#!/bin/bash

# Improve debug logs
PRGNAME=`basename $0`
PS4='+ $PRGNAME: ${FUNCNAME+"$FUNCNAME : "}$LINENO: '

set -e

arch="native"
dist="default"
schroot_master="$(dirname "$0")"
gen_schroot=false
target_ssh_opts=""
profile="tcwg-test"

while getopts "a:d:go:P:qv" OPTION; do
    case $OPTION in
	a) arch=$OPTARG ;;
	d) dist=$OPTARG ;;
	g) gen_schroot=true ;;
	o) target_ssh_opts="$OPTARG" ;;
	P) profile="$OPTARG" ;;
	q) exec > /dev/null ;;
	v) set -x ;;
    esac
done
shift $((OPTIND-1))

target="${1%:*}"
port="${1#*:}"

triplet_to_deb_arch()
{
    set -e
    case "$1" in
	aarch64-*linux-gnu) echo arm64 ;;
	arm-*linux-gnueabi*) echo armhf ;;
	i686-*linux-gnu) echo i386 ;;
	x86_64-*linux-gnu) echo amd64 ;;
	*) return 1 ;;
    esac
}

triplet_to_deb_dist()
{
    set -e
    case "$arch" in
	aarch64-*linux-gnu) echo trusty ;;
	arm-*linux-gnueabi*) echo trusty ;;
	i686-*linux-gnu) echo trusty ;;
	x86_64-*linux-gnu) echo trusty ;;
	*) return 1 ;;
    esac
}

print_apt_sources()
{
    set -e

    local deb_arch="$1"
    local deb_dist="$2"

    case "$deb_dist" in
	"precise"|"trusty")
	    local deb_mirror
	    case "$deb_arch" in
		amd64|i386) deb_mirror="http://archive.ubuntu.com/ubuntu/" ;;
		*) deb_mirror="http://ports.ubuntu.com/ubuntu-ports/" ;;
	    esac

	    cat <<EOF
deb $deb_mirror $deb_dist main restricted universe multiverse
deb-src $deb_mirror $deb_dist main restricted universe multiverse
deb $deb_mirror $deb_dist-updates main restricted universe multiverse
deb-src $deb_mirror $deb_dist-updates main restricted universe multiverse
deb $deb_mirror $deb_dist-security main restricted universe multiverse
deb-src $deb_mirror $deb_dist-security main restricted universe multiverse
deb $deb_mirror $deb_dist-backports main restricted universe multiverse
deb-src $deb_mirror $deb_dist-backports main restricted universe multiverse
EOF
	    ;;
	"jessie")
	    cat <<EOF
deb http://http.debian.net/debian/ $deb_dist main contrib non-free
deb-src http://http.debian.net/debian/ $deb_dist main contrib non-free
deb http://security.debian.org/ $deb_dist/updates main contrib non-free
deb-src http://security.debian.org/ $deb_dist/updates main contrib non-free
EOF
	    ;;
    esac
}

if [ -z "$target" ]; then
    echo ERROR: no target specified
    exit 1
fi

if [ -z "$port" ]; then
    port="22"
fi

cpu="$(ssh $target uname -m)"
case "$cpu" in
    aarch64) native_arch=aarch64-linux-gnu ;;
    armv7l) native_arch=arm-linux-gnueabihf ;;
    armv7*) native_arch=arm-linux-gnueabi ;;
    i686) native_arch=i686-linux-gnu ;;
    x86_64) native_arch=x86_64-linux-gnu ;;
    *)
	echo "ERROR: unrecognized native target $cpu"
	exit 1
	;;
esac

if [ x"$arch" = x"native" ]; then
    arch="$native_arch"
fi

deb_arch="$(triplet_to_deb_arch $arch)"

if [ x"deb_dist" = x"default" ]; then
    deb_dist="$(triplet_to_deb_dist $arch)"
else
    deb_dist="$dist"
fi

orig_target_ssh_opts="$target_ssh_opts"
target_ssh_opts="$target_ssh_opts -o ControlMaster=auto -o ControlPersist=1m -o ControlPath=$(mktemp --suffix -ssh)"

schroot_id=$profile-$deb_arch-$deb_dist

schroot="ssh $target_ssh_opts $target schroot -r -c session:$profile-$port -d / -u root --"
rsh_opts="$target_ssh_opts -o Port=$port -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null"
rsh="ssh $rsh_opts"
user="$(ssh $target_ssh_opts $target echo \$USER)"
home="$(ssh $target_ssh_opts $target pwd)"

if $gen_schroot; then
    chroot=/tmp/$schroot_id.$$

    # Make sure machine in the lab agree on what time it is.
    ssh $target_ssh_opts $target \
	sudo ntpdate pool.ntp.org >/dev/null 2>&1 || true

    ssh $target_ssh_opts $target \
	sudo rm -rf $chroot
    ssh $target_ssh_opts $target \
	sudo debootstrap \
	--arch=$deb_arch \
	--variant=minbase \
	--include=iptables,openssh-server,rsync,sshfs \
	$deb_dist $chroot

    # Configure APT sources.
    print_apt_sources "$deb_arch" "$deb_dist" \
	| ssh $target_ssh_opts $target sudo chroot $chroot bash -c "\"cat > /etc/apt/sources.list\""
    case "$deb_arch" in
	amd64|i386)
	    ssh $target_ssh_opts $target \
		sudo chroot $chroot bash -c "\"echo deb http://ftp.linuxfoundation.org/pub/lsb/repositories/debian lsb-4.1 main >> /etc/apt/sources.list\""
    esac

    extra_packages=""
    force_packages=""
    case "$deb_arch" in
	amd64) extra_packages="$extra_packages qemu-user" ;;
    esac

    case "$profile" in
	"tcwg-build")
	    extra_packages="$extra_packages autoconf autogen automake bash bison build-essential ccache ccrypt dejagnu flex gawk gdb gdbserver git g++ gcc libncurses5-dev libtool lsb-release make texinfo wget xz-utils"
	    case "$deb_arch" in
		amd64) extra_packages="$extra_packages gcc-multilib g++-multilib" ;;
	    esac
	    case "$deb_arch" in
		amd64|i386)
		    force_packages="$force_packages lsb-build-cc" ;;
	    esac
	    extra_packages="$extra_packages emacs vim"
	    # Install arp and nc for ssh's ProxyCommand
	    extra_packages="$extra_packages net-tools netcat"
	    # Install sudo to simplify root access
	    extra_packages="$extra_packages sudo"
	    ;;
    esac

    if [ x"$extra_packages" != x"" -o x"$force_packages" != x"" ]; then
	ssh $target_ssh_opts $target \
	    sudo chroot $chroot apt-get update
	if [ x"$extra_packages" != x"" ]; then
	    ssh $target_ssh_opts $target \
		sudo chroot $chroot apt-get install -y "$extra_packages"
	fi
	if [ x"$force_packages" != x"" ]; then
	    ssh $target_ssh_opts $target \
		sudo chroot $chroot apt-get install -y --force-yes "$force_packages"
	fi
    fi

    ssh $target_ssh_opts $target \
	sudo chroot $chroot rm -rf /var/cache/apt /var/lib/apt/lists

    if echo "$extra_packages" | grep -q "git"; then
	ssh $target_ssh_opts $target \
	    sudo ln -s /usr/share/doc/git/contrib/workdir/git-new-workdir $chroot/usr/local/bin/
	ssh $target_ssh_opts $target \
	    sudo chmod a+x $chroot/usr/share/doc/git/contrib/workdir/git-new-workdir
    fi

    # Install the Foundation Model on x86_64 build hosts
    if [ x"$profile" = xtcwg-build -a x"$deb_arch" = xamd64 ]; then
	if ! [ -e $schroot_master/FM000-KT-00035-r9p5-41rel0.tgz ]; then
	    echo "ERROR: cannot find Foundation Model tarball: $schroot_master/FM000-KT-00035-r9p5-41rel0.tgz"
	    exit 1
	fi
	ssh $target_ssh_opts $target \
	    sudo mkdir $chroot/linaro
	cat $schroot_master/FM000-KT-00035-r9p5-41rel0.tgz | ssh $target_ssh_opts $target \
	    sudo tar xzf - -C $chroot/linaro
    fi

    half_ram="$(ssh $target_ssh_opts $target free | grep "Mem:" | sed -e "s/Mem: *\([0-9]*\).*/\1/")"
    if [ x"$half_ram" = x"" -o "$half_ram" -lt "$((1024*1024))" ]; then
	# Don't limit RAM on starved boards (<1GB RAM).
	half_ram=""
    else
	half_ram="$(($half_ram / 2))"
    fi

    # Limit users to 5000 processes and half of RAM to avoid fork-bombs and
    # OOMs.
    for group in tcwg tcwg-infra; do
	ssh $target_ssh_opts $target \
	    sudo sh -c "\"echo @$group - nproc 5000 > $chroot/etc/security/limits.d/$group.conf\""
	if [ x"$half_ram" != x"" ]; then
	    ssh $target_ssh_opts $target \
		sudo sh -c "\"echo @$group - data $half_ram >> $chroot/etc/security/limits.d/$group.conf\""
	fi
    done

    # Tweak /etc/init.d/ssh to workaround upstart
    ssh $target_ssh_opts $target \
	sudo sed -i -e "'/check_for_upstart [0-9]/d'" $chroot/etc/init.d/ssh
    # Debian (but not Ubuntu) has wrong permissions on /bin/fusermount.
    ssh $target_ssh_opts $target \
	sudo chmod +x $chroot/bin/fusermount || true

    ssh $target_ssh_opts $target \
	sudo mkdir -p /var/chroots/
    ssh $target_ssh_opts $target \
	sudo bash -c "\"cd $chroot && tar --one-file-system -czf /var/chroots/$schroot_id.tgz .\""

    ssh $target_ssh_opts $target \
	sudo rm -rf $chroot

    case "$deb_arch" in
	armhf|i386) personality="
personality=linux32" ;;
	*) personality="" ;;
    esac

    case "$profile" in
	# Allow root access in test schroots (to install new system libs, etc)
	"tcwg-test") root_groups="
root-groups=users" ;;
	*) root_groups="" ;;
    esac

    ssh $target_ssh_opts $target \
	sudo bash -c "\"cat > /etc/schroot/chroot.d/$schroot_id\"" <<EOF
[$schroot_id]
type=file
file=/var/chroots/$schroot_id.tgz
groups=users
profile=$profile$personality$root_groups
EOF

    if ! [ -z "$schroot_master" ]; then
	scp $target_ssh_opts $target:/var/chroots/$schroot_id.tgz $schroot_master/
	mkdir -p $schroot_master/chroot.d/
	scp $target_ssh_opts $target:/etc/schroot/chroot.d/$schroot_id $schroot_master/chroot.d/
    fi
fi

if ! [ -z "$schroot_master" ]; then
    if ! (cd $schroot_master && git diff-files --quiet); then
	echo "Warning: Local tree has unstaged changes"
    fi

    # Make sure machine in the lab agree on what time it is.
    ssh $target_ssh_opts $target \
	sudo ntpdate pool.ntp.org >/dev/null 2>&1 || true

    ssh $target_ssh_opts $target \
	sudo mkdir -p /var/chroots/

    cat $schroot_master/$schroot_id.tgz | ssh $target_ssh_opts $target \
	sudo bash -c "\"cat > /var/chroots/$schroot_id.tgz\""
    cat $schroot_master/chroot.d/$schroot_id | ssh $target_ssh_opts $target \
	sudo bash -c "\"cat > /etc/schroot/chroot.d/$schroot_id\""

    (cd $schroot_master && tar -ch $profile/ setup.d/ | ssh $target_ssh_opts $target \
	sudo flock -x /etc/schroot -c "\"cd /etc/schroot && rm -rf $profile && tar -x && chown -R root:root $profile/ setup.d/\"")
fi