#!/bin/bash

# Partially based on https://github.com/mdaffin/arch-pkgs/blob/master/installer/install-arch
# Kudos to mdaffin

set -uo pipefail # exit on any failure
trap 's=$?; echo "$0: Error on line "$LINENO": $BASH_COMMAND"; exit $s' ERR

MIRRORLIST_URL="https://archlinux.org/mirrorlist/?country=DE&protocol=https&use_mirror_status=on"

pacman -Sy --noconfirm archlinux-keyring
pacman-key --init

pacman -Sy --noconfirm pacman-contrib dialog

echo "Updating mirror list"
curl -s "$MIRRORLIST_URL" | \
    sed -e 's/^#Server/Server/' -e '/^#/d' | \
    rankmirrors -n 5 - > /etc/pacman.d/mirrorlist


#########################################################################################
## Get information from user ###
hostname=$(dialog --stdout --inputbox "Enter hostname" 0 0) || exit 1
clear
: ${hostname:?"hostname cannot be empty"}

user=$(dialog --stdout --inputbox "Enter admin username" 0 0) || exit 1
clear
: ${user:?"user cannot be empty"}

password=$(dialog --stdout --passwordbox "Enter admin password" 0 0) || exit 1
clear
: ${password:?"password cannot be empty"}
password2=$(dialog --stdout --passwordbox "Enter admin password again" 0 0) || exit 1
clear
[[ "$password" == "$password2" ]] || ( echo "Passwords did not match"; exit 1; )

devicelist=$(lsblk -dplnx size -o name,size | grep -Ev "boot|rpmb|loop" | tac)
device=$(dialog --stdout --menu "Select installation disk" 0 0 0 ${devicelist}) || exit 1
clear

# Determine automatically if system is AMD or INTEL or neither
# however make sure the user has to confirm this anyway
# Detect the CPU vendor
cpu_vendor=$(grep -m 1 'vendor_id' /proc/cpuinfo | awk '{print $3}')

# Set the preselected option
preselected=""
if [ "$cpu_vendor" == "GenuineIntel" ]; then
    preselected="intel"
elif [ "$cpu_vendor" == "AuthenticAMD" ]; then
    preselected="amd"
else
    preselected="nothing"
fi

preselected=nothing

# Reorder options so that the preselected one comes first
if [ "$preselected" == "intel" ]; then
    options="intel 'Intel Processor' on amd 'AMD Processor' off nothing 'No specific processor' off"
elif [ "$preselected" == "amd" ]; then
    options="amd 'AMD Processor' on intel 'Intel Processor' off nothing 'No specific processor' off"
else
    options="nothing 'No specific processor' on intel 'Intel Processor' off AMD 'AMD Processor' off"
fi

# Use eval to expand options into individual arguments
cpu_selection=$(eval dialog --radiolist \"Select your CPU type:\" 15 50 3 $options 3>&1 1>&2 2>&3)
clear

#########################################################################################
#########################################################################################

### Set up logging ###
exec 1> >(tee "stdout.log")
exec 2> >(tee "stderr.log")

# Update system clock
timedatectl set-ntp true

### Setup the disk and partitions ###
swap_size=$(free --mebi | awk '/Mem:/ {print $2}')
swap_end=$(( $swap_size + 1024 + 550))MiB
echo "Using $swap_size+ 1024 MiB of swap"

# get rid of any partition tables etc.
sgdisk --zap-all ${device}

parted --script ${device} -- mklabel gpt \
  mkpart "EFI" fat32 1Mib 550MiB \
  set 1 boot on \
  mkpart "swap" linux-swap 550MiB ${swap_end} \
  mkpart "system" btrfs ${swap_end} 100%

# EFI
mkfs.vfat -n EFI /dev/disk/by-partlabel/EFI

# SWAP
mkswap -L swap /dev/disk/by-partlabel/swap
swapon -L swap

# SYSTEM / ROOT
mkfs.btrfs -f -L system /dev/disk/by-partlabel/system
mount -t btrfs LABEL=system /mnt
btrfs subvolume create /mnt/@
btrfs subvolume create /mnt/@home
btrfs subvolume create /mnt/@snapshots
btrfs subvolume create /mnt/@var
umount -R /mnt

opts_btrfs=noatime,compress=zstd,discard=async,ssd

mount -o $opts_btrfs,subvol=@ /dev/disk/by-partlabel/system /mnt
mkdir /mnt/home
mount -o $opts_btrfs,subvol=@home /dev/disk/by-partlabel/system /mnt/home
mkdir /mnt/.snapshots
mount -o $opts_btrfs,subvol=@snapshots /dev/disk/by-partlabel/system /mnt/.snapshots
mkdir -p /mnt/var
mount -o $opts_btrfs,subvol=@var /dev/disk/by-partlabel/system /mnt/var

mkdir /mnt/boot
mount LABEL=EFI /mnt/boot/

# install base system
pacstrap /mnt base linux linux-firmware git btrfs-progs base-devel
pacstrap /mnt man-db man-pages nano pacman-contrib zsh dialog
if [ "$cpu_selection" != "nothing" ]; then
    cpuucode="${cpu_selection}-ucode"
    echo "CPU microcode will be installed: $cpuucode"
    pacstrap /mnt $cpuucode
else
    echo "No microcrode will be installed."
fi

# some networking
pacstrap /mnt openssh
arch-chroot /mnt systemctl enable sshd

pacstrap /mnt networkmanager
arch-chroot /mnt systemctl enable NetworkManager.service

# generate fstab
genfstab -U /mnt >> /mnt/etc/fstab

# set hostname + networking
echo "${hostname}" > /mnt/etc/hostname
echo '127.0.0.1 localhost
::1   localhost
127.0.1.1 ${hostname}.localdomain  ${hostname}' > /etc/hosts

ln -sf /usr/share/zoneinfo/Europe/Berlin /mnt/etc/localtime
echo "LANG=en_GB.UTF-8" > /mnt/etc/locale.conf
arch-chroot /mnt locale-gen

echo "Updating mirror list"
curl -s "$MIRRORLIST_URL" | \
    sed -e 's/^#Server/Server/' -e '/^#/d' | \
    rankmirrors -n 5 - > /mnt/etc/pacman.d/mirrorlist

echo "Setting default shell for created user"
arch-chroot /mnt useradd -mU -s /usr/bin/zsh -G wheel,uucp,video,audio,storage,games,input "$user"
arch-chroot /mnt chsh -s /usr/bin/zsh
touch /mnt/home/$user/.zshrc

echo "Setting passwords"
echo "$user:$password" | chpasswd --root /mnt
echo "root:$password" | chpasswd --root /mnt
echo "$user ALL=(ALL) ALL" >> /mnt/etc/sudoers.d/$user

echo "Setting up GRUB"
pacstrap /mnt grub efibootmgr

arch-chroot /mnt grub-install --target=x86_64-efi --efi-directory=/boot --bootloader-id=GRUB
arch-chroot /mnt grub-mkconfig -o /boot/grub/grub.cfg

echo ">>>>>>>> Basic System Installed <<<<<<<<"