import json
from unittest.mock import AsyncMock, MagicMock, patch

import httpx
import pytest

from litellm.llms.sagemaker.common_utils import AWSEventStreamDecoder
from litellm.llms.sagemaker.completion.transformation import SagemakerConfig


# --------------------------------------------------------------------------- #
# get_sagemaker_response_stream_shape lazy-load tests                         #
# --------------------------------------------------------------------------- #


@pytest.fixture(autouse=True)
def _reset_sagemaker_response_stream_shape_cache():
    """Prevent lru_cache leakage between tests in this module."""
    import litellm.llms.sagemaker.common_utils as mod

    mod.get_sagemaker_response_stream_shape.cache_clear()
    yield
    mod.get_sagemaker_response_stream_shape.cache_clear()


def test_sagemaker_response_stream_shape_lazy_loads_once():
    """
    get_sagemaker_response_stream_shape() loads from botocore at most once per process.
    """
    from unittest.mock import MagicMock, patch

    import litellm.llms.sagemaker.common_utils as mod

    sentinel = MagicMock()
    with patch.object(
        mod, "_load_sagemaker_response_stream_shape", return_value=sentinel
    ) as mock_load:
        assert mod.get_sagemaker_response_stream_shape() is sentinel
        assert mod.get_sagemaker_response_stream_shape() is sentinel
        mock_load.assert_called_once()


def test_sagemaker_response_stream_shape_loaded_on_first_access():
    """
    get_sagemaker_response_stream_shape() loads once on first use.
    In a standard environment with botocore installed it must be non-None.
    """
    pytest.importorskip("botocore")
    from litellm.llms.sagemaker.common_utils import get_sagemaker_response_stream_shape

    assert get_sagemaker_response_stream_shape() is not None


def test_sagemaker_response_stream_shape_load_failure_returns_none():
    """
    If botocore's Loader raises (e.g. missing data files), _load_sagemaker_response_stream_shape
    should return None rather than propagating the exception, so the module
    still imports cleanly.
    """
    from unittest.mock import patch

    import litellm.llms.sagemaker.common_utils as mod

    pytest.importorskip("botocore")
    with patch(
        "botocore.loaders.Loader.load_service_model",
        side_effect=Exception("no data"),
    ):
        shape = mod._load_sagemaker_response_stream_shape()
        assert shape is None


def test_sagemaker_response_stream_shape_is_structure_shape():
    """
    The loaded shape should be the botocore StructureShape for
    InvokeEndpointWithResponseStreamOutput, not a plain dict or any other type.
    """
    pytest.importorskip("botocore")
    from botocore.model import StructureShape

    from litellm.llms.sagemaker.common_utils import get_sagemaker_response_stream_shape

    shape = get_sagemaker_response_stream_shape()
    assert (
        shape is not None
    ), "get_sagemaker_response_stream_shape() is None — botocore may not be installed"
    assert isinstance(shape, StructureShape)
    assert shape.name == "InvokeEndpointWithResponseStreamOutput"


def test_sagemaker_response_stream_shape_not_reloaded_on_new_decoder():
    """
    Creating multiple AWSEventStreamDecoder instances must not trigger
    additional botocore Loader calls — the shape is cached after first access.
    """
    from litellm.llms.sagemaker.common_utils import get_sagemaker_response_stream_shape

    decoder_a = AWSEventStreamDecoder.__new__(AWSEventStreamDecoder)
    decoder_b = AWSEventStreamDecoder.__new__(AWSEventStreamDecoder)

    assert "_response_stream_shape_cache" not in decoder_a.__dict__
    assert "_response_stream_shape_cache" not in decoder_b.__dict__

    first = get_sagemaker_response_stream_shape()
    second = get_sagemaker_response_stream_shape()
    assert first is second


def test_sagemaker_parse_message_from_event_raises_on_none_shape():
    """
    When get_sagemaker_response_stream_shape() returns None (botocore unavailable),
    _parse_message_from_event must raise SagemakerError before touching the
    botocore parser — not an opaque AttributeError from inside botocore.
    """
    from unittest.mock import MagicMock, patch

    import litellm.llms.sagemaker.common_utils as mod
    from litellm.llms.sagemaker.common_utils import SagemakerError

    decoder = AWSEventStreamDecoder.__new__(AWSEventStreamDecoder)
    decoder.model = "test-model"
    decoder.parser = MagicMock()
    decoder.content_blocks = []
    decoder.is_messages_api = None
    mock_event = MagicMock()

    with patch.object(mod, "get_sagemaker_response_stream_shape", return_value=None):
        with pytest.raises(SagemakerError) as exc_info:
            decoder._parse_message_from_event(mock_event)

    assert exc_info.value.status_code == 500
    assert "botocore" in str(exc_info.value.message).lower()
    # The botocore parser must never have been called
    mock_event.to_response_dict.assert_not_called()


@pytest.mark.asyncio
async def test_aiter_bytes_unicode_decode_error():
    """
    Test that AWSEventStreamDecoder.aiter_bytes() does not raise an error when encountering invalid UTF-8 bytes. (UnicodeDecodeError)


    Ensures stream processing continues despite the error.

    Relevant issue: https://github.com/BerriAI/litellm/issues/9165
    """
    # Create an instance of AWSEventStreamDecoder
    decoder = AWSEventStreamDecoder(model="test-model")

    # Create a mock event that will trigger a UnicodeDecodeError
    mock_event = MagicMock()
    mock_event.to_response_dict.return_value = {
        "status_code": 200,
        "headers": {},
        "body": b"\xff\xfe",  # Invalid UTF-8 bytes
    }

    # Create a mock EventStreamBuffer that yields our mock event
    mock_buffer = MagicMock()
    mock_buffer.__iter__.return_value = [mock_event]

    # Mock the EventStreamBuffer class
    with patch("botocore.eventstream.EventStreamBuffer", return_value=mock_buffer):
        # Create an async generator that yields some test bytes
        async def mock_iterator():
            yield b""

        # Process the stream
        chunks = []
        async for chunk in decoder.aiter_bytes(mock_iterator()):
            if chunk is not None:
                print("chunk=", chunk)
                chunks.append(chunk)

        # Verify that processing continued despite the error
        # The chunks list should be empty since we only sent invalid data
        assert len(chunks) == 0


@pytest.mark.asyncio
async def test_aiter_bytes_valid_chunk_followed_by_unicode_error():
    """
    Test that valid chunks are processed correctly even when followed by Unicode decode errors.
    This ensures errors don't corrupt or prevent processing of valid data that came before.

    Relevant issue: https://github.com/BerriAI/litellm/issues/9165
    """
    decoder = AWSEventStreamDecoder(model="test-model")

    # Create two mock events - first valid, then invalid
    mock_valid_event = MagicMock()
    mock_valid_event.to_response_dict.return_value = {
        "status_code": 200,
        "headers": {},
        "body": json.dumps({"token": {"text": "hello"}}).encode(),  # Valid data first
    }

    mock_invalid_event = MagicMock()
    mock_invalid_event.to_response_dict.return_value = {
        "status_code": 200,
        "headers": {},
        "body": b"\xff\xfe",  # Invalid UTF-8 bytes second
    }

    # Create a mock EventStreamBuffer that yields valid event first, then invalid
    mock_buffer = MagicMock()
    mock_buffer.__iter__.return_value = [mock_valid_event, mock_invalid_event]

    with patch("botocore.eventstream.EventStreamBuffer", return_value=mock_buffer):

        async def mock_iterator():
            yield b"test_bytes"

        chunks = []
        async for chunk in decoder.aiter_bytes(mock_iterator()):
            if chunk is not None:
                chunks.append(chunk)

        # Verify we got our valid chunk despite the subsequent error
        assert len(chunks) == 1
        assert chunks[0]["text"] == "hello"  # Verify the content of the valid chunk


class TestSagemakerTransform:
    def setup_method(self):
        self.config = SagemakerConfig()
        self.model = "test"
        self.logging_obj = MagicMock()

    def test_map_mistral_params(self):
        """Test that parameters are correctly mapped"""
        test_params = {
            "temperature": 0.7,
            "max_tokens": 200,
            "max_completion_tokens": 256,
        }

        result = self.config.map_openai_params(
            non_default_params=test_params,
            optional_params={},
            model=self.model,
            drop_params=False,
        )

        # The function should properly map max_completion_tokens to max_tokens and override max_tokens
        assert result == {"temperature": 0.7, "max_new_tokens": 256}

    def test_mistral_max_tokens_backward_compat(self):
        """Test that parameters are correctly mapped"""
        test_params = {
            "temperature": 0.7,
            "max_tokens": 200,
        }

        result = self.config.map_openai_params(
            non_default_params=test_params,
            optional_params={},
            model=self.model,
            drop_params=False,
        )

        # The function should properly map max_tokens if max_completion_tokens is not provided
        assert result == {"temperature": 0.7, "max_new_tokens": 200}