git_find_closest_tag

#!/bin/bash
## git_find_closest_tag v1.0
## Copyright (C) Luke Hudson
##
## This program tries to determine the closet tag for a given directory.
## Compare a directory to all the tags in remote
## and determine the closest tag
##
## WARNING: The directory in question may be modified
## WARNING: run this on a copy if unsure.
##
## Usage:
##     @script.name [option] <DIR> <GIT REMOTE URL>
##
## Options:
##     -h, --help              All client scripts have this by default,
##                             it shows this double-hash documentation.
##
##     -p, --prompt            Prompt for each tag to examine diffs, or abort, or continue
##
##         --start-tag=VALUE   Do not compare tags until tag VALUE is reached
##
##
THIS=$0
DIR="$(readlink -f $(dirname "$THIS"))"

START_TAG=""
TARGETDIR=""
REMOTE=""
PROMPT=false

function get_args() {
	source $DIR/easyoptions.sh
	if [[ $prompt == 'yes' ]]; then
		PROMPT=true
	fi
	START_TAG="$start_tag"
	TARGETDIR="${arguments[0]}"
	if [[ -z $TARGETDIR ]]; then
		show_error "DIR is required"
		exit 1
	fi
	TARGETDIR=$(readlink -f "$TARGETDIR")
	REMOTE="${arguments[1]}"
	if [[ -z $REMOTE ]]; then
		show_error "GIT REMOTE URL is required"
		exit 1
	fi
	echo "$TARGETDIR $REMOTE"
}

function prompt() {
	local REPL=true
	local response=""

	while $REPL; do
		echo -n "[C]ontinue [E]xamine [A]bort? "
		read response
		case "$response" in 
			[aA])
				REPL=false
				exit 0
				;;
			[eE])
				git -c core.fileMode=false diff
				;;
			[cC])
				REPL=false
				;;
		esac
	done
}

function compare() {
	local me=$(whoami)
	local diffs=""
	local output="$(mktemp)"
	local response=""
	local addedGit=false
	local ignore

	echo "Output in $output"
	pushd $TARGETDIR
	if [[ ! -d .git ]]; then
		echo "Run git init on $TARGETDIR Later you may delete the .git dir if not needed."
		echo "Now adding all files to git for first time"
		addedGit=true
		git init
		ignore=$(git add . 2>&1) # capture and ignore output
		ignore=$(git commit -m 'find_closest_tag initial commit of working dir' 2>&1) # capture and ignore output
	fi
	git remote add find_closest $REMOTE
	echo -e "Fetching remote: find_closest\t$REMOTE"
	ignore=$(git fetch --quiet find_closest --tags) # capture and ignore output

	local skippingTags=false
	if [[ -n $START_TAG ]]; then
		skippingTags=true
	fi

	for tag in $(git tag -l); do
		if [[ $tag == $START_TAG ]]; then
			skippingTags=false
		fi
		if [[ $skippingTags == true ]]; then
			echo "# Skipping tag $tag"
			continue
		fi

		echo "# Comparing $tag"

		diffs=$(git -c core.fileMode=false diff --shortstat $tag | tail -1 | sed -r 's/([0-9]+).*\s([0-9]+).*\s([0-9]+).*/\1\t\2\t\3/')

		echo -e "$diffs\t$tag" >> $output
		echo $diffs
		if [[ $PROMPT == true ]]; then
			prompt
		fi
	done

	echo "-----------------------------------------------------------"
	echo "Done"
	echo "Output is in $output"
	echo "To clean up after this script:"
	if [[ $addedGit == true ]]; then
		echo " Remove the .git directory we added to $TARGETDIR"
		echo " Be sure before you do this!"
	fi
	echo "You may remove the remote we added"
	echo "# git remote rm find_closest"
	sort -n $output | less
}

function main() {
	get_args "$@"
	compare
}

main "$@"