#!/bin/bash
# wslu - Windows 10 linux Subsystem Utility
# Component of Windows 10 linux Subsystem Utility
# <https://github.com/wslutilities/wslu>
# Copyright (C) 2019 Patrick Wu
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# Version
wslu_version=3.2.4-1

# Speed up script by not using unicode.
LC_ALL=C
LANG=C

# prevent bash -x
set +x

# conf handling module
__wsl_conf_read() {
	[ -f /etc/wsl.conf ] && sed -nr "/^\[${1}\]/ { :l /^${2}[ ]*=/ { s/[^=]*=[ ]*//; p; q;}; n; b l;}" /etc/wsl.conf
}

# checking interopability
if __wsl_conf_read interop enabled | grep false >/dev/null; then
	 echo -e "WSL Interopability is disabled and WSL Utilities won't work. Please enable it by:
	1. open /etc/wsl.conf using root or equivalent editing permission;
	2. under [interop] section, set enabled to true;
	3. restart your distribution."
	exit 1
elif grep ^disabled /proc/sys/fs/binfmt_misc/WSLInterop >/dev/null; then
	 echo -e "WSL Interopability is temporarily disabled and WSL Utilities won't work. Please enable it by:
	# echo 1 > /proc/sys/fs/binfmt_misc/WSLInterop"
	exit 1
fi

# when --verbose, verbose; when --debug, debug.
#
# They should not exist at the same time, otherwise
# the output would be too messy.
wslu_debug=0
if [ "$1" == "--verbose" ]; then
	echo -e '\e[38;5;202m\033[1m[verbose] Showing verbose output. \033(B\033[m'
	shift
	set -x
elif [ "$1" == "--debug" ]; then
	wslu_debug=1
	echo -e '\e[38;5;202m\033[1m[debug] Showing debug output. \033(B\033[m'
	shift
fi

# variables
## color
black=$(echo -e '\e[30m')
red=$(echo -e '\e[31m')
green=$(echo -e '\e[32m')
brown=$(echo -e '\e[33m')
blue=$(echo -e '\e[34m')
purple=$(echo -e '\e[35m')
cyan=$(echo -e '\e[36m')
yellow=$(echo -e '\e[33m')
white=$(echo -e '\e[37m')
dark_gray=$(echo -e '\e[1;30m')
light_red=$(echo -e '\e[1;31m')
light_green=$(echo -e '\e[1;32m')
light_blue=$(echo -e '\e[1;34m')
light_purple=$(echo -e '\e[1;35m')
light_cyan=$(echo -e '\e[1;36m')
light_gray=$(echo -e '\e[37m')
orange=$(echo -e '\e[38;5;202m')
light_orange=$(echo -e '\e[38;5;214m')
deep_purple=$(echo -e '\e[38;5;140m')
bold=$(echo -e '\033[1m')
reset=$(echo -e '\033(B\033[m')

## indicator
info="${green}[info]${reset}"
input_info="${cyan}[input]${reset}"
error="${red}[error]${reset}"
warn="${orange}[warn]${reset}"

## Windows build number constant
# Windows 10
readonly BN_SPR_CREATORS=15063		#1703, Redstone 2, Creators Update
readonly BN_FAL_CREATORS=16299		#1709, Redstone 3, Fall Creators Update
readonly BN_APR_EIGHTEEN=17134		#1803, Redstone 4, April 2018 Update
readonly BN_OCT_EIGHTEEN=17763		#1809, Redstone 5, October 2018 Update
readonly BN_MAY_NINETEEN=18362		#1903, 19H1, May 2019 Update
readonly BN_NOV_NINETEEN=18363		#1909, 19H2, November 2019 Update
readonly BN_OCT_NINETEEN=19042		#20H2, Windows 10 October 2020 Update
readonly BN_MAY_TWNETONE=19043		#21H1, Windows 10 May 2021 Update
readonly BN_NOV_TWENTONE=19044		#21H2, Windows 10 November 2021 Update
# Windows 11
readonly BN_ELEVEN_21H2=22000		#21H2, Windows 11

# functions
function debug_echo {
	[ $wslu_debug -eq 1 ] && echo "${orange}${bold}[debug]${reset} $@"
}

function error_echo {
	echo "${error} $1"
	exit $2
}

function help {
	app_name=$(basename "$1")
	echo -e "$app_name - Part of wslu, a collection of utilities for Windows 10 Windows Subsystem for Linux
Usage: $2

For more help for $app_name, please use the command \`man $app_name\` or visit the following site: https://wslutiliti.es/wslu/man/$app_name.html.
For overall help, you can use the command \`man wslu\` or visite the following site: https://wslutiliti.es/wslu."
}

function double_dash_p {
	echo "${@//\\/\\\\}"
}

function interop_prefix {

	win_location="/mnt/"
	tmp="$(__wsl_conf_read automount root)"
	[ "$tmp" == "" ] || win_location="$tmp"
	[[ "$win_location" =~ ^.*/$ ]] || win_location="$win_location/" # make sure it always end with slash
	unset tmp
	echo "$win_location"

	unset win_location
}

function sysdrive_prefix {
	win_location="$(interop_prefix)"
	hard_reset=0
	for pt in $(ls "$win_location"); do
		if [ $(echo "$pt" | wc -l) -eq 1 ]; then
			if [ -d "$win_location$pt/Windows/System32" ]; then
				hard_reset=1
				win_location="$pt"
				break
			fi
		fi 
	done

	if [ $hard_reset -eq 0 ]; then
		win_location="c"
	fi

	echo "$win_location"

	unset win_location
	unset hard_reset
}

function wslu_get_build {
	build=$("$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/reg.exe query "HKLM\\Software\\Microsoft\\Windows NT\\CurrentVersion" /v CurrentBuild | tail -n 2 | head -n 1 | sed -e 's|\r||g')
	echo "${build##* }"
}

function wslu_get_wsl_ver {
	wslutmpbuild="$(( $(wslu_get_build) + 0 ))"
	if [ $wslutmpbuild -ge $BN_MAY_NINETEEN ]; then
		# The environment variable only available in 19H1 or later.
		wslu_distro_regpath=$("$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/reg.exe query "HKCU\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Lxss" /s /f DistributionName 2>&1 | sed -e 's|\r||g' | grep -B1 -e "$WSL_DISTRO_NAME$" | head -n1 )
		if "$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/reg.exe query "$wslu_distro_regpath" /v Flags &>/dev/null; then
			wslu_distro_version=$("$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/reg.exe query "$wslu_distro_regpath" /v Flags | tail -n 2 | head -n 1 | sed -e 's|\r||g')
			wslu_distro_version=${wslu_distro_version##* }
			wslu_distro_version_processed=$(expr $(printf "%d\n" "$wslu_distro_version") / 8)
			if [ "$wslu_distro_version_processed" == "1" ]; then
				echo "2"
			elif [ "$wslu_distro_version_processed" == "0" ]; then
				echo "1"
			fi
		else
			echo "1"
		fi
	else
		echo "1"
	fi
}

function chcp_com {
	"$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/chcp.com "$@" >/dev/null
}

function winps_exec {
	wslutmpbuild="$(( $(wslu_get_build) + 0 ))"
	cp="$(cat ~/.config/wslu/oemcp)"
	[ $wslutmpbuild -ge $BN_OCT_NINETEEN ] || chcp_com "$cp"
	cp=$(($cp+0))
	"$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/WindowsPowerShell/v1.0/powershell.exe -NoProfile -NonInteractive –ExecutionPolicy Bypass -Command "[Console]::OutputEncoding = [System.Text.Encoding]::UTF8; [Console]::InputEncoding = [System.Text.Encoding]::GetEncoding($cp); $@"
	EXIT_STATUS=$?
	[ $wslutmpbuild -ge $BN_OCT_NINETEEN ] || chcp_com 65001
	return $EXIT_STATUS
}

function baseexec_gen {
	wslutmpbuild="$(( $(wslu_get_build) + 0 ))"
	if [ $wslutmpbuild -ge $BN_MAY_NINETEEN ]; then
		# The environment variable only available in 19H1 or later.
		wslu_distro_regpath=$("$(interop_prefix)"c/Windows/System32/reg.exe query "HKCU\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Lxss" /s /f DistributionName 2>&1 | sed -e 's|\r||g' | grep -B1 -e "$WSL_DISTRO_NAME$" | head -n1 )
		if "$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/reg.exe query "$wslu_distro_regpath" /v PackageFamilyName &>/dev/null; then
			wslu_distro_packagename=$("$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/reg.exe query "$wslu_distro_regpath" /v PackageFamilyName | tail -n 2 | head -n 1 | sed -e 's|\r||g')
			# if it is a store distro
			wslu_distro_packagename=${wslu_distro_packagename##* }
			wslu_base_exec_folder_path="$(wslpath "$(winps_exec "[Environment]::GetFolderPath('LocalApplicationData')" | tr -d "\r")\\Microsoft\\WindowsApps\\$wslu_distro_packagename")"
			wslpath -w "$(find "$wslu_base_exec_folder_path" -name "*.exe" -print -quit)" > ~/.config/wslu/baseexec
		else
			# if it is imported distro
			echo "$(wslpath -w "$(interop_prefix)$(sysdrive_prefix)")Windows\\System32\\wsl.exe" > ~/.config/wslu/baseexec
		fi
	else
		# older version fallback.
		echo "$(wslpath -w "$(interop_prefix)$(sysdrive_prefix)")\\Windows\\System32\\wsl.exe" > ~/.config/wslu/baseexec
	fi
}

function var_gen {
	date +"%s" > ~/.config/wslu/triggered_time

	rm -f ~/.config/wslu/baseexec
	rm -f ~/.config/wslu/oemcp

	# generate oem codepage
	"$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/reg.exe query "HKLM\\SYSTEM\\CurrentControlSet\\Control\\Nls\\CodePage" /v OEMCP 2>&1 | sed -n 3p | sed -e 's|\r||g' | grep -o '[[:digit:]]*' > ~/.config/wslu/oemcp
	# generate base exe location
	baseexec_gen

}

function wslu_file_check {
	should_i_show=""
	[[ "$3" == "?!S" ]] && should_i_show="n"

	if [[ ! -f "$1/$2" ]]; then
		[[ -z "$should_i_show" ]] && echo "${warn} $2 not found in Windows directory. Copying right now..."
		[[ -d "$1" ]] || mkdir "$1"
		if [[ -f "/usr/share/wslu/$2" ]]; then
			cp "/usr/share/wslu/$2" "$1"
			[[ -z "$should_i_show" ]] && echo "${info} $2 copied. Located at \"$1\"."
		else
			[[ -z "$should_i_show" ]] && echo "${error} $2 not found. Failed to copy."
			exit 30
		fi
	fi
}



# pre_check to make sure WSL_INTEROP is properly set in WSL2
if [ "$(wslu_get_wsl_ver)" == "2" ] && [ -z "$WSL_INTEROP" ]; then
	for i in $(pstree -np -s $$ | grep -o -E '[0-9]+'); do
		if [[ -e "/run/WSL/${i}_interop" ]]; then
			export WSL_INTEROP=/run/WSL/${i}_interop
		fi
	done
fi

# first run, saving some information
if [ ! -d ~/.config/wslu ]; then
	mkdir -p ~/.config/wslu
fi

# This gets tirggered then:
# 1. if it's the first time the script is triggered, i.e.,
#    ~/.config/wslu/triggered time
# 2. if update_time is also not present, i.e.,
#    badly installed packages or installed via install script
if [ ! -f ~/.config/wslu/triggered_time ] || [ ! -f /usr/share/wslu/updated_time ]; then
	var_gen
# This gets triggered when:
#    installed time is larger than the last triggered time
elif [ $(cat ~/.config/wslu/triggered_time) -lt $(cat /usr/share/wslu/updated_time) ]; then
	var_gen
fi

# basic distro detection
distro="$(cat /etc/os-release | sed -n -e '/^NAME=.*/p'| sed -e 's/^NAME=\"//g')"
case $distro in
	*Pengwin*) distro="pengwin";;
	*WLinux*) distro="wlinux";;
	Ubuntu*) distro="ubuntu";;
	*Debian*) distro="debian";;
	*Kali*) distro="kali";;
	openSUSE*) distro="opensuse";;
	SLES*) distro="sles";;
	Alpine*) distro="alpine";;
	Arch*) distro="archlinux";;
	*Oracle*) distro="oracle";;
	Scientific*) distro="scilinux";;
	*Fedora\ Remix\ for\ WSL*) distro="fedoraremix";;
	*Fedora*) distro="fedora";;
	*Generic*) [ "fedora" == "$(grep -e "LIKE=" /etc/os-release | sed -e 's/ID_LIKE=//g')" ] && distro="oldfedora" || distro="unknown";;
	*) distro="unknown";;
esac
# shellcheck shell=bash
version="03"

var_type=1

help_short="wslvar [-sl] NAME\nwslvar [-hvSL]"

function call_shell {
	winps_exec "(Get-ItemProperty 'HKCU:\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders').'$*'" | cat
}

function view_shell {
	winps_exec "Get-ItemProperty 'HKCU:\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders'"| tail -n +3 | head -n -10
}

function call_sys {
	winps_exec "Write-Output \${Env:$*}" | cat
}

function view_sys {
	winps_exec "Get-ChildItem env:" | tail -n +2 | head -n -2
}

function cl_destoryer {
	echo "$@" | tr -d "\r"
}

function caller {
	if [ "$*" != "" ]; then
		case $var_type in
			1) p="$(cl_destoryer "$(call_sys "$@")")";;
			2) p="$(cl_destoryer "$(call_shell "$@")")";;
			*) error_echo "Invalid variable type. Aborted." 22;;
		esac
		echo "$p"
	else
		error_echo "No Input. Aborted." 21
	fi
}

while [ "$1" != "" ]; do
	case "$1" in
		-s|--sys) var_type=1; shift;;
		-l|--shell) var_type=2; shift;;
		-S|--getsys) view_sys; exit;;
		-L|--getshell) view_shell; exit;;
		-h|--help) help "$0" "$help_short"; exit;;
		-v|--version) echo "wslu v$wslu_version; wslvar v$version"; exit;;
		*) caller "$@"; exit;;
	esac
done

error_echo "No Input. Aborted." 21

