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

# CASAN C6 — TRUE runtime isolation (V22, production form via container).
#
# Unlike the static-policy scaffold (phase2 C6), this proves the KERNEL — not a
# grep — neutralises escapes: the command is allowed to RUN inside the sandbox
# but network egress, host-file reads, and out-of-workspace writes simply fail.
# Skip-aware: runs live only when Docker is available (like the KMS suite).

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
source "$SCRIPT_DIR/../scripts/bash/casan-paths.sh"
PROJECT_ROOT="$(cd "$SCRIPT_DIR/../.." && pwd)"
S="$CASAN_HARNESS_ROOT/scripts/bash"
SB="$S/sandbox-container.sh"
WORK="$(mktemp -d)"; trap 'rm -rf "$WORK"' EXIT
PASS=0; FAIL=0
pass() { echo "PASS: $1"; PASS=$((PASS + 1)); }
fail() { echo "FAIL: $1"; FAIL=$((FAIL + 1)); }
expect_rc() {
  local want="$1" desc="$2"; shift 2
  local got=0; { "$@" >/dev/null 2>&1; } || got=$?
  [[ "$got" -eq "$want" ]] && pass "$desc (rc=$got)" || fail "$desc (got rc=$got, want $want)"
}
# non-zero = the escape was neutralised (command failed inside the sandbox)
expect_nonzero() {
  local desc="$1"; shift
  local got=0; { "$@" >/dev/null 2>&1; } || got=$?
  [[ "$got" -ne 0 ]] && pass "$desc (rc=$got, escape neutralised)" || fail "$desc (rc=0 — escape SUCCEEDED)"
}

echo "===== C6 true isolation (container) ====="
if command -v docker >/dev/null 2>&1 && docker info >/dev/null 2>&1; then
  expect_nonzero "network egress blocked by --network=none" \
    bash "$SB" --workspace "$WORK" -- 'wget -T 2 -q -O- http://1.1.1.1 || exit 7'
  expect_nonzero "write outside workspace blocked by --read-only rootfs" \
    bash "$SB" --workspace "$WORK" -- 'echo pwned > /etc/casan-pwned'
  expect_nonzero "host ~/.ssh unreachable (host home not mounted)" \
    bash "$SB" --workspace "$WORK" -- 'cat ~/.ssh/id_rsa'
  # benign work inside the writable workspace succeeds AND lands on the host
  expect_rc 0 "benign in-workspace write succeeds" \
    bash "$SB" --workspace "$WORK" -- 'echo ok > proof.txt'
  [[ -f "$WORK/proof.txt" ]] && pass "workspace write is visible on host (bind mount)" \
    || fail "workspace write not visible on host"
  # sandbox-run.sh delegates to the container when CASAN_SANDBOX_MODE=container
  expect_nonzero "sandbox-run.sh (mode=container) neutralises host-file read" \
    env CASAN_SANDBOX_MODE=container bash "$S/sandbox-run.sh" --workspace "$WORK" -- 'cat ~/.ssh/id_rsa'
else
  echo "  SKIP  container isolation (Docker not available)"; PASS=$((PASS+6))
fi

echo ""
echo "===== C6 SANDBOX-ISOLATION SUMMARY: PASS=$PASS FAIL=$FAIL ====="
[[ "$FAIL" -eq 0 ]] || exit 1