#!/bin/sh

set -eu
#set -x

case ${GIT_EXTERNAL_DIFF-} in '')
	case "$0" in */*) cmd="$0" ;; *) cmd="./$0" ;; esac
	case ${1-} in -b|-w) XXDIFF_OPTS=$1; export XXDIFF_OPTS; shift; esac
	! git diff --shortstat --exit-code "$@" || exit 0
	PAGER=cat GIT_EXTERNAL_DIFF=$cmd
	export PAGER GIT_EXTERNAL_DIFF
	echo
	echo "***" Press Ctrl-C in this window to break all following diffs.
	echo
	echo "***" Note, you can edit the file you are diffing and then rediff
	echo "***" it with the original by pressing Ctrl-R on xxdiff window.
	echo
	exec git diff --ext-diff "$@"
	exit 1
esac

die () { echo $0: "$@" >&2; sleep 2; }

case ${5-} in
	'') die Required file argument"(s)" missing. ;;
	/dev/null) echo "\$2 = '$2', \$5 = '$5'" ; exit 0 ;;
esac

case $1 in /dev/null) echo "\$1 = '$1', \$5 = '$5'" ; exit 0 ;; esac

test -f "$5" || die "'$5': Not a file."

setdim () { # change tools which check current win in xinerama setup.
	set x `xdpyinfo | awk '/dimensions:/ {sub("x", " ", $2); print $2}'`
	width=`expr ${2:-1024} - 20`
	test $width -le 1920 || width=1900
	height=`expr ${3:-768} - 200`
}
setdim

test $width -lt 1024 && tfopt='--textfont Sans,8,-1,5,50,0,0,0,0,0' || tfopt=

echo "***" Executing xxdiff ... "'$2'" "'$5'"
xxdiff ${XXDIFF_OPTS-} $tfopt --geometry ${width}x${height}+5+5 "$2" "$5" || :