#! /bin/sh
#
# buildprep - prepare your system for an NTPsec source build.
#
# Use the -n option to dry-run this command, showing what would be done
# without actually doing it

# Set the defaults
DRYRUN="no"
NTPVIZ="no"
DOC="no"
PYVERS=""

OS=`uname -s`

# Loop through option flags
for optflag in "$@"
do
	case "$optflag" in
	 -h|--help)
		cat <<EOF
$0 - prepare your system for an NTPsec source build

  Options:
    -h --help    Show usage information and exit
    -n --dry-run Only show what would be done instead of doing it
       --ntpviz  Install dependencies for ntpviz tool
       --doc     Install dependencies for building documentation
    -a --all     Install all possible dependencies
EOF
		exit 0
		;;
	 -n|--dry-run)
		DRYRUN="yes"
		;;
	 --ntpviz)
		NTPVIZ="yes"
		;;
	 --doc)
		DOC="yes"
		;;
	 -a|--all)
		NTPVIZ="yes"
		DOC="yes"
		;;
	 *)
		echo "# WARNING: Unknown argument: $optflag"
		echo "#"
		;;
	esac
done

# Some Python 2 packages (e.g python-devel, python-psutils) conventionally have
# Python 3 equivalents with a python3 prefix.  Compute the correct value for the
# infix based on system Python.  This eill start to be significant after Python 2
# EOLs at the beginning of 2020.
PYVERS=`python --version 2>&1 | sed -n -e '/Python \([0-9]\).*/s//\1/p'`
if [ "$PYVERS" = "2" ]
then
    PYVERS=""
fi

cat <<EOF
# Preparing your system for ntpsec source build...
# This script presently knows about:
#   CentOS, Debian, Fedora, Gentoo, NetBSD, FreeBSD,
$   SLES, Ubuntu, and Alpine Linux
# If you are running something else, such as macOS or Solaris, please
# read the source for this buildprep script to get an idea of what packages
# are required.
#
EOF

if [ "$DRYRUN" = "yes" ]
then
	do=echo
	echo "# Run this without -n|--dry-run, as root, for actual installation."
	echo "#"
else
	do=""
	if [ "$(id -u)" != 0 ]
	then
		echo "# ERROR: You must be running as root for your installer to do its thing."
		echo "# ERROR: If you just wish to see what would be done, use the -n option."
		exit 1
	fi
fi

if emerge --version 2>/dev/null
then
    installer=emerge
    install="$do $installer -q y"
elif yum version 2>/dev/null
then
    installer=yum
    install="$do $installer -y install"
elif dnf --version >/dev/null 2>&1
then
    installer=dnf
    install="$do $installer -y install"
elif apt-get --version >/dev/null 2>&1
then
    installer=apt
    install="$do apt-get install -y"
elif zypper -h >/dev/null 2>&1
then
    # OpenSUSE prefers zypper over yast
    installer=zypper
    install="$do $installer install -y"
elif yast -h >/dev/null 2>&1
then
    installer=yast
    install="$do $installer --install"
elif  apk --version >/dev/null 2>&1
then
    # Alpine Linux, musl rather than glibc
    installer=apk
    install="$do $installer add"
elif test "$OS" = "NetBSD"
then
  if pkgin -v
  then
    # NetBSD binary package installer
    installer=pkgin
    install="$do $installer install"
  else
    echo "## Looks like a NetBSD system"
    echo "## You need to setup pkgin"
    echo "## The last page of install disk has a check-box to do it"
    echo "## But you don't get that option on a Raspberry Pi."
    echo "## For the Pi, do something like:"
    echo "## pkg_add ftp://ftp.netbsd.org/pub/pkgsrc/packages/NetBSD/earmv7hf/8.0/All/pkgin-0.9.4nb8.tgz"
    echo "## Adjust the version and arch to match your setup."
    exit 1
  fi
elif test "$OS" = "FreeBSD"
then
  if pkg -v
  then
    # FreeBSD binary package installer
    installer=pkg
    install="$do $installer install"
  fi
else
    echo "# ERROR: Package manager unidentified - Unsupported operating system"
    exit 1
fi
echo "# Your package installer is ${installer}."
echo ""

# In order to have a single point of truth about prerequisite package names,
# these package name lists have been *removed* from INSTALL.

# Build time vs. run time:
# Build dependencies are marked.  You'll need them all when building from a
# repository copy; the unmarked (run-time) dependencies are information for
# packagers.  Under Gentoo, all dependencies are build dependencies.

# Notes on optional packages:
# libdnssd is optional for ntpd. Support for mDNS Service Discovery registration
# libcap (under Linux) enables dropping root and is not strictly required.

daemon () {
    # Prerequisites to build the daemon: bison, pps-tools, service libraries
    case $installer in
	apk)
	    $install build-base python                  # basic tools
	    $install bison python${PYVERS}-dev linux-headers
	    $install openssl-dev libcap-dev libseccomp-dev
	    # probably needs more, but this builds
	    # can't find timepps.h: gpsd and chrony have their own ??
	    ;;
	apt)
	    $install build-essential			# Build environment
	    $install bison libssl-dev			# build
	    $install libcap-dev libseccomp-dev		# build
	    $install libavahi-compat-libdnssd-dev	# optional build
	    $install pps-tools
	    ;;
	emerge)
						# Build environment included!
	    $install sys-libs/libcap sys-libs/libseccomp
	    $install sys-devel/bison net-misc/pps-tools
	    ;;
	pkgin)
	    # NetBSD
	    #  There is nothing magic about 3.7.
	    #  In Dec 2018, 3.6 and 2.7 are also good candidates.
	    $install bison python37 py37-curses-3.7
	    # certificates for NTS
	    $install mozilla-rootcerts mozilla-rootcerts-openssl
	    # Also needs "nts ca /etc/openssl/certs/"
	    # setup "python" from command line
	    $do ln -s /usr/pkg/bin/python3.7 /usr/pkg/bin/python
	    $do ln -s /usr/pkg/bin/python3.7 /usr/pkg/bin/python3
	    # Add to Python search path
	    if [ "$DRYRUN" = "yes" ]
            then
		echo echo /usr/local/lib/python3.7/site-packages \> \\
		echo "  " /usr/pkg/lib/python3.7/site-packages/ntpsec.pth
	    else
		echo /usr/local/lib/python3.7/site-packages > \
			/usr/pkg/lib/python3.7/site-packages/ntpsec.pth
	    fi
	    ;;
	pkg)
	    # FreeBSD
	    $install bison python3
	    $do ln -s /usr/local/bin/python3 /usr/local/bin/python
	    # certificates for NTS
	    $install ca_root_nss
	    ;;
	yum|dnf)
	    $do $installer groupinstall "Development Tools" 	# Build environment
	    $install bison openssl-devel 		# build
	    $install libcap-devel libseccomp-devel	# build
	    $install pps-tools-devel			# build
	    $install avahi-compat-libdns_sd-devel	# optional build
	    $install libcap openssl-libs pps-tools
	    ;;
	yast)
	    echo "# SLES versions 12 and earlier do not have pps-tools"
	    $install basis-devel 			# Build environment
	    $install libcap-devel libseccomp-devel 	# build
	    $install openssl-devel			# build
	    $install libcap2 openssl-libs
	    $install python${PYVERS}-curses
	    ;;
	zypper)
	    $install -t pattern devel_basis		# Build environment
	    $install bison				# build
	    $install libcap-devel libseccomp-devel	# build
	    $install openssl-devel			# build
	    echo "# SLES versions 12 and earlier do not have pps-tools"
	    $install pps-tools-devel			# build
	    $install pps-tools
	    $install libcap2 openssl-libs
	    $install python${PYVERS}-curses
	    ;;
    esac
}

tools () {
    # Prerequisites for the client Python tools: python extensions
    case $installer in
	apt)
	    $install python${PYVERS}-dev
	    ;;
	yum|dnf|yast|zypper)
	    $install python${PYVERS}-devel
	    ;;
    esac
}

ntpviz () {
    # Prerequisites to use ntpviz: gnuplot and liberation fonts
    case $installer in
	apk)
	    $install gnuplot || echo "# You need to enable the community repository"
	    $install ttf-liberation
	    ;;
	apt)
	    distro=`lsb_release -i -s`
	    if [ "$distro" = "Ubuntu" ]
	    then
		echo "# Looks like an Ubuntu system"
		$install gnuplot5
	    else
		echo "# Looks like a generic Debian system"
		$install gnuplot
	    fi
	    $install fonts-liberation python${PYVERS}-psutil
	    ;;
	emerge)
	    $install sci-visualization/gnuplot
	    $install media-fonts/liberation-fonts
	    ;;
	yum|dnf)
	    $install gnuplot
	    $install liberation-fonts-common.noarch
	    $install liberation-mono-fonts.noarch
	    $install liberation-narrow-fonts.noarch
	    $install liberation-sans-fonts.noarch
	    $install liberation-serif-fonts.noarch
	    ;;
	yast|zypper)
	    $install gnuplot liberation-fonts
	    ;;
    esac
}

doc () {
	# prerequisites to build documentation
	case $installer in
	 apk)
		$install asciidoc
		;;
	 apt)
		$install asciidoc
		;;
	 emerge)
		$install app-text/asciidoc
		;;
	 yum|dnf)
		echo "# Please check that your asciidoc is at least 8.6.0"
		echo "# You may need to enable EPEL repositories"
		$install asciidoc
		;;
	 pkgin)
		$install asciidoc
		;;
	 pkg)
		$install asciidoc
		;;
	 yast|zypper)
		$install asciidoc
		;;
	esac
}

# Main sequence
daemon
tools

if [ "$NTPVIZ" = "yes" ]
then
	ntpviz
else
	echo ""
	echo "# Skipping ntpviz dependencies [--ntpviz]"
fi

if [ "$DOC" = "yes" ]
then
	doc
else
	echo ""
	echo "# Skipping documentation dependencies [--doc]"
fi

echo ""
echo "# Done."