#!/bin/sh

# Parse git version into its separate components.
#
# Copyright (C) 2017 Robert Krawitz
#
# This program 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 2, or (at your option)
# any later version.
#
# This program 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 this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.


usage() {
    echo "Usage: $cmd [info] [default] [version]"
    echo "       info can be empty, or one of major, minor, micro, extra, git"
    echo "       info can also be extra-git, core-version (major.minor),"
    echo "            base-version (major.minor.micro),"
    echo "            full-version (major.minor.micro[-extra]), or all"
    echo "       default is the default value if not in a git repository."
    echo "       version is the input version in lieu of git describe (for testing)"
    exit 1
}

cmd="$0"

if [ "$#" -gt 3 ] ; then
    usage
fi

root="@PKGROOT@"

if [ -z "$3" ] ; then
    if [ -d "$root/.git" ] ; then
	git describe --dirty --always --first-parent 2>/dev/null | sed 's/^[^0-9]*-//' > "$root/git-version-stamp"
    fi

    if [ -f "$root/git-version-stamp" ] ; then
	description=`cat "$root/git-version-stamp"`
    else
	description='(unknown)'
    fi
else
    description=$3
fi

# If we don't have git or this is not a repository, simply return the default value
if [ -z "$description" ] ; then
    echo "$2"
    exit 0
fi

get_major() {
    echo "$1" | sed -e 's/[-_\.].*//'
}

get_minor() {
    echo "$1" | sed -e 's/^[0-9]*[-_\.]//' \
		    -e 's/[-_\.].*//'
}

get_micro() {
    echo "$1" | sed -e 's/^[0-9]*[-_\.][0-9]*[-_\.]//' \
		    -e 's/[-_\.].*//'
}

get_extra() {
    echo "$1" | sed -e 's/^[0-9]*[-_\.][0-9]*[-_\.][0-9]*\([a-zA-Z]\|\)//' \
		    -e 's/-\([0-9]*-\|\)g[0-9a-zA-Z]*\(-dirty\|\)$//' \
    		    -e 's/^_/-/'
}

get_git() {
    echo "$1" | sed -e 's/^[0-9]*[-_\.][0-9]*[-_\.][0-9]*\([a-zA-Z]\|\)//' \
		    -e 's/^[-_\.][a-zA-Z][a-zA-Z]*[0-9]*\([a-zA-Z]\|\)//' \
		    -e 's/^[-_\.]/-/'
}

get_extra_git() {
    echo "$1" | sed -e 's/^[0-9]*[-_\.][0-9]*[-_\.][0-9]*\([a-zA-Z]\|\)//' \
		    -e 's/^[-_\.]/-/'
}

get_core_version() {
    echo "$1" | sed -e 's/^\([0-9]*[-_\.][0-9]*\).*/\1/' \
		    -e 's/[-_\.]/./g'
}

get_base_version() {
    echo "$1" | sed -e 's/^\([0-9]*[-_\.][0-9]*[-_\.][0-9]*\([a-zA-Z]\|\)\).*/\1/' \
		    -e 's/[-_\.]/./g'
}

get_full_version() {
    echo "$1" | sed -e 's/-[0-9]*-g[0-9a-z]*\(-dirty\|\)$//' \
		    -e 's/[-_\.]/=/g' \
		    -e 's/=/./' \
		    -e 's/=/./' \
		    -e 's/=/-/'
}

get_all() {
    echo "$1" | sed -e 's/[-_\.]/=/g' \
		    -e 's/=/./' \
		    -e 's/=/./' \
		    -e 's/=/-/g'
}

case "$1" in
    major)        get_major        "$description" ;;
    minor)        get_minor        "$description" ;;
    micro)        get_micro        "$description" ;;
    extra)        get_extra        "$description" ;;
    git)          get_git          "$description" ;;
    extra-git)    get_extra_git    "$description" ;;
    core-version) get_core_version "$description" ;;
    base-version) get_base_version "$description" ;;
    full-version) get_full_version "$description" ;;
    ''|all)       get_all          "$description" ;;
    *)            usage                           ;;
esac

exit 0