#!/bin/bash
set -puo pipefail
#
# Quick'n dirty helper to pickup a Kobo's USBMS mountpoint...
#
##

# Force a cd to the script's directory, because on macOS, a command script has a fixed $PWD set to $HOME...
cd -P -- "$(dirname "${BASH_SOURCE[0]}")" || exit 255

# We're ultimately going to need unzip...
if ! unzip -v &>/dev/null ; then
	echo "This script relies on unzip!"
	exit 255
fi

# Are we on Linux or macOS?
PLATFORM="$(uname -s)"

# Find out where the Kobo is mounted...
KOBO_MOUNTPOINT="/dev/null"

case "${PLATFORM}" in
	"Linux" )
		# Use findmnt, it's in util-linux, which should be present in every sane distro.
		if ! findmnt -V &>/dev/null ; then
			echo "This script relies on findmnt, from util-linux!"
			exit 255
		fi

		# Match on the FS Label, which is common to all models.
		KOBO_MOUNTPOINT="$(findmnt -nlo TARGET LABEL=KOBOeReader)"
	;;
	"Darwin" )
		# Same idea, via diskutil
		KOBO_MOUNTPOINT="$(diskutil info -plist "KOBOeReader" | grep -A1 "MountPoint" | tail -n 1 | cut -d'>' -f2 | cut -d'<' -f1)"
	;;
	* )
		echo "Unsupported OS!"
		exit 255
	;;
esac

# Sanity check...
if [[ -z "${KOBO_MOUNTPOINT}" ]] ; then
	echo "Couldn't find a Kobo eReader volume! Is one actually mounted?"
	exit 255
fi

KOBO_DIR="${KOBO_MOUNTPOINT}/.kobo"
if [[ ! -d "${KOBO_DIR}" ]] ; then
	echo "Can't find a .kobo directory, ${KOBO_MOUNTPOINT} doesn't appear to point to a Kobo eReader... Is one actually mounted?"
	exit 255
fi

# Tiny DRY helper for the failure message...
recap_failure() {
	echo "* As a result, the device may have been left in an inconsistent state!"
	echo "* Please note that NO automatic cleanup will be done!"
	echo "* As such, before unplugging your device, consider removing:"
	echo "* The following folders:"
	for kfm_folder in .adds/kfmon .adds/koreader .adds/plato ; do
		local current_folder="${KOBO_MOUNTPOINT}/${kfm_folder}"
		if [[ -d "${current_folder}" ]] ; then
			printf "\t%s\n" "${current_folder}"
		else
			printf "\t%-96s%32s\n" "${current_folder}" "[OK: Already gone]"
		fi
	done
	echo "* As well as the following files:"
	for kfm_file in .kobo/KoboRoot.tgz kfmon.png koreader.png icons/plato.png ; do
		local current_file="${KOBO_MOUNTPOINT}/${kfm_file}"
		if [[ -f "${current_file}" ]] ; then
			printf "\t%s\n" "${current_file}"
		else
			printf "\t%-96s%32s\n" "${current_file}" "[OK: Already gone]"
		fi
	done
}

# Ask the user what they want to install...
AVAILABLE_PKGS=()
for file in OCP-KOReader-v*.zip OCP-Plato-*.zip OCP-KFMon-*.zip KFMon-Uninstaller.zip ; do
	[[ -f "${file}" ]] && AVAILABLE_PKGS+=("${file}")
done

# Sanity check...
if [[ ${#AVAILABLE_PKGS[@]} -eq 0 ]] ; then
	echo "No supported packages found in the current directory (${PWD})!"
	exit 255
fi

echo "* Here are the available packages:"
for i in "${!AVAILABLE_PKGS[@]}" ; do
	echo "${i}: ${AVAILABLE_PKGS[${i}]}"
done

read -r -p "* Enter the number corresponding to the one you want to install: " j

# Check if that was a sane reply...
if ! [[ "${j}" -eq "${j}" ]] 2>/dev/null ; then
	echo "That wasn't a number!"
	exit 255
fi

if [[ ${j} -lt 0 ]] || [[ ${j} -ge ${#AVAILABLE_PKGS[@]} ]] ; then
	echo "That number was out of range!"
	exit 255
fi

# We're good to go!
SELECTED_PACKAGE="${AVAILABLE_PKGS[${j}]}"

# NOTE: Since FW 4.17, Nickel will attempt to index content found in hidden directories.
#       Since all of this stuff lives in *nix hidden directories, this won't do.
#       Thankfully, FW 4.17.13694 introduced a hidden setting to control that behavior.
#       We'll enforce the "legacy" behavior of basically ignoring non-default hidden directories.
#       c.f., https://www.mobileread.com/forums/showpost.php?p=3892463&postcount=10
#          &  https://www.mobileread.com/forums/showpost.php?p=3894033&postcount=70
#          &  https://www.mobileread.com/forums/showpost.php?p=4076372&postcount=452
# NOTE: We can simply push a (potentially) duplicate section + entry at the end of the file,
#       QSettings will do the right thing, that is, pick up this new key, use it,
#       and save everything in the right place without leaving duplicates around.
KOBO_CONFIG="${KOBO_DIR}/Kobo/Kobo eReader.conf"
echo "* Preventing Nickel from scanning hidden directories . . ."
cat >> "${KOBO_CONFIG}" <<-\EoM

	[FeatureSettings]
	ExcludeSyncFolders=(\\.(?!kobo|adobe).+|([^.][^/]*/)+\\..+)
EoM

# Check for a cat failure, as unlikely as it might be (permissions?)...
ret=$?
if [[ ${ret} -ne 0 ]] ; then
	echo "* Installation FAILED: Failed to update Nickel config!"
	echo "* No permanent changes have been made."
	exit ${ret}
fi

# Double-check that it was updated, in case of gremlins attack...
if ! grep -Fq 'ExcludeSyncFolders=(\\.(?!kobo|adobe).+|([^.][^/]*/)+\\..+)' "${KOBO_CONFIG}" ; then
	echo "* Installation FAILED: Nickel config update was ineffective o_O !"
	echo "* No permanent changes have been made."
	exit 255
fi

# We've got a Kobo, we've got a package, let's go!
if [[ "${SELECTED_PACKAGE}" == "KFMon-Uninstaller.zip" ]] ; then
	echo "* Uninstalling KFMon . . ."
	unzip -o "${SELECTED_PACKAGE}" -d "${KOBO_DIR}"
else
	echo "* Installing ${AVAILABLE_PKGS[${j}]} . . ."
	unzip -o "${SELECTED_PACKAGE}" -d "${KOBO_MOUNTPOINT}"
fi

ret=$?
if [[ ${ret} -ne 0 ]] ; then
	echo "* Installation FAILED: Failed to unpack archive!"
	recap_failure
	exit ${ret}
fi

# Double-check that we ended up with a KoboRoot in the right place...
echo "* Sanity check . . ."
if [[ ! -f "${KOBO_DIR}/KoboRoot.tgz" ]] ; then
	echo "* Installation FAILED: Unpacking was ineffective (no KoboRoot tarball) o_O !"
	recap_failure
	exit 255
fi

# In case it was an install, double-check that we ended up with (at least) KFMon's own icon in the right place...
if [[ "${SELECTED_PACKAGE}" != "KFMon-Uninstaller.zip" ]] ; then
	echo "* More sanity checks . . ."
	if [[ ! -f "${KOBO_MOUNTPOINT}/kfmon.png" ]] ; then
		echo "* Installation FAILED: Unpacking was ineffective (no KFMon icon) o_O !"
		recap_failure
		exit 255
	fi
fi

# Flush to disk, for good measure...
echo "* Flush to storage device . . ."
sync

# Double-check that sync did its magic...
# NOTE: sync may not actually ever be able to return an error, depending on the platform.
#       If/when it does, it's usually with extremely bad news, so let's be overly pessimistic here...
ret=$?
if [[ ${ret} -eq 0 ]] ; then
	echo "* Installation successful!"
	echo "* Please make sure to eject & unplug your device safely!"
else
	echo "* Installation FAILED: I/O error when flushing to disk (failing storage? check kernel logs)!"
	recap_failure
	exit ${ret}
fi

# We're done!
exit 0