#!/bin/bash
#
# make a diff between ./tmp_merged_foocanvas and ./tmp_zmap_foocanvas
# or between a single file in ./tmp_zmap_foocanvas specified on the
# command line and that file in ./tmp_merged_foocanvas. In the case
# of the latter specify the file as ./tmp_zmap_foocanvas/xxxxxxx
#
# Returns 0 on success or 1 if anything fails.
#

scriptname=`basename $0`


msgAndExit ()
{
  errmsg="$scriptname - Fatal Error: $1 !!"

  echo "$errmsg"

  exit 1
}


old='./tmp_merged_foocanvas'
new='./tmp_zmap_foocanvas'


# set up file list as single file from zmap_foocanvas given on command line or all files
# in zmap_foocanvas, it's critical that the list of filenames is given as "./XXXXXX" so
# that patch will pick up the correct files to patch from the diff file.
#
if [ -n "$1" ]
then

  # umm, this isn't nearly good enough a test....
  if [ ! -f $1 ]
  then
    msgAndExit "File $1 does not exist in $new"
  else
    # Normalise file name by chopping off leading "./" _if_ it's present and then
    # adding a leading "./" so that it's always present.

    file_path=${1#./}

    file_path="./$file_path"

    file_list=$file_path
  fi
else
  file_list=`find $new -name "*" -type f | grep -v \.diff`
fi


for i in $file_list
do

  file_name=`basename $i`
  dir_name=`dirname $i`

  old_file="$old/${i#./*/}"

  new_file=$i

  diff_file="$dir_name/$file_name.diff"

  if [[ -f $diff_file && ! -w $diff_file ]]
  then
    echo "$diff_file exists, but is read-only, make writeable [y] ?"
    read reply

    if [[ $reply == 'y' || $reply == '' ]]
    then
      chmod u+w $diff_file || msgAndExit "Could not make $diff_file writeable"
    fi
  fi

#  echo "making diff between  $old_file and $new_file,  output in $diff_file"
#  echo "LC_ALL=C TZ=UTC0 diff -Naur $old_file $new_file > $diff_file"
  LC_ALL=C TZ=UTC0 diff -Naur $old_file $new_file > $diff_file

done


exit 0