#!/bin/sh

set -e

# determining the image type
if [ -f "/etc/cloud/build.info" ] || [ -d "/var/log/installer" ]; then
    if $(grep --max-count=1 --quiet --no-messages "ubuntu-oci" /etc/cloud/build.info); then
        IMAGE_TYPE="ubuntu-oci"
    elif $(grep --max-count=1 --quiet --no-messages "ubuntu-base" /etc/cloud/build.info); then
        IMAGE_TYPE="ubuntu-base"
    elif $(grep --max-count=1 --quiet --no-messages "build_name: minimal" /etc/cloud/build.info); then
        IMAGE_TYPE="ubuntu-cloud"
    else
        IMAGE_TYPE="ubuntu-server"
    fi
fi

echo "This system has been minimized by removing packages and content that are"
echo "not required on a system that users do not log into."
echo ""
echo "This script restores content and packages that are found on a default"
echo "Ubuntu server system in order to make this system more suitable for"
echo "interactive use."
echo ""
echo "Reinstallation of packages may fail due to changes to the system"
echo "configuration, the presence of third-party packages, or for other"
echo "reasons."
echo ""
echo "This operation may take some time."
echo ""
read -p "Would you like to continue? [y/N] " REPLY
echo    # (optional) move to a new line
if [ "$REPLY" != "y" ] && [ "$REPLY" != "Y" ]
then
    exit 1
fi

if [ -f /etc/dpkg/dpkg.cfg.d/excludes ] || [ -f /etc/dpkg/dpkg.cfg.d/excludes.dpkg-tmp ]; then
    echo "Re-enabling installation of all documentation in dpkg..."
    if [ -f /etc/dpkg/dpkg.cfg.d/excludes ]; then
        mv /etc/dpkg/dpkg.cfg.d/excludes /etc/dpkg/dpkg.cfg.d/excludes.dpkg-tmp
    fi
    echo "Updating package list and upgrading packages..."
    apt-get update
    # apt-get upgrade asks for confirmation before upgrading packages to let the user stop here
    apt-get upgrade
    echo "Restoring system documentation..."
    echo "Reinstalling packages with files in /usr/share/man/ ..."
    # Reinstallation takes place in two steps because a single dpkg --verified
    # command generates very long parameter list for "xargs dpkg -S" and may go
    # over ARG_MAX. Since many packages have man pages the second download
    # handles a much smaller amount of packages.
    dpkg -S /usr/share/man/ |sed 's|, |\n|g;s|: [^:]*$||' | DEBIAN_FRONTEND=noninteractive xargs --no-run-if-empty apt-get install --reinstall -y
    echo "Reinstalling packages with system documentation in /usr/share/doc/ .."
    # This step processes the packages which still have missing documentation
    dpkg --verify --verify-format rpm | awk '$2 ~ /\/usr\/share\/doc/ {print $2}' | sed 's|/[^/]*$||' | sort | uniq \
         | xargs --no-run-if-empty dpkg -S | sed 's|, |\n|g;s|: [^:]*$||' | uniq | DEBIAN_FRONTEND=noninteractive xargs --no-run-if-empty apt-get install --reinstall -y
    echo "Restoring system translations..."
    # This step processes the packages which still have missing translations
    dpkg --verify --verify-format rpm | awk '$2 ~ /\/usr\/share\/locale/ {print $2}' | sed 's|/[^/]*$||' | sort | uniq \
         | xargs --no-run-if-empty dpkg -S | sed 's|, |\n|g;s|: [^:]*$||' | uniq | DEBIAN_FRONTEND=noninteractive xargs --no-run-if-empty apt-get install --reinstall -y
    if dpkg --verify --verify-format rpm | awk '$2 ~ /\/usr\/share\/doc/ {exit 1}'; then
        echo "Documentation has been restored successfully."
        rm /etc/dpkg/dpkg.cfg.d/excludes.dpkg-tmp
    else
        echo "There are still files missing from /usr/share/doc/:"
        dpkg --verify --verify-format rpm | awk '$2 ~ /\/usr\/share\/doc/ {print " " $2}'
        echo "You may want to try running this script again or you can remove"
        echo "/etc/dpkg/dpkg.cfg.d/excludes.dpkg-tmp and restore the files manually."
    fi
fi

if  [ "$(dpkg-divert --truename /usr/bin/man)" = "/usr/bin/man.REAL" ]; then
    # Remove diverted man binary
    rm -f /usr/bin/man
    dpkg-divert --quiet --remove --rename /usr/bin/man
fi

if [ "$IMAGE_TYPE" != "ubuntu-oci" ] && [ "$IMAGE_TYPE" != "ubuntu-base" ]; then
    # ubuntu-minimal is too much for a docker container (it contains systemd and other things)

    if ! dpkg-query --show --showformat='${db:Status-Status}\n' ubuntu-minimal 2> /dev/null | grep -q '^installed$'; then
        echo "Installing ubuntu-minimal package to provide the familiar Ubuntu minimal system..."
        DEBIAN_FRONTEND=noninteractive apt-get install -y ubuntu-minimal ubuntu-standard
    fi

    if dpkg-query --show --showformat='${db:Status-Status}\n' ubuntu-server 2> /dev/null | grep -q '^installed$' \
       && ! dpkg-query --show --showformat='${db:Status-Status}\n' landscape-common 2> /dev/null | grep -q '^installed$'; then
        echo "Installing ubuntu-server recommends..."
        DEBIAN_FRONTEND=noninteractive apt-get install -y landscape-common
    fi
fi

if [ "$IMAGE_TYPE" = "ubuntu-cloud" ]; then
    # we'd like to transform a cloud minimized image to a cloud base image when unminimize is run.

    # even if ubuntu-server is installed, we should re-install it with --fix-policy --install-recommends
    # to ensure all the Recommends of dependencies of ubuntu-server are installed, which aids in transforming
    # this minimized image to an equivalent base image.
    DEBIAN_FRONTEND=noninteractive apt-get --reinstall --fix-policy --install-recommends install -y ubuntu-server

    if dpkg-query --show --showformat='${db:Status-Status}\n' linux-image-virtual 2> /dev/null | grep -q '^installed$'; then
        echo "Installing linux-virtual for installing the headers which were stripped in a minimized image"
        DEBIAN_FRONTEND=noninteractive apt-get install -y linux-virtual
    fi
fi

# unminimization succeeded, there is no need to mention it in motd
rm -f /etc/update-motd.d/60-unminimize