#!/bin/bash
if [ "$(whoami)" != "root" ]; then
    echo "this script needs to be run as root in order to modify partitions etc. please provide your root password for sudo to execute this script as root"
    sudo -s /bin/bash "$0" "$@"
    exit $?
fi

image=$1
card=$2

if [ -z $1 ]; then
    echo "usage: raspberry_f2fs.sh <image> <sdcard>"
    echo "example: raspberry_f2fs.sh Downloads/raspberryos.img /dev/sdb"
    exit 100
fi 

if [ ! -f $image ]; then 
    echo "ERROR"
    echo "file $image not found,"
    echo "first parameter should be the raspberry os image"
    exit 1
fi

if ! kpartx -l $image  | grep -q "loop.\+p1 : 0"; then 
    echo "ERROR"
    echo "image $image not readable by kpartx or kpartx not found"
    echo "first parameter should be the raspberry os image, and make sure kpartx is installed"
    exit 2
fi

if [ ! -b $card ]; then 
    echo "ERROR"
    echo "$card is not a block device"
    echo "second argument should be a block device"
    exit 3
fi
echo 
read -p "I will now ERASE EVERYTHING on $card, do you want to continue! (yN)" -n 1 -r
echo
if [[ ! $REPLY =~ ^[Yy]$ ]]; then
    echo "aborted"
    exit 101
fi

# ok we are good to go :) 

set -e 
function clean_up(){
    umount /tmp/sd
    umount /tmp/img
    kpartx -d $image
    rmdir /tmp/{sd,img}
    echo 
    echo "aborted"
}
trap clean_up EXIT SIGINT

echo "make sure the card is unmounted"
set +e
umount $card* 2>/dev/null
set -e

echo "erase old partitions"
wipefs -af $card
echo "create new partitions"
parted -s $card mklabel msdos
parted -s $card mkpart primary fat32 0% 256MB
parted -s $card mkpart primary 256MB 100%
partprobe $card
sleep 2

if echo "$card" | grep -q "mmcblk"; then 
    partbase="${card}p"
else
    partbase=$card
fi

echo "format boot partition"
mkfs.vfat ${partbase}1

echo "format os partition with f2fs"
mkfs.f2fs -f ${partbase}2

echo "create mountpoints and mount boot partition"
mkdir -p /tmp/{sd,img}
mount ${partbase}1 /tmp/sd

echo "load image as loopback device and mount boot partition"
out=$(kpartx -av $image)
echo "$out"
loopdev=$(echo "$out" | sed 's/^add map \(loop[^p]\+\)p. .*$/\1/' | head -1)
mount /dev/mapper/${loopdev}p1 /tmp/img

echo "copy the contents of the boot partition"
rsync -av /tmp/img/ /tmp/sd/

echo "adjust cmdline.txt"
partuuidbase=$(blkid $card | sed -e 's/^.*PTUUID="\([^"]*\)".*$/\1/')
sed -i "s/\(PARTUUID=\)[^ ]*\(-02 \)/\1$partuuidbase\2/" /tmp/sd/cmdline.txt
sed -i 's/init=[^ ]*//' /tmp/sd/cmdline.txt
sed -i 's/ext4/f2fs/' /tmp/sd/cmdline.txt

echo
echo 
echo "I am done with the boot partition, now is the time to configure your network for headless operation if you want to.."
echo 
read -p "do you want to configure a wireless lan? if so, type \"y\" and i will open a configuration template in nano for you. simply adjust, quit and save and you are all set, otherwise press any key to continue without configuring a wlan" -n 1 -r
echo
if [[ $REPLY =~ ^[Yy]$ ]]; then
    cat > /tmp/sd/wpa_supplicant.conf <<EOF
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=«your_ISO-3166-1_two-letter_country_code»

network={
    ssid="«your_SSID»"
    psk="«your_PSK»"
}
EOF
    nano /tmp/sd/wpa_supplicant.conf
fi
echo
read -p "do you want to enable the ssh-server on this raspberry right from the start? if so, type \"y\" or else press any key to continue without enabling ssh" -n 1 -r
echo
if [[ $REPLY =~ ^[Yy]$ ]]; then
    touch /tmp/sd/ssh
    ssh=1
else
    ssh=0
fi

echo 
echo "we are done with the boot partition"
echo "unmount boot partition and mount root partition of both the card and the image"
umount /tmp/sd
umount /tmp/img
mount ${partbase}2 /tmp/sd
mount /dev/mapper/${loopdev}p2 /tmp/img

echo "copy the contents of the root partition to the card, this can take a few minutes..."
rsync --progress -aAHhvxX /tmp/img/ /tmp/sd/
echo "done copying"

echo "adjust fstab for f2fs"
sed -i "s/\(PARTUUID=\)[^ ]*\(-0[12] \)/\1$partuuidbase\2/" /tmp/sd/etc/fstab
sed -i 's/ext4/f2fs/' /tmp/sd/etc/fstab
rm -f /tmp/sd/etc/rc3.d/S01resize2fs_once

if [ $ssh -eq 1 ]; then
    echo "creating empty authorized_keys files for users root and pi"
    mkdir -p /tmp/sd/root/.ssh /tmp/sd/home/pi/.ssh
    chmod 700 /tmp/sd/root/.ssh /tmp/sd/home/pi/.ssh
    touch {/tmp/sd/root/.ssh,/tmp/sd/home/pi/.ssh}/authorized_keys
    chmod 600 {/tmp/sd/root/.ssh,/tmp/sd/home/pi/.ssh}/authorized_keys
    chown -R 1000 /tmp/sd/home/pi/.ssh
    echo "done, to add your private key, boot the raspberry pi and login as user pi with password \"raspberry\" to add your public key to those files. make sure you don't forget to chagne the default password!"
fi
echo 
echo
echo "done preparing the root partition"
echo 
read -p "do you want to configure a fixed ip address? if so, type \"y\" and i will open the /etc/dhcpcd.conf file in a nano editor for you. simply adjust, quit and save and you are all set, otherwise press any key to continue without configuring your network interface" -n 1 -r
echo
if [[ $REPLY =~ ^[Yy]$ ]]; then
    nano /tmp/sd/etc/dhcpcd.conf
fi
echo
read -p "do you want to change the hostname to something meaningful right now? if so, type \"y\" and i will open the /etc/hostname file in a nano editor for you. simply adjust, quit and save and you are all set, otherwise press any key to continue without changing the hostname" -n 1 -r
echo
if [[ $REPLY =~ ^[Yy]$ ]]; then
    nano /tmp/sd/etc/hostname
fi
echo 
echo 'okay, we are done, time to clean up! mind you, this can take some time as we weill have to wait for everything to be written to the SD card. do not abort!'
umount /tmp/sd
umount /tmp/img
kpartx -d $image
rmdir /tmp/{sd,img}
echo 
echo "you are all set, you can now remove the sd card and put it into your raspberry, boot it up and start using it" 
echo 'if you want to insert this card into your pc in the future to modify some things on it, I strongly recommend to disable gnomes automount temporarily, as it may mess up your f2fs filesystem'
echo "to do that you can simply run this command:"
echo "    gsettings set org.gnome.desktop.media-handling automount 'false'"
echo "to re-enable simply use 'true' as value instead"
trap - EXIT