#!/usr/local/bin/bash

JFLAGS="-d classes"

## remove the ## comment in function show below to
## see in more detail what this script is doing.

function show
{
	# echo $name: $*
	echo_this=mesg_line
}
function mesg
{
	echo $name: $*
}
function fail
{
	echo $name: $*
	exit 1
}

function test_args
{
	if [ $# -eq 0 ]
	then
		fail no files to compile
	else
		show args = $*
	fi
}

function test_null
{
	if [ -z "$2" ]
	then
		mesg $1 not set?
	else
		show $1 = $2
	fi
}

function test_next
{
	test_null $1 $2

	if [ -d $2 ]
	then
		show $1 = $2
	else
		fail $1 = "$2" is not a directory
	fi
}

function test_dirs
{
	test_null CLASSPATH $CLASSPATH

	test_next DLP_ROOT  $DLP_ROOT
	test_next SWI_EXEC  $SWI_EXEC
	test_next JAVA_ROOT  $JAVA_ROOT
	test_next JIKES_EXEC  $JIKES_EXEC

}

function test_temp
{
	declare -x temp=`pwd`/classes

	if [ -d $temp ]
	then
		show directory $temp exists
	else
		mesg creating directory $temp
		mkdir $temp
	fi
}

function test_tool
{
	declare -x dlp_boot=$SWI_EXEC/pl

	if [ -e $dlp_boot ]
	then
		show pl = $dlp_boot
	else
		fail no pl command found
	fi

	dlp_comp=$DLP_ROOT/lib/execomp.qlf

	if [ -e $dlp_comp ]
	then
		show DLP_COMP = $dlp_comp
	else
		fail $dlp_comp doesnt exist
	fi
}

function test_java
{
	declare -r javac=$JAVA_ROOT/bin/javac
	declare -r jikes=$JIKES_EXEC/jikes

	if [ -e $jikes ]
	then
		java_comp=$jikes
	elif [ -e $javac ]
	then
		java_comp=$javac
	else
		java_comp="unknown"
		mesg no java compiler found
		fail check PATH and JAVA_ROOT or JIKES_EXEC environment variable
	fi

	show java compiler = $java_comp
}

function comp_dtoc
{
	if [ -f $1.pl ]
	then
		show compiling $1.pl to classes/$1.java
		mesg pl -f $dlp_comp -g "(comp('$1.pl','classes/$1.java'),halt)"
		if pl -f $dlp_comp -g "(comp('$1.pl','classes/$1.java'),halt)"
		then
			show compiling classes/$1.java to classes/$1.class
			mesg $java_comp $JFLAGS classes/$1.java
			$java_comp $JFLAGS classes/$1.java
		else
			rm classes/$1.java
			fail compilation errors
		fi
	else
		fail file $1.pl doesnt exist
	fi
}

function comp_jtoc
{
	if [ -f $1.java ]
	then
		show compiling $1.java to classes/$1.class
		mesg $java_comp $JFLAGS $1.java
		$java_comp $JFLAGS $1.java
	else
		fail file $1.java doesnt exist
	fi
}

function comp_list
{
	for i do
		case $i in
			*.pl)	base=`basename $i .pl`
				comp_dtoc $base
			;;
			*.java)	base=`basename $i .java`
				comp_jtoc $base
			;;
			*)	mesg skipping file $i, unknown file extension
				skip=skip+1
			;;
		esac
	done
}

declare -i -x file=0 skip=0
declare -r -x name=`basename $0`
declare -x java_comp
declare -x java_path
declare -x dlp_comp

test_args $*
test_dirs
test_temp
test_tool
test_java
comp_list $*