#!/bin/bash
set -e

mirror=http://ftp.md.debian.org/debian/
zone=Europe/Moscow
# guest = release as arg

echo

function template_ready {
	echo -n clean-up host keys ...
	rm -f lala/etc/ssh/ssh_host_* && echo done

	#dpkg-reconfigure openssh-server
	echo -n generating edwards host key ...
	ssh-keygen -f lala/etc/ssh/ssh_host_ed25519_key -t ed25519 -N '' -C "$guest" && echo done

	echo -n indexing ...
	chroot lala/ bash -c "updatedb" && echo done

	echo -n clean-up shell history ...
	chroot lala/ bash -c "history -c"
	rm -f lala/root/.bash_history && echo done

	echo -n un-mounting ...
	umount -R lala/ && echo done
	rmdir lala/
}

function setup_network {
	echo -n setting up host name ...
	echo $guest > lala/etc/hostname && echo done

	echo -n setting up static names ...
	cat > lala/etc/hosts <<EOF && echo done
127.0.0.1       localhost
::1             localhost ip6-localhost ip6-loopback
ff02::1         ip6-allnodes
ff02::2         ip6-allrouters

127.0.0.1	$guest
::1		$guest

EOF

	echo -n setting up interfaces ...
	[[ -d lala/etc/network/interfaces.d/ ]] && rmdir lala/etc/network/interfaces.d/
	cat > lala/etc/network/interfaces <<EOF && echo done
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
        address $cidr
	gateway $gw

EOF

	rm -f lala/etc/resolv.conf
	for entry in $dns; do
		echo nameserver $entry >> lala/etc/resolv.conf && echo dns $entry
	done; unset entry
}

function setup_repo {
	echo -n setting up debian mirror ...

	# syntax differs a little bit for buster, on the security repo
	if [[ $guest = buster ]]; then
	        cat > lala/etc/apt/sources.list <<EOF && echo done
deb $mirror $guest main contrib non-free
deb $mirror $guest-updates main contrib non-free
deb $mirror $guest-backports main contrib non-free
deb http://security.debian.org/debian-security $guest/updates main contrib non-free

EOF
	else
	        cat > lala/etc/apt/sources.list <<EOF && echo done
deb $mirror $guest main contrib non-free non-free-firmware
deb $mirror $guest-updates main contrib non-free non-free-firmware
deb $mirror $guest-backports main contrib non-free non-free-firmware
deb http://security.debian.org/debian-security $guest-security main contrib non-free non-free-firmware

EOF
	fi
}

function setup_env {
	echo -n mounting dev ...
	mount -o bind /dev lala/dev && echo done || echo already

	echo -n mounting proc ...
	mount -o bind /proc lala/proc && echo done || echo already

	echo -n mounting sys ...
	mount -o bind /sys lala/sys && echo done || echo already

	echo -n updating repository - prep.log ...
	chroot lala/ bash -c "apt-get -q update" > prep.log && echo done

	echo -n fixup locale - prep.log ...
	chroot lala/ bash -c "apt-get -qy install locales" >> prep.log

	echo -n setting up en_US.UTF-8 locale ...
	chroot lala/ bash -c "dpkg-reconfigure locales"

	echo -n checking locale ...
	chroot lala/ bash -c "perl -e exit" && echo done

	echo -n installing additional packages - prep.log ...
	chroot lala/ bash -c "apt-get -qy install \
                ifupdown \
                net-tools \
                man-db \
                manpages \
                openssh-server \
                openssh-client \
                mlocate \
                netcat-openbsd \
                nmap \
                wget \
                elvis-tiny \
                bash-completion" >> prep.log && echo done

	echo -n default shell ...
	chroot lala/ bash -c "useradd -D -s /bin/bash" && echo done

	echo -n setting up shell env ...
	[[ -f lala/etc/bash.bashrc.dist ]] && echo already && return
        cp -pi lala/etc/bash.bashrc lala/etc/bash.bashrc.dist
        cat >> lala/etc/bash.bashrc <<EOF

source /usr/share/bash-completion/bash_completion

export LANGUAGE="en_US:en"
export LC_ALL="C.UTF-8"
export LC_COLLATE="C.UTF-8"
export LANG="C.UTF-8"

alias ll='ls --group-directories-first --color=auto -alh'
alias ls='ls --group-directories-first --color=auto'
alias cp='cp -i'
alias mv='mv -i'
alias rm='rm -i'

EOF

	echo -n setting up time-zone ...
	ln -sf ../usr/share/zoneinfo/$zone lala/etc/localtime
        echo $zone > lala/etc/timezone && echo done

	# TODO w/o password
	echo -n unlocking root user ...
	chroot lala/ bash -c "passwd -d root" && echo done

	echo -n setting up default init ...
	chroot lala/ systemctl bash -c "set-default multi-user" && echo done
}

[[ -z $1 ]] && echo ${0##*/} GUEST-NAME && exit 1
guest=$1

[[ ! -f network.conf ]] && define ip gw dns in network.conf && exit 1
source network.conf

[[ -z $ip ]] && echo \$ip not defined && exit 1
[[ -z $gw]] && echo \$gw not defined && exit 1
[[ -z $dns]] && echo \$dns not defined && exit 1

[[ ! -d lala/ ]] && echo expecting lala/ folder && exit 1
[[ -z `mount | grep $guest | grep lala` ]] && echo expecting mounted lala/ folder && exit 1

setup_network
setup_repo
echo

setup_env
echo

template_ready
echo

echo all done
echo