#!/bin/bash
# Convert a MSYS path list to absolute, Windows-native format.
# Status is zero if successful, nonzero otherwise.

# Copyright (C) 2013-2014 Free Software Foundation, Inc.

# This program 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.

# This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.

# Take only the basename from the full pathname
me=${0//*\//}

usage="usage: ${me} PATHLIST"

help="$usage
  or:  ${me} OPTION

Convert a MSYS path list to absolute, Windows-native format.

PATHLIST should be a colon-separated list of MSYS paths, which will be
written to the standard output after performing these transformations:

1. Discard empty paths.
2. Replace: '\' with '/', '//' with '/' and ':' with ';'.
3. Translate each path to absolute, Windows-native format.

Paths starting with '%emacs_dir%' will be passed verbatim to the
standard output.

Each non existing path will be translated by looking for its deepest
existing directory, which will be translated and the remainder
appended.

Options:
  --help     display this help and exit

Report bugs to <bug-gnu-emacs@gnu.org>."

for arg
do
  case $arg in
    --help | --hel | --he | --h)
      exec echo "$help" ;;
    --)
      shift
      break ;;
    -*)
      echo "${me}: invalid option: $arg" >&2
      exit 1 ;;
    *)
      break ;;
  esac
done

[ $# -eq 1 ] || {
    echo "${me}: $usage" >&2
    exit 1
}

w32pathlist=""

# Put each MSYS path in one positional parameter and iterate through
# them
IFS=:
set -- $1

for p
do
    [ -z "$p" ] && continue

    if [ "${p:0:11}" = "%emacs_dir%" ]
    then
	w32p=$p
    elif [ -d "$p" ]
    then
	w32p=$(cd "$p" && pwd -W)
    else
	# Make some cleanup in the path and look for its deepest
	# existing directory

	p=${p//\\//}
	p=${p//\/\///}
	p=${p%/}

	p1=$p # last candidate tried
	while :
	do
	    p2=${p1%/*} # next candidate to try
	    [ "$p2" = "$p1" ] && {
		# No more candidates to try
		echo "Invalid path '$p'." >&2
		exit 1
	    }
	    [ -z "$p2" ] && p2="/" && break
	    [ -d "$p2" ] && break
	    p1=$p2
	done

	# translate the existing part and append the rest
	w32p=$(cd "${p2}" && pwd -W)
	remainder=${p#$p2}
	w32p+=/${remainder#/}
    fi

    w32pathlist="${w32pathlist};${w32p}"

done

echo "${w32pathlist:1}"