"""Tests for the optional agent completion guard."""
from __future__ import annotations

from collections.abc import Sequence

import pytest

from agents.find_agent.completion_guard import (
    configure_find_agent_completion_guard,
    create_find_completion_guard,
)
from supply_agent import Agent
from supply_agent.agent.loop import AgentLoop
from supply_agent.tools.registry import ToolRegistry
from supply_agent.types import Message, Role


class _FakeLLM:
    def __init__(self, responses: list[Message]) -> None:
        self.responses = list(responses)

    def chat(self, *_args, **_kwargs) -> Message:
        return self.responses.pop(0)

    async def achat(self, *_args, **_kwargs) -> Message:
        return self.responses.pop(0)


def _loop(
    responses: list[Message],
    *,
    max_iterations: int = 3,
    completion_guard=None,
) -> AgentLoop:
    return AgentLoop(
        llm=_FakeLLM(responses),  # type: ignore[arg-type]
        tools=ToolRegistry(),
        system_message=Message(role=Role.SYSTEM, content="system"),
        messages=[Message(role=Role.USER, content="task")],
        max_iterations=max_iterations,
        completion_guard=completion_guard,
    )


def test_completion_guard_is_disabled_by_default() -> None:
    agent = Agent()
    loop = _loop([Message(role=Role.ASSISTANT, content="final")])

    result = loop.run()

    assert agent.completion_guard is None
    assert result.content == "final"
    assert result.iterations == 1


def test_agent_forwards_configured_completion_guard_to_loop() -> None:
    def guard(_response: Message, _messages: Sequence[Message]) -> None:
        return None

    agent = Agent(completion_guard=guard)

    assert agent.completion_guard is guard
    assert agent._create_loop([]).completion_guard is guard


def test_completion_guard_feedback_continues_sync_loop() -> None:
    calls = 0

    def guard(_response: Message, messages: Sequence[Message]) -> str | None:
        nonlocal calls
        calls += 1
        assert messages[-1].role == Role.ASSISTANT
        return "run.status 仍为 running，请先更新为终态" if calls == 1 else None

    loop = _loop(
        [
            Message(role=Role.ASSISTANT, content="尚未完成"),
            Message(role=Role.ASSISTANT, content="最终结果"),
        ],
        completion_guard=guard,
    )

    result = loop.run()

    assert result.content == "最终结果"
    assert result.iterations == 2
    assert result.messages[-2].content == "run.status 仍为 running，请先更新为终态"


def test_completion_guard_feedback_continues_stream_loop() -> None:
    calls = 0

    def guard(_response: Message, _messages: Sequence[Message]) -> str | None:
        nonlocal calls
        calls += 1
        return "not ready" if calls == 1 else None

    loop = _loop(
        [
            Message(role=Role.ASSISTANT, content="premature"),
            Message(role=Role.ASSISTANT, content="done"),
        ],
        completion_guard=guard,
    )

    events = list(loop.stream())

    assert events[-1].data["content"] == "done"
    assert events[-1].data["iterations"] == 2


@pytest.mark.asyncio
async def test_completion_guard_feedback_continues_async_loop() -> None:
    calls = 0

    def guard(_response: Message, _messages: Sequence[Message]) -> str | None:
        nonlocal calls
        calls += 1
        return "not ready" if calls == 1 else None

    loop = _loop(
        [
            Message(role=Role.ASSISTANT, content="premature"),
            Message(role=Role.ASSISTANT, content="done"),
        ],
        completion_guard=guard,
    )

    result = await loop.arun()

    assert result.content == "done"
    assert result.iterations == 2


def test_iteration_limit_takes_priority_over_completion_guard() -> None:
    def guard(_response: Message, _messages: Sequence[Message]) -> str:
        return "run.status 仍为 running"

    loop = _loop(
        [
            Message(role=Role.ASSISTANT, content="premature"),
            Message(role=Role.ASSISTANT, content="forced final"),
        ],
        max_iterations=1,
        completion_guard=guard,
    )

    result = loop.run()

    assert result.content == "forced final"
    assert result.iterations == 1


@pytest.mark.parametrize("status", ["finished", "failed"])
def test_find_agent_completion_guard_accepts_terminal_status(
    monkeypatch: pytest.MonkeyPatch,
    status: str,
) -> None:
    class _Service:
        @staticmethod
        def lookup_run(_run_id: str) -> dict[str, str]:
            return {"status": status}

    monkeypatch.setattr(
        "agents.find_agent.completion_guard.get_video_discovery_service",
        lambda: _Service(),
    )
    guard = create_find_completion_guard("run-1")

    assert guard(
        Message(role=Role.ASSISTANT, content="final"),
        (),
    ) is None


def test_find_agent_completion_guard_rejects_running_status(
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    class _Service:
        @staticmethod
        def lookup_run(_run_id: str) -> dict[str, str]:
            return {"status": "running"}

    monkeypatch.setattr(
        "agents.find_agent.completion_guard.get_video_discovery_service",
        lambda: _Service(),
    )
    guard = create_find_completion_guard("run-1")

    feedback = guard(
        Message(role=Role.ASSISTANT, content="premature"),
        (),
    )

    assert feedback is not None
    assert "run.status 仍为 running" in feedback
    assert "update_video_discovery_run_status" in feedback


def test_configure_find_agent_completion_guard_only_when_missing() -> None:
    agent = Agent()

    configure_find_agent_completion_guard(agent, "scheduled-run")

    assert agent.completion_guard is not None