from pathlib import Path

import pytest
from langchain_core.messages import AIMessage

from gcode.graph import Agent
from gcode.safety import SafetyGate
from gcode.tools.fs import make_fs_tools


class ScriptedLLM:
    def __init__(self, responses: list[AIMessage]) -> None:
        self.responses = list(responses)
        self.calls = 0

    def bind_tools(self, tools):
        return self

    async def ainvoke(self, messages, **kwargs):
        if self.calls >= len(self.responses):
            return AIMessage(content="(script exhausted)")
        msg = self.responses[self.calls]
        self.calls += 1
        return msg


async def _always(kind: str, detail: str) -> bool:
    return True


async def _never(kind: str, detail: str) -> bool:
    return False


@pytest.mark.asyncio
async def test_one_tool_call_then_end(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.chdir(tmp_path)
    (tmp_path / "README.md").write_text("hello gcode\n", encoding="utf-8")
    safety = SafetyGate(_always)
    tools = make_fs_tools(safety, tmp_path)
    llm = ScriptedLLM(
        [
            AIMessage(
                content="",
                tool_calls=[
                    {
                        "name": "read_file",
                        "args": {"path": "README.md"},
                        "id": "call_1",
                        "type": "tool_call",
                    }
                ],
            ),
            AIMessage(content="README 只有一句 hello gcode。"),
        ]
    )
    agent = Agent(llm, tools, cwd=tmp_path)
    messages = await agent.invoke_turn("请读 README")
    texts = [getattr(m, "content", "") for m in messages]
    assert any("hello gcode" in str(t) for t in texts)
    assert any("README 只有一句" in str(t) for t in texts)
    assert llm.calls == 2


@pytest.mark.asyncio
async def test_replace_denied_file_unchanged(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.chdir(tmp_path)
    target = tmp_path / "app.py"
    target.write_text("print(1)\n", encoding="utf-8")
    safety = SafetyGate(_never)
    tools = make_fs_tools(safety, tmp_path)
    llm = ScriptedLLM(
        [
            AIMessage(
                content="",
                tool_calls=[
                    {
                        "name": "replace_in_file",
                        "args": {
                            "path": "app.py",
                            "old_text": "print(1)",
                            "new_text": "print(2)",
                        },
                        "id": "call_w",
                        "type": "tool_call",
                    }
                ],
            ),
            AIMessage(content="用户拒绝了写入，我改用其它办法。"),
        ]
    )
    agent = Agent(llm, tools, cwd=tmp_path)
    messages = await agent.invoke_turn("把 print(1) 改成 print(2)")
    joined = "\n".join(str(getattr(m, "content", "")) for m in messages)
    assert "用户拒绝本次写入" in joined
    assert target.read_text(encoding="utf-8") == "print(1)\n"
    assert llm.calls == 2