#!/bin/bash

# WARNING: this script will destroy data on the selected disk.

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

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

if [ "${FS}" == "zfs" ]; then
  source ./zfs.sh
elif [ "${FS}" == "ext4" ]; then
  source ./ext4.sh
else
  echo "You must specify FS=zfs or FS=ext4!"
  exit 1
fi

CLEAN=${CLEAN:-""}

# Set this to 'dvorak' for a dvorak keymap on a laptop.
KEYMAP=${KEYMAP:-""}

# If CLEAN is set, clean up any broken state we may have lying around
if [ -n "$CLEAN" ]; then
  clean
fi

# Ensure we've got the system booted in EFI
ls /sys/firmware/efi/efivars > /dev/null

# Check to ensure we've got whatever dependencies we need for whichever mode
# we're running in (ZFS, ext4, etc.)
checkdeps

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

# Only rank the mirrors if we're not cleaning up, indicating this is a fresh run
if [ -z "$CLEAN" ]; then
  echo "Updating mirror list"
  curl -s "$MIRRORLIST_URL" | \
      sed -e 's/^#Server/Server/' -e '/^#/d' | \
      rankmirrors -n 5 - > /etc/pacman.d/mirrorlist
fi

# Set the time from NTP
timedatectl set-ntp true

### Setup the disk and partitions ###
### Make sure we provide enough room on boot for multiple kernels.
devicelist=$(lsblk --nodeps --paths --list --noheadings --sort size -o name,size | grep -Ev "boot|rpmb|loop" | tac)
device=$(dialog --stdout --menu "Select installation disk" 0 0 0 ${devicelist}) || exit 1
clear

# Make 3 partitions:
# * 2G boot
# * 1G secrets/encryption/whatev partition
# * remaining root partition, for ZFS
parted --script "${device}" -- \
  mklabel gpt \
  mkpart ESP fat32 1Mib 2GiB \
  set 1 boot on \
  mkpart primary ext4 2GiB 3GiB \
  mkpart primary ext4 3GiB 100%

# Simple globbing was not enough as on one device I needed to match /dev/mmcblk0p1
# but not /dev/mmcblk0boot1 while being able to match /dev/sda1 on other devices.
part_boot="$(ls "${device}"* | grep -E "^${device}p?1$")"
part_root="$(ls "${device}"* | grep -E "^${device}p?3$")"

# Wipe any old fs stuff from the new partitions
wipefs "${part_boot}"
wipefs "${part_root}"
# Write some random data to the beginning of the partitions to guarantee we
# don't confuse anything later
dd if=/dev/urandom of="$part_root" bs=512 count=20480

# Set up the EFI partition
mkfs.vfat -F32 "${part_boot}"

# Set up root fs filesystem and mount it
format_root "${part_root}"

# Make a /boot directory and mount our EFI boot partition there
mkdir /mnt/boot
mount "$part_boot" /mnt/boot

### Install and configure the base system ###

# usage: pacstrap [options] root [packages...]
#
#   Options:
#     -C config      Use an alternate config file for pacman
#     -c             Use the package cache on the host, rather than the target
#     -G             Avoid copying the host's pacman keyring to the target
#     -i             Prompt for package confirmation when needed
#     -M             Avoid copying the host's mirrorlist to the target
#
#     -h             Print this help message
#
# pacstrap installs packages to the specified new root directory. If no packages
# are given, pacstrap defaults to the "base" group.
pacstrap /mnt \
  base \
  dnsutils \
  git \
  gnu-netcat \
  intel-ucode \
  linux \
  linux-firmware \
  linux-headers \
  linux-lts \
  linux-lts-headers \
  lsof \
  neovim \
  net-tools \
  networkmanager \
  openssh \
  smartmontools \
  socat \
  strace \
  sudo \
  sysstat \
  tar \
  tmux \
  traceroute \
  unzip \
  wget \
  whois

make_fstab "${part_boot}" "${part_root}"

# Set up the hostname
hostname=$(dialog --stdout --inputbox "Enter hostname" 0 0) || exit 1
clear
: ${hostname:?"hostname cannot be empty"}

echo "$hostname" > /mnt/etc/hostname

# Add the hostname to /etc/hosts
hostname_short="$(echo "$hostname" | cut -d '.' -f 1)"
cat <<EOF > /mnt/etc/hosts
127.0.0.1 localhost
::1       localhost
127.0.1.1 $hostname $hostname_short
::1       $hostname $hostname_short
EOF

# Set the timezone
arch-chroot /mnt ln -sf /usr/share/zoneinfo/America/Los_Angeles /etc/localtime

# Sync time
arch-chroot /mnt hwclock --systohc

# Truncate the vconsole file, since we'll append to it below, and don't want to
# duplicate contents on subsequent runs of the script.
truncate --size 0 /mnt/etc/vconsole.conf

# Set up the locale. Setting this before installing the zfs modules means that
# the language setting should get picked up and be set correctly in the ramdisk.
echo "en_US.UTF-8 UTF-8" > /mnt/etc/locale.gen
arch-chroot /mnt locale-gen
echo "LANG=en_US.UTF-8" > /mnt/etc/locale.conf

# If a keymap was passed, set it on the system
if [ -n "${KEYMAP}" ]; then
  echo "KEYMAP=${KEYMAP}" >> /mnt/etc/vconsole.conf
fi

# Update the hooks we need to boot, if necessary.
if [ -n "$(hooks)" ]; then
  sed -i \
    "s/^HOOKS.*/HOOKS=($(hooks))/" \
    /mnt/etc/mkinitcpio.conf
fi

# Install any additional packages we want before rebooting.
add_packages

# Install the bootloader
arch-chroot /mnt bootctl install

# Enable SSH, nm and timesyncd
arch-chroot /mnt systemctl enable sshd
arch-chroot /mnt systemctl enable NetworkManager.service
arch-chroot /mnt systemctl enable systemd-timesyncd.service

# Set up wifi
# TODO: Figure out why this seems not to work. I think there's a system uuid
# that's somehow part of the nm config filename?
if dialog --yesno "Configure wifi for target system?" 0 0; then
  wifi_ssid=$(dialog --stdout --inputbox "Enter wifi SSID" 0 0) || exit 1
  clear
  : ${wifi_ssid:?"Wifi SSID cannot be empty"}

  wifi_password=$(dialog --stdout --inputbox "Enter wifi password (will print)" 0 0) || exit 1
  clear
  : ${wifi_password:?"Wifi password cannot be empty"}

  cat <<EOF > "/mnt/etc/NetworkManager/system-connections/$wifi_ssid.nmconnection"
[connection]
id=$wifi_ssid
type=wifi

[wifi]
mode=infrastructure
ssid=$wifi_ssid

[wifi-security]
auth-alg=open
key-mgmt=wpa-psk
psk=$wifi_password

[ipv4]
dns-search=
method=auto

[ipv6]
addr-gen-mode=stable-privacy
dns-search=
method=auto
EOF
fi

# Figure out what system we're installing on, in case we need to make any
# customization to the boot options.
product_name=$(dmidecode --string system-product-name)

# TODO: Use regex here instead of all the grepping and cutting.
boot_options="$(additional_boot_options $part_root)"
if [ "${product_name}" == "XPS 15 9560" ]; then
  # The XPS 15 9560 has a hi-res display with a discrete graphics card, so we'll
  # install and make default a larger font
  arch-chroot /mnt pacman -Sy --needed --noconfirm terminus-font
  echo FONT=ter-132n >> /mnt/etc/vconsole.conf

  # We also need to set the following options to avoid hanging at some point
  # after boot, in improve power consumption
  boot_options="${boot_options} nouveau.modeset=0 acpi_rev_override=1 enable_fbc=1 enable_psr=1 disable_power_well=0 pci=noaer"
fi

# Write bootloader entries for the standard kernel.
cat <<EOF > /mnt/boot/loader/entries/arch.conf
title    Arch Linux
linux    /vmlinuz-linux
initrd   /intel-ucode.img
initrd   /initramfs-linux.img
options  $boot_options
EOF

# Write the bootloader entries for the LTS kernel, and should stay stable even
# if something breaks with the zfs-linux module.
cat <<EOF > /mnt/boot/loader/entries/arch-lts.conf
title    Arch Linux LTS
linux    /vmlinuz-linux-lts
initrd   /initramfs-linux-lts.img
options  $boot_options
EOF

# Boot the standard kernel by default
cat <<EOF > /mnt/boot/loader/loader.conf
default arch.conf
timeout 3
EOF

# figure out which user we want to use
user=$(dialog --stdout --inputbox "Enter admin username" 0 0) || exit 1
clear
: ${user:?"user cannot be empty"}

# Add the user
arch-chroot /mnt useradd -mU \
  --uid 1185 \
  -G wheel,uucp,video,audio,storage,games,input \
  "$user"

# Set the password
echo -n "$user password: "; arch-chroot /mnt passwd "$user"

# Write a first-boot file that we'll run the first time the system is
# rebooted after running this install script. This will configure things
# correctly so that the system continues booting.
first_boot_script > "/mnt/home/$user/first-boot.sh"
chmod +x "/mnt/home/$user/first-boot.sh"

cat <<EOF >> "/mnt/home/$user/.bashrc"
# Run the first-boot.sh script on first boot, delete it, and clear the line from
# bashrc
~/first-boot.sh && rm ~/first-boot.sh && sed -i '/first-boot/d' ~/.bashrc
EOF

# Make sure everything in the user's home directory is owned by them
arch-chroot /mnt chown -R "$user:" "/home/$user"

# Set up the wheel group to have sudo access
echo "%wheel ALL=(ALL) ALL" >> /mnt/etc/sudoers

# Set a random password for the root user.
echo "root:$(openssl rand -base64 32)" | chpasswd --root /mnt

# Copy this script into the new installation for reference
cp "$0" /mnt/home/$user/$(basename "$0")

# Unmount everything to get ready for reboot
umount_all

cat <<EOF



Installation complete!

You may now reboot, or enter the installed environment
via \`arch-chroot /mnt\`.
EOF