#!/bin/sh
#AUTHOR:  JT Moree <moreejt @ pcxperience.com>
#LICENSE:  This code is in the public domain

PROG=`basename "$0"`
VERSION='0.1'
BUILD='$Id$'

ARGS=

usage()
{
  if [ "$PROG" = "ext2lc" ] ; then
    C=lower
  else
    C=upper
  fi
  cat << FOO

  $PROG - change file extensions to ${C}case

  Usage:  $PROG [options] file1 file2 ...
    -f force overwrite of files (will not prompt by default)
    -h help
    -i prompt before overwrite
    -S skip warning
    -V Verbose
    -v version

FOO
  if [ "$PROG" = "ext2lc" ] ; then
    cat << FOO
  File extensions such as '.JPG' and '. A BC' will be lowercased
  (ie. '.jpg' and '. a bc').

FOO
  else
    cat << FOO
  File extensions such as '.jpg' and '. a bc' will be uppercased
  (ie. '.JPG' and '. A BC').

FOO
  fi
}

COUNT=0 #count up args to shift off later
while getopts fhiSVvx OPTION
do
  COUNT=$(($COUNT + 1))
  case "$OPTION" in
    f) FORCE="-f"
    ;;
    h) usage ; exit 1
    ;;
    i) INTERACTIVE="-i"
    ;;
    S) SKIP=y
    ;;
      V) VERBOSE=y ;
    ;;
      v) echo $0 Version: $VERSION; exit 1
    ;;
      x) set -x ;
    ;;
      *) echo Invalid Option >&2
      usage
      exit 1
    ;;
  esac
done

shift $COUNT

if [ ${#@} -lt 1 ] ; then
  echo "No input files given" >&2
  usage
  exit 1
fi

if [ -z "$SKIP" ] ; then
  cat << BAR
#########################################################
                    WARNING!
This program will rename your files!!!
Please make backup copies first.
Press Ctrl + C now to quit.  Enter to continue
#########################################################

BAR
  read FOO
fi

while [ $# -gt 0 ]; do
  FILE=$1
  shift 1
  if [ ! -r "$FILE" ] ; then
    echo "Warning:  '$FILE' is not valid.  Skipping. . ." >&2
  else
    EXT=${FILE##*.}
  #  EXT=`echo $file | sed 's/^\(.*\.\)\(.*\)$/\2/g'`
    if [ -z "$EXT" ] || [ "$FILE" = "$EXT" ] ; then
      echo "$FILE does not have an extention.  Skipping . . ." >&2
    else
      NAME=`basename "$FILE" ".$EXT"`
      if [ -z "$NAME" ] ; then
        echo "Error.  Could not parse the name portion of $FILE" >&2
      else

        #if in lower mode
        if [ "$PROG" = "ext2lc" ] ; then
          CASE=`echo "$EXT" | tr '[A-Z]' '[a-z]'`
        else
          CASE=`echo "$EXT" | tr '[a-z]' '[A-Z]'`
        fi
        if [ "$FILE" != "$NAME.$CASE" ] ; then  #skip if file is same
          if [ -f "$NAME.$CASE" ] && [ -z "$FORCE" ] ; then #file already exists
            echo "File $NAME.$CASE already exists.  Skipping $FILE . . ." >&2
          else
            mv -v $FORCE $INTERACTIVE "$FILE" "$NAME.$CASE"
          fi
        fi

      fi
    fi
  fi
done