#!/bin/sh
# Copyright (c) 2007, Nanako Shiraishi

setvar dashless = $(basename "$0" | sed -e 's/-/ /')
setvar USAGE = ""list [<options>]
   or: $dashless show [<stash>]
   or: $dashless drop [-q|--quiet] [<stash>]
   or: $dashless ( pop | apply ) [--index] [-q|--quiet] [<stash>]
   or: $dashless branch <branchname> [<stash>]
   or: $dashless [save [--patch] [-k|--[no-]keep-index] [-q|--quiet]
		       [-u|--include-untracked] [-a|--all] [<message>]]
   or: $dashless clear""

setvar SUBDIRECTORY_OK = 'Yes'
setvar OPTIONS_SPEC = ''
setvar START_DIR = $(pwd)
source git-sh-setup
require_work_tree
cd_to_toplevel

setvar TMP = ""$GIT_DIR/.git-stash.$Pid""
setvar TMPindex = "${GIT_INDEX_FILE-"$(git rev-parse --git-path index)"}.stash.$Pid"
trap 'rm -f "$TMP-"* "$TMPindex"' 0

setvar ref_stash = 'refs/stash'

if git config --get-colorbool color.interactive {
       setvar help_color = "$(git config --get-color color.interactive.help 'red bold')"
       setvar reset_color = "$(git config --get-color '' reset)"
} else {
       setvar help_color = ''
       setvar reset_color = ''
}

proc no_changes {
	git diff-index --quiet --cached HEAD --ignore-submodules -- &&
	git diff-files --quiet --ignore-submodules &&
	shell {test -z $untracked || test -z $(untracked_files)}
}

proc untracked_files {
	setvar excl_opt = '--exclude-standard'
	test $untracked = "all" && setvar excl_opt = ''
	git ls-files -o -z $excl_opt
}

proc clear_stash {
	if test $Argc != 0
	{
		die $(gettext "git stash clear with parameters is unimplemented")
	}
	if setvar current = $(git rev-parse --verify --quiet $ref_stash)
	{
		git update-ref -d $ref_stash $current
	}
}

proc create_stash {
	setvar stash_msg = "$1"
	setvar untracked = "$2"

	git update-index -q --refresh
	if no_changes
	{
		exit 0
	}

	# state of the base commit
	if setvar b_commit = $(git rev-parse --verify HEAD)
	{
		setvar head = $(git rev-list --oneline -n 1 HEAD --)
	} else {
		die $(gettext "You do not have the initial commit yet")
	}

	if setvar branch = $(git symbolic-ref -q HEAD)
	{
		setvar branch = ${branch#refs/heads/}
	} else {
		setvar branch = ''(no branch)''
	}
	setvar msg = $(printf '%s: %s' "$branch" "$head")

	# state of the index
	setvar i_tree = $(git write-tree) &&
	setvar i_commit = $(printf 'index on %s\n' "$msg" |
		git commit-tree $i_tree -p $b_commit) ||
		die $(gettext "Cannot save the current index state")

	if test -n $untracked
	{
		# Untracked files are stored by themselves in a parentless commit, for
		# ease of unpacking later.
		setvar u_commit = $(
			untracked_files | (
				GIT_INDEX_FILE="$TMPindex" &&
				export GIT_INDEX_FILE &&
				rm -f "$TMPindex" &&
				git update-index -z --add --remove --stdin &&
				u_tree=$(git write-tree) &&
				printf 'untracked files on %s\n' "$msg" | git commit-tree $u_tree  &&
				rm -f "$TMPindex"
		) ) || die $(gettext "Cannot save the untracked files")

		setvar untracked_commit_option = ""-p $u_commit"";
	} else {
		setvar untracked_commit_option = ''
	}

	if test -z $patch_mode
	{

		# state of the working tree
		setvar w_tree = $( (
			git read-tree --index-output="$TMPindex" -m $i_tree &&
			GIT_INDEX_FILE="$TMPindex" &&
			export GIT_INDEX_FILE &&
			git diff --name-only -z HEAD -- >"$TMP-stagenames" &&
			git update-index -z --add --remove --stdin <"$TMP-stagenames" &&
			git write-tree &&
			rm -f "$TMPindex"
		) ) ||
			die $(gettext "Cannot save the current worktree state")

	} else {

		rm -f "$TMP-index"" &&
		GIT_INDEX_FILE="$TMP-index"" git read-tree HEAD" &&

		# find out what the user wants
		GIT_INDEX_FILE="$TMP-index"" \
			git add--interactive --patch=stash -- &&

		# state of the working tree
		setvar w_tree = $(GIT_INDEX_FILE="$TMP-index" git write-tree) ||
		die $(gettext "Cannot save the current worktree state")

		git diff-tree -p HEAD $w_tree -- >"$TMP-patch" &&
		test -s "$TMP-patch" ||
		die $(gettext "No changes selected")

		rm -f "$TMP-index" ||
		die $(gettext "Cannot remove temporary index (can't happen)")

	}

	# create the stash
	if test -z $stash_msg
	{
		setvar stash_msg = $(printf 'WIP on %s' "$msg")
	} else {
		setvar stash_msg = $(printf 'On %s: %s' "$branch" "$stash_msg")
	}
	setvar w_commit = $(printf '%s\n' "$stash_msg" |
	git commit-tree $w_tree -p $b_commit -p $i_commit $untracked_commit_option) ||
	die $(gettext "Cannot record working tree state")
}

proc store_stash {
	while test $# != 0
	{
		match $1 {
		with -m|--message
			shift
			setvar stash_msg = "$1"
			
		with -q|--quiet
			setvar quiet = 't'
			
		with *
			break
			
		}
		shift
	}
	test $Argc = 1 ||
	die $(eval_gettext "\"$dashless store\" requires one <commit> argument")

	setvar w_commit = "$1"
	if test -z $stash_msg
	{
		setvar stash_msg = ""Created via \"git stash store\".""
	}

	git update-ref --create-reflog -m $stash_msg $ref_stash $w_commit
	setvar ret = "$Status"
	test $ret != 0 && test -z $quiet &&
	die $(eval_gettext "Cannot update \$ref_stash with \$w_commit")
	return $ret
}

proc save_stash {
	setvar keep_index = ''
	setvar patch_mode = ''
	setvar untracked = ''
	while test $# != 0
	{
		match $1 {
		with -k|--keep-index
			setvar keep_index = 't'
			
		with --no-keep-index
			setvar keep_index = 'n'
			
		with -p|--patch
			setvar patch_mode = 't'
			# only default to keep if we don't already have an override
			test -z $keep_index && setvar keep_index = 't'
			
		with -q|--quiet
			setvar GIT_QUIET = 't'
			
		with -u|--include-untracked
			setvar untracked = 'untracked'
			
		with -a|--all
			setvar untracked = 'all'
			
		with --help
			show_help
			
		with --
			shift
			break
			
		with -*
			setvar option = "$1"
			# TRANSLATORS: $option is an invalid option, like
			# `--blah-blah'. The 7 spaces at the beginning of the
			# second line correspond to "error: ". So you should line
			# up the second line with however many characters the
			# translation of "error: " takes in your language. E.g. in
			# English this is:
			#
			#    $ git stash save --blah-blah 2>&1 | head -n 2
			#    error: unknown option for 'stash save': --blah-blah
			#           To provide a message, use git stash save -- '--blah-blah'
			eval_gettextln "error: unknown option for 'stash save': \$option
       To provide a message, use git stash save -- '\$option'"
			usage
			
		with *
			break
			
		}
		shift
	}

	if test -n $patch_mode && test -n $untracked
	{
		die $(gettext "Can't use --patch and --include-untracked or --all at the same time")
	}

	setvar stash_msg = ""$ifsjoin(ARGV)""

	git update-index -q --refresh
	if no_changes
	{
		say $(gettext "No local changes to save")
		exit 0
	}
	git reflog exists $ref_stash ||
		clear_stash || die $(gettext "Cannot initialize stash")

	create_stash $stash_msg $untracked
	store_stash -m $stash_msg -q $w_commit ||
	die $(gettext "Cannot save the current status")
	say $(eval_gettext "Saved working directory and index state \$stash_msg")

	if test -z $patch_mode
	{
		git reset --hard ${GIT_QUIET:+-q}
		test $untracked = "all" && setvar CLEAN_X_OPTION = '-x' || setvar CLEAN_X_OPTION = ''
		if test -n $untracked
		{
			git clean --force --quiet -d $CLEAN_X_OPTION
		}

		if test $keep_index = "t" && test -n $i_tree
		{
			git read-tree --reset -u $i_tree
		}
	} else {
		git apply -R < "$TMP-patch" ||
		die $(gettext "Cannot remove worktree changes")

		if test $keep_index != "t"
		{
			git reset
		}
	}
}

proc have_stash {
	git rev-parse --verify --quiet $ref_stash >/dev/null
}

proc list_stash {
	have_stash || return 0
	git log --format="%gd: %gs" -g --first-parent -m @ARGV $ref_stash --
}

proc show_stash {
	setvar ALLOW_UNKNOWN_FLAGS = 't'
	assert_stash_like @ARGV

	if test -z $FLAGS
	{
		if test $(git config --bool stash.showStat || echo true) = "true"
		{
			setvar FLAGS = '--stat'
		}

		if test $(git config --bool stash.showPatch || echo false) = "true"
		{
			setvar FLAGS = "${FLAGS}${FLAGS:+ }-p"
		}

		if test -z $FLAGS
		{
			return 0
		}
	}

	git diff ${FLAGS} $b_commit $w_commit
}

proc show_help {
	exec git help stash
	exit 1
}

#
# Parses the remaining options looking for flags and
# at most one revision defaulting to ${ref_stash}@{0}
# if none found.
#
# Derives related tree and commit objects from the
# revision, if one is found.
#
# stash records the work tree, and is a merge between the
# base commit (first parent) and the index tree (second parent).
#
#   REV is set to the symbolic version of the specified stash-like commit
#   IS_STASH_LIKE is non-blank if ${REV} looks like a stash
#   IS_STASH_REF is non-blank if the ${REV} looks like a stash ref
#   s is set to the SHA1 of the stash commit
#   w_commit is set to the commit containing the working tree
#   b_commit is set to the base commit
#   i_commit is set to the commit containing the index tree
#   u_commit is set to the commit containing the untracked files tree
#   w_tree is set to the working tree
#   b_tree is set to the base tree
#   i_tree is set to the index tree
#   u_tree is set to the untracked files tree
#
#   GIT_QUIET is set to t if -q is specified
#   INDEX_OPTION is set to --index if --index is specified.
#   FLAGS is set to the remaining flags (if allowed)
#
# dies if:
#   * too many revisions specified
#   * no revision is specified and there is no stash stack
#   * a revision is specified which cannot be resolve to a SHA1
#   * a non-existent stash reference is specified
#   * unknown flags were set and ALLOW_UNKNOWN_FLAGS is not "t"
#

proc parse_flags_and_rev
{
	test $PARSE_CACHE = "$ifsjoin(ARGV)" && return 0 # optimisation
	setvar PARSE_CACHE = ""$ifsjoin(ARGV)""

	setvar IS_STASH_LIKE = ''
	setvar IS_STASH_REF = ''
	setvar INDEX_OPTION = ''
	setvar s = ''
	setvar w_commit = ''
	setvar b_commit = ''
	setvar i_commit = ''
	setvar u_commit = ''
	setvar w_tree = ''
	setvar b_tree = ''
	setvar i_tree = ''
	setvar u_tree = ''

	setvar REV = $(git rev-parse --no-flags --symbolic --sq "$@") || exit 1

	setvar FLAGS = ''for opt in @ARGV {
		match $opt {
			with -q|--quiet
				setvar GIT_QUIET = '-t'
			
			with --index
				setvar INDEX_OPTION = '--index'
			
			with --help
				show_help
			
			with -*
				test $ALLOW_UNKNOWN_FLAGS = t ||
					die $(eval_gettext "unknown option: \$opt")
				setvar FLAGS = ""${FLAGS}${FLAGS:+ }$opt""
			
		}
	}

	eval set -- $REV

	match $Argc {
		with 0
			have_stash || die $(gettext "No stash found.")
			set -- ${ref_stash}@{0}
		
		with 1
			:
		
		with *
			die $(eval_gettext "Too many revisions specified: \$REV")
		
	}

	setvar REV = $(git rev-parse --symbolic --verify --quiet "$1") || do {
		setvar reference = "$1"
		die $(eval_gettext "\$reference is not a valid reference")
	}

	setvar i_commit = $(git rev-parse --verify --quiet "$REV^2") &&
	set -- $(git rev-parse "$REV" "$REV^1" "$REV:" "$REV^1:" "$REV^2:" 2>/dev/null) &&
	setvar s = "$1" &&
	setvar w_commit = "$1" &&
	setvar b_commit = "$2" &&
	setvar w_tree = "$3" &&
	setvar b_tree = "$4" &&
	setvar i_tree = "$5" &&
	setvar IS_STASH_LIKE = 't' &&
	test $ref_stash = $(git rev-parse --symbolic-full-name "${REV%@*}") &&
	setvar IS_STASH_REF = 't'

	setvar u_commit = $(git rev-parse --verify --quiet "$REV^3") &&
	setvar u_tree = $(git rev-parse "$REV^3:" 2>/dev/null)
}

proc is_stash_like
{
	parse_flags_and_rev @ARGV
	test -n $IS_STASH_LIKE
}

proc assert_stash_like {
	is_stash_like @ARGV || do {
		setvar args = ""$ifsjoin(ARGV)""
		die $(eval_gettext "'\$args' is not a stash-like commit")
	}
}

proc is_stash_ref {
	is_stash_like @ARGV && test -n $IS_STASH_REF
}

proc assert_stash_ref {
	is_stash_ref @ARGV || do {
		setvar args = ""$ifsjoin(ARGV)""
		die $(eval_gettext "'\$args' is not a stash reference")
	}
}

proc apply_stash {

	assert_stash_like @ARGV

	git update-index -q --refresh || die $(gettext "unable to refresh index")

	# current index state
	setvar c_tree = $(git write-tree) ||
		die $(gettext "Cannot apply a stash in the middle of a merge")

	setvar unstashed_index_tree = ''
	if test -n $INDEX_OPTION && test $b_tree != $i_tree &&
			test $c_tree != $i_tree
	{
		git diff-tree --binary $s^2^..$s^2 | git apply --cached
		test $Status -ne 0 &&
			die $(gettext "Conflicts in index. Try without --index.")
		setvar unstashed_index_tree = $(git write-tree) ||
			die $(gettext "Could not save index tree")
		git reset
	}

	if test -n $u_tree
	{"
		GIT_INDEX_FILE=$TMPindex" git-read-tree $u_tree" &&
		GIT_INDEX_FILE=$TMPindex" git checkout-index --all &&
		rm -f $TMPindex ||
		die $(gettext "Could not restore untracked files from stash")
	}

	eval "
		GITHEAD_$w_tree='Stashed changes' &&
		GITHEAD_$c_tree='Updated upstream' &&
		GITHEAD_$b_tree='Version stash was based on' &&
		export GITHEAD_$w_tree GITHEAD_$c_tree GITHEAD_$b_tree
	"

	if test -n $GIT_QUIET
	{
		setvar GIT_MERGE_VERBOSITY = '0' && export GIT_MERGE_VERBOSITY
	}
	if git merge-recursive $b_tree -- $c_tree $w_tree
	{
		# No conflict
		if test -n $unstashed_index_tree
		{
			git read-tree $unstashed_index_tree
		} else {
			setvar a = ""$TMP-added"" &&
			git diff-index --cached --name-only --diff-filter=A $c_tree >"$a" &&
			git read-tree --reset $c_tree &&
			git update-index --add --stdin <"$a" ||
				die $(gettext "Cannot unstage modified files")
			rm -f $a
		}
		setvar squelch = ''
		if test -n $GIT_QUIET
		{
			setvar squelch = ''>/dev/null 2>&1''
		}
		shell {cd $START_DIR && eval "git status $squelch"} || :
	} else {
		# Merge conflict; keep the exit status from merge-recursive
		setvar status = "$Status"
		git rerere
		if test -n $INDEX_OPTION
		{
			gettextln "Index was not unstashed." >&2
		}
		exit $status
	}
}

proc pop_stash {
	assert_stash_ref @ARGV

	if apply_stash @ARGV
	{
		drop_stash @ARGV
	} else {
		setvar status = "$Status"
		say $(gettext "The stash is kept in case you need it again.")
		exit $status
	}
}

proc drop_stash {
	assert_stash_ref @ARGV

	git reflog delete --updateref --rewrite ${REV} &&
		say $(eval_gettext "Dropped \${REV} (\$s)") ||
		die $(eval_gettext "\${REV}: Could not drop stash entry")

	# clear_stash if we just dropped the last stash entry
	git rev-parse --verify --quiet "$ref_stash@{0}" >/dev/null ||
	clear_stash
}

proc apply_to_branch {
	test -n $1 || die $(gettext "No branch name specified")
	setvar branch = "$1"
	shift 1

	set -- --index @ARGV
	assert_stash_like @ARGV

	git checkout -b $branch $REV^ &&
	apply_stash @ARGV && do {
		test -z $IS_STASH_REF || drop_stash @ARGV
	}
}

setvar PARSE_CACHE = ''--not-parsed''
# The default command is "save" if nothing but options are given
setvar seen_non_option = ''for opt in @ARGV {
	match $opt {
	with -* 
	with * setvar seen_non_option = 't'; break 
	}
}

test -n $seen_non_option || set "save" @ARGV

# Main command set
match $1 {
with list
	shift
	list_stash @ARGV
	
with show
	shift
	show_stash @ARGV
	
with save
	shift
	save_stash @ARGV
	
with apply
	shift
	apply_stash @ARGV
	
with clear
	shift
	clear_stash @ARGV
	
with create
	shift
	create_stash "$ifsjoin(ARGV)" && echo $w_commit
	
with store
	shift
	store_stash @ARGV
	
with drop
	shift
	drop_stash @ARGV
	
with pop
	shift
	pop_stash @ARGV
	
with branch
	shift
	apply_to_branch @ARGV
	
with *
	match $Argc {
	with 0
		save_stash &&
		say $(gettext "(To restore them type \"git stash apply\")")
		
	with *
		usage
	}
	
}