#!/bin/sh
 
APP=$0
search=""
translate=""
move=0
aFile="*"
aRecurse=0
 
doUsage() {
  echo
  echo " $APP (-s|-t) [options]"
  echo
  echo "   Options:"
  echo "     -s      : SED expression (e.g. \"s/_/-/g\" will replace \"_\" with \"-\" for all filenames)"
  echo "     -t      : Character translation map (e.g. \"abc|def\" will change \"apple\" to \"dpple\" )"
  echo "     -m      : Move files, will not move files otherwise"
  echo "     -r      : Recursive renaming in child directories"
  echo "     -a : Set file match condition (current: $aFile)"
  echo "     -h|-H   : Displays this usage screen"
  echo
}
 
transformSed() {
 
  # perform sed op
  F=`echo "$1" | sed "$search"`
 
  # see if we have problems with sed op
  if [ $? -gt 0 ]; then
    echo "Problem detected with sed expression." >&2
    return 1
  fi
 
  # echo out the new string
  echo "$F"
  return 0
}
 
transformTranslate() {
 
  INF=$1
 
  declare -a TSTR
 
  echo "$translate" | tr "|" "\n" | while read T
  do
 
    if [ -z "$T" ]; then
      T=' '
    fi
 
    TSTR[${#TSTR[@]}]="$T"
 
    if [ ${#TSTR[@]} -eq 2 ] ; then
 
      TF=${TSTR[0]}
      TT=${TSTR[1]} 
 
      F=`echo "$INF" | tr "$TF" "$TT"`
 
      # see if we have problems with sed op
      if [ $? -gt 0 ]; then
        echo "Problem detected with translate expression." >&2
        return 1
      fi
 
      echo "$F"
      return 0
    fi
  done
}
 
procFile() {
 
  F="$1"
 
  # skip dirs
  if [ -d "$F" ]; then
    return 1;
  fi
 
  # get original file path
  cpath=`dirname "$F"`
 
  # get original file name
  cfile=`basename "$F"`
 
  if [ ! -z "$search" ]; then # do sed transformation
    cfile=`transformSed "$cfile"`
    if [ $? -gt 0 ]; then return 2; fi
  fi
 
  if [ ! -z "$translate" ]; then # do translate transformation
    cfile=`transformTranslate "$cfile"`
    if [ $? -gt 0 ]; then return 2; fi
  fi
 
  # put filepath together again
  N="$cpath/$cfile"
 
  echo -e "\n BEFORE: '$F'\n  AFTER: '$N'"
 
  # optionally move files to replaced name
  if [ $move -eq 1 ]; then
 
    # only if files have changed
    if [ "$N" != "$F" ]; then
 
      mv "$F" "$N"
 
      if [ $? -eq 0 ]; then
        echo "Moved Successfully"
      else
        echo "Problem while moving.."
      fi;
 
    else
      echo "No filename change detected.."
    fi
 
  fi
}
 
findFiles() {
  if [ $aRecurse -eq 1 ] ; then
    find . -name '* *' -o -name '*' -a -name "$aFile"
  else
    find . -maxdepth 1 -name '* *' -o -name '*' -a -name "$aFile"
  fi
}
 
# read arguments
while getopts 'a:s:t:mrhH' o; do
  case $o in
    a)
      aFile="$OPTARG"
    ;;
    s)
      search="$OPTARG"
    ;;
    t)
      translate="$OPTARG"
    ;;
    m)
      move=1
    ;;
    r)
      aRecurse=1
    ;;
    h|H)
      doUsage
      exit 0
    ;;
    :|\?)
      doUsage >&2
      exit 1
    ;;
  esac
done
 
# validate arguments
if [ -z "$search" ] && [ -z "$translate" ]; then
  echo "No search/replace (-s ) or translate (-t ) operation was provided" >&2
  doUsage >&2
  exit 1
fi
 
# begin processing
findFiles | while read F
do
 
  # process file
  procFile "$F"
 
  # see if we have problems, if so exit early
  if [ $? -gt 1 ]; then
    exit 1
  fi
 
done
 
exit 0