"""Unit tests for muse.cli.domain_command_registry — muse#74 Phase 1.

A dependency-free registry mapping a domain name to its dedicated
`muse <name> <verb>` CLI subcommand names, populated as a side effect of
argparse tree construction. Never hand-typed anywhere — see muse#74 for
the bug (a hardcoded literal in `muse domains publish`) this replaces.
"""

import pytest

from muse.cli.domain_command_registry import get_supported_commands, register_namespace


@pytest.fixture(autouse=True)
def _clean_registry() -> "object":
    """Reset module-level registry state between tests — it's a shared
    process-wide singleton by design (populated once per CLI invocation),
    which makes tests order-dependent unless explicitly isolated."""
    from muse.cli import domain_command_registry

    saved = dict(domain_command_registry._REGISTRY)
    domain_command_registry._REGISTRY.clear()
    yield
    domain_command_registry._REGISTRY.clear()
    domain_command_registry._REGISTRY.update(saved)


class TestRegistryContract:
    def test_unregistered_name_returns_empty_list(self) -> None:
        assert get_supported_commands("nonexistent-domain") == []

    def test_register_then_query_returns_registered_commands(self) -> None:
        register_namespace("mist", ["create", "list", "read", "fork"])
        assert get_supported_commands("mist") == ["create", "fork", "list", "read"]

    def test_returned_list_is_a_copy_not_a_live_reference(self) -> None:
        register_namespace("mist", ["create", "list"])
        result = get_supported_commands("mist")
        result.append("mutated")
        assert get_supported_commands("mist") == ["create", "list"]


class TestIdempotentReregistration:
    def test_registering_twice_replaces_not_appends(self) -> None:
        register_namespace("code", ["grep", "impact"])
        register_namespace("code", ["grep", "impact", "gravity"])
        result = get_supported_commands("code")
        assert result == ["grep", "gravity", "impact"] or sorted(result) == sorted(
            ["grep", "impact", "gravity"]
        )
        # Must not have duplicated "grep"/"impact" from the first call.
        assert result.count("grep") == 1
        assert result.count("impact") == 1

    def test_registering_twice_does_not_merge_old_and_new(self) -> None:
        register_namespace("code", ["old-command"])
        register_namespace("code", ["new-command"])
        result = get_supported_commands("code")
        assert "old-command" not in result
        assert "new-command" in result


class TestDeterministicOrdering:
    def test_output_is_sorted_regardless_of_insertion_order(self) -> None:
        register_namespace("social", ["zebra", "alpha", "mike"])
        assert get_supported_commands("social") == ["alpha", "mike", "zebra"]

    def test_output_is_sorted_from_a_set_input(self) -> None:
        register_namespace("social", {"zebra", "alpha", "mike"})
        assert get_supported_commands("social") == ["alpha", "mike", "zebra"]

    def test_output_is_sorted_from_dict_keys_input(self) -> None:
        # argparse's ._SubParsersAction.choices is a dict — this is the
        # real shape callers will pass in Phase 2.
        choices = {"zebra": object(), "alpha": object(), "mike": object()}
        register_namespace("social", choices.keys())
        assert get_supported_commands("social") == ["alpha", "mike", "zebra"]