#!/bin/bash
set -euo pipefail

SCRIPT_ROOT=$(dirname "$0")
# @TODO: Implement more soft-coding and interactivity to this script
ZFS_POOL_NAME="medialib"
ZFS_COMPAT="openzfs-2.1-linux"
ZFS_KEY_LOC="file:///etc/zfs/keys/zroot.key"
ZFS_KEY_FORMAT="passphrase"
ZFS_COMPRESSION="zstd-3"

create_zpool () {
	sudo zpool create \
		-o ashift=12 \
		-o autotrim=on \
		-o compatibility="$3" \
		-O encryption=on \
		-O keylocation="$4" \
		-O keyformat="$5" \
		-O acltype=posixacl \
		-O xattr=sa \
		-O dnodesize=auto \
		-O compression="$6" \
		-O normalization=formD \
		-O relatime=on \
		-O canmount=off \
		-O mountpoint=none \
		"$2" \
		/dev/disk/by-id/"${1}"
}

mkdataset () {
	mkdir -p "$1"
	sudo zfs create -v -o mountpoint="$1" "$2"
}

create_datasets () {
	read -r -p "Provide custom datasets? (y/n): " CUSTOMIZE_DATASETS
	
	if [[ "$CUSTOMIZE_DATASETS" =~ [Nn]* ]]; then
		DATASET=("${HOME}/Documents/.calibre" "${1}/LITERATURE")
		mkdataset "${DATASET[0]}" "${DATASET[1]}"

		DATASET=("${HOME}/Videos" "${1}/FILM")
		mkdataset "${DATASET[0]}" "${DATASET[1]}"

		DATASET=("${HOME}/.var/app/com.valvesoftware.Steam" "${1}/STEAMGAMES")
		mkdataset "${DATASET[0]}" "${DATASET[1]}"

		DATASET=("${HOME}/.var/app/org.libretro.RetroArch" "${1}/RARCHGAMES")
		mkdataset "${DATASET[0]}" "${DATASET[1]}"

		DATASET=("${HOME}/Games" "${1}/GAMES")
		mkdataset "${DATASET[0]}" "${DATASET[1]}"
		ln -s "${HOME}/.var/app/com.valvesoftware.Steam" "${DATASET[0]}/Steam"
		ln -s "${HOME}/.var/app/org.libretro.RetroArch" "${DATASET[0]}/libRetro"

		DATASET=("${HOME}/.var/app/org.libretro.RetroArch" "${1}/RARCHGAMES")
		mkdataset "${DATASET[0]}" "${DATASET[1]}"

		DATASET=("${HOME}/.XXX" "${1}/XXX")
		mkdir -p "${DATASET[0]}"
		sudo zfs create -o keylocation=prompt -o keyformat=passphrase -o mountpoint="${DATASET[0]}" "${DATASET[1]}"
	elif [[ "$CUSTOMIZE_DATASETS" =~ [Yy]* ]]; then
		while true; do
			read -r -a DATASET -p "Define a mount path and its corresponding dataset name or route, in that order: "

			if [ ${#DATASET[@]} -eq 2 ]; then
				mkdataset "${DATASET[0]}" "${1}"/"${DATASET[1]}"
				
				read -r -p "Create another ZFS dataset? (y/n): " ANOTHER_DATASET

				if [[ "$ANOTHER_DATASET" =~ [Yy]* ]]; then
					continue
				elif [[ "$ANOTHER_DATASET" =~ [Nn]* ]]; then
					break
				fi
			else
				printf "Error: must provide 2 arguments (i.e., mount path and dataset name or route)."
				read -r -p "Try again? (y/n): " RETRY_PROMPT

				if [[ "$RETRY_PROMPT" =~ [Yy]* ]]; then
					continue
				elif [[ "$RETRY_PROMPT" =~ [Nn]* ]]; then
					break
				fi
			fi
		done
	else
		exit 1
	fi
}

print_menu () {
	printf "%s" "$(<"${SCRIPT_ROOT}"/zfs-media-drive.help)"
}

if [ -z "$1" ]; then
	printf "Subcommand must be provided"
	exit 1
fi

if [ -n "$1" ] && [ "$1" == "init" ]; then
	shift
	
	while getopts "d:p:k:f:c:v:" opt; do
		case $opt in
			k) ZFS_KEY_LOC="${OPTARG}";;
			f) ZFS_KEY_FORMAT="${OPTARG}";;
			c) ZFS_COMPRESSION="${OPTARG}";;
			v) ZFS_COMPAT="${OPTARG}";;
			p) ZFS_POOL_NAME="${OPTARG}";;
			d) ZFS_TARGET_DRIVE="${OPTARG}";;
			*) exit 1;
		esac
	done

	if [ -z "$ZFS_TARGET_DRIVE" ]; then
		printf "Error: It is necessary to argue a -d option."
		exit 1
	fi

	export ZFS_POOL_NAME
	create_zpool "$ZFS_TARGET_DRIVE" "$ZFS_POOL_NAME" "$ZFS_COMPAT" "$ZFS_KEY_LOC" "$ZFS_KEY_FORMAT" "$ZFS_COMPRESSION"
	printf "Following pool has been created: \n"
	zpool list -v | grep "$ZFS_POOL_NAME"
	create_datasets "$ZFS_POOL_NAME"
	printf "Following datasets have been created: \n"
	zfs list | grep "$ZFS_POOL_NAME"
elif [ -n "$1" ] && [ "$1" == "enc" ]; then
	while true; do
		read -r -a DATASET -p "Define a mount path and its corresponding dataset name or route, in that order: "

		if [ ${#DATASET[@]} -eq 2 ]; then
			mkdir -p "${DATASET[0]}"
			sudo zfs create -v -o keylocation=prompt -o keyformat=passphrase -o mountpoint="${DATASET[0]}" "${ZFS_POOL_NAME}"/"${DATASET[1]}"
				
			read -r -p "Create another ZFS dataset? (y/n): " ANOTHER_DATASET

			if [[ "$ANOTHER_DATASET" =~ [Yy]* ]]; then
				continue
			elif [[ "$ANOTHER_DATASET" =~ [Nn]* ]]; then
				break
			fi
		else
			printf "Error: must provide 2 arguments (i.e., mount path and dataset name or route)."
			read -r -p "Try again? (y/n): " RETRY_PROMPT

			if [[ "$RETRY_PROMPT" =~ [Yy]* ]]; then
				continue
			elif [[ "$RETRY_PROMPT" =~ [Nn]* ]]; then
				break
			fi
		fi
	done
elif [ -n "$1" ] && [ "$1" == "link" ]; then
	while true; do
		read -r -a LINKAGE -p "Define a symbolic link source path and destination dataset: "

		if [ ${#LINKAGE[@]} -eq 2 ]; then
			if ! [ -d "${LINKAGE[0]}" ]; then
				mkdir -p "${LINKAGE[0]}"
			fi
			ln -s "${LINKAGE[0]}" "${ZFS_POOL_NAME}"/"${LINKAGE[1]}"

			read -r -p "Create another symbolic link? (y/n): " ANOTHER_LINKAGE

			if [[ "$ANOTHER_LINKAGE" =~ [Yy]* ]]; then
				continue
			elif [[ "$ANOTHER_LINKAGE" =~ [Nn]* ]]; then
				break
			fi
		else
			printf "Error: must provide 2 arguments (i.e., source path and destination path)."
			read -r -p "Try again? (y/n): " RETRY_PROMPT

			if [[ "$RETRY_PROMPT" =~ [Yy]* ]]; then
				continue
			elif [[ "$RETRY_PROMPT" =~ [Nn]* ]]; then
				break
			fi
		fi
	done
else
	while getopts "h" flag; do
		case "$flag" in
			h) print_menu;;
			*) exit 1;;
		esac
	done
fi