#! /bin/bash
#
# Copyright 2020, Stormux, <storm_dragon@linux-a11y.org>
#
# This is free software; you can redistribute it and/or modify it under the
# terms of the GNU General Public License as published by the Free
# Software Foundation; either version 3, or (at your option) any later
# version.
#
# This software is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this package; see the file COPYING.  If not, write to the Free
# Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301, USA.
#

# keep track of mounted status for exit function
mounted=1

set -e # Don't want to destroy stuff if this goes majorly wrong.
trap cleanup EXIT # make sure the script cleans up after itself before closing.


cleanup() {
    if [[ $mounted -eq 0 ]]; then
        umount -R /mnt
        partx -d ${loopdev}
        losetup --detach ${loopdev}
    fi
    exit 0
}

help() {
    echo -e "Usage:\n"
    echo "With no arguments, build with default parameters."
    for i in "${!command[@]}" ; do
        echo "-${i}: ${command[${i}]}"
    done | sort
    exit 0
}
 
# Array of command line arguments
declare -A command=(
    [h]="This help screen."
    [n]="Image name, default is stormux-pi<3|4>-<yyyy-mm-dd>.img"
    [s]="image size in GB, default is 4."
    [v]="Version of the Raspberry Pi for which you are building. (3|4 default)"
)
                                                                                                                                                                          
# Convert the keys of the associative array to a format usable by getopts
args="${!command[*]}"
args="${args//[[:space:]]/}"
while getopts "${args}" i ; do
    case "$i" in
        n)
            shift
            imageName="$1"
            shift
        ;;
        h) help;;
        s)
            shift
            if [[ "$1" =~ ^[[:digit:]]+$ ]]; then
                imageSize="${1}G"
            else
                echo "Image size must be numeric."
                exit 1
            fi
            shift
        ;;
        v)
            shift
            if [[ "$1" =~ ^[34]$ ]]; then
                imageVersion="$1"
            else
                echo "Image version must be 3 for the Raspberry Pi 3, or 4 for the Raspberry Pi 4 (default)."
                exit 1
            fi
            shift
        ;;
    esac
done
 
# make sure variables are set, or use defaults.
export imageVersion="${imageVersion:-4}"
export imageSize="${imageSize:-4G}"
export imageName="${imageName:-stormux-pi${imageVersion}-$(date '+%Y-%m-%d').img}"

# Make sure the image file doesn't exist.
if [[ -e "$imageName" ]]; then
    echo "${imageName} exists, please remove or move it for this script to continue."
    exit 1
fi

# Make sure this script is ran as root.
if [ "$(whoami)" != "root" ] ; then
    echo "Error: This script must be run as root."
    exit 1
fi

# make sure the needed tools are installed
if [[ "$(uname -m)" == "x86_64" ]]; then
    if ! pacman -Q qemu-user-static &> /dev/null ; then
        echo "Please install pacman -Q qemu-user-static before continuing."
        exit 1
    fi
fi
for i in parted wget ; do
    if ! pacman -Q $i &> /dev/null ; then
        echo "Please install $i before continuing."
        exit 1
    fi
done


# Url for the image to be downloaded.
url[3]="http://os.archlinuxarm.org/os/ArchLinuxARM-rpi-aarch64-latest.tar.gz"
url[4]="http://os.archlinuxarm.org/os/ArchLinuxARM-rpi-aarch64-latest.tar.gz"

fallocate -l $imageSize "$imageName"
loopdev="$(losetup --find --show "${imageName}")"
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 ${loopdev}p1 /mnt/boot
# Things are mounted now, so set mounted to 0 (bash true)
mounted=0
wget "${url[$imageVersion]}" -O- | bsdtar -xpf - -C /mnt
arch-chroot /mnt << EOF
# set up pacman
pacman-key --init
pacman-key --populate archlinuxarm
pacman -Syu --needed --noconfirm base base-devel bash-completion cronie espeak-ng git
# Set the distribution name.
echo 'Stormux \r (\l)' > /etc/issue
echo >> /etc/issue
# Change the alarm user to be stormux
usermod -a -g users -G wheel,audio,video -m -d /home/stormux -l stormux alarm
# Grant sudo privileges to the stormux user for package installation.
echo 'stormux ALL=(ALL) NOPASSWD: ALL' >> /etc/sudoers.d/wheel
# Set the password for the stormux user
echo -e "stormux\nstormux" | passwd "stormux"
# Change to the stormux user and install some packages
sudo su - stormux
git clone https://aur.archlinux.org/yay.git
cd yay
makepkg -si
cd ~
rm -rf yay
yay -S fenrir-git informant magic-wormhole
exit
# Make sure informant is up to date with news
informant read --all
# Configure sudo for group wheel, remove nopasswd for the stormux user
sed '/stormux/d' /etc/sudoers.d/wheel
sed 's/^# %wheel ALL=(ALL) ALL$/%wheel ALL=(ALL) ALL/' /etc/sudoers.d/wheel
# Set the hostname
echo stormux > /etc/hostname
# Enable services
systemctl enable cronie.service fenrirscreenreader.service
# Update fstab for Raspberry Pi 4.
[[ $imageVersion -eq 4 ]] && sed -i 's/mmcblk0/mmcblk1/g' /etc/fstab
EOF

exit 0