#!/bin/bash

#
#    Copyright 2019 Google LLC. All Rights Reserved.
#    Copyright 2014-2017 Nest Labs Inc. All Rights Reserved.
#
#    Licensed under the Apache License, Version 2.0 (the "License");
#    you may not use this file except in compliance with the License.
#    You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS,
#    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#    See the License for the specific language governing permissions and
#    limitations under the License.
#

#
#    Description:
#      This file is a convenience script that will bootstrap the GNU
#      autotools system for a project after any build system changes.
#

#
# usage
#
# Display program usage.
#
usage() {
    name=`basename $0`

    echo "Usage: ${name} [ options ] [ -w <what> ]"

    if [ $1 -ne 0 ]; then
        echo "Try '${name} -h' for more information."
    fi

    if [ $1 -ne 1 ]; then
        echo ""
        echo "  -h, --help       Print this help, then exit."
        echo "  -I DIR           Specify directory DIR as the root of the "
        echo "                   nlbuild-autotools repository."
        echo "  -v, --verbose    Verbosely report bootstrap progress."
        echo "  -w, --what WHAT  Specify what part of the package should be "
        echo "                   bootstrapped: all, config, make, or none "
        echo "                   (default: all)."
        echo ""
    fi

    exit $1
}

#
# check_required_executable <path variable> <executable name>
#
# Check to ensure that the named executable with the path in the
# provided variable exists and is executable by the current user.
#
check_required_executable() {
    variable="${1}"
    path="${!variable}"
    name="${2}"
    output="${3}"
    stem="The required executable '${name}'"

    if [ -z "${path}" ]; then
        echo "${stem} could not be found."

        eval "${output}"="no"

        return 1
    elif [ ! -e "${path}" ] || [ ! -x "${path}" ]; then
        stem="${stem} at '${path}'"

        if [ ! -e ${path} ]; then
            echo "${stem} does not exist."
        elif [ ! -x ${path} ]; then
            echo "${stem} is not executable."
        fi

        echo "Please ensure '${name}' is available in PATH."

	eval "${output}"="no"

        return 1
    fi

    eval "${output}"="yes"

    return 0
}

check_required_executables()
{
    check_required_executable ACLOCAL aclocal have_aclocal
    check_required_executable AUTOCONF autoconf have_autoconf
    check_required_executable AUTOHEADER autoheader have_autoheader
    check_required_executable AUTOMAKE automake have_automake
    check_required_executable LIBTOOLIZE libtoolize have_libtoolize
    check_required_executable M4 m4 have_m4

    if [ "${have_aclocal}" = "no" ] || [ "${have_autoconf}" = "no" ] || [ "${have_autoheader}" = "no" ] || [ "${have_automake}" = "no" ] || [ "${have_libtoolize}" = "no" ] || [ "${have_m4}" = "no" ]; then
	cat << EOF
--------------------------------------------------------------------------------
Your build host system is missing one or more of the above executables required
for bootstrapping this nlbuild-autotools-based package. You can either install
these yourself using package management tools available and appropriate for your
build host platform or you can build preselected versions of these executables
from source for this package on this build host by invoking:

    make -C ${nlbuild_autotools_dir} tools

and then re-running this script which will use those executables.
--------------------------------------------------------------------------------
EOF
    
      exit 1
    
    fi
}

#
# removetmp
#
# Remove temporary files and directories used during the run of this
# script.
#
removetmp() {
    if [ -n "${LIBTOOLIZE}"  ] && [ "${LIBTOOLIZE}" = "${BOOTSTRAP_TMPDIR}/libtoolize" ]; then
        rm -f "${LIBTOOLIZE}"
    fi

    if [ -n "${AUTOM4TE_CFG}" ]; then
        rm -f "${AUTOM4TE_CFG}"
    fi

    rm -r -f "${BOOTSTRAP_TMPDIR}"
}

what="all"
verbose=
nlbuild_autotools_dir=

# Parse out any command line options

while [ ${#} -gt 0 ]; do
    case ${1} in
    -h|--help)
        usage 0
        ;;

    -I)
        nlbuild_autotools_dir="${2}"
        shift 2
        ;;

    -v|--verbose)
        verbose="--verbose"
        shift 1
        ;;

    -w|--what)
        case "${2}" in

        all|make*|conf*|none)
            what="${2}"
            shift 2
            ;;

        *)
	    echo "Unknown what value '${2}'." >&2
            usage 1
            ;;

        esac
        ;;

    *)
        usage 1
        ;;

    esac
done

# Check to ensure that the location of the nlbuild-autotools directory
# is sane.

if [ -z "${nlbuild_autotools_dir}" ]; then
    echo "$0: No -I option specified. Please provide the location of the nlbuild-autotools directory." >&2
    exit 1

elif [ ! -d "${nlbuild_autotools_dir}" ]; then
    echo "$0: No such directory: ${nlbuild_autotools_dir}. Please provide a valid path to the nlbuild-autotools directory." >&2
    exit 1

fi

# Establish some key directories

srcdir=`dirname ${0}`
abs_srcdir=`pwd`
abs_top_srcdir="${abs_srcdir}"

abs_top_hostdir="${nlbuild_autotools_dir}/tools/host"

# Figure out what sort of build host we are running on, stripping off
# any trailing version number information typically included on Darwin
# / Mac OS X.

host=`${nlbuild_autotools_dir}/third_party/autoconf/config.guess | sed -e 's/[[:digit:].]*$//g'`

# If possible, attempt to be self-sufficient, relying on GNU autotools
# executables installed along with the SDK itself.

if [ -d "${abs_top_hostdir}/${host}/bin" ]; then
    export PATH="${abs_top_hostdir}/${host}/bin:${PATH}"
fi

if [ -d "${abs_top_hostdir}/bin" ]; then
    export PATH="${abs_top_hostdir}/bin:${PATH}"
fi

export ACLOCAL=`which aclocal`
export AUTOCONF="`which autoconf`"
export AUTOHEADER="`which autoheader`"
export AUTOM4TE="`which autom4te`"
export AUTOMAKE="`which automake`"
export LIBTOOLIZE="`which libtoolize || which glibtoolize`"
export M4=`which m4`

# Establish, if necessary, some SDK-specific directories needed to
# override various paths in GNU autotools that otherwise expect to be
# absolute (e.g. /usr/share, etc.).

if [ -d "${abs_top_hostdir}/share" ]; then
    if [ -d "${abs_top_hostdir}/share/autoconf" ]; then
        export AC_MACRODIR="${abs_top_hostdir}/share/autoconf"

        export autom4te_perllibdir="${abs_top_hostdir}/share/autoconf"
    fi

    if [ -d "${abs_top_hostdir}/share/automake-1.14" ]; then
        export PERL5LIB="${abs_top_hostdir}/share/automake-1.14:${PERL5LIB}"

	make_action_options="--libdir ${abs_top_hostdir}/share/automake-1.14"
    fi

    if [ -d "${abs_top_hostdir}/share/aclocal-1.14" ]; then
        local_action_options="--automake-acdir=${abs_top_hostdir}/share/aclocal-1.14 ${local_action_options}"
    fi

    if [ -d "${abs_top_hostdir}/share/aclocal" ]; then
        local_action_options="--system-acdir=${abs_top_hostdir}/share/aclocal ${local_action_options}"
    fi
fi

# Both autom4te.cfg and libtoolize, as installed from source, want to
# use absolute file system paths that cannot be
# overridden. Consequently, we create temporary, local versions of
# these, patched up with SDK-specific paths.

BOOTSTRAP_TMPDIR="`mktemp -d /tmp/tmp.bootstrapXXXXXX`"

trap "removetmp" 1 2 3 9 15

#
# Generate any temporary files that need to be patched at run time
# with the location of the SDK tree, including:
#
#   -  The autom4te configuration file
#   -  The libtoolize executable script
#

if [ -r "${abs_top_hostdir}/share/autoconf/autom4te.cfg" ]; then
    export AUTOM4TE_CFG="${BOOTSTRAP_TMPDIR}/autom4te.cfg"

    sed -e "s,//share/autoconf,${abs_top_hostdir}/share/autoconf,g" < "${abs_top_hostdir}/share/autoconf/autom4te.cfg" > "${AUTOM4TE_CFG}"
fi

if [ -r "${abs_top_hostdir}/${host}/bin/libtoolize" ]; then
    export LIBTOOLIZE="${BOOTSTRAP_TMPDIR}/libtoolize"

    sed -e "s,//share/libtool,${abs_top_hostdir}/share/libtool,g" -e "s,//share/aclocal,${abs_top_hostdir}/share/aclocal,g" < "${abs_top_hostdir}/${host}/bin/libtoolize" > "${LIBTOOLIZE}"

    chmod 775 "${LIBTOOLIZE}"
fi

# Before we get much further, check to ensure that the required
# executables are available and, if not, provide some actionable
# guidance.

check_required_executables
 
if [ -n "${verbose}" ]; then
    echo PATH="${PATH}"

    echo ACLOCAL="${ACLOCAL}"
    echo AUTOCONF="${AUTOCONF}"
    echo AUTOHEADER="${AUTOHEADER}"
    echo AUTOM4TE="${AUTOM4TE}"
    echo AUTOMAKE="${AUTOMAKE}"
    echo LIBTOOLIZE="${LIBTOOLIZE}"
    echo M4="${M4}"

    echo AC_MACRODIR="${AC_MACRODIR}"
    echo AUTOM4TE_CFG="${AUTOM4TE_CFG}"
    echo PERL5LIB="${PERL5LIB}"
    echo autom4te_perllibdir="${autom4te_perllibdir}"

    echo local_action_options="${local_action_options}"
    echo make_action_options="${make_action_options}"
fi

# Set up the default actions for each bootstrap stage.

local_action="${ACLOCAL} ${verbose} ${local_action_options}"
header_action="${AUTOHEADER} ${verbose}"
tool_action="${LIBTOOLIZE} ${verbose} --automake --copy --force"
make_action="${AUTOMAKE} ${verbose} ${make_action_options} --add-missing --copy"
config_action="${AUTOCONF} ${verbose}"

# Determine what needs to be short-circuited based on the
# user-specified "what".

case "${what}" in

    all)
        ;;

    conf*)
        local_action=true
        header_action=true
        tool_action=true
        make_action=true
        ;;

    make*)
        local_action=true
        header_action=true
        config_action=true
        ;;

    none)
        local_action=true
        header_action=true
        tool_action=true
        make_action=true
        config_action=true
        ;;

esac

# Bootstrap the package.

if [ -n "${verbose}" ]; then
    echo "${local_action} && ${tool_action} && ${header_action} && ${make_action} && ${config_action}"
fi

${local_action} && ${tool_action} && ${header_action} && ${make_action} && ${config_action}

# Clean up any temporary files created.

removetmp