"""
Unit tests for ScriptGenerator.
[AC-IDS-04, AC-IDS-11] Test script generation for flexible mode.
"""

import asyncio
import pytest

from app.services.flow.script_generator import ScriptGenerator


class MockLLMClient:
    """Mock LLM client for testing."""

    def __init__(self, response: str = "您好，请问怎么称呼您？", delay: float = 0):
        self._response = response
        self._delay = delay

    async def generate_text(self, prompt: str) -> str:
        if self._delay > 0:
            await asyncio.sleep(self._delay)
        return self._response

    async def generate(self, messages: list) -> "MockResponse":
        if self._delay > 0:
            await asyncio.sleep(self._delay)
        return MockResponse(self._response)


class MockResponse:
    """Mock LLM response."""
    def __init__(self, content: str):
        self.content = content


class TestScriptGenerator:
    """[AC-IDS-04, AC-IDS-11] Test cases for ScriptGenerator."""

    @pytest.mark.asyncio
    async def test_generate_fixed_mode_returns_fallback(self):
        """Test that fixed mode returns fallback content."""
        generator = ScriptGenerator(llm_client=None)

        result = await generator.generate(
            intent="获取用户姓名",
            intent_description="礼貌询问用户姓名",
            constraints=["必须礼貌"],
            context=None,
            history=None,
            fallback="请问怎么称呼您？",
        )

        assert result == "请问怎么称呼您？"

    @pytest.mark.asyncio
    async def test_generate_with_llm_client(self):
        """Test script generation with LLM client."""
        llm_client = MockLLMClient(response="您好，请问您贵姓？")
        generator = ScriptGenerator(llm_client=llm_client)

        result = await generator.generate(
            intent="获取用户姓名",
            intent_description="礼貌询问用户姓名",
            constraints=["必须礼貌", "语气自然"],
            context={"inputs": [{"step": 1, "input": "我想咨询"}]},
            history=[{"role": "user", "content": "我想咨询"}],
            fallback="请问怎么称呼您？",
        )

        assert result == "您好，请问您贵姓？"

    @pytest.mark.asyncio
    async def test_generate_timeout_fallback(self):
        """Test that timeout returns fallback content."""
        llm_client = MockLLMClient(response="生成的话术", delay=6.0)
        generator = ScriptGenerator(llm_client=llm_client)

        result = await generator.generate(
            intent="获取用户姓名",
            intent_description=None,
            constraints=None,
            context=None,
            history=None,
            fallback="请问怎么称呼您？",
        )

        assert result == "请问怎么称呼您？"

    @pytest.mark.asyncio
    async def test_generate_exception_fallback(self):
        """Test that exception returns fallback content."""
        class FailingLLMClient:
            async def generate_text(self, prompt: str) -> str:
                raise RuntimeError("LLM service unavailable")

        generator = ScriptGenerator(llm_client=FailingLLMClient())

        result = await generator.generate(
            intent="获取用户姓名",
            intent_description=None,
            constraints=None,
            context=None,
            history=None,
            fallback="请问怎么称呼您？",
        )

        assert result == "请问怎么称呼您？"

    def test_build_prompt_basic(self):
        """Test prompt building with basic parameters."""
        generator = ScriptGenerator(llm_client=None)

        prompt = generator._build_prompt(
            intent="获取用户姓名",
            intent_description=None,
            constraints=None,
            context=None,
            history=None,
        )

        assert "获取用户姓名" in prompt
        assert "步骤目标" in prompt

    def test_build_prompt_with_description(self):
        """Test prompt building with intent description."""
        generator = ScriptGenerator(llm_client=None)

        prompt = generator._build_prompt(
            intent="获取用户姓名",
            intent_description="需要获取用户的真实姓名用于后续身份确认",
            constraints=None,
            context=None,
            history=None,
        )

        assert "获取用户姓名" in prompt
        assert "需要获取用户的真实姓名用于后续身份确认" in prompt
        assert "详细说明" in prompt

    def test_build_prompt_with_constraints(self):
        """Test prompt building with constraints."""
        generator = ScriptGenerator(llm_client=None)

        prompt = generator._build_prompt(
            intent="获取用户姓名",
            intent_description=None,
            constraints=["必须礼貌", "语气自然", "不要生硬"],
            context=None,
            history=None,
        )

        assert "约束条件" in prompt
        assert "- 必须礼貌" in prompt
        assert "- 语气自然" in prompt
        assert "- 不要生硬" in prompt

    def test_build_prompt_with_history(self):
        """Test prompt building with conversation history."""
        generator = ScriptGenerator(llm_client=None)

        prompt = generator._build_prompt(
            intent="获取用户姓名",
            intent_description=None,
            constraints=None,
            context=None,
            history=[
                {"role": "user", "content": "你好"},
                {"role": "assistant", "content": "您好，有什么可以帮您？"},
                {"role": "user", "content": "我想咨询"},
            ],
        )

        assert "对话历史" in prompt
        assert "用户: 你好" in prompt
        assert "客服: 您好，有什么可以帮您？" in prompt

    def test_build_prompt_with_context(self):
        """Test prompt building with session context."""
        generator = ScriptGenerator(llm_client=None)

        prompt = generator._build_prompt(
            intent="获取用户姓名",
            intent_description=None,
            constraints=None,
            context={
                "inputs": [
                    {"step": 1, "input": "我想咨询产品"},
                    {"step": 2, "input": "手机"},
                ]
            },
            history=None,
        )

        assert "已收集信息" in prompt
        assert "步骤1: 我想咨询产品" in prompt
        assert "步骤2: 手机" in prompt

    def test_build_prompt_complete(self):
        """Test prompt building with all parameters."""
        generator = ScriptGenerator(llm_client=None)

        prompt = generator._build_prompt(
            intent="获取用户姓名",
            intent_description="需要获取用户的真实姓名",
            constraints=["必须礼貌", "语气自然"],
            context={"inputs": [{"step": 1, "input": "咨询"}]},
            history=[{"role": "user", "content": "你好"}],
        )

        assert "步骤目标" in prompt
        assert "详细说明" in prompt
        assert "约束条件" in prompt
        assert "对话历史" in prompt
        assert "已收集信息" in prompt
        assert "不超过200字" in prompt