#!/bin/ksh
#
# ncd clone
#
# Partially based in:
#     Fergal Goggin 11-April-2000, SSL ncd clone
#
# Create a list of directories with find and store in .ncd.MACHINENAME
# Zgrep the file each time user requests the change dir
#
# Compare requested dir name with each $line##*/ from grep to see if it matches even partially and store
# 
# check if current dir is in the list of matched and jump to the next in the list
# if not currently in any of the dirs in the list, jump to the first in the list
#
#
# Don't forget to create an alias, otherwise you won't change anywhere:
#    alias go='. go'
#
#  Versions
#    V1.0  2008/07/18   Search based in the beginning of the directory name and with a second file
#                       to implement the rotation along the existing dirs that start with the same
#                       pattern
#
#    V1.1  2008/07/21   Fixed a bug where a pattern belonging to the middle of the directory name
#                       causes noLines to be non-zero and later $NCDTMPROTFILE not being created,
#                       since the pattern is not at the begin of the directory name, although it
#                       exists!
#
#    V1.2  2008/07/22   Removed all TABS
#                       Fixed +($1*) to $1* to work also in bash
#                       There is still a variable visibility problem in bash at lines 109, 118 

#treat unset variables as if they were set
# and errors like "ksh: @: parameter not set" go away
set +u

BOLD_TYPE=""
NORMAL_TYPE=""
INVERSE_TYPE=""
if [ $TERM = "xterm" ]
then 
   BOLD_TYPE=""
   NORMAL_TYPE=""
   INVERSE_TYPE=""
fi

NCDDATABASE=$HOME/.ncd.`uname -n`
NCDTMPFILE=/tmp/$$.ncd
NCDTMPROTFILE=/tmp/$$rot.ncd
if [ "$BASEDIR" = "" ] 
then
   BASEDIR=$HOME
fi

if [ ! -f $NCDDATABASE ]
then 
   echo "re-creating database from $BASEDIR"
   find $BASEDIR -type d 2> /dev/null | gzip > $NCDDATABASE
elif [ $# -lt 1 ]
then 
   echo "go, change directory for UNIX, fgoggin 2000 --- based on ncd, by fgoggin 2000"
   echo "usage: go <directory>     - change directory to <directory>"
   echo "usage: [BASEDIR=XXX] go   - recreate database (delete .ncd.* in case of trouble) "
else
   zgrep $1 $NCDDATABASE > $NCDTMPFILE
   trap 'rm -f $NCDTMPFILE $NCDTMPROTFILE' 2
   noLines=0
   # wc -l seems to stick a tab in front of it output 
   # so it is just as easy to use grep -c
   noLines=`grep -c ^ $NCDTMPFILE`
   if [ $noLines -eq 0 ] 
   then 
      echo "No match"
   elif [ $noLines -eq 1 ]
   then 
      # exact match
      cd `cat $NCDTMPFILE`
   else
      # search for those whose basename contain $1 partially or as a whole
      rm -f $NCDTMPROTFILE

      cat  $NCDTMPFILE |
      {
          while read LINE; do
            BASENAME=${LINE##*/};
#if [[ $BASENAME = +($1*) ]];  # nice! if basename equals something that has 1 or more times $1
            if [[ $BASENAME = $1* ]];  # nice! if basename equals something that has 1 or more times $1
            then
              #echo MATCH: $LINE;
              echo $LINE >> $NCDTMPROTFILE
            fi
          done
      }
      #cat $NCDTMPROTFILE

      # sometimes the user inserts a pattern that occurs in the middle of the directory name
      # and that causes noLines to be non-zero.
      # Since the previous if (the one with the nice! comment) only catches directories that
      # start with the pattern, this file may not be created! and so that problem is prevented here!
      if [ ! -f $NCDTMPROTFILE ]; then
         echo "No match"
         rm -f $NCDTMPFILE;
         return 1;
      fi

      # check if the pwd is any of the list and if it is jump to the next
      CHOICE=1
      DESTINATION=""
      DESTINATIONROTATION=""
      CWD=`pwd`
      cat  $NCDTMPROTFILE |
      {
          while read LINE; do
            #echo Processing: $LINE
            # keep the first to use by default
            if [ $CHOICE -eq 1 ]; then
              DESTINATION=$LINE
              DESTINATIONROTATION=$LINE
            fi

            if [[ "$LINE" = "$CWD" ]]; then 
               echo Multiple choices for [$1] and you are at ${INVERSE_TYPE}${LINE}${NORMAL_TYPE};
               read DESTINATION;
               break;
            fi

            CHOICE=`expr $CHOICE + 1`
            #echo $CHOICE
          done
      }

      # at the end of the list, it should rotate to the home dir
      if [ "$DESTINATION" = "" ]; then
        DESTINATION=$DESTINATIONROTATION
      fi

      echo "switching to $DESTINATION";
      cd $DESTINATION
   fi
fi
rm -f $NCDTMPFILE $NCDTMPROTFILE
unset CHOICE
unset DESTINATION
unset DESTINATIONROTATION
unset CWD
unset NCDDATABASE
unset NCDTMPFILE
unset NCDTMPROTFILE
unset NORMAL_TYPE
unset INVERSE_TYPE
unset BOLD_TYPE
unset noLines
BASEDIR=""