#!/bin/bash

# # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
#											#
#	Custom Debian Installer								#
#											#
#	Copyright (c) 2022, Ian LeCorbeau <I-LeCorbeau (at) protonmail (dot) com>	#
#											#
#	Permission to use, copy, modify, and/or distribute this software for any	#
#	purpose with or without fee is hereby granted, provided that the above		#
#	copyright notice and this permission notice appear in all copies.		#
#											#
#	THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES	#
#	WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF		#
#	MERCHANTABILITY AND FITNESS IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR		#
#	ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES		#
#	WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN		#
#	ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF		#
#	OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.			#
#											#
# # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #

CONF=disk.conf

get_deps() {
	printf '%s\n' "Getting installer dependencies" &&
	apt update && apt install debootstrap arch-install-scripts -y
}

# writing to disk.conf
d_conf() {
	local _conf=$1 _value=$2
	printf '%s\n' "${_conf}=${_value}" >> "$CONF"
}

# Parsing values from disk.conf
d_read() {
	local _conf=$1
	grep "${_conf}" "$CONF" | cut -d '=' -f2
}

mk_disk() {
	echo
	printf '%s\n' "Disk partitioning. Available devices are: "
	echo
	lsblk -lp | awk '/disk/ { print $1, "(" $4 ")" }' | cut -d '/' -f3
	echo
	read -r -p "Which disk should the system be installed on? (e.g. sdX): " disk
	d_conf DISK "$disk"
	echo
	read -r -p "Will you boot in bios or EFI mode? " mode
	d_conf MODE "$mode"
	echo
	printf '%s\n' "Custom partitioning schemes are not yet supported. The default scheme will be:
a 500mb boot partition on /dev/${disk}1
a swap partition the size of your choosing on /dev/${disk}2
a root partition the size of your choosing on /dev/${disk}3
a home partition on /dev/${disk}4 occupying the rest of the disk space, or the size of your choosing."
	echo
	read -r -p "Proceed? (all data on $disk will be deleted, so make sure you backed up anything important) (Y/n): " yesno
	if [ "$yesno" == "no" ]; then
		printf '%s\n' "Exiting script... Start again."
		rm "$CONF"
	else
		d_conf BOOTP "$disk"1
		d_conf SWAPP "$disk"2
		d_conf ROOTP "$disk"3
		d_conf HOMEP "$disk"4
		ask_part
	fi
}

# Asking user for size of partitions
ask_part() {
	echo
	read -r -p "Choose the size of swap in GB (e.g. 4): " swaps
	d_conf SWAPS "$swaps"
	echo
	read -r -p "Choose the size of root in GB (e.g. 25): " roots
	d_conf ROOTS "$roots"
	echo
	read -r -p "Choose the size of home in GB (leave blank to fill the rest of the disk): " homes
	if [ -z "$homes" ]; then
		: # do nothing
	else
		d_conf HOMES "$homes"
	fi
}

# Partitioning disk and running mkfs.
mk_part() {
	local _disk _mode _swaps _roots _homes
	_disk=$(d_read DISK)
	_mode=$(d_read MODE)
	_swaps=$(d_read SWAPS)
	_roots=$(d_read ROOTS)
	_homes=$(d_read HOMES)
	echo
	printf '%s\n' "Partitioning /dev/$_disk."
	sfdisk --delete /dev/"$_disk"
	partprobe /dev/"$_disk" && sleep 1
	if [ "$_mode" == "bios" ]; then
		(echo o) | fdisk /dev/"$_disk"
		(echo n; echo p; echo 1; echo 2048; echo +500M; echo w) | fdisk /dev/"$_disk"
		sfdisk -A /dev/"$_disk" 1
	else
		(echo g) | fdisk /dev/"$_disk"
		(echo n; echo p; echo 1; echo 2048; echo +500M; echo w) | fdisk /dev/"$_disk"
		fdisk --part-type /dev/"$_disk" 1 EF
	fi
	(echo n; echo p; echo 2; echo ; echo +"$_swaps"G; echo w) | fdisk /dev/"$_disk"
	sfdisk --part-type /dev/"$_disk" 2 82
	(echo n; echo p; echo 3; echo ; echo +"$_roots"G; echo w) | fdisk /dev/"$_disk"
	if [ -z "$_homes" ]; then
		(echo n; echo p; echo 4; echo ; echo ; echo w) | fdisk /dev/"$_disk"
	else
		(echo n; echo p; echo 5; echo ; echo +"$_homes"G; echo w) | fdisk /dev/"$_disk"
	fi

	partprobe /dev/"$_disk" && sleep 1
	printf '%s\n' "Creating Partitions on /dev/$_disk" && sleep 1
	if [ "$_mode" == "bios" ]; then
		mkfs.ext4 /dev/"$_disk"1
	else
		mkfs.fat -F 32 /dev/"$_disk"1
	fi
	mkswap /dev/"$_disk"2
	swapon /dev/"$_disk"2
	mkfs.ext4 /dev/"$_disk"3
	mkfs.ext4 /dev/"$_disk"4

	printf '%s\n' "Mounting Partitions" && sleep 1
	mount /dev/"$_disk"3 /mnt
	mkdir -p /mnt/home
	mount /dev/"$_disk"4 /mnt/home
	if [ "$_mode" == "bios" ]; then
		mkdir -p /mnt/boot
		mount /dev/"$_disk"1 /mnt/boot
	else
		mkdir -p /mnt/boot/efi
		mount /dev/"$_disk"1 /mnt/boot/efi
	fi
}

bootstrap() {
	echo
	printf '%s\n' "Deboostraping base system" && sleep 1
	/usr/sbin/debootstrap --variant=minbase bullseye /mnt http://deb.debian.org/debian/
}

gen_fstab() {
	echo
	printf '%s\n' "Generating fstab..." && sleep 1
	genfstab -U /mnt >> /mnt/etc/fstab
}

apt_src_list() {
	echo
	printf '%s\n' "Generating /etc/apt/sources.list" && sleep 1
	printf '%s\n' "deb http://deb.debian.org/debian/ bullseye main contrib non-free
deb-src http://deb.debian.org/debian/ bullseye main contrib non-free

deb http://security.debian.org/debian-security bullseye-security main contrib non-free
deb-src http://security.debian.org/debian-security bullseye-security main contrib non-free

deb http://deb.debian.org/debian/ bullseye-updates main contrib non-free
deb-src http://deb.debian.org/debian/ bullseye-updates main contrib non-free" > /mnt/etc/apt/sources.list
}

apt_update() {
	echo
	printf '%s\n' "Updating apt..."
	arch-chroot /mnt apt update
	arch-chroot /mnt apt upgrade -y
}

cp_files() {
	mkdir -p /mnt/etc/network/
	cp /etc/network/interfaces /mnt/etc/network/interfaces
	cp /etc/skel/{.bash_aliases,.bashrc,.profile} /mnt/etc/skel/
	cp /etc/skel/.bash_aliases /mnt/root/
}

initsys() {
	echo
	read -r -p "Preparing to install kernel and init... Which init system to use? (choice: systemd, sysvinit or openrc): " initsys
	case "$initsys" in
		systemd) arch-chroot /mnt apt install linux-image-amd64 systemd systemd-sysv libpam-systemd libsystemd0 -y ;;
		sysvinit) arch-chroot /mnt apt install linux-image-amd64 sysvinit-core elogind libpam-elogind \
			orphan-sysvinit-scripts systemctl -y ;;
		openrc) arch-chroot /mnt apt install linux-image-amd64 sysvinit-core openrc elogind libpam-elogind \
			orphan-sysvinit-scripts systemctl procps -y ;;
		*) arch-chroot /mnt apt install linux-image-amd64 systemd systemd-sysv libpam-systemd libsystemd0 -y ;;
	esac	
}

install_base() {
	arch_chroot /mnt xargs apt install --no-install-recommends -y <base.pkgs
}

timezone() {
	echo
	printf '%s\n' "Setting timezone..." && sleep 1
	arch-chroot /mnt dpkg-reconfigure tzdata
}

set_hostname() {
	echo
	read -r -p "Hostname for this machine: " hostname
	echo "$hostname" > /mnt/etc/hosts
	cat <<EOF > /mnt/etc/hosts
127.0.0.1	localhost
127.0.1.1	$hostname

# The following lines are desirable for IPv6 capable hosts
::1     localhost ip6-localhost ip6-loopback
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
EOF
}

locales() {
	sleep 1 && echo
	printf "Setting locale..." && sleep 1
	arch-chroot /mnt apt install locales -y
	arch-chroot /mnt dpkg-reconfigure locales
}

xkb_cons() {
	sleep 1 && echo
	printf "Setting up console... "
	arch-chroot /mnt apt install console-setup keyboard-configuration -y
}

set_pass() {
	echo
	printf '%s\n' "Enter password for the root account (will not echo)"
	arch-chroot /mnt passwd
	printf '%s\n' "Root password set. You may wish to disable the root account with passwd -l later on."
}

set_wheel() {
	echo
	printf '%s\n' "Setting up wheel group" && sleep 1
	sed -i '15 s/^# //' /mnt/etc/pam.d/su
	arch-chroot /mnt addgroup --system wheel
	echo "permit :wheel" > /mnt/etc/doas.conf
}

set_default_user() {
	echo
	read -r -p "Enter the name of default user: " name
	arch-chroot /mnt useradd -m "$name"
	printf '%s\n' "Password for $name (will not echo):"
	arch-chroot /mnt passwd "$name"
	arch-chroot /mnt usermod -aG wheel,cdrom,floppy,audio,dip,video,plugdev,netdev "$name"
	arch-chroot /mnt usermod -s /bin/bash "$name"
}

# ask the user to choose extra packages (or not)
pkg_sets() {
	read -r -p "By default, only a base system is installed. You can choose extra \"sets\" for a more complete installation.
	The choices are:

1) Base only (no extra packages, still includes vim + tmux)
2) Base + X11 (inclues: xserver-xorg-core, xinit, dwm, st and dmenu+scripts)
3) Base + X11 + Userland (extras: vifm, mutt, mpv, newsboat, calcurse, dunst, zathura ...)

Select by entering corresponding number (defaults to 1): " choice
	case "$choice" in
		1) ;; # do nothing, base is already installed
		2) arch-chroot /mnt xargs apt install <x11.pkgs -y 
			inst_suckless_base ;;
		3) arch-chroot /mnt xargs apt install <x11.pkgs -y 
			arch-chroot /mnt xargs apt install <userland.pkgs -y
			inst_suckless_base
			ask_dots ;;
		*) ;; # same as 1
	esac
}

inst_suckless_base() {
	echo
	printf '%s\n' "Building custom suckless tools..." && sleep 1
	mkdir -p /mnt/etc/skel/.local/
	cp -r .local/src /mnt/etc/skel/.local/
	arch-chroot /mnt /bin/bash <<"EOT"
cd /etc/skel/.local/src/dwm
make
make clean install
EOT

	arch-chroot /mnt /bin/bash <<"EOT"
cd /etc/skel/.local/src/dmenu
make
make clean install
EOT

	arch-chroot /mnt /bin/bash <<"EOT"
cd /etc/skel/.local/src/st
make
make clean install
EOT
}

ask_dots() {
	read -r -p "Do you wish to install the dotfiles from this live iso onto your system? (Y/n): " yn
	case "$yn" in
		n) ;; # do nothing
		*) set_dots ;;
	esac
}

set_dots() {
	echo
	printf '%s\n' "Setting up user dotfiles..."
	cp -r /etc/skel /mnt/etc/
	rm /mnt/etc/skel/install.sh
	chmod +x /mnt/etc/skel/.local/bin/{chwall-dmenu,mpvload,poweroffreboot,usbmount,usbpoweroff,usbunmount}
}

setup_grub() {
	local _mode _disk
	echo
	printf '%s\n' "seting up the GRUB bootloader..."
	_mode=$(d_read MODE)
	_disk=$(d_read DISK)
	if [ "$_mode" == "bios" ]; then
		arch-chroot /mnt apt install grub-pc -y
		arch-chroot /mnt grub-install /dev/"$_disk"
		arch-chroot /mnt update-grub
	else
		arch-chroot /mnt apt install grub-efi-amd64 -y
		arch-chroot /mnt grub-install --target=x86_64-efi --efi-directory=/boot/efi
		arch-chroot /mnt update-grub
	fi
}

finish() {
	read -r -p "Installation finished. R to reboot, E to exit and continue in the live environment.
> " re
	case "$re" in
		R) reboot ;;
		E) exit ;;
		*) ;;
	esac
}

do_install() {
	printf '%s\n' "Launching the installer..."
	get_deps
	mk_disk
	mk_part
	bootstrap
	gen_fstab
	apt_src_list
	apt_update
	cp_files
	initsys
	install_base
	timezone
	set_hostname
	locale
	xkb_cons
	set_pass
	set_wheel
	set_default_user
	pkg_sets
	setup_grub
	finish
}

do_install