115200,
                    help="serial only; the USB-A/FTDI path runs at 115200. "
                         "Ignored by the USB-B 'PC' port, which is CDC-ACM "
                         "and negotiates its own rate.")
    ap.add_argument("--timeout", type=float, default=10.0)
    ap.add_argument("--download", action="store_true",
                    help="also download the first stored event (read-only)")
    ap.add_argument("--lenient", action="store_true",
                    help="do not raise on a bad checksum — for diagnosis only")
    a = ap.parse_args()

    if ":" in a.target and not Path(a.target).exists():
        host, _, port = a.target.rpartition(":")
        inner = TcpTransport(host, int(port), connect_timeout=a.timeout)
        path = f"TCP {host}:{port}"
    else:
        inner = StdlibSerial(a.target, baud=a.baud)
        path = f"serial {a.target} @ {a.baud}"

    transport = _Timed(inner)
    mm = MicromateClient(transport, recv_timeout=a.timeout,
                         strict_checksums=not a.lenient)

    print(f"\n{path}   (read-only: POLL, SERIAL, state, status, setups)\n")
    t0 = time.monotonic()
    try:
        mm.open()
    except OSError as e:
        print(f"  connect....................  FAILED  {e}")
        return 2
    print(f"  {'connect':.<26} {1000*(time.monotonic()-t0):7.0f} ms")

    try:
        info = step("connect() identity", mm.connect)
        if info:
            print(f"       serial={info.serial}  model={info.model}  "
                  f"fw={info.firmware_line}  monitoring={info.monitoring}")
            print(f"       active setup={info.active_setup!r}")
            if info.firmware_line == "thor":
                print("       *** 11.0BD unit — the FIRST one this code has met. ***")
                print("       *** Check the battery and clock below carefully:  ***")
                print("       *** its 0x1C block is 4 bytes longer.             ***")

        state = step("get_state()", mm.get_state)
        if state:
            print(f"       {state}")
            if state.battery_volts and not 2.5 < state.battery_volts < 9.0:
                print(f"       *** battery {state.battery_volts} V is impossible — "
                      f"this is the from-the-end offset bug. ***")
            if state.device_time is None:
                print("       *** device clock did not decode — dump raw below. ***")
                print(f"       raw 0x1C content: {_content(state.raw).hex(' ')}")

        setups = step("list_setups()", mm.list_setups)
        if setups:
            print(f"       first={setups[0]!r}  last={setups[-1]!r}")

        if a.download:
            print("\n  event chain (read-only):")
            proto = mm.protocol
            proto.arm_event()
            hdr = _content(proto.read_event_first())
            key, size = hdr[0:4], int.from_bytes(hdr[4:8], "big")
            if not size:
                print("       no events stored")
            else:
                print(f"       first event key={key.hex()} size={size} B")
                t1 = time.monotonic()
                blob = proto.read_event_file(key, size)
                dt = time.monotonic() - t1
                print(f"       downloaded {len(blob)} B in {dt:.1f} s "
                      f"({len(blob)/dt/1024:.1f} KiB/s)")
                assert len(blob) == size
                # Decode it with the existing codec to prove the bytes are real.
                try:
                    from micromate.idf_file import read_idf_file
                    import tempfile
                    with tempfile.NamedTemporaryFile(suffix=".IDFW", delete=False) as f:
                        f.write(blob)
                        tmp = f.name
                    ev = read_idf_file(tmp)
                    print(f"       decoded OK: {ev}")
                except Exception as e:
                    print(f"       decode failed: {type(e).__name__}: {e}")
                    out = Path(f"./{key.hex()}.IDFW")
                    out.write_bytes(blob)
                    print(f"       saved to {out} for offline analysis")

    except ProtocolError as e:
        print(f"\n  ABORTED  {type(e).__name__}: {e}")
        return 3
    finally:
        mm.close()

    print(f"\n  transport: {transport.reads} reads, "
          f"{transport.bytes_in} B in, {transport.bytes_out} B out")
    print("  A modem path should show MORE reads for the same bytes than USB —")
    print("  that is the buffering, and it is exactly what needed proving.\n")
    return 0


if __name__ == "__main__":
    raise SystemExit(main())