"""Tests for the shared agent runner and its integration contracts."""

from __future__ import annotations

from unittest.mock import AsyncMock, MagicMock, patch

import pytest

from nanobot.providers.base import LLMResponse, ToolCallRequest


def _make_loop(tmp_path):
    from nanobot.agent.loop import AgentLoop
    from nanobot.bus.queue import MessageBus

    bus = MessageBus()
    provider = MagicMock()
    provider.get_default_model.return_value = "test-model"

    with patch("nanobot.agent.loop.ContextBuilder"), \
         patch("nanobot.agent.loop.SessionManager"), \
         patch("nanobot.agent.loop.SubagentManager") as MockSubMgr:
        MockSubMgr.return_value.cancel_by_session = AsyncMock(return_value=0)
        loop = AgentLoop(bus=bus, provider=provider, workspace=tmp_path)
    return loop


@pytest.mark.asyncio
async def test_runner_preserves_reasoning_fields_and_tool_results():
    from nanobot.agent.runner import AgentRunSpec, AgentRunner

    provider = MagicMock()
    captured_second_call: list[dict] = []
    call_count = {"n": 0}

    async def chat_with_retry(*, messages, **kwargs):
        call_count["n"] += 1
        if call_count["n"] == 1:
            return LLMResponse(
                content="thinking",
                tool_calls=[ToolCallRequest(id="call_1", name="list_dir", arguments={"path": "."})],
                reasoning_content="hidden reasoning",
                thinking_blocks=[{"type": "thinking", "thinking": "step"}],
                usage={"prompt_tokens": 5, "completion_tokens": 3},
            )
        captured_second_call[:] = messages
        return LLMResponse(content="done", tool_calls=[], usage={})

    provider.chat_with_retry = chat_with_retry
    tools = MagicMock()
    tools.get_definitions.return_value = []
    tools.execute = AsyncMock(return_value="tool result")

    runner = AgentRunner(provider)
    result = await runner.run(AgentRunSpec(
        initial_messages=[
            {"role": "system", "content": "system"},
            {"role": "user", "content": "do task"},
        ],
        tools=tools,
        model="test-model",
        max_iterations=3,
    ))

    assert result.final_content == "done"
    assert result.tools_used == ["list_dir"]
    assert result.tool_events == [
        {"name": "list_dir", "status": "ok", "detail": "tool result"}
    ]

    assistant_messages = [
        msg for msg in captured_second_call
        if msg.get("role") == "assistant" and msg.get("tool_calls")
    ]
    assert len(assistant_messages) == 1
    assert assistant_messages[0]["reasoning_content"] == "hidden reasoning"
    assert assistant_messages[0]["thinking_blocks"] == [{"type": "thinking", "thinking": "step"}]
    assert any(
        msg.get("role") == "tool" and msg.get("content") == "tool result"
        for msg in captured_second_call
    )


@pytest.mark.asyncio
async def test_runner_returns_max_iterations_fallback():
    from nanobot.agent.runner import AgentRunSpec, AgentRunner

    provider = MagicMock()
    provider.chat_with_retry = AsyncMock(return_value=LLMResponse(
        content="still working",
        tool_calls=[ToolCallRequest(id="call_1", name="list_dir", arguments={"path": "."})],
    ))
    tools = MagicMock()
    tools.get_definitions.return_value = []
    tools.execute = AsyncMock(return_value="tool result")

    runner = AgentRunner(provider)
    result = await runner.run(AgentRunSpec(
        initial_messages=[],
        tools=tools,
        model="test-model",
        max_iterations=2,
    ))

    assert result.stop_reason == "max_iterations"
    assert result.final_content == (
        "I reached the maximum number of tool call iterations (2) "
        "without completing the task. You can try breaking the task into smaller steps."
    )


@pytest.mark.asyncio
async def test_runner_returns_structured_tool_error():
    from nanobot.agent.runner import AgentRunSpec, AgentRunner

    provider = MagicMock()
    provider.chat_with_retry = AsyncMock(return_value=LLMResponse(
        content="working",
        tool_calls=[ToolCallRequest(id="call_1", name="list_dir", arguments={})],
    ))
    tools = MagicMock()
    tools.get_definitions.return_value = []
    tools.execute = AsyncMock(side_effect=RuntimeError("boom"))

    runner = AgentRunner(provider)

    result = await runner.run(AgentRunSpec(
        initial_messages=[],
        tools=tools,
        model="test-model",
        max_iterations=2,
        fail_on_tool_error=True,
    ))

    assert result.stop_reason == "tool_error"
    assert result.error == "Error: RuntimeError: boom"
    assert result.tool_events == [
        {"name": "list_dir", "status": "error", "detail": "boom"}
    ]


@pytest.mark.asyncio
async def test_loop_max_iterations_message_stays_stable(tmp_path):
    loop = _make_loop(tmp_path)
    loop.provider.chat_with_retry = AsyncMock(return_value=LLMResponse(
        content="working",
        tool_calls=[ToolCallRequest(id="call_1", name="list_dir", arguments={})],
    ))
    loop.tools.get_definitions = MagicMock(return_value=[])
    loop.tools.execute = AsyncMock(return_value="ok")
    loop.max_iterations = 2

    final_content, _, _ = await loop._run_agent_loop([])

    assert final_content == (
        "I reached the maximum number of tool call iterations (2) "
        "without completing the task. You can try breaking the task into smaller steps."
    )


@pytest.mark.asyncio
async def test_subagent_max_iterations_announces_existing_fallback(tmp_path, monkeypatch):
    from nanobot.agent.subagent import SubagentManager
    from nanobot.bus.queue import MessageBus

    bus = MessageBus()
    provider = MagicMock()
    provider.get_default_model.return_value = "test-model"
    provider.chat_with_retry = AsyncMock(return_value=LLMResponse(
        content="working",
        tool_calls=[ToolCallRequest(id="call_1", name="list_dir", arguments={})],
    ))
    mgr = SubagentManager(provider=provider, workspace=tmp_path, bus=bus)
    mgr._announce_result = AsyncMock()

    async def fake_execute(self, name, arguments):
        return "tool result"

    monkeypatch.setattr("nanobot.agent.tools.registry.ToolRegistry.execute", fake_execute)

    await mgr._run_subagent("sub-1", "do task", "label", {"channel": "test", "chat_id": "c1"})

    mgr._announce_result.assert_awaited_once()
    args = mgr._announce_result.await_args.args
    assert args[3] == "Task completed but no final response was generated."
    assert args[5] == "ok"