#!/bin/bash
set -e # fail on any error
mountpoint=/mnt/img

if [ -z "$1" ]; then
    echo "Usage: pi_create_image_from_img path/to/file.img"
    exit 1
fi

if [ ! -f "$1" ]; then
    echo "$1 not found"
    exit 1
fi

if [ ! -d "$mountpoint" ]; then
    echo "$mountpoint not found, creating"
    sudo mkdir -p "$mountpoint"
fi

imgpath="$(realpath $1)"
imgdir="$(dirname $imgpath)"
xzpath="$imgpath.xz"
renamepath="${imgpath:0:-4}_$(date -I).img.xz"

echo -e "\nsettings:\n\tmountpoint: $mountpoint\n\timgpath: $imgpath\n\timgdir: $imgdir\n\txzpath: $xzpath\n\trenamepath: $renamepath\n"
cd "$imgdir"

echo "mapping $imgpath"
sudo kpartx -av "$imgpath"

echo "mounting $imgpath"
sudo mount /dev/mapper/loop0p2 "$mountpoint"

cd "$mountpoint"
echo "now edit the image pwd: $PWD"
read teeeemp

echo "unmounting $mountpoint"
sudo umount "$mountpoint"

echo "unmapping $imgpath"
sudo kpartx -dv "$imgpath"

echo "shrinking $imgpath to $imgpath.xz"
sudo pishrink -Z -r -v -a "$imgpath"

echo "renaming $xzpath to $renamepath"
mv "$xzpath" "$renamepath"

# rm "$imgpath"