#!/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, see <https://www.gnu.org/licenses/>.


usage() {
    echo "Usage: $cmd [info] [default] [version]"
    echo "       info can be empty, or one of major, minor, micro, extra, git, hash, pkg"
    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="/home/rlk/sandbox/gimp-print-source"
gutenprint_version=5.3.1

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

xed() {
    if [[ -n "$PREFIX" ]] ; then
	sed -e h -e "s/$/ $PREFIX => /" -e x -e 's/^[^0-9]*-//' "$@" -e H -e x -e "s/\n//"
    else
	sed -e 's/^[^0-9]*-//' "$@"
    fi
}

get_major() {
    xed -e 's/[-_\.].*//'
}

get_minor() {
    xed -e 's/^[0-9]*[-_\.]//' \
	-e 's/[-_\.].*//'
}

get_micro() {
    xed -e 's/^[0-9]*[-_\.][0-9]*[-_\.]//' \
	-e 's/[-_\.].*//'
}

get_extra() {
    xed -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() {
    xed -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/^[-_\.]/-/' \
	-e 's/-0-g[0-9a-f]*\(-dirty\|\)//'
}

get_git_hash() {
    xed -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/^[-_\.]/-/' \
	-e 's/^-[0-9]*-g//' \
	-e 's/-dirty$//'
}

get_extra_git() {
    xed -e 's/^[0-9]*[-_\.][0-9]*[-_\.][0-9]*\([a-zA-Z]\|\)//' \
	-e 's/^[-_\.]/-/' \
	-e 's/-0-g[0-9a-f]*\(-dirty\|\)$/\1/'
}

get_core_version() {
    xed -e 's/^\([0-9]*[-_\.][0-9]*\).*/\1/' \
	-e 's/[-_\.]/./g'
}

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

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

get_all() {
    xed -e 's/[-_\.]/=/g' \
	-e 's/=/./' \
	-e 's/=/./' \
	-e 's/=/-/g' \
	-e 's/-0-g[0-9a-f]*\(-dirty\|\)$/\1/'
}

get_everything() {
    xed -e 's/[-_\.]/=/g' \
	-e 's/=/./' \
	-e 's/=/./' \
	-e 's/=/-/g'
}

get_pkg() {
    echo "$gutenprint_version"
}

doit() {
    case "$1" in
	major)        get_major        ;;
	minor)        get_minor        ;;
	micro)        get_micro        ;;
	extra)        get_extra        ;;
	git)          get_git          ;;
	git-hash)     get_git_hash     ;;
	extra-git)    get_extra_git    ;;
	core-version) get_core_version ;;
	base-version) get_base_version ;;
	full-version) get_full_version ;;
	''|all)       get_all          ;;
	everything)   get_everything   ;;
	pkg)          get_pkg          ;;
	*)            usage            ;;
    esac
}

case "$description" in
    -) doit $1 ;;
    --) PREFIX="$1" doit $1 ;;
    *) doit $1 <<< $description
esac

exit 0