#!/usr/bin/env python3
"""Installer safety guards contract (flake check `installer-safety`).

Usage: check-install-safety.py <nomarchy-install.sh>

Locks the three BACKLOG #54 guards against silent regression:

  1. Offline compose-lock failure fail-closes (no network `flake lock`).
  2. Disk signature warn for NTFS / BitLocker / Microsoft / LUKS.
  3. HM pre-activate failure drops NOMARCHY-DESKTOP-NOT-THEMED.txt.

Also re-checks the password ≥8 interactive floors (V0-complete).
Pure — no VM, no ISO.
"""

from __future__ import annotations

import re
import sys
from pathlib import Path

script = Path(sys.argv[1]).read_text(encoding="utf-8")


def check(cond: bool, msg: str) -> None:
    if not cond:
        sys.exit(f"installer-safety: {msg}")


# ── 1. Offline compose-lock fail-closed ─────────────────────────────────
# The offline branch must fail hard; `nix flake lock` only on the online path.
check(
    "Offline lock composition failed and there is no network to fall back to"
    in script,
    "missing offline compose-lock fail-closed message",
)
# Fail-closed is gated on OFFLINE=true.
check(
    re.search(
        r'if \[\[ "\$OFFLINE" == true \]\]; then\s*\n'
        r'\s*fail "Offline lock composition failed',
        script,
    ),
    "offline fail-closed is not gated on OFFLINE=true",
)
# Network flake lock must sit in the non-offline fallback, not the offline arm.
flake_lock = script.find('nix --extra-experimental-features "nix-command flakes" flake lock')
offline_fail = script.find("Offline lock composition failed and there is no network")
check(flake_lock > 0 and offline_fail > 0, "compose-lock / flake lock markers missing")
check(
    flake_lock > offline_fail,
    "network `flake lock` appears before the offline fail-closed arm",
)
# Between offline fail and flake lock there must not be an unguarded lock call
# earlier in the file for this recovery path.
check(
    "Offline lock composition failed — resolving over the network." in script,
    "missing online-only compose-lock fallback warn",
)

# ── 2. Disk signature warn ──────────────────────────────────────────────
sig_re = re.search(
    r"grep -qiE '([^']+)'\s*<<<\s*\"\$existing_sig\"",
    script,
)
check(sig_re is not None, "disk signature grep missing")
pat = sig_re.group(1)
check(
    all(tok in pat for tok in ("ntfs", "bitlocker", "microsoft", "crypto_luks")),
    f"signature pattern incomplete: {pat!r}",
)
check(
    "Windows/BitLocker/NTFS or LUKS" in script,
    "missing user-facing disk-signature warn text",
)

# Pure behavioural: the same regex the installer uses.
rx = re.compile(pat, re.I)
samples_hit = [
    "ntfs\n",
    "TYPE=\"ntfs\"",
    "BitLocker",
    "Microsoft reserved",
    "crypto_LUKS",
    "TYPE=\"crypto_LUKS\"",
]
samples_miss = [
    "",
    "ext4\n",
    "btrfs\nvfat",
    "TYPE=\"xfs\"",
]
for s in samples_hit:
    check(bool(rx.search(s)), f"signature regex should match {s!r}")
for s in samples_miss:
    check(not rx.search(s), f"signature regex should NOT match {s!r}")

# ── 3. Pre-activate recovery hint ───────────────────────────────────────
check(
    "NOMARCHY-DESKTOP-NOT-THEMED.txt" in script,
    "missing pre-activate hint filename",
)
check(
    "home-manager switch --flake ~/.nomarchy -b bak" in script,
    "hint must tell the user the recovery command",
)
check(
    'hint_file="/mnt/home/$USERNAME/NOMARCHY-DESKTOP-NOT-THEMED.txt"' in script
    or 'hint_file="/mnt/home/$USERNAME/NOMARCHY-DESKTOP-NOT-THEMED.txt"'
    in script.replace(" ", ""),
    "hint must land on the target home under /mnt",
)
# Hint is only written on the failure arm (else of nixos-enter activate).
activate_if = script.find("if nixos-enter --root /mnt -- bash /root/nomarchy-hm-activate.sh")
hint_pos = script.find("NOMARCHY-DESKTOP-NOT-THEMED.txt")
check(activate_if > 0 and hint_pos > activate_if, "hint is not on the activate-failure arm")

# ── Password floors (V0-complete, keep the floor) ───────────────────────
check(
    re.search(r"password for \$USERNAME \(min 8 chars\)", script) is not None,
    "account password min-8 prompt missing",
)
check(
    re.search(r"LUKS passphrase \(min 8 chars\)", script) is not None,
    "LUKS passphrase min-8 prompt missing",
)
check(
    script.count("[[ ${#") >= 2 and " -ge 8 ]]" in script,
    "min-8 length checks missing",
)

print("installer-safety: all contracts hold")