amberjs 1.17.0

// Stage 89 Phase 2: 优雅降级模块
// 提供功能降级策略和自动恢复机制
pub mod manager;

pub use manager::{FallbackEvent, FallbackManager, FallbackStats, FallbackStrategy, Feature};
/// 创建降级管理器的便捷函数
pub fn create_fallback_manager() -> FallbackManager {
    FallbackManager::new()
}
/// 创建带有预定义策略的降级管理器
pub async fn create_fallback_manager_with_strategies() -> FallbackManager {
    let mut manager = FallbackManager::new();
    // V8 优化降级策略
    manager
        .register_strategies(vec![
            (
                Feature::V8Optimization,
                FallbackStrategy::RetryLater(std::time::Duration::from_millis(100)),
            ),
            (Feature::V8Optimization, FallbackStrategy::DegradeToBasic),
            (Feature::V8Optimization, FallbackStrategy::DisableFeature),
        ])
        .await;
    // Python 运行时降级策略
    manager
        .register_strategies(vec![
            (
                Feature::PythonRuntime,
                FallbackStrategy::UseAlternative("Python subprocess".to_string()),
            ),
            (Feature::PythonRuntime, FallbackStrategy::Ignore),
        ])
        .await;
    // Go 运行时降级策略
    manager
        .register_strategies(vec![
            (
                Feature::GoRuntime,
                FallbackStrategy::SwitchToBackup("Go subprocess".to_string()),
            ),
            (Feature::GoRuntime, FallbackStrategy::LogAndContinue),
        ])
        .await;
    // WebAssembly 降级策略
    manager
        .register_strategies(vec![
            (
                Feature::WebAssembly,
                FallbackStrategy::RetryLater(std::time::Duration::from_millis(200)),
            ),
            (
                Feature::WebAssembly,
                FallbackStrategy::UseAlternative("V8 interpretation".to_string()),
            ),
        ])
        .await;
    // 企业级功能降级策略
    manager
        .register_strategies(vec![
            (
                Feature::KubernetesIntegration,
                FallbackStrategy::LogAndContinue,
            ),
            (Feature::ServiceMesh, FallbackStrategy::Ignore),
            (Feature::SecurityManager, FallbackStrategy::DisableFeature),
            (Feature::ComplianceManager, FallbackStrategy::DisableFeature),
        ])
        .await;
    // 边缘计算降级策略
    manager
        .register_strategies(vec![
            (Feature::EdgeComputing, FallbackStrategy::DegradeToBasic),
            (Feature::OfflineMode, FallbackStrategy::Ignore),
            (
                Feature::DistributedCoordination,
                FallbackStrategy::LogAndContinue,
            ),
        ])
        .await;
    manager
}
/// 降级工具函数
pub struct FallbackUtils;
impl FallbackUtils {
    /// 检查功能是否应该降级
    pub fn should_fallback(error: &crate::error::AmberError) -> bool {
        match error {
            crate::error::AmberError::V8Error(_) => true,
            crate::error::AmberError::MultiLanguageError(_) => true,
            crate::error::AmberError::PlatformError(_) => true,
            crate::error::AmberError::PerformanceError(_) => true,
            crate::error::AmberError::NetworkError(_) => true,
            _ => false,
        }
    }
    /// 获取默认的降级策略
    pub fn get_default_strategy(feature: &Feature) -> FallbackStrategy {
        match feature {
            Feature::V8Optimization => FallbackStrategy::DegradeToBasic,
            Feature::PythonRuntime => FallbackStrategy::UseAlternative("Subprocess".to_string()),
            Feature::GoRuntime => FallbackStrategy::SwitchToBackup("Subprocess".to_string()),
            Feature::WebAssembly => FallbackStrategy::UseAlternative("V8".to_string()),
            Feature::IOSRuntime | Feature::AndroidRuntime => FallbackStrategy::LogAndContinue,
            Feature::KubernetesIntegration | Feature::ServiceMesh => FallbackStrategy::Ignore,
            Feature::SecurityManager | Feature::ComplianceManager => {
                FallbackStrategy::DisableFeature
            }
            _ => FallbackStrategy::LogAndContinue,
        }
    }
    /// 创建降级建议
    pub fn create_fallback_suggestions(feature: &Feature) -> Vec<String> {
        match feature {
            Feature::V8Optimization => vec![
                "Consider using simplified V8 flags".to_string(),
                "Reduce optimization level".to_string(),
                "Disable V8 optimization temporarily".to_string(),
            ],
            Feature::PythonRuntime => vec![
                "Use Python subprocess instead".to_string(),
                "Switch to Python C extension".to_string(),
                "Disable Python integration".to_string(),
            ],
            Feature::GoRuntime => vec![
                "Use Go subprocess".to_string(),
                "Switch to Go shared library".to_string(),
                "Disable Go integration".to_string(),
            ],
            Feature::WebAssembly => vec![
                "Use V8 interpretation mode".to_string(),
                "Compile to native code".to_string(),
                "Disable WASM support".to_string(),
            ],
            Feature::KubernetesIntegration => vec![
                "Use standalone deployment".to_string(),
                "Disable K8s integration".to_string(),
            ],
            Feature::ServiceMesh => vec![
                "Use direct service calls".to_string(),
                "Disable service mesh".to_string(),
            ],
            _ => vec![
                "Check feature documentation".to_string(),
                "Consider disabling the feature".to_string(),
            ],
        }
    }
}
/// 降级宏
#[macro_export]
macro_rules! with_fallback {
    ($manager:expr, $feature:expr, $operation:block) => {{
        let result: _ = $operation;
        if let Err(error) = result {
            if $crate::fallback::FallbackUtils::should_fallback(&error) {
                match $manager.handle_feature_failure($feature).await {
                    Ok(_) => {
                        eprintln!("Fallback successful for feature: {}", $feature);
                        // 重试操作
                        $operation
                    }
                    Err(fallback_error) => {
                        eprintln!("Fallback failed: {}", fallback_error);
                        Err(error)
                    }
                }
            } else {
                Err(error)
            }
        } else {
            result
        }
    }};
}
#[cfg(test)]
mod tests {
    use super::*;

    #[tokio::test]
    async fn test_fallback_manager_creation() {
        let manager: _ = create_fallback_manager();
        assert!(manager.is_feature_active(&Feature::V8Optimization).await);
    }
    #[tokio::test]
    async fn test_fallback_manager_with_strategies() {
        let mut manager = create_fallback_manager();
        manager
            .register_strategy(
                Feature::PythonRuntime,
                FallbackStrategy::UseAlternative("Test alternative".to_string()),
            )
            .await;
        let strategies: _ = manager.get_strategies(&Feature::PythonRuntime).await;
        assert!(strategies.is_some());
        assert!(!strategies.unwrap().is_empty());
    }
    #[test]
    fn test_should_fallback() {
        let v8_error: _ = crate::error::AmberError::V8Error("Test".to_string());
        let config_error: _ = crate::error::AmberError::ConfigurationError("Test".to_string());
        assert!(FallbackUtils::should_fallback(&v8_error));
        assert!(!FallbackUtils::should_fallback(&config_error));
    }
    #[test]
    fn test_default_strategy() {
        let v8_strategy: _ = FallbackUtils::get_default_strategy(&Feature::V8Optimization);
        assert!(matches!(v8_strategy, FallbackStrategy::DegradeToBasic));
        let python_strategy: _ = FallbackUtils::get_default_strategy(&Feature::PythonRuntime);
        assert!(matches!(
            python_strategy,
            FallbackStrategy::UseAlternative(_)
        ));
    }
    #[test]
    fn test_fallback_suggestions() {
        let suggestions: _ = FallbackUtils::create_fallback_suggestions(&Feature::V8Optimization);
        assert!(!suggestions.is_empty());
        assert!(suggestions.iter().any(|s| s.contains("V8")));
    }
}