#! /bin/bash

set -e # Don't want to destroy stuff if this goes majorly wrong.
# Args: <image_name> [size]
size="4G"
if [ $# -eq 0 ] ; then
echo "Usage: $0 <image_name> [size]" >&2
exit 1
fi
if [ -e "$1" ] ; then
echo "$1 exists, please remove or move it for this script to continue." >&2
exit 1
fi
if [ $# -eq 2 ] ; then
size="$2"
fi
if [ "$(whoami)" != "root" ] ; then
echo "Error: This script must be run as root." >&2
exit 1
fi
fallocate -l $size "$1"
loopdev="$(losetup --find --show "$1")"
parted --script ${loopdev} mklabel msdos mkpart primary fat32 0% 100M mkpart primary ext4 100M 100%
mkfs.vfat -F32 ${loopdev}p1
mkfs.ext4 -F ${loopdev}p2
mount ${loopdev}p2 /mnt
mkdir /mnt/boot
mount ${loopdev}p1 /mnt/boot
wget http://os.archlinuxarm.org/os/ArchLinuxARM-rpi-4-latest.tar.gz -O- | bsdtar -xpf - -C /mnt
arch-chroot /mnt << "EOF"
pacman-key --init
pacman-key --populate archlinuxarm
pacman -Syu --needed --noconfirm vim bash-completion espeakup base base-devel
mkdir -p /etc/systemd/system/sound.target.wants
ln -s /usr/lib/systemd/system/espeakup.service /etc/systemd/system/sound.target.wants/
echo '%wheel ALL=(ALL) ALL' >> /etc/sudoers.d/wheel
EOF
umount -R /mnt
partx -d ${loopdev}
losetup --detach ${loopdev}