#!/bin/bash

# Define required programs and libraries
program_list=("ifuse" "ldconfig" "rsync")
library_list=("libimobiledevice")

sync_folder="$HOME/iPhone"
sync_mount="${sync_folder}/.mnt"
sync_data="${sync_folder}/data"
sync_archive="${sync_folder}/archive"
current_date=$(date +%F)
safety_dir="changes_${current_date}"

# Check if required programs are installed
for program in "${program_list[@]}"; do
	if command -v "${program}" >/dev/null 2>&1
	then
		echo "OK, ${program} exists."
	else
		echo "Error: ${program} is missing. Please install: ${program_list[*]}"
		exit 1
	fi
done

# iteration thru list of libraries
for library in "${library_list[@]}"; do
	if ldconfig -p | grep ${library} >/dev/null 2>&1
	then
		echo "OK, ${library} exists."
	else
		echo "Error: Library ${library} is missing. Please install: ${library_list[*]}"
		exit 2
	fi
done

# Clear older dead mounts if they block the directory
if [ -d "${sync_mount}" ]; then
	fusermount -u "${sync_mount}" >/dev/null 2>&1 || umount -l "${sync_mount}" >/dev/null 2>&1
	rmdir "${sync_mount}" >/dev/null 2>&1
fi

echo "Create the folder ${sync_mount} ..."
if mkdir -p ${sync_mount} >/dev/null 2>&1
then
	echo "done."
else
	echo "Folder ${sync_mount} already exists."
fi

echo "Mount the iPhone into that folder using ifuse ..."
if ifuse ${sync_mount}
then
	echo "ok."
else
	echo "did not work. Check your connection to the iPhone. Check PIN on the iPhone."
	exit 3
fi

# Display storage capacity of the iPhone
echo -e "\n--- IPHONE STORAGE USAGE ---"
df -h "${sync_mount}"
echo -e "----------------------------\n"

echo "RSYNC the iPhone ..."
FROM="${sync_mount}/"
TO="${sync_data}/"

while true; do
	echo "** Synchronization from ${FROM} to ${TO} **"
	echo "Options:"
	echo "  (s) sync & delete from 'data' (matches iPhone state)"
	echo "  (n) normal sync to 'data' (keeps files deleted on iPhone)"
	echo "  (a) safety-net ARCHIVE (syncs 'data' to 'archive', backups changed files, NEVER deletes)"
	echo "  (m) mount only & exit"
	echo "  (c) cancel"
	read -n 1 -p "Action: " response
	echo
	case ${response} in
		[Nn]* )
			mkdir -p "${sync_data}"
			rsync -avP "${FROM}" "${TO}"
			break
			;;
		[Ss]* )
			mkdir -p "${sync_data}"
			rsync -avP --delete "${FROM}" "${TO}"
			break
			;;
		[Mm]* )
			echo "iPhone remains mounted at ${sync_mount}. Remember to unmount manually later!"
			exit 0 
			;;
		[Aa]* )
			# Ensure the archive folder exists
			mkdir -p "${sync_archive}"
			if [ ! -d "${sync_data}" ] || [ -z "$(ls -A "${sync_data}")" ]; then
				echo "Error: The 'data' folder is empty or does not exist. Run a sync (n or s) first!"
			else
				echo "Starting safety-net archive backup from ${sync_data} to ${sync_archive}..."
				# Safety-net sync: moves modified/overwritten files into a dated subfolder
				rsync -avP --backup --backup-dir="${safety_dir}" "${sync_data}/" "${sync_archive}/"
				echo "Archive completed. Safe directory for modified files today: ${sync_archive}/${safety_dir}"
			fi
			break
			;;
		[Cc]* )
			echo "Synchronization skipped by user."
			break
			;;
		* )
			echo "Invalid selection. Please choose s, n, a, m, or c."
			;;
	esac
done

echo "Unmounting iPhone..."
if fusermount -u "${sync_mount}" 2>/dev/null || umount "${sync_mount}" 2>/dev/null; then
	echo "Successfully unmounted."
	rmdir "${sync_mount}"
else
	echo "WARNING: Unmount failed. A process might still be accessing the mount directory."
fi

echo "Process finished."