#!/bin/sh

test_description='built-in file system watcher'

. ./test-lib.sh

if ! test_have_prereq FSMONITOR_DAEMON
then
	skip_all="fsmonitor--daemon is not supported on this platform"
	test_done
fi

stop_daemon_delete_repo () {
	r=$1 &&
	test_might_fail git -C $r fsmonitor--daemon stop &&
	rm -rf $1
}

start_daemon () {
	r= tf= t2= tk= &&

	while test "$#" -ne 0
	do
		case "$1" in
		-C)
			r="-C ${2?}"
			shift
			;;
		--tf)
			tf="${2?}"
			shift
			;;
		--t2)
			t2="${2?}"
			shift
			;;
		--tk)
			tk="${2?}"
			shift
			;;
		-*)
			BUG "error: unknown option: '$1'"
			;;
		*)
			BUG "error: unbound argument: '$1'"
			;;
		esac
		shift
	done &&

	(
		if test -n "$tf"
		then
			GIT_TRACE_FSMONITOR="$tf"
			export GIT_TRACE_FSMONITOR
		fi &&

		if test -n "$t2"
		then
			GIT_TRACE2_PERF="$t2"
			export GIT_TRACE2_PERF
		fi &&

		if test -n "$tk"
		then
			GIT_TEST_FSMONITOR_TOKEN="$tk"
			export GIT_TEST_FSMONITOR_TOKEN
		fi &&

		git $r fsmonitor--daemon start &&
		git $r fsmonitor--daemon status
	)
}

# Is a Trace2 data event present with the given catetory and key?
# We do not care what the value is.
#
have_t2_data_event () {
	c=$1 &&
	k=$2 &&

	grep -e '"event":"data".*"category":"'"$c"'".*"key":"'"$k"'"'
}

test_expect_success 'explicit daemon start and stop' '
	test_when_finished "stop_daemon_delete_repo test_explicit" &&

	git init test_explicit &&
	start_daemon -C test_explicit &&

	git -C test_explicit fsmonitor--daemon stop &&
	test_must_fail git -C test_explicit fsmonitor--daemon status
'

test_expect_success 'implicit daemon start' '
	test_when_finished "stop_daemon_delete_repo test_implicit" &&

	git init test_implicit &&
	test_must_fail git -C test_implicit fsmonitor--daemon status &&

	# query will implicitly start the daemon.
	#
	# for test-script simplicity, we send a V1 timestamp rather than
	# a V2 token.  either way, the daemon response to any query contains
	# a new V2 token.  (the daemon may complain that we sent a V1 request,
	# but this test case is only concerned with whether the daemon was
	# implicitly started.)

	GIT_TRACE2_EVENT="$PWD/.git/trace" \
		test-tool -C test_implicit fsmonitor-client query --token 0 >actual &&
	nul_to_q <actual >actual.filtered &&
	grep "builtin:" actual.filtered &&

	# confirm that a daemon was started in the background.
	#
	# since the mechanism for starting the background daemon is platform
	# dependent, just confirm that the foreground command received a
	# response from the daemon.

	have_t2_data_event fsm_client query/response-length <.git/trace &&

	git -C test_implicit fsmonitor--daemon status &&
	git -C test_implicit fsmonitor--daemon stop &&
	test_must_fail git -C test_implicit fsmonitor--daemon status
'

test_expect_success 'implicit daemon stop (delete .git)' '
	test_when_finished "stop_daemon_delete_repo test_implicit_1" &&

	git init test_implicit_1 &&

	start_daemon -C test_implicit_1 &&

	# deleting the .git directory will implicitly stop the daemon.
	rm -rf test_implicit_1/.git &&

	# [1] Create an empty .git directory so that the following Git
	#     command will stay relative to the `-C` directory.
	#
	#     Without this, the Git command will override the requested
	#     -C argument and crawl out to the containing Git source tree.
	#     This would make the test result dependent upon whether we
	#     were using fsmonitor on our development worktree.
	#
	sleep 1 &&
	mkdir test_implicit_1/.git &&

	test_must_fail git -C test_implicit_1 fsmonitor--daemon status
'

test_expect_success 'implicit daemon stop (rename .git)' '
	test_when_finished "stop_daemon_delete_repo test_implicit_2" &&

	git init test_implicit_2 &&

	start_daemon -C test_implicit_2 &&

	# renaming the .git directory will implicitly stop the daemon.
	mv test_implicit_2/.git test_implicit_2/.xxx &&

	# See [1] above.
	#
	sleep 1 &&
	mkdir test_implicit_2/.git &&

	test_must_fail git -C test_implicit_2 fsmonitor--daemon status
'

test_expect_success 'cannot start multiple daemons' '
	test_when_finished "stop_daemon_delete_repo test_multiple" &&

	git init test_multiple &&

	start_daemon -C test_multiple &&

	test_must_fail git -C test_multiple fsmonitor--daemon start 2>actual &&
	grep "fsmonitor--daemon is already running" actual &&

	git -C test_multiple fsmonitor--daemon stop &&
	test_must_fail git -C test_multiple fsmonitor--daemon status
'

# These tests use the main repo in the trash directory

test_expect_success 'setup' '
	>tracked &&
	>modified &&
	>delete &&
	>rename &&
	mkdir dir1 &&
	>dir1/tracked &&
	>dir1/modified &&
	>dir1/delete &&
	>dir1/rename &&
	mkdir dir2 &&
	>dir2/tracked &&
	>dir2/modified &&
	>dir2/delete &&
	>dir2/rename &&
	mkdir dirtorename &&
	>dirtorename/a &&
	>dirtorename/b &&

	cat >.gitignore <<-\EOF &&
	.gitignore
	expect*
	actual*
	flush*
	trace*
	EOF

	git -c core.fsmonitor=false add . &&
	test_tick &&
	git -c core.fsmonitor=false commit -m initial &&

	git config core.fsmonitor true
'

# The test already explicitly stopped (or tried to stop) the daemon.
# This is here in case something else fails first.
#
redundant_stop_daemon () {
	test_might_fail git fsmonitor--daemon stop
}

test_expect_success 'update-index implicitly starts daemon' '
	test_when_finished redundant_stop_daemon &&

	test_must_fail git fsmonitor--daemon status &&

	GIT_TRACE2_EVENT="$PWD/.git/trace_implicit_1" \
		git update-index --fsmonitor &&

	git fsmonitor--daemon status &&
	test_might_fail git fsmonitor--daemon stop &&

	# Confirm that the trace2 log contains a record of the
	# daemon starting.
	test_subcommand git fsmonitor--daemon start <.git/trace_implicit_1
'

test_expect_success 'status implicitly starts daemon' '
	test_when_finished redundant_stop_daemon &&

	test_must_fail git fsmonitor--daemon status &&

	GIT_TRACE2_EVENT="$PWD/.git/trace_implicit_2" \
		git status >actual &&

	git fsmonitor--daemon status &&
	test_might_fail git fsmonitor--daemon stop &&

	# Confirm that the trace2 log contains a record of the
	# daemon starting.
	test_subcommand git fsmonitor--daemon start <.git/trace_implicit_2
'

edit_files () {
	echo 1 >modified &&
	echo 2 >dir1/modified &&
	echo 3 >dir2/modified &&
	>dir1/untracked
}

delete_files () {
	rm -f delete &&
	rm -f dir1/delete &&
	rm -f dir2/delete
}

create_files () {
	echo 1 >new &&
	echo 2 >dir1/new &&
	echo 3 >dir2/new
}

rename_files () {
	mv rename renamed &&
	mv dir1/rename dir1/renamed &&
	mv dir2/rename dir2/renamed
}

file_to_directory () {
	rm -f delete &&
	mkdir delete &&
	echo 1 >delete/new
}

directory_to_file () {
	rm -rf dir1 &&
	echo 1 >dir1
}

# The next few test cases confirm that our fsmonitor daemon sees each type
# of OS filesystem notification that we care about.  At this layer we just
# ensure we are getting the OS notifications and do not try to confirm what
# is reported by `git status`.
#
# We run a simple query after modifying the filesystem just to introduce
# a bit of a delay so that the trace logging from the daemon has time to
# get flushed to disk.
#
# We `reset` and `clean` at the bottom of each test (and before stopping the
# daemon) because these commands might implicitly restart the daemon.

clean_up_repo_and_stop_daemon () {
	git reset --hard HEAD &&
	git clean -fd &&
	test_might_fail git fsmonitor--daemon stop &&
	rm -f .git/trace
}

test_expect_success 'edit some files' '
	test_when_finished clean_up_repo_and_stop_daemon &&

	start_daemon --tf "$PWD/.git/trace" &&

	edit_files &&

	test-tool fsmonitor-client query --token 0 &&

	grep "^event: dir1/modified$"  .git/trace &&
	grep "^event: dir2/modified$"  .git/trace &&
	grep "^event: modified$"       .git/trace &&
	grep "^event: dir1/untracked$" .git/trace
'

test_expect_success 'create some files' '
	test_when_finished clean_up_repo_and_stop_daemon &&

	start_daemon --tf "$PWD/.git/trace" &&

	create_files &&

	test-tool fsmonitor-client query --token 0 &&

	grep "^event: dir1/new$" .git/trace &&
	grep "^event: dir2/new$" .git/trace &&
	grep "^event: new$"      .git/trace
'

test_expect_success 'delete some files' '
	test_when_finished clean_up_repo_and_stop_daemon &&

	start_daemon --tf "$PWD/.git/trace" &&

	delete_files &&

	test-tool fsmonitor-client query --token 0 &&

	grep "^event: dir1/delete$" .git/trace &&
	grep "^event: dir2/delete$" .git/trace &&
	grep "^event: delete$"      .git/trace
'

test_expect_success 'rename some files' '
	test_when_finished clean_up_repo_and_stop_daemon &&

	start_daemon --tf "$PWD/.git/trace" &&

	rename_files &&

	test-tool fsmonitor-client query --token 0 &&

	grep "^event: dir1/rename$"  .git/trace &&
	grep "^event: dir2/rename$"  .git/trace &&
	grep "^event: rename$"       .git/trace &&
	grep "^event: dir1/renamed$" .git/trace &&
	grep "^event: dir2/renamed$" .git/trace &&
	grep "^event: renamed$"      .git/trace
'

test_expect_success 'rename directory' '
	test_when_finished clean_up_repo_and_stop_daemon &&

	start_daemon --tf "$PWD/.git/trace" &&

	mv dirtorename dirrenamed &&

	test-tool fsmonitor-client query --token 0 &&

	grep "^event: dirtorename/*$" .git/trace &&
	grep "^event: dirrenamed/*$"  .git/trace
'

test_expect_success 'file changes to directory' '
	test_when_finished clean_up_repo_and_stop_daemon &&

	start_daemon --tf "$PWD/.git/trace" &&

	file_to_directory &&

	test-tool fsmonitor-client query --token 0 &&

	grep "^event: delete$"     .git/trace &&
	grep "^event: delete/new$" .git/trace
'

test_expect_success 'directory changes to a file' '
	test_when_finished clean_up_repo_and_stop_daemon &&

	start_daemon --tf "$PWD/.git/trace" &&

	directory_to_file &&

	test-tool fsmonitor-client query --token 0 &&

	grep "^event: dir1$" .git/trace
'

# The next few test cases exercise the token-resync code.  When filesystem
# drops events (because of filesystem velocity or because the daemon isn't
# polling fast enough), we need to discard the cached data (relative to the
# current token) and start collecting events under a new token.
#
# the 'test-tool fsmonitor-client flush' command can be used to send a
# "flush" message to a running daemon and ask it to do a flush/resync.

test_expect_success 'flush cached data' '
	test_when_finished "stop_daemon_delete_repo test_flush" &&

	git init test_flush &&

	start_daemon -C test_flush --tf "$PWD/.git/trace_daemon" --tk true &&

	# The daemon should have an initial token with no events in _0 and
	# then a few (probably platform-specific number of) events in _1.
	# These should both have the same <token_id>.

	test-tool -C test_flush fsmonitor-client query --token "builtin:test_00000001:0" >actual_0 &&
	nul_to_q <actual_0 >actual_q0 &&

	>test_flush/file_1 &&
	>test_flush/file_2 &&

	test-tool -C test_flush fsmonitor-client query --token "builtin:test_00000001:0" >actual_1 &&
	nul_to_q <actual_1 >actual_q1 &&

	grep "file_1" actual_q1 &&

	# Force a flush.  This will change the <token_id>, reset the <seq_nr>, and
	# flush the file data.  Then create some events and ensure that the file
	# again appears in the cache.  It should have the new <token_id>.

	test-tool -C test_flush fsmonitor-client flush >flush_0 &&
	nul_to_q <flush_0 >flush_q0 &&
	grep "^builtin:test_00000002:0Q/Q$" flush_q0 &&

	test-tool -C test_flush fsmonitor-client query --token "builtin:test_00000002:0" >actual_2 &&
	nul_to_q <actual_2 >actual_q2 &&

	grep "^builtin:test_00000002:0Q$" actual_q2 &&

	>test_flush/file_3 &&

	test-tool -C test_flush fsmonitor-client query --token "builtin:test_00000002:0" >actual_3 &&
	nul_to_q <actual_3 >actual_q3 &&

	grep "file_3" actual_q3
'

# The next few test cases create repos where the .git directory is NOT
# inside the one of the working directory.  That is, where .git is a file
# that points to a directory elsewhere.  This happens for submodules and
# non-primary worktrees.

test_expect_success 'setup worktree base' '
	git init wt-base &&
	echo 1 >wt-base/file1 &&
	git -C wt-base add file1 &&
	git -C wt-base commit -m "c1"
'

test_expect_success 'worktree with .git file' '
	git -C wt-base worktree add ../wt-secondary &&

	start_daemon -C wt-secondary \
		--tf "$PWD/trace_wt_secondary" \
		--t2 "$PWD/trace2_wt_secondary" &&

	git -C wt-secondary fsmonitor--daemon stop &&
	test_must_fail git -C wt-secondary fsmonitor--daemon status
'

# NEEDSWORK: Repeat one of the "edit" tests on wt-secondary and
# confirm that we get the same events and behavior -- that is, that
# fsmonitor--daemon correctly watches BOTH the working directory and
# the external GITDIR directory and behaves the same as when ".git"
# is a directory inside the working directory.

test_expect_success 'cleanup worktrees' '
	stop_daemon_delete_repo wt-secondary &&
	stop_daemon_delete_repo wt-base
'

# The next few tests perform arbitrary/contrived file operations and
# confirm that status is correct.  That is, that the data (or lack of
# data) from fsmonitor doesn't cause incorrect results.  And doesn't
# cause incorrect results when the untracked-cache is enabled.

test_lazy_prereq UNTRACKED_CACHE '
	git update-index --test-untracked-cache
'

test_expect_success 'Matrix: setup for untracked-cache,fsmonitor matrix' '
	test_unconfig core.fsmonitor &&
	git update-index --no-fsmonitor &&
	test_might_fail git fsmonitor--daemon stop
'

matrix_clean_up_repo () {
	git reset --hard HEAD &&
	git clean -fd
}

matrix_try () {
	uc=$1 &&
	fsm=$2 &&
	fn=$3 &&

	if test $uc = true && test $fsm = false
	then
		# The untracked-cache is buggy when FSMonitor is
		# DISABLED, so skip the tests for this matrix
		# combination.
		#
		# We've observed random, occasional test failures on
		# Windows and MacOS when the UC is turned on and FSM
		# is turned off.  These are rare, but they do happen
		# indicating that it is probably a race condition within
		# the untracked cache itself.
		#
		# It usually happens when a test does F/D trickery and
		# then the NEXT test fails because of extra status
		# output from stale UC data from the previous test.
		#
		# Since FSMonitor is not involved in the error, skip
		# the tests for this matrix combination.
		#
		return 0
	fi &&

	test_expect_success "Matrix[uc:$uc][fsm:$fsm] $fn" '
		matrix_clean_up_repo &&
		$fn &&
		if test $uc = false && test $fsm = false
		then
			git status --porcelain=v1 >.git/expect.$fn
		else
			git status --porcelain=v1 >.git/actual.$fn &&
			test_cmp .git/expect.$fn .git/actual.$fn
		fi
	'
}

uc_values="false"
test_have_prereq UNTRACKED_CACHE && uc_values="false true"
for uc_val in $uc_values
do
	if test $uc_val = false
	then
		test_expect_success "Matrix[uc:$uc_val] disable untracked cache" '
			git config core.untrackedcache false &&
			git update-index --no-untracked-cache
		'
	else
		test_expect_success "Matrix[uc:$uc_val] enable untracked cache" '
			git config core.untrackedcache true &&
			git update-index --untracked-cache
		'
	fi

	fsm_values="false true"
	for fsm_val in $fsm_values
	do
		if test $fsm_val = false
		then
			test_expect_success "Matrix[uc:$uc_val][fsm:$fsm_val] disable fsmonitor" '
				test_unconfig core.fsmonitor &&
				git update-index --no-fsmonitor &&
				test_might_fail git fsmonitor--daemon stop
			'
		else
			test_expect_success "Matrix[uc:$uc_val][fsm:$fsm_val] enable fsmonitor" '
				git config core.fsmonitor true &&
				git fsmonitor--daemon start &&
				git update-index --fsmonitor
			'
		fi

		matrix_try $uc_val $fsm_val edit_files
		matrix_try $uc_val $fsm_val delete_files
		matrix_try $uc_val $fsm_val create_files
		matrix_try $uc_val $fsm_val rename_files
		matrix_try $uc_val $fsm_val file_to_directory
		matrix_try $uc_val $fsm_val directory_to_file

		if test $fsm_val = true
		then
			test_expect_success "Matrix[uc:$uc_val][fsm:$fsm_val] disable fsmonitor at end" '
				test_unconfig core.fsmonitor &&
				git update-index --no-fsmonitor &&
				test_might_fail git fsmonitor--daemon stop
			'
		fi
	done
done

test_done