#!/usr/bin/env bash

# set flag variables to null/default
optExcludeBoot=false
optExcludeConfidential=false
optExcludeLost=true
optQuiet=false
optUserExclude=()


function showHelp() {
	echo "Usage:"
	echo "$(basename "$0") [-b -c -l -q] [-s || -t <target>] [-e <exclude>...] [-i <include>...] <dest> [-- [rsync-opts]]"
	echo "Position Arguments:"
	echo "    <dest>       destination path to copy system files to"
	echo "    [rsync-opts] additional options to pass to rsync command"
	echo
	echo "Options:"
	echo "    -b           excludes boot directory"
	echo "    -c           excludes some confidential files (currently only .bash_history and connman network lists)"
	echo "    -l           includes lost+found directory"
	echo "    -q           activates quiet mode (no confirmation)"
	echo "    -s           makes copy of current system"
	echo "    -t <path>    makes copy of system located at the <path>"
	echo "    -e <exclude> an additional exclude directory (one dir one -e, do not use it with *)"
	echo "    -i <include> an additional include. This has higher precedence than -e, -t, and -s"
	echo "    -h           display this help message."

	if [[ "$1" -ge 0 ]]; 	then
		exit "$1"
	else
		exit 0
	fi
}

function errorMsg() {
	local rc=0

	if [[ "$1" -gt 0 ]]; then
		rc="$1"
		shift
	fi

	echo "$*" >&2

	if [[ "$rc" -gt 0 ]]; then
		exit "$rc"
	fi
}


# reads options:
while [[ $# -gt 0 ]]; do
	while getopts ":t:e:i:sqcblh" flag; do
		case "$flag" in
			t)	sourcePath="$OPTARG";;
			s)	sourcePath="/";;
			q)	optQuiet=true;;
			c)	optExcludeConfidential=true;;
			b)	optExcludeBoot=true;;
			l)	optExcludeLost=false;;
			e)	optUserExclude+=("$OPTARG");;
			i)	optUserInclude+=("$OPTARG");;
			h)	showHelp 0;;
			\?)	errorMsg 1 "Invalid option: -$OPTARG";;
			:)	errorMsg 1 "Option -$OPTARG requires an argument.";;
		esac
	done || exit 1

	[[ $OPTIND -gt $# ]] && break # reached the end of parameters

	shift $((OPTIND - 1)) # Free processed options so far
	OPTIND=1              # we must reset OPTIND
	if [[ -z "$targetPath" ]]; then
		targetPath=$1
	else
		rsyncArgs[${#rsyncArgs[*]}]=$1
	fi
	#args[${#args[*]}]=$1  # save first non-option argument (a.k.a. positional argument)
	shift                 # remove saved arg
done


# checks if run as root:
if [[ "$(id -u)" -ne 0 ]]; then
	echo "$(basename "$0"): must run as root"
	exit 250
fi

if [[ -z "$sourcePath" ]]; then
	echo "$(basename "$0"): no source path specified"
	exit 1
elif [[ ! -d "$sourcePath" ]]; then
	echo "$(basename "$0"): no source path does not exist"
	exit 1
elif [[ "$sourcePath" != */ ]]; then
	# make sure source path ends with slash
	sourcePath="${sourcePath}/"
fi

if [[ -z "$targetPath" ]]; then
	echo "$(basename "$0"): no destination path specified"
	exit 1
elif [[ ! -d "$targetPath" ]]; then
	echo "$(basename "$0"): destination path (\`$targetPath\`) does not exist"
	exit 1
elif [[ "$targetPath" != */ ]]; then
	# make sure destination path ends with slash
	targetPath="${targetPath}/"
fi

# Excludes:
syncExcludes=(
	"dev/*"
	"var/tmp/*"
	"media/*"
	"mnt/*/*"
	"proc/*"
	"run/*"
	"sys/*"
	"tmp/*"
	"var/lock/*"
	"var/log/*"
	"var/run/*"
	"var/lib/docker/*"
	"var/lib/containers/*"
	"var/lib/machines/*"
	"var/lib/libvirt/*"
	"var/lib/lxd/*"
	"home/*/*"
)

#EXCLUDES_DEFAULT_PORTAGE=(
syncExcludesPortage=(
	"var/db/repos/*/*"
	"var/cache/distfiles/*"
	"var/cache/binpkgs/*"
	"usr/portage/*"
)

syncIncludes=(
	"dev/console"
	"dev/null"
	"var/db/pkg/*"
)

syncExcludes=("${syncExcludes[@]/#/"$sourcePath"}")
syncIncludes=("${syncIncludes[@]/#/"$sourcePath"}")

if [[ "$sourcePath" == '/' ]]; then
	if command -v portageq &>/dev/null; then
		portageRepos=$(portageq get_repos /)
		for i in ${portageRepos}; do
			repoPath=$(portageq get_repo_path / "${i}")
			syncExcludes+=("${repoPath}/*")
		done
		syncExcludes+=("$(portageq distdir)/*")
		syncExcludes+=("$(portageq pkgdir)/*")
	else
		syncExcludes+=("${syncExcludesPortage[@]/#/"/"}")
	fi
else
	syncExcludes+=("${syncExcludesPortage[@]/#/"$sourcePath"}")
fi

if $optExcludeConfidential; then
	syncExcludes+=("${sourcePath}home/*/.bash_history")
	syncExcludes+=("${sourcePath}root/.bash_history")
	syncExcludes+=("${sourcePath}var/lib/connman/*")
fi

if $optExcludeBoot; then
	syncExcludes+=("${sourcePath}boot/*")
fi

if $optExcludeLost; then
	syncExcludes+=("lost+found")
fi

syncExcludes+=("${optUserExclude[@]}")
syncIncludes+=("${optUserInclude[@]}")

# Generic rsync options:
rsyncOptions=(
	-avxHAXS
	--numeric-ids
	"--info=progress2"
)

rsyncOptions+=("${rsyncArgs[@]}")

# if not in quiet mode, this message will be displayed:
if ! $optQuiet; then
	echo "Are you sure that you want to copy system files located under"
	echo "$sourcePath"
	echo "to the following directory"
	echo "$targetPath"
	echo
	echo "WARNING: since all data is copied by default the user should exclude all"
	echo "security- or privacy-related files and directories, which are not"
	echo "already excluded, manually per cmdline."
	echo "example: \$ $(basename "$0") -s -e \"/etc/ssh/ssh_host*\" <destination>"
	echo
	echo "COMMAND LINE PREVIEW:"
	echo 'rsync' "${rsyncOptions[@]}" "${syncIncludes[@]/#/--include=}" "${syncExcludes[@]/#/--exclude=}" "$sourcePath" "$targetPath"
	echo
	echo -n 'Type "yes" to continue or anything else to quit: '
	read -r promptAgree
	if [[ "${promptAgree,,}" == "yes" ]]; then
		optQuiet=true
	fi
fi

# start stage4 creation:
if $optQuiet; then
	#echo "Would've worked"
	rsync "${rsyncOptions[@]}" "${syncExcludes[@]/#/--exclude=}" "$sourcePath" "$targetPath"
fi