#!/bin/bash

. "tests/lib.sh"

SFLL=${1:-./squashfuse_ll}         # The squashfuse_ll binary.
TIMEOUT=20

case linux-gnu in
    linux*)
        ;;
    *)
        echo "This test is only enabled on linux hosts."
        exit 0
        ;;
esac

function cleanup {
    set +e
    if [[ -n "$TAIL_PID" ]]; then
        kill "$TAIL_PID"
    fi
    fusermount -u "$MNTDIR" >& /dev/null
    rm -rf "$WORKDIR"
}

set -e
WORKDIR=$(mktemp -d)
MNTDIR="$WORKDIR/mountpoint"
mkdir -p "$MNTDIR"
mkdir -p "$WORKDIR/source"
trap cleanup EXIT

# Make a tiny squashfs filesystem.
echo "Hello world" >"$WORKDIR/source/hello"
mksquashfs "$WORKDIR/source" "$WORKDIR/squashfs.image" -comp zstd -no-progress >& /dev/null

# Mount it.
$SFLL "$WORKDIR/squashfs.image" "$MNTDIR"
SFPID=$(pgrep -f "squashfuse_ll.*$MNTDIR")

if ! [[ -d /proc/$SFPID ]]; then
    echo "squashfuse process missing"
    exit 1
fi
if ! grep -q "$MNTDIR" /proc/mounts; then
    echo "mount missing."
    exit 1
fi

# background a task to hold a file open from the image.
tail -f "${MNTDIR}/hello" >/dev/null &
TAIL_PID=$!

# SIGTERM the squashfuse process.
kill -15 "$SFPID"

# Now we expect the mountpoint to disappear due to lazy umount.
if ! timeout $TIMEOUT bash -c \
    "while grep -q $MNTDIR /proc/mounts; do \
        sleep 1;
     done"; then
     echo "$MNTDIR did not dismount in response to SIGTERM."
     exit 1
fi

# but the process should remain alive, because of the background task.
if ! [[ -d /proc/$SFPID ]]; then
    echo "squashfuse process missing"
    exit 1
fi

# Now kill the background process.
kill $TAIL_PID
TAIL_PID=

# Now we expect the process to die.
if ! timeout $TIMEOUT bash -c \
    "while [[ -d /proc/$SFPID ]]; do \
        sleep 1;
     done"; then
     echo "squashfuse process did not die once filesystem was released."
     exit 1
fi

echo "Success."