#!/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: drain returns immediately when the RC API is unavailable.
# Specifically tests the drain path: write a dirty file with long write-back,
# kill rclone (removing the RC API), then send SIGTERM. The drain function
# should detect the RC API is gone and return immediately without hanging.

require_root
setup_test_env
trap teardown_test_env EXIT

start_mock_nas

# Use a very long write-back delay so the file stays dirty
gen_config write_back=300s

start_warpgate
wait_for_mount
wait_for_rc_api

# Write a dirty file through the mount — it will stay dirty due to 300s delay
dd if=/dev/urandom bs=1K count=64 2>/dev/null | \
    dd of="$TEST_MOUNT/drain-test.dat" bs=1K 2>/dev/null

# Allow VFS to register the dirty write
sleep 2

# Kill rclone directly — simulates an unexpected crash, removing the RC API
pkill -f "rclone mount.*$TEST_MOUNT"

# Brief pause for the supervisor to detect rclone exit
sleep 1

# Send SIGTERM to trigger graceful shutdown with drain.
# The drain function should detect that the RC API is gone and return
# immediately rather than hanging for the drain timeout.
if kill -0 "$WARPGATE_PID" 2>/dev/null; then
    kill -TERM "$WARPGATE_PID"
fi

# Warpgate should exit quickly since drain cannot poll vfs/stats
wait_for_exit "$WARPGATE_PID" 30

# Verify warpgate noticed the unexpected rclone exit
assert_log_contains "rclone mount exited unexpectedly"

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