#!/bin/sh
#------------------------------------------------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     |
#   \\  /    A nd           | Copyright (C) 2008-2011 OpenCFD Ltd.
#    \\/     M anipulation  |
#-------------------------------------------------------------------------------
# License
#     This file is part of OpenFOAM.
#
#     OpenFOAM 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.
#
#     OpenFOAM 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
#     for more details.
#
#     You should have received a copy of the GNU General Public License
#     along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
#
# Script
#     wmakePrintBuild
#
# Description
#     Print the version used when building the project
#
#------------------------------------------------------------------------------
# persistent build tag
build="$WM_PROJECT_DIR/.build"

usage() {
    exec 1>&2

    while [ "$#" -ge 1 ]; do echo "$1"; shift; done
    cat<<USAGE
usage: ${0##*/} [OPTION]
options:
  -check          check the git head commit vs. \$WM_PROJECT_DIR/.build
                  (exit code 0 for no changes)
  -major          report \$WM_PROJECT_VERSION only and exit
  -update         update \$WM_PROJECT_DIR/.build from the git information
  -pkg TAG        specify packager/release tag ('none' marks an empty packager)
  -short          report short version information (ie, without pkg tag)
  -version VER    specify an alternative version

Print the version used when building the project, in this order of precedence:
  * the git head commit (prefixed with \$WM_PROJECT_VERSION)
  * \$WM_PROJECT_DIR/.build
  * \$WM_PROJECT_VERSION

USAGE
    exit 1
}
#------------------------------------------------------------------------------

unset checkOnly update package version shortOpt

# parse options
while [ "$#" -gt 0 ]
do
    case "$1" in
    -h | -help)
        usage
        ;;
    -c | -check)
        checkOnly=true
        shift
        ;;
    -major)
        echo ${WM_PROJECT_VERSION:-unknown}
        exit 0
        ;;
    -u | -update)
        update=true
        shift
        ;;
    -pkg | -package)
        [ "$#" -ge 2 ] || usage "'$1' option requires an argument"
        # mark empty as 'none', disallow '!' in string
        package=$(echo "${2:-none}" | sed -e 's/!//g')
        shift 2
        ;;
    -short)
        shortOpt=true
        shift
        ;;
    -v | -version)
        [ "$#" -ge 2 ] || usage "'$1' option requires an argument"
        version="$2"
        shift 2
        ;;
    *)
        usage "unknown option/argument: '$*'"
        ;;
    esac
done

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

#
# retrieve old values from the $WM_PROJECT_DIR/.build cache, stored as
#     version [packager]
#
unset oldPackage oldVersion
getOldValues()
{
    set -- $(tail -1 $build 2>/dev/null)
    oldVersion="$1"
    [ "$#" -gt 0 ] && shift
    oldPackage="$@"
    [ "${oldPackage:-none}" = none ] && unset oldPackage
}

#
# printTag - output the build tag
# reuses the old -package tag if needed
#
printTag()
{
    if [ "${package:-${oldPackage:-none}}" = none ]
    then
        echo "$version"
    else
        echo "$version ${package:-$oldPackage}"
    fi
}



if [ -n "$version" ]
then
    # specified a version - no error possible
    rc=0
else
    # get the head SHA1 when building under git
    # if there are multiple values (eg, HEAD, origin/HEAD, ...)
    # only take the first one, which is 'HEAD'
    version=$(
        cd $WM_PROJECT_DIR 2>/dev/null && \
        git show-ref --hash=12 --head HEAD 2>/dev/null | head -1
    )

    if [ -n "$version" ]
    then
        # mark as success and prefix with WM_PROJECT_VERSION
        rc=0
        version="${WM_PROJECT_VERSION}-$version"
    else
        # mark as failure
        rc=1
    fi
fi


# retrieve old values
getOldValues

if [ "$shortOpt" = true ]
then
    unset package oldPackage
fi

#
# update persistent build tag if possible
#
if [ $rc -eq 0 -a -n "$update" ]
then
    if [ "$version:$package" != "$oldVersion:$oldPackage" ]
    then
        if [ -w "$build" -o \( -w "$WM_PROJECT_DIR" -a ! -e "$build" \) ]
        then
            printTag >| "$build" 2>/dev/null
        fi
    fi
fi

# cat<< DEBUG 1>&2
# Debug information
#     version='$version'
#     package='$package'
#     oldVersion='$oldVersion'
#     oldPackage='$oldPackage'
# DEBUG


# check git vs. persistent build tag
if [ -n "$checkOnly" ]
then
    if [ $rc -eq 0 ]
    then
        test "$version:${package:-$oldPackage}" = "$oldVersion:$oldPackage"
        rc=$?
        if [ $rc -eq 0 ]
        then
            echo "same version as previous build" 1>&2
        else
            echo "version changed from previous build" 1>&2
        fi
    else
        echo "no git description found" 1>&2
    fi
    exit $rc
fi


#
# cannot get git information or  -version version
#
if [ $rc -ne 0 ]
then
    if [ -n "$oldVersion" ]
    then
        # use previous version info
        version="$oldVersion"
    else
        # fallback to WM_PROJECT_VERSION alone
        version="${WM_PROJECT_VERSION:-unknown}"
    fi
fi


# output the tag
printTag

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