from types import SimpleNamespace
from typing import Any

import pytest

from llm.core.types import LLMInput, Message, Role
from llm.providers.claude import ClaudeProvider


class FakeMessages:
    def __init__(self, response: SimpleNamespace) -> None:
        self.response = response
        self.last_params: dict[str, Any] = {}

    def create(self, **params: object) -> SimpleNamespace:
        self.last_params = dict(params)
        return self.response


class FakeClient:
    def __init__(self, response: SimpleNamespace) -> None:
        self.messages = FakeMessages(response)
        self.api_key = "test-key"


def make_provider(response: SimpleNamespace) -> ClaudeProvider:
    provider = ClaudeProvider(api_key="test-key")
    provider.client = FakeClient(response)
    return provider


def make_response(content: list[SimpleNamespace], stop_reason: str = "tool_use") -> SimpleNamespace:
    return SimpleNamespace(
        content=content,
        model="claude-test",
        usage=SimpleNamespace(input_tokens=3, output_tokens=5),
        stop_reason=stop_reason,
    )


@pytest.mark.unit
def test_generate_collects_text_and_tool_use_blocks() -> None:
    provider = make_provider(
        make_response(
            [
                SimpleNamespace(type="text", text="I will search. "),
                SimpleNamespace(type="tool_use", id="toolu_1", name="search", input={"query": "claude"}),
                SimpleNamespace(type="text", text="Done."),
            ]
        )
    )

    output = provider.generate(LLMInput(messages=[Message(role=Role.USER, content="Search")]))

    assert output.content == "I will search. Done."
    assert output.tool_calls is not None
    assert len(output.tool_calls) == 1
    assert output.tool_calls[0].id == "toolu_1"
    assert output.tool_calls[0].name == "search"
    assert output.tool_calls[0].arguments == {"query": "claude"}


@pytest.mark.unit
def test_generate_collects_multiple_tool_use_blocks() -> None:
    provider = make_provider(
        make_response(
            [
                SimpleNamespace(type="tool_use", id="toolu_1", name="search", input={"query": "claude"}),
                SimpleNamespace(
                    type="tool_use",
                    id="toolu_2",
                    name="read",
                    input=SimpleNamespace(path="README.md"),
                ),
            ]
        )
    )

    output = provider.generate(LLMInput(messages=[Message(role=Role.USER, content="Use tools")]))

    assert output.content == ""
    assert [call.id for call in output.tool_calls or []] == ["toolu_1", "toolu_2"]
    assert (output.tool_calls or [])[1].arguments == {"path": "README.md"}


@pytest.mark.unit
def test_generate_copies_tool_use_dict_arguments() -> None:
    raw_arguments: dict[str, Any] = {"query": "claude"}
    provider = make_provider(
        make_response(
            [SimpleNamespace(type="tool_use", id="toolu_1", name="search", input=raw_arguments)]
        )
    )

    output = provider.generate(LLMInput(messages=[Message(role=Role.USER, content="Use tools")]))
    raw_arguments["query"] = "mutated"

    assert (output.tool_calls or [])[0].arguments == {"query": "claude"}


@pytest.mark.unit
def test_generate_text_only_has_no_tool_calls() -> None:
    provider = make_provider(
        make_response(
            [SimpleNamespace(type="text", text="Hello.")],
            stop_reason="end_turn",
        )
    )

    output = provider.generate(LLMInput(messages=[Message(role=Role.USER, content="Hi")]))

    assert output.content == "Hello."
    assert output.tool_calls is None


@pytest.mark.unit
def test_generate_does_not_pass_cache_control_as_top_level_param() -> None:
    # cache_control is a per-content-block field on the Anthropic Messages API,
    # not a top-level parameter. Passing it at the top level raises TypeError
    # in the Anthropic Python SDK (or a 400 from the API).
    provider = make_provider(make_response([SimpleNamespace(type="text", text="ok")]))

    provider.generate(
        LLMInput(
            messages=[
                Message(role=Role.SYSTEM, content="system prompt"),
                Message(role=Role.USER, content="hi"),
            ]
        )
    )

    params = provider.client.messages.last_params
    assert "cache_control" not in params

    # When a system prompt is present, cache_control should ride on the last
    # system content block so ephemeral prompt caching still works.
    system = params.get("system")
    assert isinstance(system, list), "system should be sent as a list of content blocks"
    assert system, "system content-block list should not be empty"
    assert system[-1].get("cache_control") == {"type": "ephemeral"}


@pytest.mark.unit
def test_generate_without_system_does_not_set_system_or_cache_control() -> None:
    provider = make_provider(make_response([SimpleNamespace(type="text", text="ok")]))

    provider.generate(LLMInput(messages=[Message(role=Role.USER, content="hi")]))

    params = provider.client.messages.last_params
    assert "cache_control" not in params
    assert "system" not in params