# Copyright (c) 2025 Bytedance Ltd. and/or its affiliates
# SPDX-License-Identifier: MIT

import os
import types
import pytest
from src.llms import llm


class DummyChatOpenAI:
    def __init__(self, **kwargs):
        self.kwargs = kwargs

    def invoke(self, msg):
        return f"Echo: {msg}"


@pytest.fixture(autouse=True)
def patch_chat_openai(monkeypatch):
    monkeypatch.setattr(llm, "ChatOpenAI", DummyChatOpenAI)


@pytest.fixture
def dummy_conf():
    return {
        "BASIC_MODEL": {"api_key": "test_key", "base_url": "http://test"},
        "REASONING_MODEL": {"api_key": "reason_key"},
        "VISION_MODEL": {"api_key": "vision_key"},
    }


def test_get_env_llm_conf(monkeypatch):
    monkeypatch.setenv("BASIC_MODEL__API_KEY", "env_key")
    monkeypatch.setenv("BASIC_MODEL__BASE_URL", "http://env")
    conf = llm._get_env_llm_conf("basic")
    assert conf["api_key"] == "env_key"
    assert conf["base_url"] == "http://env"


def test_create_llm_use_conf_merges_env(monkeypatch, dummy_conf):
    monkeypatch.setenv("BASIC_MODEL__API_KEY", "env_key")
    result = llm._create_llm_use_conf("basic", dummy_conf)
    assert isinstance(result, DummyChatOpenAI)
    assert result.kwargs["api_key"] == "env_key"
    assert result.kwargs["base_url"] == "http://test"


def test_create_llm_use_conf_invalid_type(dummy_conf):
    with pytest.raises(ValueError):
        llm._create_llm_use_conf("unknown", dummy_conf)


def test_create_llm_use_conf_empty_conf(monkeypatch):
    with pytest.raises(ValueError):
        llm._create_llm_use_conf("basic", {})


def test_get_llm_by_type_caches(monkeypatch, dummy_conf):
    called = {}

    def fake_load_yaml_config(path):
        called["called"] = True
        return dummy_conf

    monkeypatch.setattr(llm, "load_yaml_config", fake_load_yaml_config)
    llm._llm_cache.clear()
    inst1 = llm.get_llm_by_type("basic")
    inst2 = llm.get_llm_by_type("basic")
    assert inst1 is inst2
    assert called["called"]