#!/bin/sh -e

## DOSLDR - Damn, Open Source Literally Defines Rubbish
## gbsn
## public domain

# --- #

version="0.8"

root="${HOME}/dosldr"
config="${HOME}/dosbox.conf"
device="/dev/sr0"
editor="dte"

password="80abf72386c3e5f475f3ab0ffc232c130300218c050912aa025c4a5ffdc934e4"

mainmenu="\
Choose an option:
 [s]elect a game
 [a]dmin menu
 [v]iew credits
 [q]uit"

adminmenu="\
Choose an option:
 [i]nstall a game
 [r]emove a game
 [g]ame config
 [d]osbox config
 [s]hutdown machine
 [q]uit to main menu"

selectmenu="\
Press Q to go back. Type a number and press ENTER to select.
Press L for last page. Press R for next page.
"

removemenu="\
WARNING: You are in the REMOVAL MENU
         If you are not supposed to be here, press Q

${selectmenu}"

ident=' ___  ___ __  __   ___   ___  ___   __  __ ___ _  _ _   _
| _ \/ __|  \/  | |   \ / _ \/ __| |  \/  | __| \| | | | |
|   / (__| |\/| | | |) | (_) \__ \ | |\/| | _|| .` | |_| |
|_|_\\\\___|_|  |_| |___/ \___/|___/ |_|  |_|___|_|\_|\___/'

adminident=' ___  ___ __  __   ___   ___  ___   __  __ ___ _  _ _   _
| _ \/ __|  \/  | |   \ / _ \/ __| |  \/  | __| \| | | | |
|   / (__| |\/| | | |) | (_) \__ \ | |\/| | _|| .` | |_| |
|_|_\\\\___|_|  |_| |___/ \___/|___/ |_|  |_|___|_|\_|\___/

(admin mode)'

# --- #

die()
{
	reset
	echo "$@" 1>&2
	exit 1
}

reexec()
{
	clear
	exec "$0"
}

readb()
{
	stty -icanon -echo
	input="$(dd count=1 bs=1 2> /dev/null)"
	stty icanon echo
}

info()
{
	clear
	echo "${ident}"
	echo ""
	echo "$@"
}

error()
{
	info "error: $@"
	echo ""
	echo "press a key to continue..."
	readb
}

errorr()
{
	error "$@"
	reexec
}

prompt()
{
	info "$@"
	echo ""
	printf ">>> "
	read input
}

menu()
{
	info "$@"
	echo ""
	printf ">>> "
	readb
}

games()
{
	for game in "${root}"/*
	do
		printf "${game##*/}\n"
	done | sort
}

gamesmenu()
{
	page=0
	max=$(($(tput lines) - $(echo "$1" | wc -l) - $(echo "${ident}" | wc -l) - 4))
	while true
	do
		info "$1"

		i=0
		n1=$((page * max + 1))
		n2=$(((page + 1) * max))

		set +e
		games | sed -n "${n1},${n2}p" | while read game
		do
			echo " ${i} - ${game}"
			i=$((i+1))
			[ ${i} -ge ${max} ] && break
		done
		set -e

		echo ""
		printf ">>> "

		while true
		do
			readb
			case "${input}" in
				0|1|2|3|4|5|6|7|8|9)
					n="${input}"
					printf "\r>>> ${n}"
					while true
					do
						readb
						hex="$(echo "${input}" | xxd -p | cut -b1,2)"
						[ "${hex}" = "7f" -o "${hex}" = "08" ] && n=${n%?} &&
							if [ -z "${n}" ]
							then
								continue 3
							else
								printf "\r>>> ${n}  \r>>> ${n}"
								continue
							fi
						[ "${hex}" = "0a" ] && break
						[ 48 -le "$((0x${hex}))" -a "$((0x${hex}))" -le 57 ] && n="${n}${input}" && printf "\r>>> ${n}"
					done
					break
					;;
				l|L)
					[ "${page}" -gt 0 ] && page=$((page - 1)) && continue 2
					;;
				r|R)
					[ "$(games | wc -l)" -ge $(((page + 1) * max)) ] && page=$((page + 1)) && continue 2
					;;
				q|Q) break 2 ;;
			esac
		done

		if ! [ "${n}" -ge 0 ]
		then
			error "invalid game id"
			continue
		fi
		game=$(games | sed -n $((page * max + n + 1))p)
		[ -z "${game}" ] && error "invalid game id" && continue
		break
	done
}

# --- #

mkdir -p "${root}"

menu "${mainmenu}"
case "${input}" in
	s)
		gamesmenu "${selectmenu}"
		if [ ! -z "${game}" ]
		then
			[ -e "${config}" ] || errorr "global config not found"
			[ -e "${root}/${game}/conf" ] || errorr "config for ${game} not found"
			[ -e "${root}/${game}/iso" ] || errorr "image for ${game} not found"
			[ -d "${root}/${game}/drive" ] || errorr "drive for ${game} not found"
			clear
			dosbox -conf "${config}" -conf "${root}/${game}/conf"
		fi
		reexec
		;;
	a)
		stty -echo
		prompt "enter admin password (blank to abort): "
		stty echo
		[ "${input}" ] || reexec
		[ "$(echo "${input}" | sha256sum | cut -d' ' -f1)" != "${password}" ] && errorr "invalid password"

		ident="${adminident}"

		while true
		do
			menu "${adminmenu}"
			case "${input}" in
				i)
					info "Installing"
					while true
					do
						prompt "Enter game name (blank to abort)"
						name="${input}"
						[ -z "${name}" ] && reexec
						[ -e "${root}/${input}" ] && error "${input} already installed" && continue
						break
					done

					echo ""
					echo "Insert disk and press enter (q to abort)"
					readb
					[ "${input}" = q -o "${input}" = Q ] && reexec
					info "Installing ${name}"

					echo ""
					echo "Creating game files..."
					mkdir "${root}/${name}"
					cd "${root}/${name}"
					mkdir "drive"
					cat > "conf" << EOF
[autoexec]
@ECHO OFF
MOUNT C "${root}/${game}/drive"
IMGMOUNT D "${root}/${game}/cue" -t iso
CLS
:: add game load here
EXIT
EOF

					echo "Creating disk image..."
					sudo cdrdao read-cd --read-raw --driver generic-mmc:0x20000 --device "${device}" --datafile bin toc
					sudo toc2cue toc cue
					sudo rm toc
					sudo chown $(id -u):$(id -g) bin cue
					cd -

					echo ""
					echo "Enter DOSBOX? [Y/n] "
					readb
					[ "${input}" != "n" -a "${input}" != "N" ] && dosbox -conf "${config}" -c "MOUNT C \"${root}/${game}/drive\"" -c "IMGMOUNT D \"${root}/${game}/cue\" -t iso"

					echo "Edit config? (HIGHLY recommended) [Y/n] "
					readb
					[ "${input}" != "n" -a "${input}" != "N" ] && ${editor} "${root}/${name}/conf"

					echo ""
					echo "Installation complete"
					echo "Press a key"
					readb
					reexec
					;;
				r)
					gamesmenu "${removemenu}"
					if [ ! -z "${game}" ]
					then
						prompt "Are you SURE you want to remove ${game}? [reenter password to confirm]"
						[ ! "$(echo ${input} | sha256sum | cut -d' ' -f1)" = "${password}" ] && error "invalid password, aborting" && continue
						rm -r "${root}/${game}"
					fi
					;;
				g)
					gamesmenu "${selectmenu}"
					if [ ! -z "${game}" ]
					then
						${editor} "${root}/${game}/conf"
					fi
					;;
				d)
					${editor} "${config}"
					;;
				s)
					sudo init 0
					;;
				q)
					reexec
					;;
			esac
		done
		;;
	v)
		clear
		echo "\
=== DOSLDR/${version} ===

George          Programming
RCM             Other stuff
The Internet    Advice
DOSBOX Team     Creating DOSBOX
Launchbox       Needing a replacement

Visit the Retro Computer Museum online -- https://retrocomputermuseum.co.uk/
View my other things -- https://tty0.xyz/
"
		readb
		reexec
		;;
	q)
		echo
		exit 0
		;;
	*) reexec ;;
esac

# --- #

#############
# CHANGELOG #
#############
#
# 0.8 (2019-04-21)
#     install: fix ripping
#     games: prevent typing invalid characters after entering a number
#     games: use ${hex} consistently
#     admin: add option to shutdown machine
#
# 0.7 (2019-04-18)
#     admin: create administration menu
#     admin: add option to edit config files
#     remove: create removal menu in admin menu
#     install: move to admin menu
#     install: fix typo
#     dosbox: new global config file
#     main: add quit option to main menu
#     ui: show different ident in admin menu
#
# 0.6 (2019-04-17)
#     select: move game menu to seperate function
#     games: proper backspace handling
#     games: clean break/continue statements
#     games: calculate ${max} properly
#     install: slightly better UI
#     credits: less calls to echo
#     credits: credit the internet
#     credits: shameless self promotion
#
# 0.5 (2019-04-16)
#     dosldr: reorganise ${root}
#     dosbox: use userconf instead of global config
#     games: remove need for catalog file
#     ui: new functions for erroring
#
# 0.4 (2019-04-15)
#     ui: new ui system
#     install: rip to bin+cue instead of iso
#     install: better default config
#     dosbox: add global config file
#     credits: more detailed credits
#
# 0.3 (2019-04-14)
#     install: create installation menu
#     select: add backspace handling
#     credits: create credits
#
# 0.2 (2019-04-13)
#     select: fix pages
#     select: configurable games per page
#     select: remove unreachable branch
#
# 0.1 (2019-04-12)
#     create dosldr