"""
Test suite for API configuration and settings.

This module tests Issue #48 configuration features:
1. Settings loading from environment variables
2. JWT configuration (secret key, algorithm, expiration)
3. Database URL configuration
4. CORS configuration
5. Environment-specific settings (dev/prod)
6. Configuration validation

Tests follow TDD - written before implementation.
"""

import pytest
import os
from typing import Dict, Any
from unittest.mock import patch


# ============================================================================
# Unit Tests: Settings Loading
# ============================================================================

class TestSettingsLoading:
    """Test configuration settings loading."""

    def test_load_settings_from_environment(self):
        """Test that settings are loaded from environment variables."""
        # Arrange
        try:
            with patch.dict(os.environ, {
                "DATABASE_URL": "sqlite+aiosqlite:///test.db",
                "JWT_SECRET_KEY": "test-secret-key",
                "JWT_ALGORITHM": "HS256",
                "JWT_EXPIRATION_MINUTES": "30",
            }):
                # Act
                from tradingagents.api.config import Settings
                settings = Settings()

                # Assert
                assert settings.DATABASE_URL == "sqlite+aiosqlite:///test.db"
                assert settings.JWT_SECRET_KEY == "test-secret-key"
                assert settings.JWT_ALGORITHM == "HS256"
                assert settings.JWT_EXPIRATION_MINUTES == 30
        except ImportError:
            pytest.skip("Config not implemented yet")

    def test_settings_default_values(self):
        """Test that settings have sensible defaults."""
        # Arrange
        try:
            with patch.dict(os.environ, {}, clear=True):
                # Act
                from tradingagents.api.config import Settings
                settings = Settings()

                # Assert: Should have defaults
                assert hasattr(settings, "JWT_ALGORITHM")
                if settings.JWT_ALGORITHM:
                    assert settings.JWT_ALGORITHM == "HS256"
        except ImportError:
            pytest.skip("Config not implemented yet")

    def test_settings_required_fields_validation(self):
        """Test that required settings raise error if missing."""
        # Arrange
        try:
            with patch.dict(os.environ, {}, clear=True):
                # Act & Assert
                from tradingagents.api.config import Settings

                # May raise ValidationError if required fields missing
                # Or may use defaults - depends on implementation
                settings = Settings()
                assert settings is not None
        except ImportError:
            pytest.skip("Config not implemented yet")
        except Exception as e:
            # Expected if required fields are missing
            assert "JWT_SECRET_KEY" in str(e) or True


# ============================================================================
# Unit Tests: JWT Configuration
# ============================================================================

class TestJWTConfiguration:
    """Test JWT-specific configuration."""

    def test_jwt_secret_key_from_env(self):
        """Test JWT secret key is loaded from environment."""
        # Arrange
        try:
            with patch.dict(os.environ, {
                "JWT_SECRET_KEY": "my-super-secret-key-123",
            }):
                # Act
                from tradingagents.api.config import Settings
                settings = Settings()

                # Assert
                assert settings.JWT_SECRET_KEY == "my-super-secret-key-123"
        except ImportError:
            pytest.skip("Config not implemented yet")

    def test_jwt_algorithm_configuration(self):
        """Test JWT algorithm can be configured."""
        # Arrange
        try:
            with patch.dict(os.environ, {
                "JWT_SECRET_KEY": "test-key",
                "JWT_ALGORITHM": "HS512",
            }):
                # Act
                from tradingagents.api.config import Settings
                settings = Settings()

                # Assert
                assert settings.JWT_ALGORITHM == "HS512"
        except ImportError:
            pytest.skip("Config not implemented yet")

    def test_jwt_expiration_minutes(self):
        """Test JWT expiration time configuration."""
        # Arrange
        try:
            with patch.dict(os.environ, {
                "JWT_SECRET_KEY": "test-key",
                "JWT_EXPIRATION_MINUTES": "60",
            }):
                # Act
                from tradingagents.api.config import Settings
                settings = Settings()

                # Assert
                assert settings.JWT_EXPIRATION_MINUTES == 60
        except ImportError:
            pytest.skip("Config not implemented yet")

    def test_jwt_secret_key_min_length(self):
        """Test that JWT secret key has minimum length requirement."""
        # Arrange
        try:
            with patch.dict(os.environ, {
                "JWT_SECRET_KEY": "short",  # Too short
            }):
                # Act
                from tradingagents.api.config import Settings

                # May raise ValidationError for weak secret
                # Or may accept it (validation in code)
                settings = Settings()

                # Assert: If no validation, at least warn
                assert len(settings.JWT_SECRET_KEY) >= 5
        except ImportError:
            pytest.skip("Config not implemented yet")
        except Exception:
            # Expected if validation is strict
            pass


# ============================================================================
# Unit Tests: Database Configuration
# ============================================================================

class TestDatabaseConfiguration:
    """Test database URL configuration."""

    def test_database_url_from_env(self):
        """Test database URL is loaded from environment."""
        # Arrange
        try:
            with patch.dict(os.environ, {
                "DATABASE_URL": "postgresql+asyncpg://user:pass@localhost/db",
            }):
                # Act
                from tradingagents.api.config import Settings
                settings = Settings()

                # Assert
                assert settings.DATABASE_URL == "postgresql+asyncpg://user:pass@localhost/db"
        except ImportError:
            pytest.skip("Config not implemented yet")

    def test_database_url_sqlite_default(self):
        """Test that SQLite is used if no DATABASE_URL provided."""
        # Arrange
        try:
            with patch.dict(os.environ, {}, clear=True):
                # Act
                from tradingagents.api.config import Settings
                settings = Settings()

                # Assert: Should have some default
                if hasattr(settings, "DATABASE_URL") and settings.DATABASE_URL:
                    assert "sqlite" in settings.DATABASE_URL.lower()
        except ImportError:
            pytest.skip("Config not implemented yet")

    def test_database_url_validation(self):
        """Test that invalid database URLs are rejected."""
        # Arrange
        try:
            with patch.dict(os.environ, {
                "DATABASE_URL": "invalid-url",
            }):
                # Act
                from tradingagents.api.config import Settings

                # May raise ValidationError or accept it
                settings = Settings()

                # Assert: At least it's set
                assert settings.DATABASE_URL is not None
        except ImportError:
            pytest.skip("Config not implemented yet")


# ============================================================================
# Unit Tests: CORS Configuration
# ============================================================================

class TestCORSConfiguration:
    """Test CORS (Cross-Origin Resource Sharing) configuration."""

    def test_cors_origins_from_env(self):
        """Test CORS allowed origins configuration."""
        # Arrange
        try:
            with patch.dict(os.environ, {
                "CORS_ORIGINS": "http://localhost:3000,https://app.example.com",
            }):
                # Act
                from tradingagents.api.config import Settings
                settings = Settings()

                # Assert
                if hasattr(settings, "CORS_ORIGINS"):
                    assert "localhost:3000" in settings.CORS_ORIGINS
        except ImportError:
            pytest.skip("Config not implemented yet")

    def test_cors_allow_credentials(self):
        """Test CORS allow credentials setting."""
        # Arrange
        try:
            with patch.dict(os.environ, {
                "CORS_ALLOW_CREDENTIALS": "true",
            }):
                # Act
                from tradingagents.api.config import Settings
                settings = Settings()

                # Assert
                if hasattr(settings, "CORS_ALLOW_CREDENTIALS"):
                    assert settings.CORS_ALLOW_CREDENTIALS is True
        except ImportError:
            pytest.skip("Config not implemented yet")

    def test_cors_wildcard_origin(self):
        """Test CORS wildcard origin (*) configuration."""
        # Arrange
        try:
            with patch.dict(os.environ, {
                "CORS_ORIGINS": "*",
            }):
                # Act
                from tradingagents.api.config import Settings
                settings = Settings()

                # Assert
                if hasattr(settings, "CORS_ORIGINS"):
                    assert "*" in settings.CORS_ORIGINS or settings.CORS_ORIGINS == "*"
        except ImportError:
            pytest.skip("Config not implemented yet")


# ============================================================================
# Unit Tests: Environment-Specific Settings
# ============================================================================

class TestEnvironmentSettings:
    """Test environment-specific configuration (dev/staging/prod)."""

    def test_debug_mode_in_development(self):
        """Test debug mode enabled in development."""
        # Arrange
        try:
            with patch.dict(os.environ, {
                "ENVIRONMENT": "development",
            }):
                # Act
                from tradingagents.api.config import Settings
                settings = Settings()

                # Assert
                if hasattr(settings, "DEBUG"):
                    assert settings.DEBUG is True
        except ImportError:
            pytest.skip("Config not implemented yet")

    def test_debug_mode_in_production(self):
        """Test debug mode disabled in production."""
        # Arrange
        try:
            with patch.dict(os.environ, {
                "ENVIRONMENT": "production",
            }):
                # Act
                from tradingagents.api.config import Settings
                settings = Settings()

                # Assert
                if hasattr(settings, "DEBUG"):
                    assert settings.DEBUG is False
        except ImportError:
            pytest.skip("Config not implemented yet")

    def test_log_level_configuration(self):
        """Test log level can be configured."""
        # Arrange
        try:
            with patch.dict(os.environ, {
                "LOG_LEVEL": "DEBUG",
            }):
                # Act
                from tradingagents.api.config import Settings
                settings = Settings()

                # Assert
                if hasattr(settings, "LOG_LEVEL"):
                    assert settings.LOG_LEVEL == "DEBUG"
        except ImportError:
            pytest.skip("Config not implemented yet")


# ============================================================================
# Integration Tests: Settings in Application
# ============================================================================

class TestSettingsIntegration:
    """Test that settings are used correctly in application."""

    def test_settings_singleton_pattern(self):
        """Test that settings use singleton or cached instance."""
        # Arrange
        try:
            from tradingagents.api.config import Settings

            # Act
            settings1 = Settings()
            settings2 = Settings()

            # Assert: May be same instance (singleton) or different but equal
            assert settings1.JWT_ALGORITHM == settings2.JWT_ALGORITHM
        except ImportError:
            pytest.skip("Config not implemented yet")

    def test_settings_in_dependency_injection(self):
        """Test that settings can be used in FastAPI dependencies."""
        # This would test get_settings() dependency
        try:
            from tradingagents.api.dependencies import get_settings

            # Act
            settings = get_settings()

            # Assert
            assert settings is not None
            assert hasattr(settings, "JWT_SECRET_KEY")
        except ImportError:
            pytest.skip("Dependencies not implemented yet")


# ============================================================================
# Edge Cases: Configuration
# ============================================================================

class TestConfigurationEdgeCases:
    """Test edge cases in configuration."""

    def test_empty_jwt_secret_key(self):
        """Test handling of empty JWT secret key."""
        # Arrange
        try:
            with patch.dict(os.environ, {
                "JWT_SECRET_KEY": "",
            }):
                # Act & Assert
                from tradingagents.api.config import Settings

                # Should either raise error or use default
                settings = Settings()
                assert settings.JWT_SECRET_KEY != ""  # Should have fallback
        except ImportError:
            pytest.skip("Config not implemented yet")
        except Exception:
            # Expected if validation is strict
            pass

    def test_negative_jwt_expiration(self):
        """Test handling of negative JWT expiration time."""
        # Arrange
        try:
            with patch.dict(os.environ, {
                "JWT_SECRET_KEY": "test-key",
                "JWT_EXPIRATION_MINUTES": "-30",
            }):
                # Act
                from tradingagents.api.config import Settings

                # Should either raise error or use default
                settings = Settings()
                assert settings.JWT_EXPIRATION_MINUTES > 0
        except ImportError:
            pytest.skip("Config not implemented yet")
        except Exception:
            # Expected if validation rejects negative values
            pass

    def test_very_large_jwt_expiration(self):
        """Test handling of very large JWT expiration time."""
        # Arrange
        try:
            with patch.dict(os.environ, {
                "JWT_SECRET_KEY": "test-key",
                "JWT_EXPIRATION_MINUTES": "525600",  # 1 year
            }):
                # Act
                from tradingagents.api.config import Settings
                settings = Settings()

                # Assert: Should accept or cap at reasonable max
                assert settings.JWT_EXPIRATION_MINUTES <= 525600
        except ImportError:
            pytest.skip("Config not implemented yet")

    def test_malformed_database_url(self):
        """Test handling of malformed database URL."""
        # Arrange
        malformed_urls = [
            "not-a-url",
            "postgresql://",  # Incomplete
            "sqlite://",  # Missing path
        ]

        try:
            from tradingagents.api.config import Settings

            for url in malformed_urls:
                with patch.dict(os.environ, {"DATABASE_URL": url}):
                    # Act: Should either accept or reject
                    settings = Settings()
                    # No assertion - just check it doesn't crash
        except ImportError:
            pytest.skip("Config not implemented yet")

    def test_unicode_in_config_values(self):
        """Test Unicode characters in configuration values."""
        # Arrange
        try:
            with patch.dict(os.environ, {
                "APP_NAME": "交易代理 🚀",
            }):
                # Act
                from tradingagents.api.config import Settings
                settings = Settings()

                # Assert
                if hasattr(settings, "APP_NAME"):
                    assert "🚀" in settings.APP_NAME
        except ImportError:
            pytest.skip("Config not implemented yet")