import os
import sys

from invoke import Program

import pytest

from _util import expect, trap, ROOT


pytestmark = pytest.mark.usefixtures("integration")


@trap
def _complete(invocation, collection=None, **kwargs):
    colstr = ""
    if collection:
        colstr = "-c {}".format(collection)
    command = "inv --complete {0} -- inv {0} {1}".format(colstr, invocation)
    Program(**kwargs).run(command, exit=False)
    return sys.stdout.getvalue()


# TODO: remove in favor of direct asserts, needs non shite way of getting at
# stderr instead of just stdout.
def _assert_contains(haystack, needle):
    assert needle in haystack


class CompletionScriptPrinter:
    """
    Printing the completion script
    """

    def setup(self):
        self.prev_cwd = os.getcwd()
        # Chdir to system root to (hopefully) avoid any tasks.py. This will
        # prove that --print-completion-script works w/o nearby tasks.
        os.chdir(ROOT)

    def teardown(self):
        os.chdir(self.prev_cwd)

    def only_accepts_certain_shells(self):
        expect(
            "--print-completion-script",
            err="needed value and was not given one",
            test=_assert_contains,
        )
        expect(
            "--print-completion-script bla",
            # NOTE: this needs updating when the real world changes, just like
            # eg our --help output tests. That's OK & better than just
            # reimplementing the code under test here.
            err='Completion for shell "bla" not supported (options are: bash, fish, zsh).',  # noqa
            test=_assert_contains,
        )

    def prints_for_custom_binary_names(self):
        out, err = expect(
            "myapp --print-completion-script zsh",
            program=Program(binary_names=["mya", "myapp"]),
            invoke=False,
        )
        # Combines some sentinels from vanilla test, with checks that it's
        # really replacing 'invoke' with desired binary names
        assert "_complete_mya() {" in out
        assert "invoke" not in out
        assert " mya myapp" in out

    def default_binary_names_is_completing_argv_0(self):
        out, err = expect(
            "someappname --print-completion-script zsh",
            program=Program(binary_names=None),
            invoke=False,
        )
        assert "_complete_someappname() {" in out
        assert " someappname" in out

    def bash_works(self):
        out, err = expect(
            "someappname --print-completion-script bash", invoke=False
        )
        assert "_complete_someappname() {" in out
        assert "complete -F" in out
        for line in out.splitlines():
            if line.startswith("complete -F"):
                assert line.endswith(" someappname")

    def fish_works(self):
        out, err = expect(
            "someappname --print-completion-script fish", invoke=False
        )
        assert "function __complete_someappname" in out
        assert "complete --command someappname" in out


class ShellCompletion:
    """
    Shell tab-completion behavior
    """

    def no_input_means_just_task_names(self):
        expect("-c simple_ns_list --complete", out="z-toplevel\na.b.subtask\n")

    def custom_binary_name_completes(self):
        expect(
            "myapp -c integration --complete -- ba",
            program=Program(binary="myapp"),
            invoke=False,
            out="bar",
            test=_assert_contains,
        )

    def aliased_custom_binary_name_completes(self):
        for used_binary in ("my", "myapp"):
            expect(
                "{0} -c integration --complete -- ba".format(used_binary),
                program=Program(binary="my[app]"),
                invoke=False,
                out="bar",
                test=_assert_contains,
            )

    def no_input_with_no_tasks_yields_empty_response(self):
        expect("-c empty --complete", out="")

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

    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 "{}\n".format(flag) in output

    def bare_double_dash_shows_only_long_core_options(self):
        output = _complete("--")
        assert "--no-dedupe" in output
        assert "-V" not in output

    def task_names_only_complete_other_task_names(self):
        # Because only tokens starting with a dash should result in options.
        assert "print-name" in _complete("print-foo", "integration")

    def task_name_completion_includes_tasks_already_seen(self):
        # Because it's valid to call the same task >1 time.
        assert "print-foo" in _complete("print-foo", "integration")

    def per_task_flags_complete_with_single_dashes(self):
        for flag in ("--name", "-n"):
            assert flag in _complete("print-name -", "integration")

    def per_task_flags_complete_with_double_dashes(self):
        output = _complete("print-name --", "integration")
        assert "--name" in output
        assert "-n\n" not in output  # newline because -n is in --name

    def flag_completion_includes_inverse_booleans(self):
        output = _complete("basic-bool -", "foo")
        assert "--no-mybool" in output

    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 "--name" in output

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

    def per_task_flags_taking_values_have_no_completion_output(self):
        assert _complete("basic-arg --arg", "foo") == ""

    def core_bool_flags_have_task_name_completion(self):
        assert "mytask" in _complete("--echo", "foo")

    def per_task_bool_flags_have_task_name_completion(self):
        assert "mytask" in _complete("basic-bool --mybool", "foo")

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

    def per_task_partial_or_invalid_flags_print_all_flags(self):
        for flag in ("--arg1", "--otherarg"):
            for given in ("--ar", "--nope"):
                completion = _complete("multiple-args {}".format(given), "foo")
                assert flag in completion