#!/usr/bin/env bash
set -euo pipefail
export PATH="$HOME/.cargo/bin:$PATH"

# Loop device integration test per spec #40
# Creates 128 MiB image, attaches loop device, writes marker, wipes, verifies

set -x

IMAGE_SIZE_MB=128
IMAGE_FILE=$(mktemp /tmp/wipe-test-XXXX.img)
LOOP_DEV=""

cleanup() {
  set +e
  echo "Cleaning up..."
  if mount | grep -q "$LOOP_DEV" 2>/dev/null; then
    umount "$LOOP_DEV" 2>/dev/null || true
  fi
  # Check for mounted filesystems on loop device partitions
  if [ -n "$LOOP_DEV" ]; then
    # Unmount any partitions?
    for mp in $(lsblk -ln -o MOUNTPOINTS "$LOOP_DEV" 2>/dev/null | grep -v "^$" || true); do
      umount "$mp" 2>/dev/null || true
    done
    losetup -d "$LOOP_DEV" 2>/dev/null || true
  fi
  rm -f "$IMAGE_FILE"
  # Also cleanup any leftover loop devices attached to our image
  losetup -j "$IMAGE_FILE" 2>/dev/null | cut -d: -f1 | xargs -r losetup -d 2>/dev/null || true
  echo "Cleanup done"
}
trap cleanup EXIT

echo "Creating ${IMAGE_SIZE_MB}MiB image at $IMAGE_FILE"
dd if=/dev/zero of="$IMAGE_FILE" bs=1M count="$IMAGE_SIZE_MB" status=none

echo "Attaching loop device"
LOOP_DEV=$(losetup --find --show "$IMAGE_FILE")
echo "Loop device: $LOOP_DEV"

if [ ! -b "$LOOP_DEV" ]; then
  echo "Failed to create loop device"
  exit 1
fi

# Verify block device
if [ ! -b "$LOOP_DEV" ]; then
  echo "Not a block device: $LOOP_DEV"
  exit 1
fi

# Create filesystem and mount to test mount detection
echo "Creating ext4 filesystem on $LOOP_DEV"
mkfs.ext4 -F "$LOOP_DEV" >/dev/null 2>&1

MNT_DIR=$(mktemp -d /tmp/wipe-mnt-XXXX)
echo "Mounting $LOOP_DEV to $MNT_DIR"
mount "$LOOP_DEV" "$MNT_DIR"

echo "Writing marker data"
echo "WIPE_TEST_MARKER_$(date +%s)" > "$MNT_DIR/marker.txt"
echo "Additional data" >> "$MNT_DIR/marker.txt"
dd if=/dev/urandom of="$MNT_DIR/random.dat" bs=1K count=100 status=none 2>/dev/null || true
sync

echo "Unmounting before wipe"
umount "$MNT_DIR"
rmdir "$MNT_DIR"

# Ensure device is not mounted
if mount | grep -q "$LOOP_DEV"; then
  echo "Device still mounted after umount"
  exit 1
fi

# Build wipe binary if not exists
if [ ! -x "target/release/wipe" ]; then
  echo "Building wipe release binary"
  cargo build --release
fi

echo "Running wipe zero on $LOOP_DEV"
# For loop device, it is considered whole-disk, need --whole-disk
# Use buffer size small for speed
set +e
sudo target/release/wipe "$LOOP_DEV" --whole-disk --method zero --yes --buffer-size 4M --verbose
WIPE_EXIT=$?
set -e

if [ $WIPE_EXIT -ne 0 ]; then
  echo "wipe failed with exit $WIPE_EXIT"
  # If it's loop device and fails due to safety, try with --force? But loop should not be system device
  echo "STDOUT/STDERR from wipe:"
  sudo target/release/wipe "$LOOP_DEV" --whole-disk --method zero --yes --buffer-size 4M --dry-run || true
  exit 1
fi

echo "Verifying zero"
# Read first 1M and check all zeros using od -v to avoid compression
if dd if="$LOOP_DEV" bs=1M count=1 status=none 2>/dev/null | od -An -v -t x1 | tr -d ' \n' | grep -q -v "^00*$"; then
  echo "Verification failed: device not zeroed"
  exit 1
else
  echo "First 1M is all zeros: PASS"
fi

# Full verify using our --verify flag: wipe again with verify
echo "Testing wipe with --verify"
# Re-create marker
echo "marker" | dd of="$LOOP_DEV" bs=1K count=1 status=none 2>/dev/null || true
sync
sudo target/release/wipe "$LOOP_DEV" --whole-disk --method zero --yes --buffer-size 4M --verify
echo "Verify wipe passed"

echo "Loop integration test PASSED"
echo "Device: $LOOP_DEV"
echo "Image: $IMAGE_FILE"