#!/bin/sh
#------------------------------------------------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     |
#   \\  /    A nd           | Copyright (C) 2011-2015 OpenFOAM Foundation
#    \\/     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
#
# Usage
#     wmakePrintBuild [OPTION]
#
# Description
#     Print the version used when building the project
#
#------------------------------------------------------------------------------
Script=${0##*/}

usage() {
    exec 1>&2

    while [ "$#" -ge 1 ]; do echo "$1"; shift; done
    cat<<USAGE
Usage: $Script [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
}


#------------------------------------------------------------------------------
# Parse arguments and options
#------------------------------------------------------------------------------
unset checkOnly update package version shortOpt

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

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

# Persistent build tag
build="$WM_PROJECT_DIR/.build"


#------------------------------------------------------------------------------
# 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
}


#------------------------------------------------------------------------------
# Get the version
#------------------------------------------------------------------------------

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


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


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