#!/bin/sh

test_description='Test automatic use of a pager.'

. ./test-lib.sh

cleanup_fail() {
	echo >&2 cleanup failed
	(exit 1)
}

test_expect_success 'set up terminal for tests' '
	rm -f stdout_is_tty ||
	cleanup_fail &&

	if test -t 1
	then
		>stdout_is_tty
	elif
		test_have_prereq PERL &&
		"$PERL_PATH" "$TEST_DIRECTORY"/t7006/test-terminal.perl \
			sh -c "test -t 1"
	then
		>test_terminal_works
	fi
'

if test -e stdout_is_tty
then
	test_terminal() { "$@"; }
	test_set_prereq TTY
elif test -e test_terminal_works
then
	test_terminal() {
		"$PERL_PATH" "$TEST_DIRECTORY"/t7006/test-terminal.perl "$@"
	}
	test_set_prereq TTY
else
	say no usable terminal, so skipping some tests
fi

test_expect_success 'setup' '
	unset GIT_PAGER GIT_PAGER_IN_USE;
	test_might_fail git config --unset core.pager &&

	PAGER="cat >paginated.out" &&
	export PAGER &&

	test_commit initial
'

test_expect_success TTY 'some commands use a pager' '
	rm -f paginated.out ||
	cleanup_fail &&

	test_terminal git log &&
	test -e paginated.out
'

test_expect_success TTY 'some commands do not use a pager' '
	rm -f paginated.out ||
	cleanup_fail &&

	test_terminal git rev-list HEAD &&
	! test -e paginated.out
'

test_expect_success 'no pager when stdout is a pipe' '
	rm -f paginated.out ||
	cleanup_fail &&

	git log | cat &&
	! test -e paginated.out
'

test_expect_success 'no pager when stdout is a regular file' '
	rm -f paginated.out ||
	cleanup_fail &&

	git log >file &&
	! test -e paginated.out
'

test_expect_success TTY 'git --paginate rev-list uses a pager' '
	rm -f paginated.out ||
	cleanup_fail &&

	test_terminal git --paginate rev-list HEAD &&
	test -e paginated.out
'

test_expect_success 'no pager even with --paginate when stdout is a pipe' '
	rm -f file paginated.out ||
	cleanup_fail &&

	git --paginate log | cat &&
	! test -e paginated.out
'

test_expect_success TTY 'no pager with --no-pager' '
	rm -f paginated.out ||
	cleanup_fail &&

	test_terminal git --no-pager log &&
	! test -e paginated.out
'

# A colored commit log will begin with an appropriate ANSI escape
# for the first color; the text "commit" comes later.
colorful() {
	read firstline <$1
	! expr "$firstline" : "[a-zA-Z]" >/dev/null
}

test_expect_success 'tests can detect color' '
	rm -f colorful.log colorless.log ||
	cleanup_fail &&

	git log --no-color >colorless.log &&
	git log --color >colorful.log &&
	! colorful colorless.log &&
	colorful colorful.log
'

test_expect_success 'no color when stdout is a regular file' '
	rm -f colorless.log &&
	git config color.ui auto ||
	cleanup_fail &&

	git log >colorless.log &&
	! colorful colorless.log
'

test_expect_success TTY 'color when writing to a pager' '
	rm -f paginated.out &&
	git config color.ui auto ||
	cleanup_fail &&

	(
		TERM=vt100 &&
		export TERM &&
		test_terminal git log
	) &&
	colorful paginated.out
'

test_expect_success 'color when writing to a file intended for a pager' '
	rm -f colorful.log &&
	git config color.ui auto ||
	cleanup_fail &&

	(
		TERM=vt100 &&
		GIT_PAGER_IN_USE=true &&
		export TERM GIT_PAGER_IN_USE &&
		git log >colorful.log
	) &&
	colorful colorful.log
'

test_expect_success 'determine default pager' '
	unset PAGER GIT_PAGER;
	test_might_fail git config --unset core.pager ||
	cleanup_fail &&

	less=$(git var GIT_PAGER) &&
	test -n "$less"
'

if expr "$less" : '[a-z][a-z]*$' >/dev/null && test_have_prereq TTY
then
	test_set_prereq SIMPLEPAGER
fi

# Use this helper to make it easy for the caller of your
# terminal-using function to specify whether it should fail.
# If you write
#
#	your_test() {
#		parse_args "$@"
#
#		$test_expectation "$cmd - behaves well" "
#			...
#			$full_command &&
#			...
#		"
#	}
#
# then your test can be used like this:
#
#	your_test expect_(success|failure) [test_must_fail] 'git foo'
#
parse_args() {
	test_expectation="test_$1"
	shift
	if test "$1" = test_must_fail
	then
		full_command="test_must_fail test_terminal "
		shift
	else
		full_command="test_terminal "
	fi
	cmd=$1
	full_command="$full_command $1"
}

test_default_pager() {
	parse_args "$@"

	$test_expectation SIMPLEPAGER "$cmd - default pager is used by default" "
		unset PAGER GIT_PAGER;
		test_might_fail git config --unset core.pager &&
		rm -f default_pager_used ||
		cleanup_fail &&

		cat >\$less <<-\EOF &&
		#!/bin/sh
		wc >default_pager_used
		EOF
		chmod +x \$less &&
		(
			PATH=.:\$PATH &&
			export PATH &&
			$full_command
		) &&
		test -e default_pager_used
	"
}

test_PAGER_overrides() {
	parse_args "$@"

	$test_expectation TTY "$cmd - PAGER overrides default pager" "
		unset GIT_PAGER;
		test_might_fail git config --unset core.pager &&
		rm -f PAGER_used ||
		cleanup_fail &&

		PAGER='wc >PAGER_used' &&
		export PAGER &&
		$full_command &&
		test -e PAGER_used
	"
}

test_core_pager_overrides() {
	if_local_config=
	used_if_wanted='overrides PAGER'
	test_core_pager "$@"
}

test_local_config_ignored() {
	if_local_config='! '
	used_if_wanted='is not used'
	test_core_pager "$@"
}

test_core_pager() {
	parse_args "$@"

	$test_expectation TTY "$cmd - repository-local core.pager setting $used_if_wanted" "
		unset GIT_PAGER;
		rm -f core.pager_used ||
		cleanup_fail &&

		PAGER=wc &&
		export PAGER &&
		git config core.pager 'wc >core.pager_used' &&
		$full_command &&
		${if_local_config}test -e core.pager_used
	"
}

test_core_pager_subdir() {
	if_local_config=
	used_if_wanted='overrides PAGER'
	test_pager_subdir_helper "$@"
}

test_no_local_config_subdir() {
	if_local_config='! '
	used_if_wanted='is not used'
	test_pager_subdir_helper "$@"
}

test_pager_subdir_helper() {
	parse_args "$@"

	$test_expectation TTY "$cmd - core.pager $used_if_wanted from subdirectory" "
		unset GIT_PAGER;
		rm -f core.pager_used &&
		rm -fr sub ||
		cleanup_fail &&

		PAGER=wc &&
		stampname=\$(pwd)/core.pager_used &&
		export PAGER stampname &&
		git config core.pager 'wc >\"\$stampname\"' &&
		mkdir sub &&
		(
			cd sub &&
			$full_command
		) &&
		${if_local_config}test -e core.pager_used
	"
}

test_GIT_PAGER_overrides() {
	parse_args "$@"

	$test_expectation TTY "$cmd - GIT_PAGER overrides core.pager" "
		rm -f GIT_PAGER_used ||
		cleanup_fail &&

		git config core.pager wc &&
		GIT_PAGER='wc >GIT_PAGER_used' &&
		export GIT_PAGER &&
		$full_command &&
		test -e GIT_PAGER_used
	"
}

test_doesnt_paginate() {
	parse_args "$@"

	$test_expectation TTY "no pager for '$cmd'" "
		rm -f GIT_PAGER_used ||
		cleanup_fail &&

		GIT_PAGER='wc >GIT_PAGER_used' &&
		export GIT_PAGER &&
		$full_command &&
		! test -e GIT_PAGER_used
	"
}

test_default_pager        expect_success 'git log'
test_PAGER_overrides      expect_success 'git log'
test_core_pager_overrides expect_success 'git log'
test_core_pager_subdir    expect_success 'git log'
test_GIT_PAGER_overrides  expect_success 'git log'

test_default_pager        expect_success 'git -p log'
test_PAGER_overrides      expect_success 'git -p log'
test_core_pager_overrides expect_success 'git -p log'
test_core_pager_subdir    expect_success 'git -p log'
test_GIT_PAGER_overrides  expect_success 'git -p log'

test_default_pager        expect_success test_must_fail 'git -p'
test_PAGER_overrides      expect_success test_must_fail 'git -p'
test_local_config_ignored expect_failure test_must_fail 'git -p'
test_no_local_config_subdir expect_success test_must_fail 'git -p'
test_GIT_PAGER_overrides  expect_success test_must_fail 'git -p'

test_doesnt_paginate      expect_success test_must_fail 'git -p nonsense'

test_done