# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project

from dataclasses import dataclass, field
from http import HTTPStatus
from typing import Any
from unittest.mock import AsyncMock, MagicMock

import pytest

from vllm.config.multimodal import MultiModalConfig
from vllm.entrypoints.openai.protocol import ChatCompletionRequest, ErrorResponse
from vllm.entrypoints.openai.serving_chat import OpenAIServingChat
from vllm.entrypoints.openai.serving_models import BaseModelPath, OpenAIServingModels
from vllm.outputs import CompletionOutput, RequestOutput
from vllm.transformers_utils.tokenizer import get_tokenizer
from vllm.v1.engine.async_llm import AsyncLLM

MODEL_NAME = "openai-community/gpt2"
MODEL_NAME_SHORT = "gpt2"
BASE_MODEL_PATHS = [
    BaseModelPath(name=MODEL_NAME, model_path=MODEL_NAME),
    BaseModelPath(name=MODEL_NAME_SHORT, model_path=MODEL_NAME_SHORT),
]


@dataclass
class MockHFConfig:
    model_type: str = "any"


@dataclass
class MockModelConfig:
    task = "generate"
    runner_type = "generate"
    tokenizer = MODEL_NAME
    trust_remote_code = False
    tokenizer_mode = "auto"
    max_model_len = 100
    tokenizer_revision = None
    multimodal_config = MultiModalConfig()
    hf_config = MockHFConfig()
    logits_processor_pattern = None
    logits_processors: list[str] | None = None
    diff_sampling_param: dict | None = None
    allowed_local_media_path: str = ""
    allowed_media_domains: list[str] | None = None
    encoder_config = None
    generation_config: str = "auto"
    media_io_kwargs: dict[str, dict[str, Any]] = field(default_factory=dict)
    skip_tokenizer_init = False

    def get_diff_sampling_param(self):
        return self.diff_sampling_param or {}


def _build_serving_chat(engine: AsyncLLM) -> OpenAIServingChat:
    models = OpenAIServingModels(
        engine_client=engine,
        base_model_paths=BASE_MODEL_PATHS,
    )
    serving_chat = OpenAIServingChat(
        engine,
        models,
        response_role="assistant",
        request_logger=None,
        chat_template=None,
        chat_template_content_format="auto",
    )

    async def _fake_process_inputs(
        request_id,
        engine_prompt,
        sampling_params,
        *,
        lora_request,
        trace_headers,
        priority,
    ):
        return dict(engine_prompt), {}

    async def _fake_preprocess_chat(*args, **kwargs):
        # return conversation, engine_prompts
        return (
            [{"role": "user", "content": "Test"}],
            [{"prompt_token_ids": [1, 2, 3]}],
        )

    serving_chat._process_inputs = AsyncMock(side_effect=_fake_process_inputs)
    serving_chat._preprocess_chat = AsyncMock(side_effect=_fake_preprocess_chat)
    return serving_chat


@pytest.mark.asyncio
async def test_chat_error_non_stream():
    """test finish_reason='error' returns 500 InternalServerError (non-streaming)"""
    mock_engine = MagicMock(spec=AsyncLLM)
    mock_engine.get_tokenizer.return_value = get_tokenizer(MODEL_NAME)
    mock_engine.errored = False
    mock_engine.model_config = MockModelConfig()
    mock_engine.input_processor = MagicMock()
    mock_engine.io_processor = MagicMock()

    serving_chat = _build_serving_chat(mock_engine)

    completion_output = CompletionOutput(
        index=0,
        text="",
        token_ids=[],
        cumulative_logprob=None,
        logprobs=None,
        finish_reason="error",
    )

    request_output = RequestOutput(
        request_id="test-id",
        prompt="Test prompt",
        prompt_token_ids=[1, 2, 3],
        prompt_logprobs=None,
        outputs=[completion_output],
        finished=True,
        metrics=None,
        lora_request=None,
        encoder_prompt=None,
        encoder_prompt_token_ids=None,
    )

    async def mock_generate(*args, **kwargs):
        yield request_output

    mock_engine.generate = MagicMock(side_effect=mock_generate)

    request = ChatCompletionRequest(
        model=MODEL_NAME,
        messages=[{"role": "user", "content": "Test prompt"}],
        max_tokens=10,
        stream=False,
    )

    response = await serving_chat.create_chat_completion(request)

    assert isinstance(response, ErrorResponse)
    assert response.error.type == "InternalServerError"
    assert response.error.message == "Internal server error"
    assert response.error.code == HTTPStatus.INTERNAL_SERVER_ERROR


@pytest.mark.asyncio
async def test_chat_error_stream():
    """test finish_reason='error' returns 500 InternalServerError (streaming)"""
    mock_engine = MagicMock(spec=AsyncLLM)
    mock_engine.get_tokenizer.return_value = get_tokenizer(MODEL_NAME)
    mock_engine.errored = False
    mock_engine.model_config = MockModelConfig()
    mock_engine.input_processor = MagicMock()
    mock_engine.io_processor = MagicMock()

    serving_chat = _build_serving_chat(mock_engine)

    completion_output_1 = CompletionOutput(
        index=0,
        text="Hello",
        token_ids=[100],
        cumulative_logprob=None,
        logprobs=None,
        finish_reason=None,
    )

    request_output_1 = RequestOutput(
        request_id="test-id",
        prompt="Test prompt",
        prompt_token_ids=[1, 2, 3],
        prompt_logprobs=None,
        outputs=[completion_output_1],
        finished=False,
        metrics=None,
        lora_request=None,
        encoder_prompt=None,
        encoder_prompt_token_ids=None,
    )

    completion_output_2 = CompletionOutput(
        index=0,
        text="Hello",
        token_ids=[100],
        cumulative_logprob=None,
        logprobs=None,
        finish_reason="error",
    )

    request_output_2 = RequestOutput(
        request_id="test-id",
        prompt="Test prompt",
        prompt_token_ids=[1, 2, 3],
        prompt_logprobs=None,
        outputs=[completion_output_2],
        finished=True,
        metrics=None,
        lora_request=None,
        encoder_prompt=None,
        encoder_prompt_token_ids=None,
    )

    async def mock_generate(*args, **kwargs):
        yield request_output_1
        yield request_output_2

    mock_engine.generate = MagicMock(side_effect=mock_generate)

    request = ChatCompletionRequest(
        model=MODEL_NAME,
        messages=[{"role": "user", "content": "Test prompt"}],
        max_tokens=10,
        stream=True,
    )

    response = await serving_chat.create_chat_completion(request)

    chunks = []
    async for chunk in response:
        chunks.append(chunk)

    assert len(chunks) >= 2
    assert any("Internal server error" in chunk for chunk in chunks), (
        f"Expected error message in chunks: {chunks}"
    )
    assert chunks[-1] == "data: [DONE]\n\n"
