#!/bin/sh
#------------------------------------------------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     |
#   \\  /    A nd           | Copyright (C) 2011-2016 OpenFOAM Foundation
#    \\/     M anipulation  | Copyright (C) 2017 OpenCFD Ltd.
#-------------------------------------------------------------------------------
# License
#     This file is part of OpenFOAM.
#
#     OpenFOAM is free software: you can redistribute it and/or modify it
#     under the terms of the GNU General Public License as published by
#     the Free Software Foundation, either version 3 of the License, or
#     (at your option) any later version.
#
#     OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
#     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
#     FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
#     for more details.
#
#     You should have received a copy of the GNU General Public License
#     along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
#
# Script
#     foamCleanPath
#
# Description
#     Usage: foamCleanPath [-strip] path [wildcard] .. [wildcard]
#
#     Prints its argument (which should be a ':' separated path)
#     without the following:
#         - duplicate elements
#         - elements whose start matches a wildcard
#         - inaccessible directories (with the -strip option)
#
# Note
#     - this routine will fail when directories have embedded spaces
#     - false matches possible if a wildcard contains '.' (sed regex)
#     - the wildcards themselves can be written together and separated
#       by colons or whitespace
#------------------------------------------------------------------------------
usage() {
    cat <<USAGE 1>&2
Usage: ${0##*/} [OPTION] path [wildcard1] .. [wildcardN]
options:
  -debug            print debug information to stderr
  -strip            remove inaccessible directories
  -help             print the usage

Prints its argument (which should be a ':' separated list) cleansed from
  - duplicate elements
  - elements whose start matches one of the wildcard(s)
  - inaccessible directories (with the -strip option)

Exit status
    0  on success
    1  for miscellaneous errors.
    2  initial value of 'path' is empty

USAGE
    exit 1
}


# Parse options
unset optDebug optStrip
while [ "$#" -gt 0 ]
do
    case "$1" in
    -h | -help*)
        usage
        ;;
    -debug)
        optDebug=true
        ;;
    -strip)
        optStrip=true
        ;;
    *)
        break
        ;;
    esac
    shift
done

# Basic checks, setup
[ "$#" -ge 1 ] || usage

dirList="$1"
shift

[ -n "$dirList" ] || exit 2     # Quick exit on empty 'dirList'

#-------------------------------------------------------------------------------

# Debugging (optional)
if [ -n "$optDebug" ]
then
    printDebug() { while [ "$#" -ge 1 ]; do echo "$1" 1>&2; shift; done; }
else
    printDebug() { true; }      # No-op
fi

# Check directory existence (optional)
if [ -n "$optStrip" ]
then
    isDir() { test -d "$1"; }   # Check for directory
else
    isDir() { true; }           # No check (always true)
fi

# The "wildcard1 ... wildcardN" may have been passed as a single parameter
# or may contain ':' separators

oldIFS="$IFS"   # Preserve initial IFS
IFS=': '        # Split on colon, whitespace
set -- $*

printDebug "input>$dirList<"

# Strip out wildcards via sed. Path and wildcard cannot contain '?'.
while [ "$#" -ge 1 ]
do
    wildcard="$1"
    shift
    if [ -n "$wildcard" ]
    then
        printDebug "remove>$wildcard<"
        dirList=$(echo "$dirList:" | sed -e "s?${wildcard}[^:]*:??g")
    fi
done
printDebug "intermediate>$dirList<"

IFS=': '        # Split on colon, whitespace (to avoid surprises)
set -- $dirList

IFS="$oldIFS"   # Restore initial IFS

# Rebuild the list
unset dirList
for dir
do
    printDebug "check>$dir< in $dirList"
    if isDir "$dir"
    then
        # Detect duplicates (ie, dir already in the list)
        duplicate=$(echo ":$dirList:" | sed -ne '\?:'"$dir"':?p')

        if [ -n "$duplicate" ]
        then
            printDebug "duplicate>$dir<"
        else
            dirList="${dirList}${dirList:+:}$dir"
        fi
    fi
done

printDebug "output>$dirList<"
echo "$dirList"

#------------------------------------------------------------------------------