#!/bin/bash

# mkatinit by Ivan Drucker, http://appleii.ivanx.com
# not licensed; please modify and redistribute as you like
# 1.0b4 1-30-11

# 1.1d1 -- uses bashByter. NOT TESTED.

# This script creates the ATINIT file required for netbooting Apple IIe and
#   IIGS clients from a netatalk server. ATINIT is put in the in the
#   (sharename)/USERS hierarchy, or the current directory if it can't.
#   The user can specify the ProDOS startup system program and default prefix.
#   If an argument is supplied, it is used as the username and the prompt is
#   skipped.

# The ATINIT file is not as complete as the ones generated by AppleShare 3.0,
#   and features such as default printer are not used.

# to do
# possibly require confirmation if AFPD_GUEST is not set correctly
#  or offer to change it

# from ID-bashByter library
decToChar () {
# converts single-byte decimal value to equivalent character
# arg: decimal number from 0-255
# out: one character
#exit: 8=extraneous arg, 11=missing arg, 21=invalid arg
    [[ $1 ]] || return 11
    [[ $2 ]] && return 8
    [[ ( $(printf %d "$1" 2> /dev/null ) == $1 ) \
     && ( $1 -ge 0 ) && ( $1 -le 255 ) ]] || return 21
    # args are valid
    echo -n -e "\x$(printf %02X "$1")"
}

writechars () {
# write one or more characters (bytes) to file
# arg1: filename
# arg2: (optional) offset (# of bytes to skip before writing)
# arg3 OR stdin: sequence of characters
#  [stdin required if writing NUL (0) or trailing LF (0x0A) chars]
#  out: nothing
# exit: 8=extraneous arg, 11=missing arg1,
#       13=missing stdin/arg3, 22=invalid arg2
    [[ $1 ]] || { [[ -t 0 ]] || cat > /dev/null; return 11; }
    [[ $2 ]] && { [[ ( $(printf %d "$2" 2> /dev/null) == $2 ) && \
     ( $2 -ge 0 ) ]] || { [[ -t 0 ]] || cat > /dev/null; return 22; } }
    [[ ( ! -t 0 ) && $3 ]] && { cat > /dev/null; return 8; }
    [[ ( -t 0 ) ]] && { [[ $4 ]] && return 8; [[ $3 ]] || return 13; }
    # args are valid
    if [[ -t 0 ]]; then
        echo -n "$3" | \
         dd of="$1" bs=1 seek=$(($2)) conv=notrunc 2> /dev/null
    else
        dd of="$1" bs=1 seek=$(($2)) conv=notrunc 2> /dev/null
    fi
}

#---- mkatinit starts here
IFS=''

#defaults
sharepath=$(grep options:prodos /usr/local/etc/netatalk/AppleVolumes.default | tail -1 | cut -d" " -f1)
prefix=/$(grep options:prodos /usr/local/etc/netatalk/AppleVolumes.default | tail -1 | cut -d" " -f2)
gsprefix=$prefix
startprog="$prefix/BASIC.SYSTEM"
gsstartprog="$prefix/SYSTEM/FINDER"
filename="ATINIT"
user=$(whoami)

echo

usersfolder=1
while [ -n "$1" ] && [ "${1:0:1}" = '-' ]; do
	flag="$1"
	if [ $flag = "-gs" ]; then
		gs=1
		shift
		continue
	elif [ $flag = "-d" ]; then
		noprompt=1
		shift
		continue
	elif [ $flag = "-f" ]; then
		overwrite=1
		shift
		continue
	elif [ $flag = "-g" ]; then
		alsoguest=1
		shift
		continue
	elif [ $flag = "-c" ]; then
		usersfolder=0
		shift
		continue
	else
		badflag=1
		break	
	fi
done

if [ $usersfolder -eq 0 ] && [ -n "$alsoguest" ]; then
	badflag=1
fi

if [ $badflag ]; then
	echo "usage: mkatinit [-gs] [-d] [-f] [-g | -c] [<username>|guest]"
	echo
	echo "<username> should be the name of a netatalk user, or 'guest'"
	echo "-gs sets the default ProDOS netboot system startup program and"
	echo "      prefix for GS/OS (if omitted, ProDOS 8 defaults are used)"
	echo "-d  use the default start program and prefix, without prompting"
	echo "-f  overwrite existing ATINIT file if present, without warning"
	echo "-g  create an ATINIT file for Guest as well as the specified user"
	echo "-c  write ATNIT to current directory instead of USERS hierarchy"
	echo
	exit
fi

arg="$1"

[[ -z $arg ]] && arg=$user

while : ; do

	if [ ${#arg} -gt 32 ]; then
		echo "User name is too long. Exiting with no action."
		exit
	elif [ -n "$arg" ]; then
		if [ `echo $arg | tr '[:upper:]' '[:lower:]'` = "guest" ]; then
			username='<Any User>'
			alsoguest=
			if [[ ! $(grep -F -s $(ls -1 /home) /etc/default/netatalk) ]]; then
				echo 'Warning: The AFPD_GUEST setting in /etc/default/netatalk is not assigned to a'
				echo 'user with a folder in /home. Guest users may be able to boot over the network'
				echo 'into ProDOS 8 for read-only access, but will not be able to boot into GS/OS.'
				if [ $gs ]; then
					echo ' Using ProDOS 8 defaults.'
					gs=
				else
					echo
				fi
				echo
			fi
		else
			username="$arg"
			if [[ ! $(ls -1 /home | grep -F -s $username) ]]; then
				echo "Warning: This username ($username) does not have a folder in /home. This user may"
				echo "not be able to boot over the network into ProDOS 8 or GS/OS."
				echo
			fi
		fi
		if [ $gs ]; then
			startprog="$gsstartprog"
			prefix="$gsprefix"
		fi
	fi
	
	# make username all caps
	username=`echo $username | tr '[:lower:]' '[:upper:]'`
	
	# prompt for folders
	if [ ! $doalsoguest ] && [ ! $noprompt ]; then
		while : ; do
			echo "Enter the ProDOS path to the startup system program."
			echo "default (CR to accept): $startprog"
			read
			if [ ${#REPLY} -gt 64 ]; then
				continue
			elif [ -n "$REPLY" ]; then
				startprog="`echo $REPLY | tr '[:lower:]' '[:upper:]'`"
				echo
			fi
			break
		done
		
		while : ; do
			echo "Enter the initial ProDOS prefix:"
			echo "default (CR to accept): $prefix"
			read
			if [ ${#REPLY} -gt 64 ]; then
				continue
			elif [ -n "$REPLY" ]; then
				prefix="`echo $REPLY | tr '[:lower:]' '[:upper:]'`"
				echo
			fi
			break
		done
	fi
		
	# create folders if needed
	filepath="$PWD/$filename"
	
	while [ $usersfolder -eq 1 ]; do
		# create folders for ATINIT
		while [ ! -d "$sharepath" ]; do
			echo "Shared volume '$sharepath' not found. Edit mkatinit to change the default."
			echo "Enter the local path to the netatalk shared volume used for netboot:"
			read sharepath
		done
	
		if [ ! -d "$sharepath/USERS" ]; then
			mkdir "$sharepath/USERS"
			if [ $? -ne 0 ]; then
				break
			fi
		fi
		if [ ! -d "$sharepath/USERS/$username" ]; then
			mkdir "$sharepath/USERS/$username"
			if [ $? -ne 0 ]; then
				break
			fi
		fi
		if [ ! -d "$sharepath/USERS/$username/SETUP" ]; then
			mkdir "$sharepath/USERS/$username/SETUP"
			if [ $? -ne 0 ]; then
				break
			fi
		else
			if [ ! -w "$sharepath/USERS/$username/SETUP" ]; then
				break
			fi
		fi
		
		# we have a valid USERS folder target for ATINIT
		filepath="$sharepath/USERS/$username/SETUP/$filename"
		usersfolder=2
	done
	
	if [ $usersfolder -eq 1 ]; then
		echo "Could not write to shared volume. Creating ATINIT in current directory."
		if [ -n "$alsoguest" ]; then
			echo "ATINIT for Guest user will not be created."
		fi
		echo
		alsoguest=
	fi

	if [ ! $doalsoguest ]; then
		echo "netboot start program: $startprog"
		echo "netboot start prefix : $prefix"
		echo
	fi
	
	#remove ATINIT if present
	if [ ! $overwrite ] && [ -f "$filepath" ]; then
		echo -n "$filepath already exists. Overwrite? "
		while read -s -n 1 > /dev/null 2>&1; do
			if [ -z "$REPLY" ]; then
				continue
			elif [ "$REPLY" = "Y" ] || [ "$REPLY" = "y" ]; then
				echo
				break
			elif [ "$REPLY" = "N" ] || [ "$REPLY" = "n" ]; then
				echo
				echo "Exiting with no action."
				exit
			fi
		done
	fi
	
	#write the file. start with zeroes
	dd if=/dev/zero of="$filepath" bs=1 count=276 2> /dev/null
	#put in startprog, prefix, username (first byte of each field is length)
	# ( echo -n "${#startprog}" | awk '{printf("%c",$0);}'; echo -n "$startprog"; ) | dd of="$filepath" bs=1 seek=7 conv=notrunc 2> /dev/null
	# ( echo -n "${#prefix}" | awk '{printf("%c",$0);}'; echo -n "$prefix"; ) | dd of="$filepath" bs=1 seek=78 conv=notrunc 2> /dev/null
	# ( echo -n "${#username}" | awk '{printf("%c",$0);}'; echo -n "$username"; ) | dd of="$filepath" bs=1 seek=143 conv=notrunc 2> /dev/null
	( decToChar "${#startprog}"; echo -n "$startprog"; ) | writechars "$filepath" 7
	( decToChar "${#prefix}"; echo -n "$prefix"; ) | writechars "$filepath" 78
	( decToChar "${#username}"; echo -n "$username"; ) | writechars "$filepath" 143
	
	echo "Created $filepath"
	if [ ! $alsoguest ]; then
		break
	fi

	if [ $usersfolder -eq 2 ]; then
		usersfolder=1
	fi
	doalsoguest=1
	arg='guest'
done

echo