#! /bin/ksh
#
#	Author: Mike Fleming mike@tauzero.co.uk
#
#	View a file using COBOL viewer

#	Possible alternative location for file viewer

FVIEWOBJ=$OBJ

#	Get filename in upper and lower case

if [[ $# > 0 ]]
then
	FN=$(echo $1 | tr [a-z] [A-Z])
	fn=$(echo $FN | tr [A-Z] [a-z])

	shift 1

#	Have we got a COBOL file viewer?

#	If we have one on COBPATH, it would probably be the best bet to
#	match the file definition

	for a in . $(echo $COBPATH | tr : ' ')
	do
		if [[ -f $a/fview$fn.int || -f $a/fview$fn.gnt ]]
		then
			cobrun fview$fn $*
			return
		fi
	done

#	If not, check a possible alternative location

	if [[ -f $FVIEWOBJ/fview$fn.int ]]
	then
		cobrun $FVIEWOBJ/fview$fn.int $*
	fi

	return

fi

#	Find available file viewers and put them into menu

COBPROGS=$(echo $COBPATH | sed 's/:/\/fview*.int /g')
COBPROGS=$COBPROGS/fview*.int

if [[ $(echo $COBPROGS | cut -c5) == /fview ]]
then
        COBPROGS=./$COBPROGS
fi

LIST=$(ls $COBPROGS $FVIEWOBJ/fview*.int 2> /dev/null)
SLIST=$(for a in $LIST;do echo $(basename $a .int) | cut -c6-;done | sort -u)
set -A names $SLIST

if [[ "${names[0]}" == "" ]]
then
	echo No viewer programs found
	return 1
fi

#	Is the menu program available?

if type menu >/dev/null 2>&1
then
	while true
	do
		menu "File viewers" "${names[@]}"
		ptr=$?
		if (( ptr > 127 || ptr < 1 ))
		then
			break
		fi
		ptr=$((ptr - 1))
		cobrun fview${names[$ptr]}
	done
	return 0
fi

PGLEN=25

#       page = current page (starts at 0)
#       index = screen array pointer for display (starts at 0)
#       line = display line number (starts at 1)
#       ptr = pointer to file to display

typeset -i page=0
typeset -i index
typeset -i line
typeset -i ptr

while [[ "$REPLY" != "Q" && "$REPLY" != "q" ]]
do

	lastline=$((PGLEN - 1))
	line=1
	index=$((page * lastline))

	while [[ -n "${names[$index]}" && $line -le $lastline ]]
	do
		if (( line < 10 ))
		then
			lno=" "$line
		else
			lno=$line
		fi
		echo "$lno" ${names[$index]}
		index=$((index + 1))
		line=$((line + 1))
	done

	FURTHER=""

	if [[ -n "${names[$index]}" ]]
	then
		FURTHER=$FURTHER" [N]ext page,"
	fi

	if (( page > 0 ))
	then
		FURTHER=$FURTHER" [P]revious,"
	fi

	read REPLY?"No. of file to view,$FURTHER [Q]uit "

	if [[ "$REPLY" == "" ]]
	then
		REPLY="X"
	fi

	if (( $(echo $REPLY | grep -c "^[0-9]*$") > 0 ))
	then
		if (( REPLY > 0 && REPLY <= lastline ))
		then
			ptr=$(((page * lastline) + (REPLY - 1)))
			if [[ -n "${names[$ptr]}" ]]
			then
				cobrun fview${names[$ptr]}
			fi
		fi
	else
		case $REPLY in
		P | p)  if (( page > 0 ))
			then
				page=$((page - 1))
			fi;;
		N | n)  if [[ -n "${names[$index]}" ]]
			then
				page=$((page + 1))
			fi;;
		esac
	fi

done