#!/bin/bash
qubes_preset_file="75-qubes-vm.preset"

###########################
## Pre-Install functions ##
###########################

update_default_user() {
    # Make sure there is a qubes group
    groupadd --force --system --gid 98 qubes

    # Archlinux bash version has a 'bug' when running su -c, /etc/profile is not loaded because bash consider there is no interactive pty when running 'su - user -c' or something like this.
    # See https://bugs.archlinux.org/task/31831
    id -u 'user' >/dev/null 2>&1 || {
        useradd --user-group --create-home --shell /bin/bash user
    }
    usermod -a --groups qubes user
}

## arg 1:  the new package version
pre_install() {
    echo "Pre install..."

    update_default_user

    # do this whole %pre thing only when updating for the first time...

    mkdir -p /var/lib/qubes

    # Backup fstab / But use archlinux defaults (cp instead of mv)
    if [ -e /etc/fstab ] ; then
        cp /etc/fstab /var/lib/qubes/fstab.orig
    fi

    # Add qubes core related fstab entries
    echo "xen	/proc/xen	xenfs	defaults	0 0" >> /etc/fstab

    usermod -L root
    usermod -L user
}


## arg 1:  the new package version
## arg 2:  the old package version
pre_upgrade() {
    # do something here
    echo "Pre upgrade..."

    update_default_user
}

###################
## Install Hooks ##
###################


configure_notification-daemon() {
    # Enable autostart of notification-daemon when installed
    if [ ! -L /etc/xdg/autostart/notification-daemon.desktop ]; then
        ln -s /usr/share/applications/notification-daemon.desktop /etc/xdg/autostart/
    fi
}

configure_selinux() {
    # SELinux is not enabled on archlinux
    #echo "--> Disabling SELinux..."
    echo "SELINUX not enabled on archlinux. skipped."
    # sed -e s/^SELINUX=.*$/SELINUX=disabled/ -i /etc/selinux/config
    # setenforce 0 2>/dev/null
}

############################
## Post-Install functions ##
############################

update_qubesconfig() {
    # Remove old firmware updates link
    if [ -L /lib/firmware/updates ]; then
      rm -f /lib/firmware/updates
    fi

    # convert /usr/local symlink to a mount point
    if [ -L /usr/local ]; then
        rm -f /usr/local
        mkdir /usr/local
        mount /usr/local || :
    fi

    # Fix fstab update to core-agent-linux 4.0.33
    grep -F -q "/rw/usrlocal" /etc/fstab || sed "/\/rw\/home/a\/rw\/usrlocal    \/usr\/local  none    noauto,bind,defaults 0 0" -i /etc/fstab

    #/usr/lib/qubes/update-proxy-configs
    # Archlinux pacman configuration is handled in update_finalize

    if ! [ -r /etc/dconf/profile/user ]; then
        mkdir -p /etc/dconf/profile
        echo "user-db:user" >> /etc/dconf/profile/user
        echo "system-db:local" >> /etc/dconf/profile/user
    fi

    dconf update &> /dev/null || :

    # Location of files which contains list of protected files
    mkdir -p /etc/qubes/protected-files.d
    # shellcheck source=init/functions
    . /usr/lib/qubes/init/functions

    # qubes-core-vm has been broken for some time - it overrides /etc/hosts; restore original content
    if ! is_protected_file /etc/hosts ; then
        if ! grep -q localhost /etc/hosts; then

          cat <<EOF > /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4 $(hostname)
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
EOF

        fi
    fi

    # ensure that hostname resolves to 127.0.0.1 resp. ::1 and that /etc/hosts is
    # in the form expected by qubes-sysinit.sh
    if ! is_protected_file /etc/hostname ; then
        for ip in '127\.0\.0\.1' '::1'; do
            if grep -q "^${ip}\(\s\|$\)" /etc/hosts; then
                sed -i "/^${ip}\s/,+0s/\(\s$(hostname)\)\+\(\s\|$\)/\2/g" /etc/hosts
                sed -i "s/^${ip}\(\s\|$\).*$/\0 $(hostname)/" /etc/hosts
            else
                echo "${ip} $(hostname)" >> /etc/hosts
            fi
        done
    fi

}

############################
## Service Management Functions ##
############################
# FIXME: add user units support to is_static()/is_masked()/mask()/unmask() functions
is_static() {
    [ -f "/usr/lib/systemd/system/$1" ] && ! grep -q '^[[].nstall]' "/usr/lib/systemd/system/$1"
}

is_masked() {
    if [ ! -L /etc/systemd/system/"$1" ]
    then
        return 1
    fi
    target=$(readlink /etc/systemd/system/"$1" 2>/dev/null) || :
    if [ "$target" = "/dev/null" ]
    then
        return 0
    fi
    return 1
}

mask() {
    ln -sf /dev/null /etc/systemd/system/"$1"
}

unmask() {
    if ! is_masked "$1"
    then
        return 0
    fi
    rm -f /etc/systemd/system/"$1"
}

preset_units() {
    local represet=
    # shellcheck disable=SC2206
    local extra_opts=( $3 )
    while read -r action unit_name
    do
        if [ "$action" = "#" ] && [ "$unit_name" = "Units below this line will be re-preset on package upgrade" ]
        then
            represet=1
            continue
        fi
        echo "$action $unit_name" | grep -q '^[[:space:]]*[^#;]' || continue
        [[ -n "$action" && -n "$unit_name" ]] || continue
        if [ "$2" = "initial" ] || [ "$represet" = "1" ]
        then
            if [ "$action" = "disable" ] && is_static "$unit_name"
            then
                if ! is_masked "$unit_name"
                then
                    # We must effectively mask these units, even if they are static.
                    mask "$unit_name"
                fi
            elif [ "$action" = "enable" ] && is_static "$unit_name"
            then
                if is_masked "$unit_name"
                then
                    # We masked this static unit before, now we unmask it.
                    unmask "$unit_name"
                fi
                systemctl --no-reload "${extra_opts[@]}" preset "$unit_name" >/dev/null 2>&1 || :
            else
                systemctl --no-reload "${extra_opts[@]}" preset "$unit_name" >/dev/null 2>&1 || :
            fi
        fi
    done < "$1"
}

restore_units() {
    # shellcheck disable=SC2206
    local extra_opts=( $2 )
    grep '^[[:space:]]*[^#;]' "$1" | while read -r action unit_name
    do
        if is_static "$unit_name" && is_masked "$unit_name"
        then
            # If the unit had been masked by us, we must unmask it here.
            # Otherwise systemctl preset will fail badly.
            unmask "$unit_name"
        fi
        systemctl --no-reload "${extra_opts[@]}" preset "$unit_name" >/dev/null 2>&1 || :
    done
}

configure_systemd() {
    if [ "$1" -eq 1 ]
    then
        preset_units /usr/lib/systemd/system-preset/$qubes_preset_file initial
        preset_units /usr/lib/systemd/user-preset/$qubes_preset_file initial --global
        changed=true
    else
        preset_units /usr/lib/systemd/system-preset/$qubes_preset_file upgrade
        preset_units /usr/lib/systemd/user-preset/$qubes_preset_file upgrade --global
        changed=true
        # Upgrade path - now qubes-iptables is used instead
        for svc in iptables ip6tables
        do
            if [ -f "$svc".service ]
            then
                systemctl --no-reload preset "$svc".service
                changed=true
            fi
        done
    fi

    if [ "$1" -eq 1 ]
    then
        # First install.
        # Set default "runlevel".
        # FIXME: this ought to be done via kernel command line.
        # The fewer deviations of the template from the seed
        # image, the better.
        rm -f /etc/systemd/system/default.target
        ln -s /lib/systemd/system/multi-user.target /etc/systemd/system/default.target
        changed=true
    fi

    # remove old symlinks
    if [ -L /etc/systemd/system/sysinit.target.wants/qubes-random-seed.service ]
    then
        rm -f /etc/systemd/system/sysinit.target.wants/qubes-random-seed.service
        changed=true
    fi
    if [ -L /etc/systemd/system/multi-user.target.wants/qubes-mount-home.service ]
    then
        rm -f /etc/systemd/system/multi-user.target.wants/qubes-mount-home.service
        changed=true
    fi

    # fix / ro mounted
    ln -sf /usr/lib/systemd/system/systemd-remount-fs.service /etc/systemd/system/sysinit.target.wants/

    if [ "x$changed" != "x" ]
    then
        systemctl daemon-reload
    fi
}

######################
## Archlinux Specific Functions ##
######################
config_prependtomark() {
    FILE=$1
    APPENDBEFORELINE=$2
    APPENDLINE=$3
    grep -F -q "$APPENDLINE" "$FILE" || sed "/$APPENDBEFORELINE/i$APPENDLINE" -i "$FILE"
}

config_appendtomark() {
    FILE=$1
    APPENDAFTERLINE=$2
    APPENDLINE=$3
    grep -F -q "$APPENDLINE" "$FILE" || sed "/$APPENDAFTERLINE/a$APPENDLINE" -i "$FILE"
}

config_cleanupmark() {
    FILE="$1"
    BEGINMARK="$2"
    ENDMARK="$3"
    if grep -F -q "$BEGINMARK" "$FILE"; then
        if grep -F -q "$ENDMARK" "$FILE"; then
            cp "$FILE" "$FILE.qubes-update-orig"
            sed -i -e "/^$BEGINMARK$/,/^$ENDMARK$/{
                /^$ENDMARK$/b
                /^$BEGINMARK$/!d
                }" "$FILE"
            rm -f "$FILE.qubes-update-orig"
        else
            echo "ERROR: found $BEGINMARK marker but not $ENDMARK in $FILE. Please cleanup this file manually."
        fi
    elif grep -F -q "$ENDMARK" "$FILE"; then
        echo "ERROR: found $ENDMARK marker but not $BEGINMARK in $FILE. Please cleanup this file manually."
    fi
}

update_finalize() {
    # Archlinux specific: If marker exists, cleanup text between begin and end marker
    QUBES_MARKER="### QUBES CONFIG MARKER ###"
    if grep -F -q "$QUBES_MARKER" /etc/pacman.conf; then
        config_prependtomark "/etc/pacman.conf" "# REPOSITORIES" "### QUBES CONFIG END MARKER ###"
        config_cleanupmark "/etc/pacman.conf" "$QUBES_MARKER" "### QUBES CONFIG END MARKER ###"
    # Else, add qubes config block marker
    else
        config_prependtomark "/etc/pacman.conf" "# REPOSITORIES" "$QUBES_MARKER"
        config_prependtomark "/etc/pacman.conf" "# REPOSITORIES" "### QUBES CONFIG END MARKER ###"
    fi

    # Include /etc/pacman.d drop-in directory
    config_appendtomark "/etc/pacman.conf" "$QUBES_MARKER" "Include = /etc/pacman.d/*.conf"

    /usr/lib/qubes/update-proxy-configs

    # Archlinux specific: ensure tty1 is enabled
    rm -f /etc/systemd/system/getty.target.wants/getty@tty*.service
    systemctl enable getty\@tty1.service

    systemctl daemon-reload
}

## arg 1:  the new package version
post_install() {
    update_qubesconfig

    # do the rest of %post thing only when updating for the first time...
    if [ -e /etc/init/serial.conf ] && ! [ -f /var/lib/qubes/serial.orig ] ; then
        cp /etc/init/serial.conf /var/lib/qubes/serial.orig
    fi

    chgrp user /var/lib/qubes/dom0-updates

    # Remove most of the udev scripts to speed up the VM boot time
    # Just leave the xen* scripts, that are needed if this VM was
    # ever used as a net backend (e.g. as a VPN domain in the future)
    #echo "--> Removing unnecessary udev scripts..."
    mkdir -p /var/lib/qubes/removed-udev-scripts
    for f in /etc/udev/rules.d/*
    do
        if [ "$(basename "$f")" == "xen-backend.rules" ] ; then
            continue
        fi

        if echo "$f" | grep -q qubes; then
            continue
        fi

        mv "$f" /var/lib/qubes/removed-udev-scripts/
    done

    mkdir -p /rw

    configure_notification-daemon
    configure_selinux

    configure_systemd 0

    update_finalize
}

## arg 1:  the new package version
## arg 2:  the old package version
post_upgrade() {
    update_qubesconfig

    configure_notification-daemon
    configure_selinux

    configure_systemd 1


    update_finalize
}

######################
## Remove functions ##
######################

## arg 1:  the old package version
pre_remove() {
    # no more packages left
    if [ -e /var/lib/qubes/fstab.orig ] ; then
    mv /var/lib/qubes/fstab.orig /etc/fstab
    fi
    mv /var/lib/qubes/removed-udev-scripts/* /etc/udev/rules.d/
    if [ -e /var/lib/qubes/serial.orig ] ; then
    mv /var/lib/qubes/serial.orig /etc/init/serial.conf
    fi

    if [ "$1" -eq 0 ] ; then
        # Run this only during uninstall.
        # Save the preset file to later use it to re-preset services there
        # once the Qubes OS preset file is removed.
        mkdir -p /run/qubes-uninstall
        cp -f /usr/lib/systemd/system-preset/$qubes_preset_file /run/qubes-uninstall/
        cp -f /usr/lib/systemd/user-preset/$qubes_preset_file \
            /run/qubes-uninstall/user-$qubes_preset_file
    fi
}

## arg 1:  the old package version
post_remove() {
    changed=

    if [ -d /run/qubes-uninstall ]
    then
        # We have a saved preset file (or more).
        # Re-preset the units mentioned there.
        restore_units /run/qubes-uninstall/$qubes_preset_file
        restore_units /run/qubes-uninstall/user-$qubes_preset_file --global
        rm -rf /run/qubes-uninstall
        changed=true
    fi

    if [ "x$changed" != "x" ]
    then
        systemctl daemon-reload
    fi


    if [ -L /lib/firmware/updates ] ; then
      rm /lib/firmware/updates
    fi

    rm -rf /var/lib/qubes/xdg

    for srv in qubes-sysinit qubes-misc-post qubes-mount-dirs qubes-qrexec-agent; do
        systemctl disable $srv.service
    done
}