#!/usr/bin/env bash
set -euo pipefail
SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
source "$SCRIPT_DIR/../harness/helpers.sh"
source "$SCRIPT_DIR/../harness/mock-nas.sh"

# Test: graceful shutdown drains the write-back queue before exiting.
# A file written through the FUSE mount with a long write-back delay should
# still arrive on the NAS after SIGTERM triggers the drain procedure.

require_root
setup_test_env
trap teardown_test_env EXIT

start_mock_nas

# Long write-back delay ensures the file stays dirty until drain
gen_config write_back=30s

start_warpgate
wait_for_mount
wait_for_rc_api

# Write a file through the FUSE mount
echo "drain-test-data" > "$TEST_MOUNT/drain.txt"

# Allow VFS to register the write
sleep 1

# Verify the file is dirty (not yet written back)
dirty=$(get_dirty_count)
if [[ "$dirty" -lt 1 ]]; then
    echo "FAIL: expected dirty count > 0, got $dirty" >&2
    exit 1
fi

# Send SIGTERM to trigger orderly shutdown with write-back drain
kill -TERM "$WARPGATE_PID"

# Wait for exit — drain must flush the file before unmounting
wait_for_exit "$WARPGATE_PID" 60

# Verify the drain procedure was logged
assert_log_contains "Waiting for write-back queue"

# Verify the file arrived on the NAS with correct content
assert_file_content "$NAS_ROOT/drain.txt" "drain-test-data"

echo "PASS: $(basename "$0" .sh)"