Complete redesign of Subsurface version numbers

- for now all versions start with v6.0
- CICD builds use the monolithic build number as patch level, e.g. v6.0.12345
- local builds use the following algorithm
  - find the newest commit with a CICD build number that is included in the
    working tree
  - count the number of commits in the working tree since that commit
  - if there are no commits since the last CICD build, the local build version
    will be v6.0.12345-local
  - if there are N commits since the last CICD build, it will be
    v6.0.12345-N-local
- test builds in the CICD that don't create artifacts simply use a dummy release
  in order to not incorrectly increment the build number and also not to waste
  time and resources by manually checking out the nightly-build repo for each of
  these builds.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

scripts/get-version

@@ -1,76 +1,80 @@
-#!/bin/sh
+#!/bin/bash
+# shellcheck disable=SC2164
 
-# $1 - os name {linux|darwin|win}
-# $2 - [optional] raw version string "vX.Y-patchN-sha1". as from `git describe'
-#      (see below)
-
-set -eu
-#set -x
+# consistently name all builds, regardless of OS or desktop/mobile
+#
+# we do need to be able to create three digit (M.m.p) and four digit (M.m.p.c) version strings
+# default is VERSION_EXTENSION version - an argument of '4' or '3' gets you a digits only version string
+#
+# we hardcode a base version - this will rarely change
+# (we actually haven't discussed a situation where it would change...)
+SUBSURFACE_BASE_VERSION=6.0
 
+# little silly helper functions
 croak() {
 	echo "$0: $*" >&2
 	exit 1
 }
+croak_usage() {
+	croak "Usage: $0 [3|4]"
+}
 
-[ $# -ge 1 ] || croak "missing OS argument"
-os=$1
-
-if [ $# -eq 2 ] && [ "$2" ]; then
-	v0=$2
-else
-	cmd="git describe --match "v[0-9]*" --abbrev=12"
-	v0=$($cmd) || v0=$(cat .gitversion) || croak "odd; command '$cmd' failed"
+if [[ $# -gt 1 ]] ; then croak_usage ; fi
+if [[ $# -eq 1 ]] ; then
+	if [[ $1 != "4" && $1 != "3" ]] ; then croak_usage ; fi
+	DIGITS="$1"
 fi
 
-# strip off the 'v' prefix, if any
-v0=${v0#v}
+# figure out where we are in the file system
+cd "$(dirname "$0")/../"
+export SUBSURFACE_SOURCE=$PWD
 
-case $os in
-	linux)
-		v=$v0
-		;;
-	darwin)
-		# just the dots in the version string - this way we can
-		# count them
-		IFS=.
-		set -- $v0		# split $v0 using $IFS separator
-		dots=$(($# - 1))	# use positional argument count
-		# split version string using a '-' separator
-		IFS=-
-		set -- $v0
-		v=$1
-		# do we need to add another digit?
-		# We know there are 1 or 2 dots in $v, so if it's just one
-		# or we are trying to get to 4, add one digit
-		if [ $dots -eq 1 ]; then
-			if [ $# -gt 1 ]; then
-				v=$v.$2
-			else
-				v=$v.0
-			fi
-		fi
-		;;
-	full|win)
-		# just the dots in the version string - this way we can
-		# count them
-		IFS=.
-		set -- $v0		# split $v0 using $IFS separator
-		dots=$(($# - 1))	# use positional argument count
-		# split version string using a '-' separator
-		IFS=-
-		set -- $v0
-		v=$1
-		if [ $dots -eq 1 ]; then
-			v=$v.0
-		fi
-		if [ $# -gt 1 ]; then
-			v=$v.$2
-		else
-			v=$v.0
-		fi
-		;;
-	*)
-		v=git.missing.please.hardcode.version
-		;;
-esac
-printf '%s' $v
+# add the build number to this as 'patch' component
+# if we run in an environment where we are given a build number (e.g. CICD builds)
+# we just grab that - otherwise we have to figure it out on the fly
+if [ ! -f latest-subsurface-buildnumber ] ; then
+	# figure out the most recent build number, given our own git history
+	# this assumes that (a) we are in a checked out git tree and
+	# (b) we have the ability to check out another git repo
+	# in situations where either of these isn't true, it's the caller's
+	# responsibility to ensure that the latest-subsurface-buildnumber file exists
+	if [ ! -d "$SUBSURFACE_SOURCE/nightly-builds" ] ; then
+		git clone https://github.com/subsurface/nightly-builds &> /dev/null || croak "failed to clone nightly-builds repo"
+	fi
+	cd nightly-builds
+	git fetch &> /dev/null
+	LAST_BUILD_BRANCHS=$(git branch -a --sort=-committerdate --list | grep remotes/origin/branch-for | head -50 | cut -d/ -f3)
+	for LAST_BUILD_BRANCH in $LAST_BUILD_BRANCHS "not-found" ; do
+		LAST_BUILD_SHA=$(cut -d- -f 3 <<< "$LAST_BUILD_BRANCH")
+		git -C "$SUBSURFACE_SOURCE" merge-base --is-ancestor "$LAST_BUILD_SHA" HEAD && break
+	done
+	[ "not-found" = "$LAST_BUILD_BRANCH" ] && croak "can't find a build number for the current working tree"
+	git checkout "$LAST_BUILD_BRANCH" &> /dev/null || croak "failed to check out $LAST_BUILD_BRANCH in nightly-builds"
+	BUILDNR=$(<./latest-subsurface-buildnumber)
+	cd "$SUBSURFACE_SOURCE"
+	VERSION_EXTENSION="-"
+	VERSION_EXTENSION+=$(git log --pretty="oneline" "${LAST_BUILD_SHA}...HEAD" | wc -l | tr -d '[:space:]')
+	VERSION_EXTENSION+="-"
+	[ "$VERSION_EXTENSION" = "-0-" ] && VERSION_EXTENSION="-"
+	VERSION_EXTENSION+="local"
+else
+	# use the files included with the sources
+	BUILDNR=$(<"$SUBSURFACE_SOURCE/latest-subsurface-buildnumber")
+	VERSION_EXTENSION=""
+	if [ -f "$SUBSURFACE_SOURCE/latest-subsurface-buildnumber-extension" ] ; then
+		VERSION_EXTENSION="-"
+		VERSION_EXTENSION+=$(<"$SUBSURFACE_SOURCE/latest-subsurface-buildnumber-extension")
+	fi
+fi
+
+COMMITS_SINCE=$(tr -cd "[:digit:]" <<<"$VERSION_EXTENSION")
+[[ -z $COMMITS_SINCE ]] && COMMITS_SINCE="0"
+
+if [[ $DIGITS == "3" ]] ; then
+	VERSION="${SUBSURFACE_BASE_VERSION}.${BUILDNR}"
+elif [[ $DIGITS == "4" ]] ; then
+	VERSION="${SUBSURFACE_BASE_VERSION}.${BUILDNR}.${COMMITS_SINCE}"
+else
+	VERSION="${SUBSURFACE_BASE_VERSION}.${BUILDNR}${VERSION_EXTENSION}"
+fi
+printf '%s' "$VERSION"