from __future__ import annotations

import ast
from typing import Any
from unittest.mock import MagicMock, patch

from behave import given, then, when

from cleveragents.providers.llm.anthropic_provider import AnthropicChatProvider

# Shared step definitions (I have sample provider domain inputs, plan generation graph steps)
# are registered by features/steps/provider_shared_steps.py which Behave loads automatically.
# Helper functions are duplicated here to avoid cross-module import issues with Behave's exec_file.


def _register_cleanup(context, cleanup):
    if hasattr(context, "add_cleanup"):
        context.add_cleanup(cleanup)
    else:
        cleanup_handlers = getattr(context, "_cleanup_handlers", [])
        cleanup_handlers.append(cleanup)
        context._cleanup_handlers = cleanup_handlers


def _parse_kwargs_string(kwargs_string: str) -> dict[str, Any]:
    if not kwargs_string:
        return {}
    result: dict[str, Any] = {}
    for entry in kwargs_string.split(","):
        entry = entry.strip()
        if not entry:
            continue
        if "=" not in entry:
            result[entry] = True
            continue
        key, value = entry.split("=", 1)
        key = key.strip()
        value = value.strip()
        try:
            parsed_value = ast.literal_eval(value)
        except Exception:
            parsed_value = value
        result[key] = parsed_value
    return result


def _setup_plan_generation_graph(context) -> MagicMock:
    patcher = patch(
        "cleveragents.providers.llm.langchain_chat_provider.PlanGenerationGraph"
    )
    context.plan_generation_patcher = patcher
    mock_graph_class = patcher.start()
    _register_cleanup(context, patcher.stop)
    mock_graph_instance = MagicMock(name="PlanGenerationGraphInstance")

    default_state = {
        "generated_changes": [],
        "validation_result": {"status": "PASS"},
        "error": None,
    }
    state_override = getattr(context, "plan_generation_state_override", None)
    mock_graph_instance.invoke.return_value = state_override or default_state

    invoke_side_effect = getattr(context, "plan_generation_invoke_side_effect", None)
    if invoke_side_effect is not None:
        mock_graph_instance.invoke.side_effect = invoke_side_effect

    stream_events = getattr(context, "plan_generation_stream_events", None)
    if stream_events is None:
        mock_graph_instance.stream.return_value = iter(())
    else:
        events_copy = list(stream_events)

        def _stream(*_args, **_kwargs):
            yield from events_copy

        mock_graph_instance.stream.side_effect = _stream

    mock_graph_class.return_value = mock_graph_instance
    context.plan_generation_graph = mock_graph_instance
    context.plan_generation_graph_class = mock_graph_class
    return mock_graph_instance


@given('I set the Anthropic provider extra kwargs "{kwargs_string}"')
def step_set_anthropic_provider_kwargs(context, kwargs_string):
    context.anthropic_provider_kwargs = _parse_kwargs_string(kwargs_string)


@given(
    'I create an Anthropic chat provider with API key "{api_key}" and model "{model_id}"'
)
@when(
    'I create an Anthropic chat provider with API key "{api_key}" and model "{model_id}"'
)
def step_create_anthropic_provider(context, api_key, model_id):
    patcher = patch("cleveragents.providers.llm.anthropic_provider.ChatAnthropic")
    context.chat_anthropic_patcher = patcher
    mock_chat_anthropic_class = patcher.start()
    _register_cleanup(context, patcher.stop)
    mock_chat_anthropic_instance = MagicMock(name="ChatAnthropicInstance")
    mock_chat_anthropic_instance.get_num_tokens = MagicMock(return_value=0)
    mock_chat_anthropic_class.return_value = mock_chat_anthropic_instance

    extra_kwargs = dict(getattr(context, "anthropic_provider_kwargs", {}))

    context.provider = AnthropicChatProvider(
        api_key=api_key,
        model=model_id,
        **extra_kwargs,
    )
    context.chat_anthropic_class = mock_chat_anthropic_class
    context.chat_anthropic_instance = mock_chat_anthropic_instance


@when("I attempt to create an Anthropic chat provider without an API key")
def step_anthropic_provider_without_api_key(context):
    context.anthropic_provider_error = None
    try:
        AnthropicChatProvider(api_key="", model="claude-sonnet-4-20250514")
    except Exception as exc:  # pragma: no cover - defensive logging only
        context.anthropic_provider_error = exc


@when("I request plan generation from the Anthropic provider")
def step_request_plan_generation(context):
    _setup_plan_generation_graph(context)

    context.response = context.provider.generate_changes(
        context.project,
        context.plan,
        context.contexts,
    )
    context.chat_anthropic_call = context.chat_anthropic_class.call_args
    context.plan_generation_graph_call = context.plan_generation_graph_class.call_args


@when("I stream plan generation from the Anthropic provider")
def step_stream_plan_generation(context):
    _setup_plan_generation_graph(context)
    context.streamed_events = list(
        context.provider.stream_changes(
            context.project,
            context.plan,
            context.contexts,
        )
    )
    context.chat_anthropic_call = context.chat_anthropic_class.call_args
    context.plan_generation_graph_call = context.plan_generation_graph_class.call_args


@then(
    'the Anthropic provider should construct ChatAnthropic with api key "{api_key}" and model "{model_id}"'
)
def step_assert_chat_anthropic_constructor(context, api_key, model_id):
    assert context.chat_anthropic_call is not None, (
        "ChatAnthropic should have been called"
    )
    call_args, call_kwargs = context.chat_anthropic_call
    assert call_args == (), "ChatAnthropic should be called with keyword arguments"
    assert call_kwargs["api_key"] == api_key
    assert call_kwargs["model"] == model_id

    assert context.plan_generation_graph_call is not None, (
        "PlanGenerationGraph should receive the ChatAnthropic instance"
    )
    _, graph_kwargs = context.plan_generation_graph_call
    assert graph_kwargs["llm"] is context.chat_anthropic_instance


@then(
    'the Anthropic provider should include kwargs "{kwargs_string}" in the ChatAnthropic call'
)
def step_assert_chat_anthropic_kwargs(context, kwargs_string):
    assert context.chat_anthropic_call is not None, (
        "ChatAnthropic should have been called"
    )
    _, call_kwargs = context.chat_anthropic_call
    expected_kwargs = _parse_kwargs_string(kwargs_string)
    for key, value in expected_kwargs.items():
        assert key in call_kwargs, f"Expected {key} in ChatAnthropic kwargs"
        assert call_kwargs[key] == value, (
            f"Expected ChatAnthropic kwargs[{key!r}] to equal {value!r}"
        )


@then(
    'the Anthropic provider metadata should report name "{expected_name}" and model "{expected_model}"'
)
def step_assert_provider_metadata(context, expected_name, expected_model):
    provider = getattr(context, "provider", None)
    assert provider is not None, "Provider should exist"
    assert provider.name == expected_name
    assert provider.model_id == expected_model
    response = getattr(context, "response", None)
    if response is not None:
        assert response.model_used == expected_model


@then(
    "the Anthropic provider response should report the requested model without errors"
)
def step_assert_placeholder_metadata(context):
    assert context.response is not None
    assert context.response.model_used == context.provider.model_id
    assert context.response.error_message in (None, "")


@then("the Anthropic provider response should contain no generated changes")
def step_assert_no_changes(context):
    assert context.response is not None, "Provider response should exist"
    assert len(context.response.changes) == 0, "Expected no generated changes"


@then(
    'the Anthropic provider response should include {count:d} generated change for "{file_path}"'
)
def step_assert_generated_change(context, count, file_path):
    assert context.response is not None, "Provider response should exist"
    assert len(context.response.changes) == count, (
        f"Expected {count} changes, got {len(context.response.changes)}"
    )
    assert any(
        getattr(change, "file_path", None) == file_path
        for change in context.response.changes
    ), f"Expected change for {file_path}"


@then('the Anthropic provider response should report error "{message}"')
def step_assert_response_error(context, message):
    assert context.response is not None
    assert context.response.error_message == message


@then('the Anthropic provider streaming events should include nodes "{node_list}"')
def step_assert_stream_events(context, node_list):
    expected = [node.strip() for node in node_list.split(",") if node.strip()]
    actual = [
        next(iter(event.keys()))
        for event in getattr(context, "streamed_events", [])
        if "__end__" not in event
    ]
    assert actual == expected


@then(
    "the Anthropic provider streaming result should finish with a response containing {count:d} generated change"
)
def step_assert_stream_final_response(context, count):
    events = getattr(context, "streamed_events", [])
    assert events, "Expected streamed events"
    final_event = events[-1]
    assert "__end__" in final_event, "Expected final __end__ event"
    response = final_event["__end__"].get("response")
    assert response is not None, "Expected ProviderResponse in __end__ event"
    assert len(response.changes) == count


@then('the Anthropic provider creation should fail with error "{message}"')
def step_assert_anthropic_provider_error(context, message):
    error = getattr(context, "anthropic_provider_error", None)
    assert error is not None, "Expected the provider to raise an error"
    assert isinstance(error, ValueError)
    assert str(error) == message


@then("the Anthropic provider should support streaming responses")
def step_assert_anthropic_supports_streaming(context):
    provider = getattr(context, "provider", None)
    assert provider is not None, "Provider should exist"
    assert provider._supports_streaming is True, (
        "Anthropic provider should support streaming"
    )