from __future__ import annotations

from types import SimpleNamespace
from unittest.mock import MagicMock

from relay.anthropic_client import AnthropicClient


def _fake_message(
    text: str, *, in_tokens: int = 100, out_tokens: int = 50, cache_w: int = 0, cache_r: int = 0
):
    """Build a stand-in for anthropic.types.Message with .content + .usage."""
    return SimpleNamespace(
        content=[SimpleNamespace(type="text", text=text)],
        usage=SimpleNamespace(
            input_tokens=in_tokens,
            output_tokens=out_tokens,
            cache_creation_input_tokens=cache_w,
            cache_read_input_tokens=cache_r,
        ),
    )


def _client_with_mock(model: str = "claude-opus-4-7") -> tuple[AnthropicClient, MagicMock]:
    client = AnthropicClient(api_key="sk-fake", model=model)
    mock_create = MagicMock(return_value=_fake_message("response text"))
    client._sdk = SimpleNamespace(messages=SimpleNamespace(create=mock_create))
    return client, mock_create


def test_send_returns_assistant_text_and_usage() -> None:
    client, _ = _client_with_mock()
    result = client.send(system_prompt="sys", messages=[{"role": "user", "content": "u1"}])
    assert result.text == "response text"
    assert result.input_tokens == 100
    assert result.output_tokens == 50


def test_send_passes_system_prompt_with_cache_control() -> None:
    client, mock_create = _client_with_mock()
    client.send(system_prompt="SYSTEM PROMPT", messages=[{"role": "user", "content": "u"}])
    call = mock_create.call_args
    system_arg = call.kwargs["system"]
    assert system_arg[0]["text"] == "SYSTEM PROMPT"
    assert system_arg[0]["cache_control"] == {"type": "ephemeral"}


def test_cost_estimation_opus() -> None:
    client, _ = _client_with_mock()
    # Override response with specific token counts
    client._sdk.messages.create = MagicMock(
        return_value=_fake_message("x", in_tokens=1_000_000, out_tokens=0)
    )
    result = client.send(system_prompt="s", messages=[{"role": "user", "content": "u"}])
    # Opus: $15/M input → $15
    assert abs(result.estimated_cost_usd - 15.0) < 0.01


def test_cost_estimation_includes_cache_savings() -> None:
    client, _ = _client_with_mock()
    client._sdk.messages.create = MagicMock(
        return_value=_fake_message(
            "x",
            in_tokens=0,
            out_tokens=0,
            cache_w=1_000_000,  # 1M cache write at $18.75/M
            cache_r=1_000_000,  # 1M cache read at $1.50/M
        )
    )
    result = client.send(system_prompt="s", messages=[{"role": "user", "content": "u"}])
    # cache_w 1M @ $18.75 + cache_r 1M @ $1.50 = $20.25
    assert abs(result.estimated_cost_usd - 20.25) < 0.01


def test_cost_estimation_unknown_model_falls_back_to_opus() -> None:
    client = AnthropicClient(api_key="sk-fake", model="claude-future-9000")
    client._sdk = SimpleNamespace(
        messages=SimpleNamespace(
            create=MagicMock(return_value=_fake_message("x", in_tokens=1_000_000, out_tokens=0))
        )
    )
    result = client.send(system_prompt="s", messages=[{"role": "user", "content": "u"}])
    # Falls back to Opus pricing
    assert abs(result.estimated_cost_usd - 15.0) < 0.01


def test_send_concatenates_multiple_text_blocks() -> None:
    client, _ = _client_with_mock()
    multi = SimpleNamespace(
        content=[
            SimpleNamespace(type="text", text="hello "),
            SimpleNamespace(type="text", text="world"),
        ],
        usage=SimpleNamespace(
            input_tokens=0,
            output_tokens=0,
            cache_creation_input_tokens=0,
            cache_read_input_tokens=0,
        ),
    )
    client._sdk.messages.create = MagicMock(return_value=multi)
    result = client.send(system_prompt="s", messages=[{"role": "user", "content": "u"}])
    assert result.text == "hello world"


def test_send_ignores_non_text_blocks() -> None:
    client, _ = _client_with_mock()
    mixed = SimpleNamespace(
        content=[
            SimpleNamespace(type="text", text="text part"),
            SimpleNamespace(type="tool_use"),  # no .text — would crash if not filtered
        ],
        usage=SimpleNamespace(
            input_tokens=0,
            output_tokens=0,
            cache_creation_input_tokens=0,
            cache_read_input_tokens=0,
        ),
    )
    client._sdk.messages.create = MagicMock(return_value=mixed)
    result = client.send(system_prompt="s", messages=[{"role": "user", "content": "u"}])
    assert result.text == "text part"