#!/usr/bin/env bash
set -uo pipefail

# CASAN Plan-16 SEC-29 (X-05) — audit write fails CLOSED.
#
# If the audit log cannot be written (disk full, read-only, quota), a governed
# action must NOT proceed — there is no action without its accountability record.
# Proves governance-check denies (and empties the output) when the audit log is
# unwritable, and still works normally otherwise.
#
# Restores the audit log it perturbs on exit.

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_ROOT="$(cd "$SCRIPT_DIR/../.." && pwd)"
GC="$PROJECT_ROOT/.specify/scripts/bash/governance-check.sh"
AUD="$PROJECT_ROOT/.specify/logs/audit/audit.jsonl"
WORK="$(mktemp -d)"
export CASAN_AUDIT_KEY_DIR="$WORK/keys"

restore() {
  [[ -f "$AUD" ]] && chmod 644 "$AUD" 2>/dev/null || true
  git -C "$PROJECT_ROOT" checkout -- .specify/logs/ .specify/level5/central-governance/ 2>/dev/null || true
}
trap 'restore; rm -rf "$WORK"' EXIT

PASS=0; FAIL=0
pass() { echo "PASS: $1"; PASS=$((PASS + 1)); }
fail() { echo "FAIL: $1"; FAIL=$((FAIL + 1)); }
rc_of() { set +e; "$@" >/dev/null 2>&1; echo $?; set -e 2>/dev/null || true; }

echo "===== Plan-16 SEC-29: audit fail-closed when unwritable ====="

echo "benign objective text" > "$WORK/in.txt"

# Normal (writable) path works.
[[ "$(rc_of bash "$GC" "$WORK/in.txt" "$WORK/ok-out.txt" agent_step)" -eq 0 ]] \
  && pass "governed action succeeds when audit is writable" || fail "normal governed action failed"

# Make the audit log read-only so the append fails; the action must be denied.
echo "PREEXISTING_OUTPUT" > "$WORK/blocked-out.txt"
[[ -f "$AUD" ]] || echo '{}' > "$AUD"
chmod 444 "$AUD"
RC="$(rc_of bash "$GC" "$WORK/in.txt" "$WORK/blocked-out.txt" agent_step)"
chmod 644 "$AUD"
[[ "$RC" -ne 0 ]] \
  && pass "unwritable audit → governed action DENIED (fail-closed)" \
  || fail "action proceeded despite unwritable audit (fail-open)"

[[ ! -s "$WORK/blocked-out.txt" ]] \
  && pass "output emptied on audit failure (no unaudited output leaks)" \
  || fail "stale output left after audit failure"

echo ""
echo "===== SEC-29 SUMMARY: PASS=$PASS FAIL=$FAIL ====="
[[ "$FAIL" -eq 0 ]] || exit 1