#!/usr/bin/env bash
# Test: cached files survive SIGKILL and remain readable after restart
#
# Verifies that read-through cached files persist on disk through a
# simulated power loss (SIGKILL).  After restarting warpgate, the files
# should be readable through the mount with content matching the originals
# on the NAS.
#
# Sequence:
#   1. Create 3 test files (100 KB each) on the mock NAS.
#   2. Start warpgate, read all files through the mount to cache them.
#   3. Verify all files are cached.
#   4. simulate_power_loss.
#   5. Start a fresh warpgate instance.
#   6. Read the cached files again through the mount.
#   7. Verify content matches the NAS originals.
set -euo pipefail
SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
source "$SCRIPT_DIR/../harness/helpers.sh"
source "$SCRIPT_DIR/../harness/mock-nas.sh"

require_root
setup_test_env
trap teardown_test_env EXIT

# Start the mock NAS and create 3 test files
start_mock_nas
nas_create_file "photo-001.dat" 100
nas_create_file "photo-002.dat" 100
nas_create_file "photo-003.dat" 100

# Record checksums of the original NAS files
cksum_001=$(nas_file_checksum "photo-001.dat")
cksum_002=$(nas_file_checksum "photo-002.dat")
cksum_003=$(nas_file_checksum "photo-003.dat")

# Generate default config
gen_config

# Start warpgate and wait for readiness
start_warpgate
wait_for_mount
wait_for_rc_api

# Read all files through the FUSE mount to pull them into cache
cat "$TEST_MOUNT/photo-001.dat" > /dev/null
cat "$TEST_MOUNT/photo-002.dat" > /dev/null
cat "$TEST_MOUNT/photo-003.dat" > /dev/null

# Verify all files are cached
assert_cached "photo-001.dat"
assert_cached "photo-002.dat"
assert_cached "photo-003.dat"
echo "INFO: all 3 files cached successfully"

# Simulate power loss
simulate_power_loss

# Verify cache files persist on disk
for f in photo-001.dat photo-002.dat photo-003.dat; do
    if [[ ! -f "$CACHE_DIR/vfs/nas/$f" ]]; then
        echo "FAIL: cache file missing after power loss: $f" >&2
        exit 1
    fi
done
echo "INFO: all cache files persist on disk after SIGKILL"

# Clean up any stale FUSE mount
if mountpoint -q "$TEST_MOUNT" 2>/dev/null; then
    fusermount3 -uz "$TEST_MOUNT" 2>/dev/null || fusermount -uz "$TEST_MOUNT" 2>/dev/null || true
fi

# Start a fresh warpgate instance
start_warpgate
wait_for_mount 60
wait_for_rc_api

# Read the files again through the mount and verify checksums
actual_001=$(md5sum "$TEST_MOUNT/photo-001.dat" | awk '{print $1}')
actual_002=$(md5sum "$TEST_MOUNT/photo-002.dat" | awk '{print $1}')
actual_003=$(md5sum "$TEST_MOUNT/photo-003.dat" | awk '{print $1}')

fail=0
if [[ "$actual_001" != "$cksum_001" ]]; then
    echo "FAIL: photo-001.dat checksum mismatch after restart" >&2
    echo "  expected: $cksum_001  actual: $actual_001" >&2
    fail=1
fi
if [[ "$actual_002" != "$cksum_002" ]]; then
    echo "FAIL: photo-002.dat checksum mismatch after restart" >&2
    echo "  expected: $cksum_002  actual: $actual_002" >&2
    fail=1
fi
if [[ "$actual_003" != "$cksum_003" ]]; then
    echo "FAIL: photo-003.dat checksum mismatch after restart" >&2
    echo "  expected: $cksum_003  actual: $actual_003" >&2
    fail=1
fi

if [[ "$fail" -ne 0 ]]; then
    exit 1
fi

echo "INFO: all 3 files readable with correct content after crash + restart"
echo "PASS: $(basename "$0" .sh)"