#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""Settle the pre-match kit selector gate: who, if anyone, writes item `+0x60`.

READ-ONLY. /proc/PID/mem is opened 'rb'; there is no write path in this file.

WHY THIS EXISTS
---------------
`plan-2026-08-06-card-subsystem.md` section 5 calls `+0x60` "the single blocker
between 'we can mark a kit equipped' and 'we can equip a kit'", and records that
two attempts to find its writer drowned: scanning for the offset returned 1688
and 4144 instructions depending on method.

The scan drowns because `+0x60` is a common struct offset. Two cheap filters cut
it to something a person can read:

  * only IMMEDIATE stores can introduce a constant (a register store propagates
    one from somewhere else), and
  * item-record code is recognisable by touching `+0x4c` (cardtype) or `+0x5c`
    (itemState) within a few instructions.

WHAT IT REPORTS
---------------
1. The live `+0x60` distribution over every resident CardsDb record.
2. Every `cmp dword [reg+0x60], imm8` in CardsDLL .text -- the readers.
3. Every immediate store to `[reg+0x60]` and the constants they use.
4. Which of those stores sit next to item-record code.

MEASURED 2026-08-21 (pid 6580, 27 resident records):
    live +0x60      : {1: 23 (players), 0: 4 (staff)} -- never 4
    readers         : 4 total; exactly ONE compares against 4, at 0x1801c34f2,
                      which is the kit gate in FUN_1801c3480
    immediate stores: 27 total; constants {-2, 0, 1, 908, 0x3f800000} -- NO 4
    FIFA17.exe      : 0 immediate stores of 4 to +0x60 across its 79MB of code,
                      and 0 comparisons against 4
    gate xrefs      : 1 (a jmp from 0x1801a5329); address never taken

The gate at 0x1801c34f2 decodes as:

    cmp [rdi+0x4c], 7        cardtype 7 = kit/stadium/badge   <- we produce this
    cmp [rdi+0x60], 4        <- THE BLOCKER
    mov eax, [rdi+0x5c]      itemState
    cmp eax, 0x65 / 0x66     101 activeHomeKit / 102 activeAwayKit <- we produce
    mov r8d, [rdi+0x94]      teamid                            <- we produce
    mov r9d, [rdi+0xba]      kit variant selector (unresolved)

So every input EXCEPT `+0x60` is already satisfied by what OpenFUT serves, and
no instruction in either module ever stores the constant 4 there.

Usage:  python3 kit_gate_probe.py
"""
import collections
import struct
import sys

import watch_club_model as W

try:
    import card_identity_probe as P
except Exception:  # pragma: no cover - probe is optional for the static half
    P = None

TEXT_START = 0x180001000
FIELD = 0x60
REGS = ["rax", "rcx", "rdx", "rbx", "rsp", "rbp", "rsi", "rdi"]
REC_SIZE = 0x158
F_SUBTYPE = 0x50


def live_distribution(mem, base):
    """(+0x60 histogram, (subtype,+0x60) histogram) over resident records."""
    if P is None:
        return None, None
    obj = mem.q(base + (W.G_CARDSDB - W.IMG_BASE))
    if not obj:
        return None, None
    by_value = collections.Counter()
    by_pair = collections.Counter()
    for node in P.nodes(mem, obj):
        buf = mem.read(node + 0x28, REC_SIZE)
        if not buf or len(buf) < REC_SIZE:
            continue
        subtype = struct.unpack_from("<I", buf, F_SUBTYPE)[0]
        value = struct.unpack_from("<i", buf, FIELD)[0]
        by_value[value] += 1
        by_pair[(subtype, value)] += 1
    return by_value, by_pair


def scan_text(text):
    """(readers, immediate stores, item-record markers) over a .text image."""
    readers, stores, markers = [], [], set()
    for i in range(len(text) - 8):
        op, modrm = text[i], text[i + 1]
        mod, reg, rm = modrm >> 6, (modrm >> 3) & 7, modrm & 7
        if mod != 1 or rm == 4:
            continue
        disp = text[i + 2]
        if disp in (0x4C, 0x5C) and op in (0x8B, 0x89, 0x83, 0x39, 0x3B, 0xC7, 0x0F):
            markers.add(TEXT_START + i)
        if disp != FIELD:
            continue
        if op == 0x83 and reg == 7:                       # cmp dword [reg+0x60], imm8
            readers.append((TEXT_START + i, REGS[rm], text[i + 3]))
        elif op == 0xC7 and reg == 0:                     # mov dword [reg+0x60], imm32
            stores.append((TEXT_START + i, REGS[rm], struct.unpack_from("<i", text, i + 3)[0], "dword"))
        elif op == 0xC6 and reg == 0:                     # mov byte [reg+0x60], imm8
            stores.append((TEXT_START + i, REGS[rm], text[i + 3], "byte"))
    return readers, stores, markers


def main():
    pid = W.find_pid()
    if pid is None:
        print("FIFA17.exe is not running.")
        return 1
    base = W.dll_base(pid)
    if base is None:
        print("pid %d is up but %s is not mapped." % (pid, W.DLL))
        return 1
    mem = W.Mem(pid)

    print("pid=%d  %s base=%#x" % (pid, W.DLL, base))
    print()

    by_value, by_pair = live_distribution(mem, base)
    print("── live records ──")
    if by_value is None:
        print("  CardsDb is empty (no FUT session loaded); static half still runs.")
    else:
        print("  +0x60 distribution      : %s" % dict(by_value))
        print("  (cardsubtypeid, +0x60)  : %s" % dict(by_pair))
        print("  holds the gate value 4  : %s" % ("YES" if 4 in by_value else "NO"))
    print()

    # .text is the second CardsDLL mapping; read it whole and scan.
    size = 0x1E4000
    buf, bad = mem.read_pages(base + 0x1000, size)
    if bad:
        print("  WARNING: %d unreadable page(s); the scan is incomplete." % len(bad))
    text = bytes(buf)

    readers, stores, markers = scan_text(text)
    print("── readers: cmp dword [reg+0x60], imm8 ──")
    for va, reg, imm in readers:
        flag = "   <-- THE KIT GATE" if imm == 4 else ""
        print("  %#x  cmp [%s+0x60], %d%s" % (va, reg, imm, flag))
    print()

    print("── immediate stores to [reg+0x60] ──")
    consts = collections.Counter(s[2] for s in stores)
    print("  %d store(s); constants %s" % (len(stores), dict(sorted(consts.items()))))
    near = [s for s in stores if any(abs(m - s[0]) <= 96 for m in markers)]
    print("  %d of them sit within 96B of item-record code (+0x4c/+0x5c):" % len(near))
    for va, reg, imm, width in near:
        print("    %#x  mov %s [%s+0x60], %d" % (va, width, reg, imm))
    print()

    print("=" * 70)
    if any(s[2] == 4 for s in stores):
        print("A store of 4 EXISTS -- the gate is reachable. Follow the sites above.")
        return 0
    print("NO instruction in CardsDLL stores the constant 4 into +0x60.")
    print("Combined with the live records (never 4) and the fact that every OTHER")
    print("gate input is already served, the pre-match kit selector cannot be")
    print("opened by anything the server sends. This is a CLIENT-side dead end,")
    print("not a missing wire field.")
    print()
    print("Scope of the claim: immediate stores, all widths, disp8 form. A value")
    print("could still arrive by register copy -- but in CardsDLL every register")
    print("store to +0x60 is a field-by-field struct copy or an init to 0/1/-2.")
    print("=" * 70)
    return 0


if __name__ == "__main__":
    sys.exit(main())