#!/bin/bash

#
#    Copyright 2015-2018 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 create a skeleton
#      build layout using the nlbuild-autotools package.
#

YEAR=`date "+%Y"`
NAME=""
DESCRIPTION=""
DIR=""
VERSION="1.0"
verbose=1

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

    echo "Usage: ${name} [ options ]"

    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 mkskeleton progress (default: yes)."
        echo "  --package-description DESC  Specify description DESC as a the "
        echo "                              package description."
        echo "  --package-name NAME         Specify name NAME as the package name."
        echo "  --package-version VERSION   Specify version VERSION as the initial "
        echo "                              version for the package (default: ${VERSION})."
        echo "  --package-year YEAR         Specify year YEAR as the creation "
        echo "                              year for the package (default: ${YEAR})."
        echo "  -q, --quiet                 Do not verbosely report mkskeleton progress (default: no)."

        echo ""
    fi

    exit $1
}

#
# log
#
log() {
    if [ ! -z ${verbose} ] && [ ${verbose} -eq 1 ]; then
        echo $*
    fi
}

transform() {
    local from="${1}"
    local to="${2}"

    sed                                                   \
        -e "s,\@NLBUILD_AUTOTOOLS_STEM\@,${DIR},g"        \
        -e "s,\@PACKAGE_DESCRIPTION\@,${DESCRIPTION},g"   \
        -e "s,\@PACKAGE_SHORT_LOWER\@,${LOWER},g"         \
        -e "s,\@PACKAGE_SHORT_UPPER\@,${UPPER},g"         \
        -e "s,\@PACKAGE_YEAR\@,${YEAR},g"                 \
        < "${from}" > "${to}"
}

populate() {
    local nlbuild="${1}"
    local perm=${2}
    local file="${3}"
    local directory="${4}"
    local stem="${file%.*}"
    local extension="${file##*.}"
    local from
    local to

    if [ -r "${nlbuild}/examples/${file}" ]; then
        from="${nlbuild}/examples/${file}"

    elif [ -r "${nlbuild}/examples/${stem}-${directory}.${extension}" ]; then
        from="${nlbuild}/examples/${stem}-${directory}.${extension}"

    elif [ "${directory}" = "." ] && [ -r "${nlbuild}/examples/${stem}-toplevel.${extension}" ]; then
        from="${nlbuild}/examples/${stem}-toplevel.${extension}"

    else
        echo "Cannot find an example file \"${file}\" for directory \"${directory}\"."
        exit 1

    fi

    to="${directory}/${file}"

    log "Creating \"${to}\"..."

    transform "${from}" "${to}"

    if [ $? = 0 ]; then
        chmod ${perm} "${to}"
    fi
}

#
# link
#
link() {
    local nlbuild="${1}"
    local perm=${2}
    local source="${3}"
    local directory="${4}"
    local from="${nlbuild}/scripts/${source}"
    local to="${directory}/${source}"

    log "Creating \"${to}\"..."

    ln -sf "${from}" "${to}"
}

# Parse out any command line options

while [ ${#} -gt 0 ]; do
    if [ ${1} == "-h" ] || [ ${1} == "--help" ]; then
        usage 0

    elif [ ${1} == "-I" ]; then
        DIR="${2}"
        shift 2

    elif [ ${1} == "--package-description" ]; then
        DESCRIPTION="${2}"
        shift 2

    elif [ ${1} == "--package-name" ]; then
        NAME="${2}"
        shift 2

        UPPER="`echo ${NAME} | tr '[[:lower:]]' '[[:upper:]]'`"
        LOWER="`echo ${NAME} | tr '[[:upper:]]' '[[:lower:]]'`"

    elif [ ${1} == "--package-version" ]; then
        VERSION="${2}"
        shift 2

    elif [ ${1} == "--package-year" ]; then
        YEAR="${2}"
        shift 2

    elif [ ${1} == "-q" ] || [ ${1} == "--quiet" ]; then
        verbose=0
        shift 1

    elif [ ${1} == "-v" ] || [ ${1} == "--verbose" ]; then
        verbose=1
        shift 1

    else
        usage 1

    fi
done

# Sanity check the command line arguments

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

fi

if [ -z "${DESCRIPTION}" ]; then
    echo "$0: Please provide a package description via --package-description."
    exit 1
fi

if [ -z "${NAME}" ]; then
    echo "$0: Please provide a package name via --package-name."
    exit 1
fi

if [ -z "${VERSION}" ]; then
    echo "$0: Please provide a package default version via --package-version."
    exit 1
fi

if [ -z "${YEAR}" ]; then
    echo "$0: Please provide a package creation year via --package-year."
    exit 1
fi

# Create the skeleton directories

DIRS="doc third_party include src tests"

for dir in ${DIRS}; do
    log "Creating \"${dir}\"..."
    mkdir -p "${dir}"
done

# Populate the skeleton directories

populate "${DIR}" 664 configure.ac        .
populate "${DIR}" 775 bootstrap           .
populate "${DIR}" 664 repos.conf          .
populate "${DIR}" 664 Makefile.am         .
populate "${DIR}" 664 Makefile-bootstrap  .
populate "${DIR}" 664 Makefile.am         doc
populate "${DIR}" 664 Doxyfile.in         doc
populate "${DIR}" 664 Makefile.am         third_party 
populate "${DIR}" 664 Makefile.am         src
populate "${DIR}" 664 Makefile.am         tests
link     "${DIR}" 775 bootstrap-configure .

# Create the default package version

log "Creating default version ${VERSION}..."

echo "${VERSION}" > ".default-version"