#!/bin/sh
#------------------------------------------------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     |
#   \\  /    A nd           | Copyright (C) 2019 OpenCFD Ltd.
#    \\/     M anipulation  |
#-------------------------------------------------------------------------------
# License
#     This file is part of OpenFOAM, licensed under GNU General Public License
#     <http://www.gnu.org/licenses/>.
#
# Script
#     wrap-bison
#
# Usage
#     wrap-bison -input=*.yy -output=*.cc [bison-options]
#
# Description
#     A wrapper to handle renaming/relocation of bison-generated files.
#
#     When bison is used, it generates several output files.
#     The names of the regular output files may not match our expectations.
#     The skeleton files are always named the same, which can cause
#     file-name collisions in some cases.
#
#     Input:
#       - myFile.yy
#
#     Output: <myFile.yy>
#       - myFile.tab.hh
#       - myFile.tab.cc
#       - location.hh
#       - position.hh
#       - stack.hh
#
#     Approach
#       - call bison from within a local Make/some-name/ directory.
#       - use sed to modify the #include contents and rename files.
#         From location.hh -> myFile.location.hh
#       - place generated *.hh files directly into lnInclude/
#       - place generated *.cc file into the build/ directory
#
# Note
#     General idea lifted from swak
#------------------------------------------------------------------------------
usage() {
    exec 1>&2
    while [ "$#" -ge 1 ]; do echo "$1"; shift; done
    cat<<USAGE

Usage: ${0##*/} [options] [bison args/options]

options:
  -input=NAME       Perform the renaming actions
  -output=NAME      Perform the renaming actions
  -h, -help         Print the usage

A bison wrapper with renaming of skeleton files

USAGE
    exit 1
}

# File extensions used
extCode="cc"
extHead="hh"

#------------------------------------------------------------------------------
# Parse arguments and options
#------------------------------------------------------------------------------

# wrap-bison -input=... -output=...
unset inputFile outputFile
while [ "$#" -gt 0 ]
do
    case "$1" in
    (-h | -help*) usage ;;

    (-input=*)    inputFile="${1#*=}" ;;
    (-output=*)   outputFile="${1#*=}" ;;

    (*) break ;;
    esac
    shift
done

# No rename action supplied? Juet execute bison directly.
if [ -z "$inputFile" ]
then
    bison $*
    exit $?
fi

#------------------------------------------------------------------------------
# Renaming requested

# Need lnInclude/ directory
[ -d lnInclude ] || mkdir lnInclude 2>/dev/null || {
    echo "Cannot continue without an lnInclude directory" 1>&2
    pwd -L
    exit 1
}

# Get a baseName (stem) for the output
baseName="${inputFile##*/}"
baseName="${baseName%.*}"

# Fallback for output
if [ -z "$outputFile" ]
then
    outputFile="$(dirname ${inputFile})/${baseName}.$extCode"
fi

# Execute in a temporary directory (keeps files together)
cwd="$(pwd -L)"
tmpDir="Make/bisonWrapper-$baseName"
rm -rf "$tmpDir" 2>/dev/null
mkdir "$tmpDir" 2>/dev/null

cd "$tmpDir" || exit
rc=1

# DO WE WANT THIS?
# trap 'cd $cwd; rm -f $tmpDir 2>/dev/null; exit $rc' EXIT TERM INT

bison "$@" "../../$inputFile"
rc=$?

cd "../.." || exit

if [ "$rc" -ne 0 ]
then
    rm -rf "$tmpDir" 2>/dev/null
    exit "$rc"   # Exit with bison return code
fi


# Check for/remove .tab. tag?
unset untabFilter

# withTab=$/include *"stack/s/"/"'"${baseName}."'/;' \

hasTab="${outputFile##*/}"
hasTab="${hasTab%.*}"

if [ "$hasTab" = "${hasTab%.tab}" ]
then
    untab='/^#.*".*\.tab\./s/\.tab\././'
fi

# Filter include names to generate new files
# "$1" = input
# "$2" = output
filterRename()
{
    if [ -f "$1" ] && [ -n "$2" ]
    then
        sed \
            -e '/include *"location/s/"/"'"${baseName}."'/;' \
            -e '/include *"position/s/"/"'"${baseName}."'/;' \
            -e '/include *"stack/s/"/"'"${baseName}."'/;' \
            -e "$untab;" \
            "$1" >| "$2"
    fi
}


# Boilerplate -> lnInclude/ directory with new name
for file in position location stack
do
    filterRename \
        "${tmpDir}/${file}.$extHead" \
        "lnInclude/${baseName}.${file}.$extHead"
done

# Header -> lnInclude/ directory, possibly with .tab.hh to .hh
filterRename \
    "${tmpDir}/${baseName}.tab.$extHead" \
    "lnInclude/${baseName}${untab:-.tab}.$extHead"

# Code -> build directory, possibly with .tab.hh to .hh
filterRename \
    "${tmpDir}/${baseName}.tab.$extCode" \
    "${outputFile}"


rm -rf "$tmpDir" 2>/dev/null
exit "$rc"   # Exit with bison return code

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