#! /bin/bash
# vim: set tabstop=4 shiftwidth=4 noexpandtab filetype=sh:

# mkpo - create ProDOS disk image
#
# To the extent possible under law, T. Joseph Carter and Ivan Drucker have
# waived all copyright and related or neighboring rights to the a2cloud
# scripts themselves.  Software used or installed by these scripts is subject
# to other licenses.  This work is published from the United States.

# ID-bashByter routines

function binToDec ()
{
	dec=0;
	bits=$1;
	while (( ${#bits} < 8 )); do
		bits="0$bits";
	done;
	for n in {0..7};
	do
		(( dec+=( ${bits:$n:1} * ( 2**(7-$n) ) ) ));
	done;
	echo -n $dec
};

function writecharDec ()
{
	[[ -n $1 ]] || return 11;
	[[ -n $2 ]] || return 12;
	[[ -n $3 ]] || return 13;
	[[ -n $4 ]] && return 8;
	[[ ( $(printf %d "$2" 2> /dev/null) == $2 ) && ( $2 -ge 0 ) ]] || return 22;
	[[ ( $(printf %d "$3" 2> /dev/null) == $3 ) && ( $3 -ge 0 ) && ( $3 -lt 255 ) ]] || return 23;
	echo -n -e "\x$(printf %02X "$3")" | dd of="$1" bs=1 seek=$(($2)) conv=notrunc 2> /dev/null
};

function writecharsHex ()
{
	[[ -n $1 ]] || return 11;
	[[ -n $2 ]] || return 12;
	[[ -n $3 ]] || return 13;
	[[ -n $4 ]] && return 8;
	[[ ( $(printf %d "$2" 2> /dev/null) == $2 ) && ( $2 -ge 0 ) ]] || return 22;
	p=0;
	offset=$2;
	len=${#3};
	while (( p < len )); do
		outByte=${3:$p:2};
		[[ $(printf %02X "0x$outByte" 2> /dev/null) == $(echo -n "$outByte" | tr [a-z] [A-Z]) ]] || return 23;
		echo -n -e "\x$outByte" | dd of="$1" bs=1 seek=$offset conv=notrunc 2> /dev/null;
		(( p += 3 ));
		(( offset++ ));
	done
};

# mkpo

[[ ! -n $1 ]] && { echo "Usage: mkpo [-b totalBlocks] newImageName [PRODOS.VOL.NAME]"; exit 1; };

[[ -f /usr/local/adtpro/adtpro.sh ]] && adtPath="/usr/local/adtpro" || adtPath=$(ls -1d /Applications/ADTPro* | head -1);
[[ ! -d "$adtPath" ]] && { echo "AppleCommander not found."; exit 1; }

if [[ $1 == "-b" ]]; then
	totalBlocks="$2"
	shift
	shift
fi

[[ -f $1 ]] && { echo "Image '$1' already exists."; exit 1; }

[[ $2 ]] && prodosVolName="$2" || prodosVolName="UNTITLED"
# test ProDOS name legitimacy
prodosVolName=$(tr [:lower:] [:upper:] <<< $prodosVolName )
if [[ ${#prodosVolName} -gt 15 || ! $(grep ^[A-Z][0-9A-Z\.]*$ <<< $prodosVolName) ]]; then
	echo "Invalid ProDOS name: $prodosVolName"; exit 1;
fi

# see if nulib2 is available; if so, acmd -convert will create image
#   with specified block size
nulib2 &> /dev/null
[[ $? == 2 ]] && nulib2=1 || nulib2=
if [[ $nulib2 ]]; then
	if [[ $totalBlocks ]]; then
		imageBlocks="$totalBlocks"
	else
		if [[ $(tr [:upper:] [:lower:] <<< "${1##*.}") == "dsk" ]]; then
			imageBlocks=280
		else
			imageBlocks=1600
		fi
	fi
	rm /tmp/blank.shk &> /dev/null
	orig_dir="$PWD"
	cd /tmp
	rm blank.shk EMPTY &> /dev/null
	touch EMPTY
	nulib2 -a blank.shk EMPTY &> /dev/null
	cd "$orig_dir"
	acmd -convert /tmp/blank.shk "$1" $imageBlocks
	acmd -d "$1" EMPTY
	rm /tmp/blank.shk /tmp/EMPTY
	acmd -n "$1" "$prodosVolName"
else
	# make the disk image without converting archive
	if [[ $totalBlocks || $(tr [:upper:] [:lower:] <<< "${1##*.}") == "dsk" ]]; then
		acmd -pro140 "$1" $prodosVolName;
	else
		acmd -pro800 "$1" $prodosVolName;
	fi
fi

# make the disk bootable
if [ -f "$adtPath"/disks/ADTPRO*PO ]; then
	dd bs=512 count=1 of="$1" conv=notrunc < "$adtPath"/disks/ADTPRO*PO 2> /dev/null
fi

# change .DSK to DOS-ordered
if [[ ! $totalBlocks && $(tr [:upper:] [:lower:] <<< "${1##*.}") == "dsk" ]]; then
	mv "$1" "$1".tmp
	for t in {0..34}; do
		for s in 0 14 13 12 11 10 9 8 7 6 5 4 3 2 1 15; do
			dd bs=256 count=1 if="$1".tmp of="$1" skip=$(( $t*16 + $s )) seek=$(( $t*16 + ( $s==0||$s==15 ? $s : 15-$s ) )) 2> /dev/null;
		done;
	done
	rm "$1".tmp
fi

# if nulib2 isn't available, patch the disk image to use specified block size
if [[ ! $nulib2 && $totalBlocks ]]; then
	# change total block count
	bcHex=$(printf "%04X" $totalBlocks);
	writecharsHex "$1" 1065 "${bcHex:2:2}.${bcHex:0:2}";

	# fix FSB
	dd if=/dev/zero of="$1" bs=512 seek=280 count=$(( $totalBlocks - 280 )) 2> /dev/null;
	dd if="$1" of="$1" bs=1 skip=3073 seek=3107 count=$(( ($totalBlocks / 8) - 35 )) conv=notrunc 2> /dev/null;
	bits=$(( $totalBlocks % 8 ));
	if (( bits > 0 )); then
		usedString="00000000";
		freeString=;
		for ((b=0; b<$bits; b++))
		do
			freeString=$freeString"1";
		done;
		binString=$freeString${usedString:$bits};
		writecharDec "$1" $(( ( ($totalBlocks / 8) - 35) + 3107 )) $(binToDec $binString);
	fi;

	# assign extra blocks to FSB if needed
	fsbExtraBlocks=$(( ($totalBlocks-1)/4096 ));
	if (( fsbExtraBlocks > 0 )); then
		dd if=/dev/zero of="$1" bs=1 seek=3072 count=$(( (fsbExtraBlocks > 8) + 1 )) conv=notrunc 2> /dev/null;
		(( fsbExtraBlocks-- ));
	fi;

	bits=$(( fsbExtraBlocks % 8 ));
	if (( bits > 0 )); then
		freeString="11111111";
		usedString=;
		for ((b=0; b<$bits; b++))
		do
			usedString=$usedString"0";
		done;
		binString=$usedString${freeString:$bits};
		writecharDec "$1" $(( (fsbExtraBlocks>7)+3073 )) $(binToDec $binString);
	fi;
fi