#!/usr/bin/env python3
"""Deterministic execution-evidence recorder for the adversary graph.

Runs ONLY the caller-declared verification commands (verification_commands)
in the project dir and records the outcomes as `exec_results` — a list of
{cmd, exit, duration_s, tail} records. Criterion branches cite this record;
they never execute anything themselves.

NO auto-detection: undeclared commands mean a "none declared" marker
(fail-visible, not fail-guessed). Any runner error degrades into an
ENVIRONMENT marker — this script never fails the node.

Budget: commands run sequentially, so TOTAL runtime is bounded by a deadline
(TOTAL_DEADLINE_SECS = 3300s, the run_checks node's 3600s timeout minus
margin). Without it, a handful of hanging commands (4 x 900s) would blow the
NODE timeout and the executor would kill this script from OUTSIDE — the
in-script degradation would never fire. Each command gets
min(PER_COMMAND_TIMEOUT_SECS, remaining budget); commands the deadline
leaves no budget for are recorded as {"cmd", "skipped": "deadline"} entries,
so the in-script handling stays authoritative. The env var
ADVERSARY_RUN_CHECKS_DEADLINE_SECS overrides the deadline (test seam).

Process hygiene: commands run through the shell. On POSIX each command gets
its own session (start_new_session) and a timeout SIGKILLs the whole process
group, so grandchildren of a hung command cannot linger. On non-POSIX
platforms only the direct shell child is killed — grandchildren of a
timed-out command may survive (documented limitation).
"""

import json
import os
import signal
import subprocess
import time

PER_COMMAND_TIMEOUT_SECS = 900
TOTAL_DEADLINE_SECS = float(os.environ.get("ADVERSARY_RUN_CHECKS_DEADLINE_SECS") or 3300)
TAIL_LINES = 50
MAX_TAIL_CHARS = 8000


def load_state():
    if path := os.environ.get("GRAPH_STATE_FILE"):
        with open(path) as f:
            return json.load(f)
    return json.loads(os.environ.get("GRAPH_STATE", "{}"))


def tail_of(text):
    tail = "\n".join(text.splitlines()[-TAIL_LINES:])
    if len(tail) > MAX_TAIL_CHARS:
        tail = "…" + tail[-MAX_TAIL_CHARS:]
    return tail


def run_one(cmd, proj, budget):
    """Run one command, hard-bounded by `budget` seconds; return its record."""
    start = time.monotonic()
    popen_kwargs = {"start_new_session": True} if os.name == "posix" else {}
    p = subprocess.Popen(
        cmd,
        shell=True,
        cwd=proj,
        stdout=subprocess.PIPE,
        stderr=subprocess.PIPE,
        text=True,
        **popen_kwargs,
    )
    try:
        out_s, err_s = p.communicate(timeout=budget)
    except subprocess.TimeoutExpired:
        if os.name == "posix":
            try:
                os.killpg(os.getpgid(p.pid), signal.SIGKILL)
            except (ProcessLookupError, PermissionError):
                pass
        else:
            p.kill()
        p.communicate()  # reap the child and drain the pipes
        return {
            "cmd": cmd,
            "exit": -1,
            "duration_s": round(time.monotonic() - start, 1),
            "tail": f"TIMEOUT: no exit within {budget:.0f}s — recorded as a failing run",
        }
    combined = (out_s or "") + (("\n" + err_s) if err_s else "")
    return {
        "cmd": cmd,
        "exit": p.returncode,
        "duration_s": round(time.monotonic() - start, 1),
        "tail": tail_of(combined),
    }


def main():
    state = load_state()
    declared = state.get("verification_commands")
    cmds = (
        [c.strip() for c in declared if isinstance(c, str) and c.strip()]
        if isinstance(declared, list)
        else []
    )
    if not cmds:
        print(
            json.dumps(
                {
                    "exec_results": (
                        "none declared — the caller supplied no verification_commands; "
                        "execution criteria (build/test/lint) cannot be independently "
                        "confirmed. Declare the exact commands in the spawn prompt to "
                        "get recorded runs."
                    )
                }
            )
        )
        return

    proj = os.path.expanduser(
        (state.get("project_dir") or "").strip() or "."
    )
    deadline = time.monotonic() + TOTAL_DEADLINE_SECS
    results = []
    for cmd in cmds:
        remaining = deadline - time.monotonic()
        if remaining <= 0:
            results.append({"cmd": cmd, "skipped": "deadline"})
            continue
        results.append(run_one(cmd, proj, min(PER_COMMAND_TIMEOUT_SECS, remaining)))
    print(json.dumps({"exec_results": results}))


try:
    main()
except Exception as e:  # noqa: BLE001 — never fail the node; degrade visibly
    print(
        json.dumps(
            {
                "exec_results": (
                    f"ENVIRONMENT: verification runner error: {e} — the declared "
                    "commands could not be executed; treat execution criteria as "
                    "PARTIAL (unproven), not as failed"
                )
            }
        )
    )