#!/bin/sh

##############################################################################
#
# Configuration script for otags III
# 
# Hendrik Tews Copyright (C) 2010 - 2016
# 
# This file is part of "Otags III".
# 
# "Otags III" 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.
# 
# "Otags III" 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 in file COPYING in this or one of the parent
# directories for more details.
# 
# You should have received a copy of the GNU General Public License
# along with "Otags III". If not, see
# <http://www.gnu.org/licenses/>.
# 
##############################################################################

set -e

REQUIRED_OCAML_VERSION=4.04
OTAGS_VERSION=1

root=/usr/local
bindir=$root/bin
mandir=$root/share/man
native=
native_goals=
byterequest=0
versioncheck=1
ocamlbindir=
die_on_3_12_0=1

usage (){
    echo "Usage:"
    echo "./configure [OPTION]..."
    echo
    echo "Recognized options are:"
    echo "  --prefix <path>	installation prefix [/usr/local]"
    echo "  --bindir <path>	user executables [PREFIX/bin]"
    echo "  --mandir <path>	man pages [PREFIX/share/man]"
    echo "  --bytecode 		don't use native compiler (for testing only)"
    echo "  --no-version-check 	don't check for correct ocaml version (not recommended)"
#    echo "  --ocaml <path>	location of ocaml binaries [searched in PATH]"
}

while : ; do
  case "$1" in
    "") break;;
    -help|--help) usage; exit 2;;
    -prefix|--prefix) bindir=$2/bin
                      mandir=$2/share/man
		      shift;;
    -bindir|--bindir) bindir=$2
		      shift;;
    -mandir|--mandir) mandir=$2
		      shift;;
    -bytecode|--bytecode)  byterequest=1;;
    -no-version-check|--no-version-check)
	  versioncheck=0;;
    -I-want-buggy-3-12-0)
	  die_on_3_12_0=0;;
    -ocaml|--ocaml)   ocamlbindir="$2/";
    	              shift;;

    # The following option is only here for simplifying the 
    # make-distribution script.
    -abra-print-version) 
	  echo $REQUIRED_OCAML_VERSION.$OTAGS_VERSION;
	  exit 0;;
     *) echo "Unknown option \"$1\"." 1>&2; usage; exit 2;;
  esac
  shift
done

# disable error checking
set +e

# check for ocaml 
ocbv=$(${ocamlbindir}ocamlc -version)
if [ $? -ne 0 ] ; then
    set -e
    echo compiler ${ocamlbindir}ocamlc not found. 
    echo Please adjust \$PATH or use --ocaml
    exit 1
else
    set -e
    echo ${ocamlbindir}ocamlc version $ocbv found.
fi

# check for buggy 3.12.0
if [ $die_on_3_12_0 = 1 ] ; then
    if [ $ocbv = "3.12.0" ] ; then
	echo
	echo "OCaml 3.12.0 contains a bug that puts ghost locations in the"
	echo "syntaxtree. Therefore otags compiled with 3.12.0 is of very"
	echo "limited use. If you nevertheless want to compile otags"
	echo "with 3.12.0 use option -I-want-buggy-3-12-0."
	exit 1
    fi
fi

# check ocamlc version
if [ $versioncheck = 1 ] ; then
    if [ "$ocbv" \< $REQUIRED_OCAML_VERSION ] ; then
	echo This version of otags needs at least OCaml $REQUIRED_OCAML_VERSION.x.
	echo Aborting.
	exit 1
    fi
    if [ "$ocbv" \> $REQUIRED_OCAML_VERSION".99" ] ; then
	cat - <<EOF

WARNING: You attempt to compile otags with a more recent OCaml version than
it was released for. (This version of otags was released for OCaml $REQUIRED_OCAML_VERSION.x.)

If it compiles without errors, otags shouls just ignore the new OCaml
features (if there are any). If you only see errors in the file
tags.ml you may get a working version by deleting the offending match
cases in tags.ml. For other errors I don't have any generic advice to
share. Good luck!

EOF
    fi
fi

# disable error checking
set +e

# check for ocamlopt.opt
ocvo=$(${ocamlbindir}ocamlopt.opt -version)
if [ $? -eq 0 ] ; then
    set -e
    if [ $ocbv != $ocvo ] ; then
	echo ${ocamlbindir}ocamlc and ${ocamlbindir}ocamlopt.opt have different versions.
	echo Please check your installation!
	echo Aborting.
	exit 1
    fi

    echo ${ocamlbindir}ocamlopt.opt version $ocvo found. 
    
    if ${ocamlbindir}ocamlopt.opt -o /dev/null \
	unix.cmxa dynlink.cmxa ;
    then
	echo Native compilation enabled.
	native=true
    else
	echo ocamlopt.opt unix.cmxa dynlink.cmxa failed.
	echo Native compilation disabled.
	native=false
    fi
else
    set -e
    echo ocamlopt.opt not found. Native compilation disabled.
    native=false
fi

if [ $byterequest = 1 ] ; then
    native=false
fi

if [ $native = "true" ] ; then
    ocamldep=${ocamlbindir}ocamldep.opt
    ocamlc=${ocamlbindir}ocamlc.opt
    ocamlopt=${ocamlbindir}ocamlopt.opt
    otags=otags.opt
else
    ocamldep=${ocamlbindir}ocamldep
    ocamlc=${ocamlbindir}ocamlc
    ocamlopt=false
    otags=otags.byte
fi

if [ $native = "true" ] ; then
    # disable error checking
    set +e

    # check ocamlc.opt if native detected
    ocvo=$(${ocamlc} -vnum)
    if [ $? -ne 0 ] ; then
	set -e
	echo $ocamlopt exists but $ocamlc not.
	echo Please check your ocaml installation!
	echo Aborting.
	exit 1
    elif [ $ocvo != $ocbv ] ; then
	set -e
	echo $ocamlc and $ocamlopt have different versions!
	echo Please check your installation!
	echo Aborting.
	exit 1
    else
	set -e
	echo ${ocamlc} version $ocvo found.
    fi
fi


# disable error checking
set +e

# check ocamldep
ocdepv=$($ocamldep -vnum)
if [ $? -ne 0 -o $ocdepv != $ocbv ] ; then
    set -e
    echo $ocamlc exists but $ocamldep not. 
    echo Please check your ocaml installation!
    echo Aborting.
    exit 1
else
    set -e
fi

if [ $ocdepv != $ocbv ] ; then
    echo $ocamlc and $ocamldep have different versions.
    echo Please check your ocaml installation!
    echo Aborting.
    exit 1
fi


# Summary of the configuration
echo
echo "  Configuration summary:"
echo "    binaries   will be installed in $bindir"
echo "    man pages  will be installed in $mandir"
if [ $native = "true" ] ; then
    echo "    native-code compilation enabled"
else
    echo "    native-code compilation disabled"
fi

# Make conf.ml
sed -e "s|@REQUIRED_OCAML_VERSION@|$REQUIRED_OCAML_VERSION|" \
    -e "s|@OTAGS_VERSION@|$OTAGS_VERSION|" \
    conf.ml.in > conf.ml


# Make the Makefile
sed -e "s|@BINDIR@|$bindir|" \
    -e "s|@MANDIR@|$mandir|" \
    -e "s|@OTAGS@|$otags|" \
    -e "s|@OCAMLC@|$ocamlc|" \
    -e "s|@OCAMLOPT@|$ocamlopt|" \
    -e "s|@OCAMLDEP@|$ocamldep|" \
    Makefile.in > Makefile
