#!/data/data/com.termux/files/usr/bin/bash

# -------------------------------------
# Helper script for samloader on Termux
# Github:	lekron42
# Version:	v1.03
# -------------------------------------

show_usage() {
	echo "This script automates firmware downloading using samloader"
	echo -e "Usage: $(basename $(readlink -f $0)) [argument]\n"
	echo "Arguments:"
	echo " -f|--force  : Force update even if no new version is found"
	echo " -r|--repair : Update samloader to fix download failure"
	echo " -h|--help   : Show this help"
	exit 0
}

update_samloader() {
	{ proceed=$(pip3 uninstall samloader | tee /dev/fd/5); } 5>&1
	if [ $(echo "$proceed" | grep -c "Successfully") -gt 0 ]; then
		pip3 install git+https://github.com/nlscc/samloader.git
		echo "Successfully reinstalled samloader."
	else
		echo "Uninstalling cancelled.."
	fi
	exit 0
}

if [ $(echo "$0" | grep -c "termux") -eq 0 ]; then
	echo "Script not executed in Termux! Exiting.." 1>&2
	exit 1
fi

if [ $# -eq 1 ]; then
	case "$1" in
		-h|--help)
			show_usage
			;;
		-f|--force)
			force_download=true
			;;
		-r|--repair)
			update_samloader
			;;
		*)
			echo "Incorrect input!" 1>&2
			show_usage
			;;
	esac
elif [ $# -gt 1 ]; then
	echo "Only 1 argument supported. $# given." 1>&2
	exit 1
fi

i_python=$(pkg list-installed "python" 2> /dev/null | grep -c "installed")
i_git=$(pkg list-installed "git" 2> /dev/null | grep -c "installed")

if [ "$i_python" -eq 0 ] && [ "$i_git" -eq 0 ]; then
	echo "Python and Git are not installed but required.."
	read -p "Install now? (y/N) " r_pg
	case "$r_pg" in
		y|Y) ;;
		*) exit 0;;
  	esac
  	apt-get update
	pkg install python git
	if [ $? -ne 0 ]; then
		echo "Failed to install python and/or git!" 1>&2
		exit 1
	fi
elif [ "$i_python" -eq 0 ]; then
	echo "Python is required but not installed.."
	read -p "Install now? (y/N) " r_p
	case "$r_p" in
		y|Y) ;;
		*) exit 0;;
	esac
	apt-get update
	pkg install python
	if [ $? -ne 0 ]; then
		echo "Failed to install python!" 1>&2
		exit 1
	fi
elif [ "$i_git" -eq 0 ]; then
	echo "Git is required but not installed.."
	read -p "Install now? (y/N) " r_g
	case "$r_g" in
		y|Y) ;;
		*) exit 0;;
	esac
	apt-get update
	pkg install git
	if [ $? -ne 0 ]; then
		echo "Failed to install git!" 1>&2
		exit 1
	fi
fi

if [ $(pip3 list 2> /dev/null | grep -c "samloader") -eq 0 ]; then
	echo "Samloader is required but not installed.."
	read -p "Install now? (y/N) " r_install
	case "$r_install" in
		y|Y) ;;
		*) exit 0;;
	esac
	pip3 install git+https://github.com/nlscc/samloader.git
fi

model="$(getprop 'ro.product.model')"
region="$(getprop 'ro.csc.sales_code')"
current_pda="$(getprop 'ro.system.build.version.incremental')"
current_csc="$(getprop 'ro.omc.build.version')"

echo -e "- Device:\t$model / $region"

latest_version="$(samloader -m $model -r $region checkupdate)"
latest_pda="$(echo $latest_version | cut -d/ -f1)"
latest_csc="$(echo $latest_version | cut -d/ -f2)"

echo -e "- Installed:\t$current_pda/$current_csc"
echo -e "- Latest:\t$latest_pda/$latest_csc"
echo "---------------"

if [ "$current_pda" = "$latest_pda" ] && [ "$current_csc" = "$latest_csc" ]; then
	if [ ! "$force_download" = true ]; then
		echo "No new version found! Use --force to download anyway.."
		exit 0
	fi
fi

read -p "Download? (y/N) " r_download
case "$r_download" in
	y|Y) ;;
	*) exit 0;;
esac

while true; do
	read -p "Please enter an absolute path to save the file to after downloading (e.g. \"/sdcard/\"): " r_path

	parse_f=$(echo "$r_path" | head -c 1)
	parse_l=$(echo "$r_path" | tail -c 2)

	if [ "$parse_f" = "\"" ] || [ "$parse_l" = "\"" ]; then
		echo "Please enter path again without quotes!" 1>&2
	else
		if [ "$parse_l" != "/" ]; then
			r_path="$r_path/"
		fi
		if [ -e "$r_path" ]; then
			break
		else
			echo "Path not valid! Please try again.." 1>&2
		fi
	fi
done

touch "$r_path.samcheck" 2> /dev/null

if [ $? -ne 0 ]; then
	echo "Permission denied! Running \"termux-setup-storage\".." 1>&2
	echo "Waiting for storage permission.."
	sleep 1
	termux-setup-storage
	count=0
	while true; do
		touch "$r_path.samcheck" 2> /dev/null
		if [ $? -eq 0 ]; then
			break
		fi
		let count++
		if [ "$count" -gt 30 ]; then
			echo "Operation timed out!" 1>&2
			exit 1
		fi
		sleep 1
	done
fi

if [ -e "$r_path.samcheck" ]; then
	rm -f "$r_path.samcheck"
fi

echo "Downloading..."

filename="$(samloader -m $model -r $region download -v $latest_version -O $r_path/. | cut -d' ' -f2)"
size=$(wc -c "$r_path$filename" | cut -d' ' -f1)

if [ "$size" -lt 4500000000 ]; then
	echo -e "\n\nDownload failed.." 1>&2
	echo "Please use $(basename $(readlink -f $0)) --repair.\n" 1>&2
	exit 1
fi

echo "Downloading finished!"

encr_protocol="$(echo $filename | tail -c 2)"
input="$r_path/$filename"
output="$r_path/$(echo $filename | cut -d. -f1-2)"

echo "Decrypting..."
samloader -m "$model" -r "$region" decrypt -v "$latest_version" -V "$encr_protocol" -i "$input" -o "$output"
echo "Decrypting finished!"

if [ -e "$input" ]; then
	rm "$input"
fi

echo "Done! Output:"
echo "$r_path$(echo $filename | cut -d. -f1-2)"

exit 0