#!/bin/bash
#
# This script will generate a Makefile according to the options one requests.
# The Makefile will then allow one to build and install the FastJet contrib.
#
# See
#   configure --help
# for information about how to use this script

#------------------------------------------------------------------------
# the list of contribs supported by this script
#------------------------------------------------------------------------
all_contribs=`find . -mindepth 2 -maxdepth 2 -name VERSION -not -print \
                 | sed 's/\.\///g;s/\/.*$//g' | grep -v "Template"`

#------------------------------------------------------------------------
# default values prior to the arg parsing
#------------------------------------------------------------------------
only_contribs=""
excluded_contribs=""

fjconfig="fastjet-config"



#------------------------------------------------------------------------
# print a usage message and exit
#------------------------------------------------------------------------
# exit code passed as argument:
#   0 if it is a normal call
#   1 if it is due to a misusage.
usage(){
cat 1>&2 <<EOF

This is a FastJet-contrib tool to configure the behaviour of
the build and installation.

Usage:
  configure [--help] [--list] [--fastjet-config=FILE] [--prefix=PREFIX] [CXX=...] [CXXFLAGS=...]

The arguments can be the following [default in square brackets]:

  --help            prints this message and exits
  --list            prints the list of existing contribs and exits
  --fastjet-config=FILE  
                    sets the 'fastjet-config' file to use [$fjconfig]
  --prefix=PREFIX   sets the installation directory [prefix returned by fastjet-config]
  --only=Contrib1,Contrib2,... 
                    only configures for compilation selected contribs 
  --exclude=Contrib1,Contrib2,...
                    excludes selected contribs from configuration
EOF
  exit $1
}

#------------------------------------------------------------------------
# write error messages and exit
#------------------------------------------------------------------------
write_error(){
    echo "Error: $1"
    echo "Use fastjet-config --help for more information"
    exit 1
}


#------------------------------------------------------------------------
# tools to parse options
#------------------------------------------------------------------------

# option_name _string
# Returns NAME if _string is of the form: --NAME[=...]
option_name(){
    echo "$1" | sed 's/^--//;s/=.*//' | tr '-' '_'
}

# option_value _string
# Returns FOO if _string is of the form: --option=FOO
option_value(){
    echo "$1" | sed 's/^[^=]*=//'
}

# is_in_list _arg _arg_list
# return true if the argument _arg is in the list _arg_list
# and false otherwise
is_in_list(){
    arg_match="$1"
    shift
    for arg_match_i do
        [ "x$arg_match_i" != "x$arg_match" ] || return 0
    done
    false
}

#------------------------------------------------------------------------
# parse the command line options
#------------------------------------------------------------------------
# first deal with the case where no argument is passed
#[ $# -gt 0 ] || usage 1

# make sure Makefile.inc is absent
makefileinc=".Makefile.inc"
[ -e $makefileinc ] && rm $makefileinc && touch $makefileinc
echo "# contrib-wide Makefile include file, generated automatically with" >> $makefileinc
echo "# $0 $*" >>  $makefileinc

for arg do
    case "$arg" in
        --help|-h)
            usage 0
            ;;
        --list)
            echo $all_contribs
	    exit 0
            ;;
        --*=*)
            arg_name=`option_name $arg`
	    arg_value=`option_value $arg`
            case $arg_name in
                prefix)
                    prefix="$arg_value"
                    ;;
                fastjet_config)
                    fjconfig="$arg_value"
                    ;;
                only)
                    only_contribs="${arg_value//,/ /}"
                    ;;
                exclude)
                    excluded_contribs="${arg_value//,/ /}"
                    ;;
		*)
		    write_error "$arg: unrecognised argument"
		    ;;
	    esac
            ;;
        [A-Z]*=*)
            # variables that go into the $makefileinc
            echo "$arg" >> $makefileinc
            ;;
        *)
            write_error "$arg is not a recognised argument. Aborting"
            ;;
    esac
done

#------------------------------------------------------------------------
# check for fastjet-config and set up prefix
#------------------------------------------------------------------------

# exit if fastjet-config is not found (bad file name or not in path)
if ! [ `command -v $fjconfig` ]; then
    echo $fjconfig" has not been found. Exiting."; exit 1 
fi

# if prefix has not been set explicitly from command line, set it to
# the one returned by 'fastjet-config --prefix'
if [ "x"$prefix == "x" ] ; then 
     prefix=`$fjconfig --prefix`
fi

# generate the rest of $makefileinc
echo "FASTJETCONFIG=$fjconfig" >> $makefileinc
echo "PREFIX=$prefix" >> $makefileinc
echo 'install_script = $(SHELL) ../utils/install-sh' >> $makefileinc
echo 'check_script = ../utils/check.sh' >> $makefileinc

    
#------------------------------------------------------------------------
# construct the list of directories to recurse into
#------------------------------------------------------------------------

included_contribs=""
if [ "x${only_contribs}" == "x" ] ; then
    included_contribs="$all_contribs"
else
    included_contribs="$only_contribs"
fi

built_contribs=""
if [ "x${excluded_contribs}" == "x" ] ; then
    built_contribs="$included_contribs"
else
    built_contribs=""
    for contrib in $included_contribs; do
	if ! is_in_list $contrib ${excluded_contribs} ; then
	    built_contribs="$built_contribs $contrib"
	fi
    done
fi

#------------------------------------------------------------------------
# create the Makefile
#------------------------------------------------------------------------
TAB="$(printf '\t')"

# cat >Makefile <<EOF
# # This Makefile has been generated by the 'configure' script.
# # Please edit this with great care.
# 
# # installation setup
# SUBDIRS=$built_contribs
# 
# # Note: we could simply use "export" here to have all variables
# # exported by default, but the explicit mention below has the advantage
# # that it overrides any default in the sub-makefile. Note also
# # that we could play some games with te MAKELEVEL variable.
# SUBMAKE=\$(MAKE) FASTJETCONFIG=${fjconfig} PREFIX=$prefix
# 
# RECURSIVE_TARGETS=all-recursive install-recursive clean examples
# 
# .PHONY: \$(RECURSIVE_TARGETS) install examples
# 
# all: all-recursive
# 
# install: all install-recursive
# 
# \$(RECURSIVE_TARGETS):
# ${TAB}@+failcom='exit 1' \\
# ${TAB}target=\`echo \$@ | sed s/-recursive//\`; \\
# ${TAB}list='\$(SUBDIRS)'; for subdir in \$(SUBDIRS); do \\
# ${TAB}  \$(SUBMAKE) -C \$\$subdir \$\$target || eval \$\$failcom; \\
# ${TAB}done
# 
# EOF

# The method below id more along the lines of what is present in the
# GNU make manual but the explicit use of $(MAKECMDGOALS) in the
# recursion causes make install to recurse as "make install" (even
# though it depends on make all... so each the contribs is built and
# installed before going to the next one, In case of a compilation
# error, it is better to build everything and then install everything.
#
# The option to avoid that would be to define an explicit recursion
# for each target e.g. doing
#
#   SUBDIRS.clean = $(SUBDIRS:=.clean)
#   clean: $(SUBDIRS.clean)
#   $(SUBDIRS.clean):
#        $(MAKE) -C $@ clean
#   .PHONY: clean $(SUBDIRS.clean)
#
# which, in our case would probably only be required for "all" (so
# that it can explicitly be called by install
#
# Note that this method may have a better behaviour when using the -j
# option.

# cat >Makefile <<EOF
# # This Makefile has been generated by the 'configure' script.
# # Please edit this with great care.
# 
# # installation setup
# SUBDIRS=$built_contribs
# SUBDIRS.all=\$(SUBDIRS:=.all)
# 
# SUBMAKE=\$(MAKE) FASTJETCONFIG=${fjconfig} PREFIX=$prefix
# 
# .PHONY: \$(SUBDIRS) \$(SUBDIRS.all) clean distclean check install examples
# 
# all: \$(SUBDIRS.all)
# 
# install: all \$(SUBDIRS)
# 
# examples check clean distclean: \$(SUBDIRS)
# 
# \$(SUBDIRS):
# ${TAB}+\$(SUBMAKE) -C \$@ \$(MAKECMDGOALS)
# 
# \$(SUBDIRS.all):
# ${TAB}+\$(SUBMAKE) -C \$(basename \$@)
# 
# EOF

# alternatively we could build this from the Makefile.in
# prefix variable

# note that the apparently bizarre construct below ensures that the
# appropriate characters are escaped in the sed replacement
escaped_built_list="$(echo ${built_contribs} | sed -e 's/[\/&]/\\&/g')"
escaped_fjconfig="$(echo ${fjconfig} | sed -e 's/[\/&]/\\&/g')"
escaped_prefix="$(echo ${prefix} | sed -e 's/[\/&]/\\&/g')"

commandline="$0 $*"
sed -e "s/@CONTRIB_BUILD_LIST@/$escaped_built_list/g;\
        s/@FJCONFIG@/$escaped_fjconfig/g;\
        s,@PREFIX@,${escaped_prefix},g;\
        s/template gets processed/was generated automatically/;\
        s,@contrib_commandline@,$commandline,;\
        s/any edits fit with the rest of the build system/you only edit Makefile.in/" Makefile.in > Makefile


#------------------------------------------------------------------------
# write output and config.log file
#------------------------------------------------------------------------
echo 
echo "Configuring fjcontrib version" `cat VERSION`
echo
echo -e "Enabled contribs: "
for contrib in $built_contribs
do
    printf "        %-20s v%s\n" $contrib `cat $contrib/VERSION`
done
echo
echo -e "Installation prefix: "$prefix
echo "--------------------------------------------------"
echo -e "Now run 'make', optionally 'make check', and 'make install'\n"

echo -e "This file was created by the fastjet contrib configure on "`date`"\n"  > config.log
echo -e "The command line invocation was\n"                                >> config.log
echo -e "    $0 $@\n"                                                      >> config.log
for contrib in $built_contribs
do
    printf "        %-20s v%s\n" $contrib `cat $contrib/VERSION`           >> config.log
done
echo -e "Installation prefix: "$prefix"\n"                                 >> config.log