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

# CASAN Plan-16 SEC-09 (M-10) — input-size cap + fail-closed reads.
#
# security-check / drift-detect / context-compress ran superlinear passes (regex,
# SequenceMatcher) with no size cap (DoS) and crashed on missing / non-UTF8 input
# instead of returning a fail-closed verdict. This proves oversize input is blocked,
# undecodable input degrades without a crash, and normal input is unaffected.
# Cap overridable via CASAN_MAX_INPUT_BYTES.
#
# Deterministic; hermetic; no model/network.

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_ROOT="$(cd "$SCRIPT_DIR/../.." && pwd)"
BASH_DIR="$PROJECT_ROOT/.specify/scripts/bash"
WORK="$(mktemp -d)"
# security-check / drift-detect touch shared logs; restore on exit.
trap 'git -C "$PROJECT_ROOT" checkout -- .specify/logs/ .specify/level5/central-governance/ 2>/dev/null; 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-09: input caps + fail-closed reads ====="

BIG="$WORK/big.txt"; head -c 200 /dev/zero | tr '\0' 'a' > "$BIG"
SMALL="$WORK/small.txt"; echo "benign objective text" > "$SMALL"

# --- security-check ---
[[ "$(rc_of env CASAN_MAX_INPUT_BYTES=10 bash "$BASH_DIR/security-check.sh" "$BIG" "$WORK/o1.txt" input)" -ne 0 ]] \
  && pass "security-check blocks oversize input" || fail "security-check allowed oversize input"
[[ "$(rc_of bash "$BASH_DIR/security-check.sh" "$SMALL" "$WORK/o2.txt" input)" -eq 0 ]] \
  && pass "security-check allows normal input (regression)" || fail "security-check rejected normal input"

# --- drift-detect ---
echo "golden reference" > "$WORK/golden.txt"
[[ "$(rc_of bash "$BASH_DIR/drift-detect.sh" "$WORK/golden.txt" "$WORK/missing.txt" "$WORK/dr1.json")" -ne 0 ]] \
  && pass "drift-detect blocks on missing candidate (fail-closed, no crash)" || fail "drift-detect did not block missing file"
if [[ -f "$WORK/dr1.json" ]] && grep -q '"status": "fail"' "$WORK/dr1.json"; then
  pass "drift-detect writes a fail verdict report (not a traceback)"
else
  fail "drift-detect did not emit a fail verdict report"
fi
[[ "$(rc_of env CASAN_MAX_INPUT_BYTES=10 bash "$BASH_DIR/drift-detect.sh" "$WORK/golden.txt" "$BIG" "$WORK/dr2.json")" -ne 0 ]] \
  && pass "drift-detect blocks oversize candidate (DoS cap)" || fail "drift-detect allowed oversize"

# --- context-compress ---
[[ "$(set +e; head -c 200 /dev/zero | tr '\0' 'a' | env CASAN_MAX_INPUT_BYTES=10 python3 "$BASH_DIR/context-compress.py" >/dev/null 2>&1; echo $?)" -ne 0 ]] \
  && pass "context-compress rejects oversize input (fail-closed)" || fail "context-compress allowed oversize input"

RC="$(set +e; printf '\xff\xfe some error line\n' | python3 "$BASH_DIR/context-compress.py" --mode extractive >/dev/null 2>&1; echo $?)"
[[ "$RC" -ne 2 ]] \
  && pass "context-compress handles non-UTF8 without crashing (rc=$RC)" || fail "context-compress crashed on non-UTF8 (rc=$RC)"

echo ""
echo "===== SEC-09 SUMMARY: PASS=$PASS FAIL=$FAIL ====="
[[ "$FAIL" -eq 0 ]] || exit 1