git-3way-merge

#!/bin/bash

function parseArgs
{
	mergeAll=false
	revision="HEAD~1"
	verbose=false
	extra_verbose=false

	finalSummary=""

	needsManualMerge=()

	while [[ $# > 0 ]]; do

		key="$1"
		case $key in
			-a|--all)
				mergeAll=true
				;;
			-h|--help)
				printHelp
				exit 0
				;;
			-r|--revision)
				revision="$2"
				shift
				;;
			-v|--verbose)
				verbose=true
				;;
			-vv|--extra-verbose)
				verbose=true
				extra_verbose=true
				;;
			*)
				echo -e "\n Invalid argument was supplied!\n"
				printHelp
				exit 1
				;;
		esac
		shift

	done
}

function merge_directory
{
	if [ -d "$2" ]; then

		local localDir=$1
		local localDirLength=${#localDir}
		local coreDir=$2

		if $extra_verbose; then

			echo -e "INFO:\t ------------------"
			echo -e "INFO:\t Merging directory $2"
			echo -e "INFO:\t    into directory $1"
			echo -e "INFO:\t ------------------"
		fi

		for current in $localDir/* ; do

			local coreEquivalent=$coreDir${current:$localDirLength}
			if [ -d "$current" ]; then

				merge_directory "$current" "$coreEquivalent"
			else
				local oldFile="/tmp/tmp-merge-old-`basename \"$coreEquivalent\"`"
				local newFile="/tmp/tmp-merge-new-`basename \"$coreEquivalent\"`"
				if [ -f "$coreEquivalent" ]; then

					git show $revision:$coreEquivalent > $oldFile
					diff3 -m "$current" "$oldFile" "$coreEquivalent" > "$newFile"

					if [ $? == 1 ]; then
						if $verbose; then
							echo -e "CONFLICT - needs manual merge!: $current"
						fi
						needsManualMerge+=("$current")
					elif $verbose; then
						echo -e "SUCCESS: Successfully merged '$current' with '$coreEquivalent'"
					fi
					cp $newFile $current
				elif $extra_verbose; then

					echo -e "INFO:\t Skipping file $current; no equivalent in core code."
				fi
			fi
		done
	elif $extra_verbose; then

		echo -e "INFO:\t Skipping directory $2; no equivalent in core code."
	fi
}

function summarizeConflicts
{
	needsManualMergeSize=${#needsManualMerge[@]}

	# Assume there will be no error
	toReturn=0

	echo -e "---------------------------------------------\n"
	echo -e " There has been recurrently merged these dirs:"
	echo -e "$finalSummary\n"

	echo -e "---------------------------------------------\n"

	if [[ $needsManualMergeSize > 0 ]]; then

		toReturn=1
		echo " There is a need for manual merge :))"
		echo -e "\t Files needed to be merged are:\n"
		for i in "${needsManualMerge[@]}"; do

			echo -e "Conflict which has to be merged manually: '$i' "
		done

		echo
		inquire "Do you wish to resolve all the conflicts with meld?" "y" "N"
		case $answer in
			y)
				for i in "${needsManualMerge[@]}"; do
					args+="--diff $i "
				done
				echo -e "  Running meld with cmd:\nmeld $args&\n"
				meld $args&
				;;
			*)
				echo -e "  Okay, not opening meld - but don't forget to merge these conflicts ;)"
				;;
		esac
	else

		echo " Everything went OK ! :)"
	fi

	echo ""
	echo "Performed 3way diff against revision '$revision'"
	echo ""

}

function printHelp
{
	echo -e "Usage: git-3way-merge [options]\n"
	echo -e "  All options are optional:\n"
	echo -e "   -a, --all                    Does include directories specified in skippable array"
	echo -e "   -h, --help                   Prints this help"
	echo -e "   -r, --revision 'HEAD~n'      This can be any string which specifies the git revision to perform the git show against"
	echo -e "                                  - for example passing 'HEAD~5' will do 'git show HEAD~5:fileToHasAsTheSecondOne'"
	echo -e "   -v, --verbose                Include also SUCCESS outputs"
	echo -e "   -vv, --extra-verbose         Include all the output possible (INFO & SUCCESS)"
	echo
}

function callMerges
{
	if $mergeAll; then

		for key in "${!skippableMergeMappings[@]}"; do

			local mergeMappingName="$key[@]"
			local mergeMapping=( "${!mergeMappingName}" )

			local dirToMergeWith=${skippableMergeMappings[$key]}

			for dirToBeMerged in "${mergeMapping[@]}"; do

				finalSummary+="\n   $dirToBeMerged"
				merge_directory $dirToBeMerged $dirToMergeWith
			done
			finalSummary+="\n"
		done
	fi

	for key in "${!mergeMappings[@]}"; do

		local mergeMappingName="$key[@]"
		local mergeMapping=( "${!mergeMappingName}" )

		local dirToMergeWith=${mergeMappings[$key]}

		for dirToBeMerged in "${mergeMapping[@]}"; do

			finalSummary+="\n   $dirToBeMerged"
			merge_directory $dirToBeMerged $dirToMergeWith
		done
	done

}

inquire ()  {
	echo -e -n "$1 [$2/$3]? "
	read answer
	finish="-1"
	while [ "$finish" = '-1' ]
	do
		finish="1"
		if [ "$answer" = '' ];
		then
			answer=""
		else
			case $answer in
				y | Y | yes | YES ) answer="y";;
				n | N | no | NO ) answer="n";;
				*) finish="-1";
					echo -n 'Invalid response -- please reenter:';
					read answer;;
			esac
		fi
	done
}

function initialize
{
	parseArgs $@

	# Load the config file
	source git-3way-merge.cfg
	
	callMerges

	summarizeConflicts
}

# Initialize with the incoming arguments
initialize $@

exit $toReturn