import sys

from _utils import (
    _output_eq, IntegrationSpec, _dispatch, trap, expect_exit, assert_contains,
    assert_not_contains, eq_
)


@trap
def _complete(invocation, collection=None):
    colstr = ""
    if collection:
        colstr = "-c {0}".format(collection)
    with expect_exit(0):
        _dispatch("inv --complete {0} -- inv {0} {1}".format(
            colstr, invocation))
    return sys.stdout.getvalue()


class ShellCompletion(IntegrationSpec):
    """
    Shell tab-completion behavior
    """

    def no_input_means_just_task_names(self):
        _output_eq('-c simple_ns_list --complete', "z_toplevel\na.b.subtask\n")

    def no_input_with_no_tasks_yields_empty_response(self):
        _output_eq('-c empty --complete', "")

    def task_name_completion_includes_aliases(self):
        for name in ('z\n', 'toplevel'):
            assert_contains(_complete('', 'alias_sorting'), name)

    def top_level_with_dash_means_core_options(self):
        output = _complete('-')
        # No point mirroring all core options, just spot check a few
        for flag in ('--no-dedupe', '-d', '--debug', '-V', '--version'):
            assert_contains(output, "{0}\n".format(flag))

    def bare_double_dash_shows_only_long_core_options(self):
        output = _complete('--')
        assert_contains(output, '--no-dedupe')
        assert_not_contains(output, '-V')

    def task_names_only_complete_other_task_names(self):
        # Because only tokens starting with a dash should result in options.
        assert_contains(_complete('print_foo', 'integration'), 'print_name')

    def task_name_completion_includes_tasks_already_seen(self):
        # Because it's valid to call the same task >1 time.
        assert_contains(_complete('print_foo', 'integration'), 'print_foo')

    def per_task_flags_complete_with_single_dashes(self):
        for flag in ('--name', '-n'):
            assert_contains(_complete('print_name -', 'integration'), flag)

    def per_task_flags_complete_with_double_dashes(self):
        output = _complete('print_name --', 'integration')
        assert_contains(output, '--name')
        assert_not_contains(output, '-n\n') # newline because -n is in --name

    def flag_completion_includes_inverse_booleans(self):
        output = _complete('basic_bool -', 'foo')
        assert_contains(output, '--no-mybool')

    def tasks_with_positional_args_complete_with_flags(self):
        # Because otherwise completing them is invalid anyways.
        # NOTE: this currently duplicates another test because this test cares
        # about a specific detail.
        output = _complete('print_name --', 'integration')
        assert_contains(output, '--name')

    def core_flags_taking_values_have_no_completion_output(self):
        # So the shell's default completion is available.
        eq_(_complete('-f'), '')

    def per_task_flags_taking_values_have_no_completion_output(self):
        eq_(_complete('basic_arg --arg', 'foo'), '')

    def core_bool_flags_have_task_name_completion(self):
        assert_contains(_complete('--echo', 'foo'), 'mytask')

    def per_task_bool_flags_have_task_name_completion(self):
        assert_contains(_complete('basic_bool --mybool', 'foo'), 'mytask')

    def core_partial_or_invalid_flags_print_all_flags(self):
        for flag in ('--echo', '--complete'):
            for given in ('--e', '--nope'):
                assert_contains(_complete(given), flag)

    def per_task_partial_or_invalid_flags_print_all_flags(self):
        for flag in ('--arg1', '--otherarg'):
            for given in ('--ar', '--nope'):
                assert_contains(
                    _complete('multiple_args {0}'.format(given), 'foo'),
                    flag
                )