#
# git-flow -- A collection of Git extensions to provide high-level
# repository operations for Vincent Driessen's branching model.
#
# Original blog post presenting this model is found at:
#    http://nvie.com/git-model
#
# Feel free to contribute to this project at:
#    http://github.com/nvie/gitflow
#
# Copyright 2010 Vincent Driessen. All rights reserved.
# 
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
# 
#    1. Redistributions of source code must retain the above copyright notice,
#       this list of conditions and the following disclaimer.
# 
#    2. Redistributions in binary form must reproduce the above copyright
#       notice, this list of conditions and the following disclaimer in the
#       documentation and/or other materials provided with the distribution.
# 
# THIS SOFTWARE IS PROVIDED BY VINCENT DRIESSEN ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
# EVENT SHALL VINCENT DRIESSEN OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
# INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
# OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
# EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
# 
# The views and conclusions contained in the software and documentation are
# those of the authors and should not be interpreted as representing official
# policies, either expressed or implied, of Vincent Driessen.
#

require_git_repo
require_gitflow_initialized
gitflow_load_settings
PREFIX=$(git config --get gitflow.prefix.feature)

usage() {
	echo "usage: git flow feature [list] [-v]"
	echo "       git flow feature start [-F] <name> [<base>]"
	echo "       git flow feature finish [-rF] <name|nameprefix>"
	echo "       git flow feature publish <name>"
	echo "       git flow feature track <name>"
	echo "       git flow feature diff [<name|nameprefix>]"
	echo "       git flow feature rebase [-i] [<name|nameprefix>]"
	echo "       git flow feature checkout [<name|nameprefix>]"
	echo "       git flow feature pull <remote> [<name>]"
}

cmd_default() {
	cmd_list "$@"
}

cmd_list() {
	DEFINE_boolean verbose false 'verbose (more) output' v
	parse_args "$@"

	local feature_branches
	local current_branch
	local short_names
	feature_branches=$(echo "$(git_local_branches)" | grep "^$PREFIX")
	if [ -z "$feature_branches" ]; then
		warn "No feature branches exist."
		warn ""
		warn "You can start a new feature branch:"
		warn ""
		warn "    git flow feature start <name> [<base>]"
		warn ""
		exit 0
	fi
	current_branch=$(git branch | grep '^\* ' | grep -v 'no branch' | sed 's/^* //g')
	short_names=$(echo "$feature_branches" | sed "s ^$PREFIX  g")

	# determine column width first
	local width=0
	local branch
	for branch in $short_names; do
		local len=${#branch}
		width=$(max $width $len)
	done
	width=$(($width+3))

	local branch
	for branch in $short_names; do
		local fullname=$PREFIX$branch
		local base=$(git merge-base "$fullname" "$DEVELOP_BRANCH")
		local develop_sha=$(git rev-parse "$DEVELOP_BRANCH")
		local branch_sha=$(git rev-parse "$fullname")
		if [ "$fullname" = "$current_branch" ]; then
			printf "* "
		else
			printf "  "
		fi
		if flag verbose; then
			printf "%-${width}s" "$branch"
			if [ "$branch_sha" = "$develop_sha" ]; then
				printf "(no commits yet)"
			elif [ "$base" = "$branch_sha" ]; then
				printf "(is behind develop, may ff)"
			elif [ "$base" = "$develop_sha" ]; then
				printf "(based on latest develop)"
			else
				printf "(may be rebased)"
			fi
		else
			printf "%s" "$branch"
		fi
		echo
	done
}

cmd_help() {
	usage
	exit 0
}

require_name_arg() {
	if [ "$NAME" = "" ]; then
		warn "Missing argument <name>"
		usage
		exit 1
	fi
}

expand_nameprefix_arg() {
	require_name_arg

	local expanded_name
	local exitcode
	expanded_name=$(gitflow_resolve_nameprefix "$NAME" "$PREFIX")
	exitcode=$?
	case $exitcode in
		0) NAME=$expanded_name
		   BRANCH=$PREFIX$NAME
		   ;;
		*) exit 1 ;;
	esac
}

use_current_feature_branch_name() {
	local current_branch=$(git_current_branch)
	if startswith "$current_branch" "$PREFIX"; then
		BRANCH=$current_branch
		NAME=${BRANCH#$PREFIX}
	else
		warn "The current HEAD is no feature branch."
		warn "Please specify a <name> argument."
		exit 1
	fi
}

expand_nameprefix_arg_or_current() {
	if [ "$NAME" != "" ]; then
		expand_nameprefix_arg
		require_branch "$PREFIX$NAME"
	else
		use_current_feature_branch_name
	fi
}

name_or_current() {
	if [ -z "$NAME" ]; then
		use_current_feature_branch_name
	fi
}

parse_cmdline() {
	# parse options
	FLAGS "$@" || exit $?
	eval set -- "${FLAGS_ARGV}"
}

parse_args() {
	parse_cmdline "$@"

	# read arguments into global variables
	NAME=$1
	BRANCH=$PREFIX$NAME
}

parse_remote_name() {
	parse_cmdline "$@"

	# read arguments into global variables
	REMOTE=$1
	NAME=$2
	BRANCH=$PREFIX$NAME
}

cmd_start() {
	DEFINE_boolean fetch false 'fetch from origin before performing local operation' F
	parse_args "$@"
	BASE=${2:-$DEVELOP_BRANCH}
	require_name_arg

	# sanity checks
	require_branch_absent "$BRANCH"

	# update the local repo with remote changes, if asked
	if flag fetch; then
		git fetch -q "$ORIGIN" "$DEVELOP_BRANCH"
	fi

	# if the origin branch counterpart exists, assert that the local branch
	# isn't behind it (to avoid unnecessary rebasing)
	if git_branch_exists "$ORIGIN/$DEVELOP_BRANCH"; then
		require_branches_equal "$DEVELOP_BRANCH" "$ORIGIN/$DEVELOP_BRANCH"
	fi

	# create branch
	if ! git checkout -b "$BRANCH" "$BASE"; then
		die "Could not create feature branch '$BRANCH'"
	fi

	echo
	echo "Summary of actions:"
	echo "- A new branch '$BRANCH' was created, based on '$BASE'"
	echo "- You are now on branch '$BRANCH'"
	echo ""
	echo "Now, start committing on your feature. When done, use:"
	echo ""
	echo "     git flow feature finish $NAME"
	echo
}

cmd_finish() {
	DEFINE_boolean fetch false "fetch from $ORIGIN before performing finish" F
	DEFINE_boolean rebase false 'rebase instead of merge' r
	parse_args "$@"
	expand_nameprefix_arg

	# sanity checks
	require_branch "$BRANCH"

	# detect if we're restoring from a merge conflict
	if [ -f "$DOT_GIT_DIR/.gitflow/MERGE_BASE" ]; then
		#
		# TODO: detect that we're working on the correct branch here!
		# The user need not necessarily have given the same $NAME twice here
		# (although he/she should).
		# 

		# TODO: git_is_clean_working_tree() should provide an alternative
		# exit code for "unmerged changes in working tree", which we should
		# actually be testing for here
		if git_is_clean_working_tree; then
			FINISH_BASE=$(cat "$DOT_GIT_DIR/.gitflow/MERGE_BASE")

			# Since the working tree is now clean, either the user did a
			# succesfull merge manually, or the merge was cancelled.
			# We detect this using git_is_branch_merged_into()
			if git_is_branch_merged_into "$BRANCH" "$FINISH_BASE"; then
				rm -f "$DOT_GIT_DIR/.gitflow/MERGE_BASE"
				helper_finish_cleanup
				exit 0
			else
				# If the user cancelled the merge and decided to wait until later,
				# that's fine. But we have to acknowledge this by removing the
				# MERGE_BASE file and continuing normal execution of the finish
				rm -f "$DOT_GIT_DIR/.gitflow/MERGE_BASE"
			fi
		else
			echo
			echo "Merge conflicts not resolved yet, use:"
			echo "    git mergetool"
			echo "    git commit"
			echo 
			echo "You can then complete the finish by running it again:"
			echo "    git flow feature finish $NAME"
			echo
			exit 1
		fi
	fi

	# sanity checks
	require_clean_working_tree

	# update local repo with remote changes first, if asked
	if flag fetch; then
		git fetch -q "$ORIGIN" "$BRANCH"
	fi

	if has "$ORIGIN/$BRANCH" "$(git_remote_branches)"; then
		require_branches_equal "$BRANCH" "$ORIGIN/$BRANCH"
	fi
	require_branches_equal "$DEVELOP_BRANCH" "$ORIGIN/$DEVELOP_BRANCH"

	# if the user wants to rebase, do that first
	if flag rebase; then
		if ! git flow feature rebase "$NAME" "$DEVELOP_BRANCH"; then
			warn "Finish was aborted due to conflicts during rebase."
			warn "Please finish the rebase manually now."
			warn "When finished, re-run:"
			warn "    git flow feature finish '$NAME' '$DEVELOP_BRANCH'"
			exit 1
		fi
	fi

	# merge into BASE
	git checkout "$DEVELOP_BRANCH"
	if [ "$(git rev-list -n2 "$DEVELOP_BRANCH..$BRANCH" | wc -l)" -eq 1 ]; then
		git merge --ff "$BRANCH"
	else
		git merge --no-ff "$BRANCH"
	fi

	if [ $? -ne 0 ]; then
		# oops.. we have a merge conflict!
		# write the given $DEVELOP_BRANCH to a temporary file (we need it later)
		mkdir -p "$DOT_GIT_DIR/.gitflow"
		echo "$DEVELOP_BRANCH" > "$DOT_GIT_DIR/.gitflow/MERGE_BASE"
		echo
		echo "There were merge conflicts. To resolve the merge conflict manually, use:"
		echo "    git mergetool"
		echo "    git commit"
		echo 
		echo "You can then complete the finish by running it again:"
		echo "    git flow feature finish $NAME"
		echo
		exit 1
	fi

	# when no merge conflict is detected, just clean up the feature branch
	helper_finish_cleanup
}

helper_finish_cleanup() {
	# sanity checks
	require_branch "$BRANCH"
	require_clean_working_tree

	# delete branch
	if flag fetch; then
		git push "$ORIGIN" ":refs/heads/$BRANCH"
	fi
	git branch -D "$BRANCH"

	echo
	echo "Summary of actions:"
	echo "- The feature branch '$BRANCH' was merged into '$DEVELOP_BRANCH'"
	#echo "- Merge conflicts were resolved"		# TODO: Add this line when it's supported
	echo "- Feature branch '$BRANCH' has been removed"
	echo "- You are now on branch '$DEVELOP_BRANCH'"
	echo
}

cmd_publish() {
	parse_args "$@"
	expand_nameprefix_arg

	# sanity checks
	require_clean_working_tree
	require_branch "$BRANCH"
	git fetch -q "$ORIGIN"
	require_branch_absent "$ORIGIN/$BRANCH"

	# create remote branch
	git push "$ORIGIN" "$BRANCH:refs/heads/$BRANCH"
	git fetch -q "$ORIGIN"

	# configure remote tracking
	git config "branch.$BRANCH.remote" "$ORIGIN"
	git config "branch.$BRANCH.merge" "refs/heads/$BRANCH"
	git checkout "$BRANCH"

	echo
	echo "Summary of actions:"
	echo "- A new remote branch '$BRANCH' was created"
	echo "- The local branch '$BRANCH' was configured to track the remote branch"
	echo "- You are now on branch '$BRANCH'"
	echo
}

cmd_track() {
	parse_args "$@"
	require_name_arg

	# sanity checks
	require_clean_working_tree
	require_branch_absent "$BRANCH"
	git fetch -q "$ORIGIN"
	require_branch "$ORIGIN/$BRANCH"

	# create tracking branch
	git checkout -b "$BRANCH" "$ORIGIN/$BRANCH"

	echo
	echo "Summary of actions:"
	echo "- A new remote tracking branch '$BRANCH' was created"
	echo "- You are now on branch '$BRANCH'"
	echo
}

cmd_diff() {
	parse_args "$@"

	if [ "$NAME" != "" ]; then
		expand_nameprefix_arg
		BASE=$(git merge-base "$DEVELOP_BRANCH" "$BRANCH")
		git diff "$BASE..$BRANCH"
	else
		if ! git_current_branch | grep -q "^$PREFIX"; then
			die "Not on a feature branch. Name one explicitly."
		fi

		BASE=$(git merge-base "$DEVELOP_BRANCH" HEAD)
		git diff "$BASE"
	fi
}

cmd_checkout() {
	parse_args "$@"

	if [ "$NAME" != "" ]; then
		expand_nameprefix_arg
		git checkout "$BRANCH"
	else
		die "Name a feature branch explicitly."
	fi
}

cmd_co() {
	# Alias for checkout
	cmd_checkout "$@"
}

cmd_rebase() {
	DEFINE_boolean interactive false 'do an interactive rebase' i
	parse_args "$@"
	expand_nameprefix_arg_or_current
	warn "Will try to rebase '$NAME'..."
	require_clean_working_tree
	require_branch "$BRANCH"

	git checkout -q "$BRANCH"
	local OPTS=
	if flag interactive; then
		OPTS="$OPTS -i"
	fi
	git rebase $OPTS "$DEVELOP_BRANCH"
}

avoid_accidental_cross_branch_action() {
	local current_branch=$(git_current_branch)
	if [ "$BRANCH" != "$current_branch" ]; then
		warn "Trying to pull from '$BRANCH' while currently on branch '$current_branch'."
		warn "To avoid unintended merges, git-flow aborted."
		return 1
	fi
	return 0
}

cmd_pull() {
	#DEFINE_string prefix false 'alternative remote feature branch name prefix' p
	parse_remote_name "$@"

	if [ -z "$REMOTE" ]; then
		die "Name a remote explicitly."
	fi
	name_or_current

	# To avoid accidentally merging different feature branches into each other,
	# die if the current feature branch differs from the requested $NAME
	# argument.
	local current_branch=$(git_current_branch)
	if startswith "$current_branch" "$PREFIX"; then
		# we are on a local feature branch already, so $BRANCH must be equal to
		# the current branch
		avoid_accidental_cross_branch_action || die
	fi

	require_clean_working_tree

	if git_branch_exists "$BRANCH"; then
		# Again, avoid accidental merges
		avoid_accidental_cross_branch_action || die

		# we already have a local branch called like this, so simply pull the
		# remote changes in
		git pull -q "$REMOTE" "$BRANCH" || die "Failed to pull from remote '$REMOTE'."
		echo "Pulled $REMOTE's changes into $BRANCH."
	else
		# setup the local branch clone for the first time
		git fetch -q "$REMOTE" "$BRANCH" || die "Fetch failed."     # stores in FETCH_HEAD
		git branch --no-track "$BRANCH" FETCH_HEAD || die "Branch failed."
		git checkout -q "$BRANCH" || die "Checking out new local branch failed."
		echo "Created local branch $BRANCH based on $REMOTE's $BRANCH."
	fi
}