#  Copyright (c) "Neo4j"
#  Neo4j Sweden AB [https://neo4j.com]
#  #
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#  #
#      https://www.apache.org/licenses/LICENSE-2.0
#  #
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.
from unittest.mock import MagicMock, Mock, patch

import openai
import pytest
from tenacity import RetryError
from neo4j_graphrag.embeddings.openai import (
    AzureOpenAIEmbeddings,
    OpenAIEmbeddings,
)
from neo4j_graphrag.exceptions import EmbeddingsGenerationError


def get_mock_openai() -> MagicMock:
    mock = MagicMock()
    mock.OpenAIError = openai.OpenAIError
    return mock


@patch("builtins.__import__", side_effect=ImportError)
def test_openai_embedder_missing_dependency(mock_import: Mock) -> None:
    with pytest.raises(ImportError):
        OpenAIEmbeddings()


@patch("builtins.__import__")
def test_openai_embedder_happy_path(mock_import: Mock) -> None:
    mock_openai = get_mock_openai()
    mock_import.return_value = mock_openai

    mock_openai.OpenAI.return_value.embeddings.create.return_value = MagicMock(
        data=[MagicMock(embedding=[1.0, 2.0])],
    )
    embedder = OpenAIEmbeddings(api_key="my key")
    res = embedder.embed_query("my text")
    assert isinstance(res, list)
    assert res == [1.0, 2.0]


@patch("builtins.__import__", side_effect=ImportError)
def test_azure_openai_embedder_missing_dependency(mock_import: Mock) -> None:
    with pytest.raises(ImportError):
        AzureOpenAIEmbeddings()


@patch("builtins.__import__")
def test_azure_openai_embedder_happy_path(mock_import: Mock) -> None:
    mock_openai = get_mock_openai()
    mock_import.return_value = mock_openai

    mock_openai.AzureOpenAI.return_value.embeddings.create.return_value = MagicMock(
        data=[MagicMock(embedding=[1.0, 2.0])],
    )
    embedder = AzureOpenAIEmbeddings(
        model_name="gpt",
        azure_endpoint="https://test.openai.azure.com/",
        api_key="my key",
        api_version="version",
    )
    res = embedder.embed_query("my text")
    assert isinstance(res, list)
    assert res == [1.0, 2.0]


def test_azure_openai_embedder_does_not_call_openai_client() -> None:
    from unittest.mock import patch

    mock_openai = get_mock_openai()

    with patch.dict("sys.modules", {"openai": mock_openai}):
        AzureOpenAIEmbeddings(
            model="text-embedding-ada-002",
            azure_endpoint="https://test.openai.azure.com/",
            api_key="my_key",
            api_version="2023-05-15",
        )

        mock_openai.OpenAI.assert_not_called()
        mock_openai.AzureOpenAI.assert_called_once_with(
            azure_endpoint="https://test.openai.azure.com/",
            api_key="my_key",
            api_version="2023-05-15",
        )


@patch("builtins.__import__")
def test_openai_embedder_non_retryable_error_handling(mock_import: Mock) -> None:
    """Test that non-retryable errors fail immediately without retries."""
    mock_openai = get_mock_openai()
    mock_import.return_value = mock_openai

    # Generic API error that doesn't match rate limit patterns - should not be retried
    mock_embeddings = mock_openai.OpenAI.return_value.embeddings.create
    mock_embeddings.side_effect = Exception("API Error")
    embedder = OpenAIEmbeddings(api_key="my key")

    with pytest.raises(
        EmbeddingsGenerationError, match="Failed to generate embedding with OpenAI"
    ):
        embedder.embed_query("my text")

    # Verify the API was called only once (no retries for non-rate-limit errors)
    assert mock_embeddings.call_count == 1


@patch("builtins.__import__")
def test_openai_embedder_rate_limit_error_retries(mock_import: Mock) -> None:
    """Test that rate limit errors are retried the expected number of times."""
    mock_openai = get_mock_openai()
    mock_import.return_value = mock_openai

    # Rate limit error that should trigger retries (matches "429" pattern)
    # Create separate exception instances for each retry attempt
    mock_embeddings = mock_openai.OpenAI.return_value.embeddings.create
    mock_embeddings.side_effect = [
        Exception("Error code: 429 - Too many requests"),
        Exception("Error code: 429 - Too many requests"),
        Exception("Error code: 429 - Too many requests"),
    ]
    embedder = OpenAIEmbeddings(api_key="my key")

    # After exhausting retries, tenacity raises RetryError
    with pytest.raises(RetryError):
        embedder.embed_query("my text")

    # Verify the API was called 3 times (default max_attempts for RetryRateLimitHandler)
    assert mock_embeddings.call_count == 3


@patch("builtins.__import__")
def test_openai_embedder_rate_limit_error_eventual_success(mock_import: Mock) -> None:
    """Test that rate limit errors eventually succeed after retries."""
    mock_openai = get_mock_openai()
    mock_import.return_value = mock_openai

    # First two calls fail with rate limit, third succeeds
    mock_embeddings = mock_openai.OpenAI.return_value.embeddings.create
    mock_embeddings.side_effect = [
        Exception("Error code: 429 - Too many requests"),
        Exception("Error code: 429 - Too many requests"),
        MagicMock(data=[MagicMock(embedding=[1.0, 2.0])]),
    ]
    embedder = OpenAIEmbeddings(api_key="my key")

    result = embedder.embed_query("my text")

    # Verify successful result
    assert result == [1.0, 2.0]
    # Verify the API was called 3 times before succeeding
    assert mock_embeddings.call_count == 3