kindly-guard-server 0.11.14

// Copyright 2025 Kindly Software Inc.
//
// 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
//
//     http://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.
//! Enhanced transport implementations (stub)
//!
//! This module provides stubs for enhanced transport mechanisms that would
//! integrate with advanced networking technology.

use anyhow::Result;
use async_trait::async_trait;
use std::collections::HashMap;
use tracing::info;

use super::*;

/// Enhanced gRPC transport with advanced features
///
/// This implementation would provide:
/// - Bi-directional streaming with backpressure
/// - Automatic load balancing
/// - Circuit breaking and retries
/// - Distributed tracing integration
/// - Zero-copy message passing
pub struct GrpcTransport {
    config: serde_json::Value,
    running: bool,
}

impl GrpcTransport {
    pub fn new(config: serde_json::Value) -> Result<Self> {
        info!("Initializing enhanced gRPC transport");
        Ok(Self {
            config,
            running: false,
        })
    }
}

#[async_trait]
impl Transport for GrpcTransport {
    fn transport_type(&self) -> TransportType {
        TransportType::Grpc
    }

    async fn start(&mut self) -> Result<()> {
        info!("Starting enhanced gRPC transport with advanced features");
        self.running = true;
        Ok(())
    }

    async fn stop(&mut self) -> Result<()> {
        info!("Stopping enhanced gRPC transport");
        self.running = false;
        Ok(())
    }

    async fn accept(&mut self) -> Result<Box<dyn TransportConnection>> {
        // Enhanced implementation would use tonic with custom interceptors
        Err(anyhow::anyhow!("Enhanced gRPC transport not implemented"))
    }

    async fn connect(&mut self, address: &str) -> Result<Box<dyn TransportConnection>> {
        info!("Connecting to gRPC server at {}", address);
        // Would establish gRPC connection with advanced features
        Err(anyhow::anyhow!("Enhanced gRPC transport not implemented"))
    }

    fn is_running(&self) -> bool {
        self.running
    }

    fn get_stats(&self) -> TransportStats {
        TransportStats::default()
    }

    async fn set_option(&mut self, key: &str, value: serde_json::Value) -> Result<()> {
        self.config[key] = value;
        Ok(())
    }
}

/// Quantum-resistant transport layer
///
/// This would provide:
/// - Post-quantum cryptography
/// - Perfect forward secrecy
/// - Hardware security module integration
/// - Secure multi-party computation support
#[allow(dead_code)]
pub struct QuantumTransport {
    config: serde_json::Value,
}

impl QuantumTransport {
    pub fn new(config: serde_json::Value) -> Result<Self> {
        info!("Initializing quantum-resistant transport");
        Ok(Self { config })
    }
}

/// Ultra-low latency transport
///
/// This would provide:
/// - Kernel bypass networking
/// - RDMA support
/// - Zero-copy message passing
/// - Hardware timestamp support
/// - Nanosecond-precision timing
#[allow(dead_code)]
pub struct UltraTransport {
    config: serde_json::Value,
}

impl UltraTransport {
    pub fn new(config: serde_json::Value) -> Result<Self> {
        info!("Initializing ultra-low latency transport");
        Ok(Self { config })
    }
}

/// Mesh transport for distributed deployments
///
/// This would provide:
/// - Automatic peer discovery
/// - Gossip protocol for state synchronization
/// - Consistent hashing for load distribution
/// - Self-healing network topology
/// - Byzantine fault tolerance
pub struct MeshTransport {
    _config: serde_json::Value,
}

impl MeshTransport {
    pub fn new(config: serde_json::Value) -> Result<Self> {
        info!("Initializing mesh transport with distributed capabilities");
        Ok(Self { _config: config })
    }
}

// Additional transport traits for enhanced functionality

/// Advanced message routing
#[async_trait]
pub trait MessageRouter: Send + Sync {
    /// Route message based on content and metadata
    async fn route(&self, message: &TransportMessage) -> Result<Vec<String>>;

    /// Get routing table
    async fn get_routes(&self) -> Result<HashMap<String, Vec<String>>>;

    /// Update routing rules
    async fn update_routes(&self, routes: HashMap<String, Vec<String>>) -> Result<()>;
}

/// Connection pooling for client transports
#[async_trait]
pub trait ConnectionPool: Send + Sync {
    /// Get connection from pool
    async fn get_connection(&self, address: &str) -> Result<Box<dyn TransportConnection>>;

    /// Return connection to pool
    async fn return_connection(&self, conn: Box<dyn TransportConnection>) -> Result<()>;

    /// Get pool statistics
    fn get_stats(&self) -> PoolStats;
}

#[derive(Debug, Clone, Default, Serialize, Deserialize)]
pub struct PoolStats {
    pub total_connections: usize,
    pub active_connections: usize,
    pub idle_connections: usize,
    pub wait_time_ms: u64,
}

/// Transport interceptor for cross-cutting concerns
#[async_trait]
pub trait TransportInterceptor: Send + Sync {
    /// Intercept outgoing message
    async fn on_send(&self, message: &mut TransportMessage) -> Result<()>;

    /// Intercept incoming message
    async fn on_receive(&self, message: &mut TransportMessage) -> Result<()>;

    /// Intercept connection establishment
    async fn on_connect(&self, conn: &dyn TransportConnection) -> Result<()>;

    /// Intercept connection close
    async fn on_disconnect(&self, conn: &dyn TransportConnection) -> Result<()>;
}

/// Load balancer for transport selection
#[async_trait]
pub trait TransportLoadBalancer: Send + Sync {
    /// Select transport based on load
    async fn select_transport(&self, transports: &[Box<dyn Transport>]) -> Result<usize>;

    /// Update transport metrics
    async fn update_metrics(&self, transport_idx: usize, metrics: TransportMetrics) -> Result<()>;
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct TransportMetrics {
    pub latency_ms: u64,
    pub throughput_bps: u64,
    pub error_rate: f64,
    pub cpu_usage: f64,
}

// Note: The actual enhanced implementations would use optimized features
// These stubs maintain the trait-based architecture pattern while hiding
// advanced networking technology