#!/bin/sh

set -e

die() {
    echo "die: $*"
    exit 1
}

if [ "$(id -u)" != 0 ]; then
    exec sudo -E -- "$0" "$@" || die "this script needs to run as root"
else
    : "${SUDO_UID:=0}" "${SUDO_GID:=0}"
fi

if [ "$(uname -s)" = "Darwin" ]; then
    export PATH="/usr/local/opt/e2fsprogs/bin:$PATH"
    export PATH="/usr/local/opt/e2fsprogs/sbin:$PATH"
fi

disk_usage() {
    du -sm "$1" | cut -f1
}

DISK_SIZE=$(($(disk_usage "$SERENITY_ROOT/Base") + $(disk_usage Root) + 100))

echo "setting up disk image..."
qemu-img create _disk_image "${DISK_SIZE:-600}"m || die "could not create disk image"
chown "$SUDO_UID":"$SUDO_GID" _disk_image || die "could not adjust permissions on disk image"
echo "done"

printf "creating new filesystem... "
if [ "$(uname -s)" = "OpenBSD" ]; then
    VND=$(vnconfig _disk_image)
    (echo "e 0"; echo 83; echo n; echo 0; echo "*"; echo "quit") | fdisk -e "$VND"
    mkfs.ext2 -I 128 -F "/dev/${VND}i" || die "could not create filesystem"
elif [ "$(uname -s)" = "FreeBSD" ]; then
    MD=$(mdconfig _disk_image)
    mke2fs -q -I 128 _disk_image || die "could not create filesystem"
else
    if [ -x /sbin/mke2fs ]; then
        /sbin/mke2fs -q -I 128 _disk_image || die "could not create filesystem"
    else
        mke2fs -q -I 128 _disk_image || die "could not create filesystem"
    fi
fi
echo "done"

printf "mounting filesystem... "
mkdir -p mnt
use_genext2fs=0
if [ "$(uname -s)" = "Darwin" ]; then
    fuse-ext2 _disk_image mnt -o rw+,allow_other,uid=501,gid=20 || die "could not mount filesystem"
elif [ "$(uname -s)" = "OpenBSD" ]; then
    mount -t ext2fs "/dev/${VND}i" mnt/ || die "could not mount filesystem"
elif [ "$(uname -s)" = "FreeBSD" ]; then
    fuse-ext2 -o rw+,direct_io "/dev/${MD}" mnt/ || die "could not mount filesystem"
else
    if ! mount _disk_image mnt/ ; then
        if command -v genext2fs 1>/dev/null ; then
            echo "mount failed but genext2fs exists, use it instead"
            use_genext2fs=1
        else
            die "could not mount filesystem and genext2fs is missing"
        fi
    fi
fi
echo "done"

cleanup() {
    if [ -d mnt ]; then
        if [ $use_genext2fs = 0 ] ; then
            printf "unmounting filesystem... "
            umount mnt || ( sleep 1 && sync && umount mnt )
            rmdir mnt
        else
            rm -rf mnt
        fi

        if [ "$(uname -s)" = "OpenBSD" ]; then
            vnconfig -u "$VND"
        elif [ "$(uname -s)" = "FreeBSD" ]; then
            mdconfig -d -u "$MD"
        fi
        echo "done"
    fi
}
trap cleanup EXIT

script_path=$(cd -P -- "$(dirname -- "$0")" && pwd -P)
"$script_path/build-root-filesystem.sh"

if [ $use_genext2fs = 1 ]; then
    # regenerate new image, since genext2fs is unable to reuse the previously written image.
    # genext2fs is very slow in generating big images, so I use a smaller image here. size can be updated
    # if it's not enough.
    # not using "-i 128" since it hangs. Serenity handles whatever default this uses instead.
    genext2fs -b 250000 -d mnt _disk_image || die "try increasing image size (genext2fs -b)"
    # if using docker with shared mount, file is created as root, so make it writable for users
    chmod 0666 _disk_image
fi