ge-svn-import

#!/bin/bash

current_dir=`pwd`
git_svn_init_args=""
git_svn_fetch_args=""
interactive_mode=0
log_file="./svn_import_`date '+%Y-%m-%d_%H.%M.%S'`.log"
svn_authors_files=""
svn_destination_dir=""
svn_repo_url=""
svn_start_revision=1
svn_username=""

function ge_svn_import() {
	touch $log_file
	(ge_svn_import_steps $@) | tee $log_file
}

function ge_svn_import_steps() {
	if [ -z "$svn_repo_url" ]; then
		echo "FATAL: No SVN repository URL was provided."
		exit 1
	fi

	echo "Importing SVN repository from $svn_repo_url into Git at $svn_destination_dir"

	if [ -z "$svn_authors_file" ]; then
		echo "WARN: No SVN authors file was found. Your new Git history will be incomplete."
	elif [ ! -f "$svn_authors_file" ]; then
		echo "FATAL: The SVN authors file ($svn_authors_file) does not exist or is not readable."
		exit 1
	else
		echo "Using $svn_authors_file to import SVN history."
	fi
	
	echo "Listing contents of SVN repository URL..."
	svn ls $svn_repo_url

	if [ 1 -eq $? ]; then
		echo "FATAL: The SVN repository URL $svn_repo_url is incorrect or does not exist."
		exit 1
	else
		echo "The SVN repository URL $svn_repo_url exists."
	fi
	
	if [ -d $svn_destination_dir ]; then
		echo "WARN: Destination directory already exists. Deleting the destination directory..."
		echo "rm -rf $svn_destination_dir"
		rm -rf $svn_destination_dir
	fi
	
	echo "Creating destination directory $svn_destination_dir..."
	echo "mkdir -vp $svn_destination_dir"
	mkdir -vp $svn_destination_dir
	
	if [ ! -d $svn_destination_dir ]; then
		echo "FATAL: Failed to create $svn_destination_dir."
		exit 1
	else
		echo "Destination directory created at $svn_destination_dir"
	fi

	echo "Initializing the Git-SVN repository..."
	echo "git svn init --stdlayout --no-metadata $svn_repo_url $svn_destination_dir"
	git svn init --stdlayout --no-metadata $svn_repo_url $svn_destination_dir
	echo "Git-SVN repository initialized."
	echo "Begin fetching commits..."
	echo "cd $svn_destination_dir"
	cd $svn_destination_dir
	echo "git svn fetch --authors-file=$svn_authors_file -r $svn_start_revision:HEAD"
	git svn fetch --authors-file=$svn_authors_file -r $svn_start_revision:HEAD
	echo "Finished fetching commits."
	ge_svn_convert_tags_to_branches	
	echo "Finished importing into Git."
}

function ge_svn_import_interactive() {
	ge_svn_import_read_repo_url
	ge_svn_import_read_destination_dir
	ge_svn_import_read_username
	ge_svn_import_read_authors_file
	ge_svn_import_read_revision
	ge_svn_import $@
}

function ge_svn_import_read_repo_url() {
	echo -n "SVN repo URL: "
	read svn_repo_url
	echo "# SVN repo located at $svn_repo_url"
}

function ge_svn_import_read_username() {
	echo -n "SVN username: "
	read svn_username
	echo "# SVN username is $svn_username"
}

function ge_svn_import_read_authors_file() {
	read -e -p "SVN authors file: " svn_authors_file
	eval svn_authors_file=$svn_authors_file
	echo "# SVN authors file located at $svn_authors_file"
}

function ge_svn_import_read_revision() {
	echo -n "Start import at revision: "
	read svn_start_revision

	if [ -z "$svn_start_revision" ]; then
		svn_start_revision=1
	fi

	echo "# Starting import at revision $svn_start_revision"
}

function ge_svn_import_read_destination_dir() {
	read -e -p "Destination directory: " svn_destination_dir
	eval svn_destination_dir=$svn_destination_dir
	echo "# Creating Git repo in $svn_destination_dir"
}

function ge_svn_debug_convert_tags_to_branches() {
	ge_svn_convert_tags_to_branches
}

function ge_svn_debug_git_branch() {
	echo "  origin/foo"
	echo "  origin/master"
	echo "  tags/1"
	echo "  tags/2"
	echo "  tags/abc"
}

function ge_svn_convert_tags_to_branches() {
	tag_branches=`git branch -r | grep -E '^  tags'`
	echo "Convert SVN tags to Git tags. SVN tags get imported to Git as Git branches. Transform the following Git branches into Git tags:"
	echo "$tag_branches"
	
	for branch in $tag_branches; do
		tag=`echo $branch | sed -E 's/tags\/([-_a-zA-Z0-9]+)/\1/'`
		echo "Convert Git-SVN branch $branch to Git tag $tag"
		echo "  git tag $tag $branch"
		git tag $tag $branch
		echo "  git branch -r -d $branch"
		git branch -r -d $branch
	done
	
	echo "git tag"
	git tag

	echo "Finished converting SVN tags to Git tags."
}

if [ -z "$1" ]; then
	interactive_mode=1
else
	while [ ! -z "$1" ]; do
		case $1 in
			'--svn-authors-file')
				shift
				svn_authors_file=$1
				shift
				;;
			'--revision')
				shift
				svn_start_revision=$1
				shift
				;;
			'--username')
				shift
				svn_username=$1
				shift
				;;
			*)
				break
				;;
		esac
	done
fi

if [ $interactive_mode -eq 1 ]; then
	echo "Entering interactive mode..."
	ge_svn_import_interactive $@
else
	svn_repo_url=$1
	shift
	svn_destination_dir=$1
	shift
	ge_svn_import $@
fi

exit $?