"""Tests for configuration module."""

import os
from unittest.mock import patch

import pytest
from pydantic import ValidationError

from embeddings.config import EmbeddingSettings, SettingsCache


class TestEmbeddingSettings:
    """Tests for EmbeddingSettings."""

    def test_required_fields(self) -> None:
        """Test that required fields must be provided."""
        with pytest.raises(ValidationError):
            EmbeddingSettings()

    def test_with_required_fields(self) -> None:
        """Test settings with all required fields provided."""
        settings = EmbeddingSettings(
            default_backend="vllm",
            enable_vllm=True,
            enable_llamacpp=False,
            external_url="http://localhost:54100",
        )

        assert settings.default_backend == "vllm"
        assert settings.enable_vllm is True
        assert settings.enable_llamacpp is False
        assert settings.external_url == "http://localhost:54100"

    def test_optional_defaults(self) -> None:
        """Test optional fields have sensible defaults."""
        settings = EmbeddingSettings(
            default_backend="vllm",
            enable_vllm=True,
            enable_llamacpp=False,
            external_url="http://localhost:54100",
        )

        assert settings.host == "0.0.0.0"
        assert settings.port == 54100
        assert settings.request_timeout == 120.0
        assert settings.rate_limit_rps == 20.0
        assert settings.max_concurrent_requests == 20

    def test_env_override(self) -> None:
        """Test environment variable overrides."""
        env_vars = {
            "EMB_DEFAULT_BACKEND": "llamacpp",
            "EMB_ENABLE_VLLM": "false",
            "EMB_ENABLE_LLAMACPP": "true",
            "EMB_EXTERNAL_URL": "http://example.com",
            "EMB_PORT": "14100",
        }

        with patch.dict(os.environ, env_vars, clear=False):
            settings = EmbeddingSettings()

            assert settings.default_backend == "llamacpp"
            assert settings.enable_vllm is False
            assert settings.enable_llamacpp is True
            assert settings.port == 14100

    def test_vllm_url_default(self) -> None:
        """Test vLLM URL default value."""
        settings = EmbeddingSettings(
            default_backend="vllm",
            enable_vllm=True,
            enable_llamacpp=False,
            external_url="http://localhost:54100",
        )
        assert settings.vllm_base_url == "http://localhost:54101"

    def test_llamacpp_url_default(self) -> None:
        """Test llama.cpp URL default value."""
        settings = EmbeddingSettings(
            default_backend="vllm",
            enable_vllm=True,
            enable_llamacpp=False,
            external_url="http://localhost:54100",
        )
        assert settings.llamacpp_base_url == "http://localhost:54110"

    def test_api_tokens_parsing(self) -> None:
        """Test API tokens are parsed from comma-separated string."""
        settings = EmbeddingSettings(
            default_backend="vllm",
            enable_vllm=True,
            enable_llamacpp=False,
            external_url="http://localhost:54100",
            api_tokens="token1,token2,token3",  # type: ignore[arg-type]
        )

        assert settings.api_tokens is not None
        assert "token1" in settings.api_tokens
        assert "token2" in settings.api_tokens
        assert "token3" in settings.api_tokens
        assert settings.auth_enabled is True

    def test_auth_disabled_by_default(self) -> None:
        """Test authentication is disabled when no tokens set."""
        settings = EmbeddingSettings(
            default_backend="vllm",
            enable_vllm=True,
            enable_llamacpp=False,
            external_url="http://localhost:54100",
        )

        assert settings.api_tokens is None
        assert settings.auth_enabled is False


class TestSettingsCache:
    """Tests for SettingsCache class."""

    def test_set_and_get(self) -> None:
        """Test setting and getting cached settings."""
        SettingsCache.clear()

        settings = EmbeddingSettings(
            default_backend="vllm",
            enable_vllm=True,
            enable_llamacpp=False,
            external_url="http://localhost:54100",
        )
        SettingsCache.set(settings)

        retrieved = SettingsCache.get()
        assert retrieved is settings

    def test_get_without_set_creates_instance(self) -> None:
        """Test that get() creates instance from environment if not set."""
        SettingsCache.clear()

        env_vars = {
            "EMB_DEFAULT_BACKEND": "vllm",
            "EMB_ENABLE_VLLM": "true",
            "EMB_ENABLE_LLAMACPP": "false",
            "EMB_EXTERNAL_URL": "http://localhost:54100",
        }

        with patch.dict(os.environ, env_vars, clear=False):
            settings = SettingsCache.get()
            assert isinstance(settings, EmbeddingSettings)
            assert settings.default_backend == "vllm"

    def test_cached_returns_same_instance(self) -> None:
        """Test that SettingsCache returns cached instance."""
        SettingsCache.clear()

        settings = EmbeddingSettings(
            default_backend="vllm",
            enable_vllm=True,
            enable_llamacpp=False,
            external_url="http://localhost:54100",
        )
        SettingsCache.set(settings)

        settings1 = SettingsCache.get()
        settings2 = SettingsCache.get()

        assert settings1 is settings2

    def test_clear_removes_cached_instance(self) -> None:
        """Test that clear() removes the cached instance."""
        settings = EmbeddingSettings(
            default_backend="vllm",
            enable_vllm=True,
            enable_llamacpp=False,
            external_url="http://localhost:54100",
        )
        SettingsCache.set(settings)

        SettingsCache.clear()

        assert SettingsCache._instance is None