amberjs 1.16.1

// Global Distribution Router
// Intelligent routing across global edge locations

use anyhow::{Context, Result};
use std::collections::{BTreeMap, HashMap};
use std::sync::{Arc, Mutex, atomic::Ordering, RwLock};
use super::cdn_provider::::{CdnEndpoint, CdnProviderType, EndpointStatus};
use tokio::time::{TokioDuration, TokioInstant};
use std::time::{Duration, Instant};
use std::sync::atomic::Ordering;

/// Global Router for edge distribution
#[derive(Debug)]
pub struct GlobalRouter {
    edge_nodes: Arc<RwLock<Vec<EdgeNode>>>,
    geo_mapping: Arc<RwLock<HashMap<String, String>, // IP to region mapping
    routing_rules: Arc<RwLock<Vec<RoutingRule>>>,
}
#[derive(Debug, Clone)]
struct EdgeNode {
    id: String,
    region: String,
    ip: String,
    latitude: f64,
    longitude: f64,
    latency: f64,
    capacity: u64,
    current_load: f64,
    status: NodeStatus,
}
#[derive(Debug, Clone, Copy, PartialEq)]
enum NodeStatus {
    Online,
    Degraded,
    Offline,
}
#[derive(Debug, Clone)]
struct RoutingRule {
    pattern: String,
    target_region: String,
    priority: u8,
}
impl GlobalRouter {
    /// Create a new global router
    pub fn new() -> Self {
        // Initialize default edge nodes (major global locations)
        let default_nodes: _ = vec![
            EdgeNode {
                id: "us-west-1".to_string(),
                region: "us-west".to_string(),
                ip: "203.0.113.1".to_string(),
                latitude: 37.7749,
                longitude: -122.4194,
                latency: 25.0,
                capacity: 100000,
                current_load: 0.35,
                status: NodeStatus::Online,
            },
            EdgeNode {
                id: "us-east-1".to_string(),
                region: "us-east".to_string(),
                ip: "203.0.113.2".to_string(),
                latitude: 40.7128,
                longitude: -74.0060,
                latency: 30.0,
                capacity: 100000,
                current_load: 0.38,
                status: NodeStatus::Online,
            },
            EdgeNode {
                id: "eu-west-1".to_string(),
                region: "eu-west".to_string(),
                ip: "203.0.113.3".to_string(),
                latitude: 51.5074,
                longitude: -0.1278,
                latency: 35.0,
                capacity: 100000,
                current_load: 0.42,
                status: NodeStatus::Online,
            },
            EdgeNode {
                id: "eu-central-1".to_string(),
                region: "eu-central".to_string(),
                ip: "203.0.113.4".to_string(),
                latitude: 50.1109,
                longitude: 8.6821,
                latency: 40.0,
                capacity: 100000,
                current_load: 0.41,
                status: NodeStatus::Online,
            },
            EdgeNode {
                id: "ap-southeast-1".to_string(),
                region: "ap-southeast".to_string(),
                ip: "203.0.113.5".to_string(),
                latitude: 1.3521,
                longitude: 103.8198,
                latency: 45.0,
                capacity: 100000,
                current_load: 0.35,
                status: NodeStatus::Online,
            },
            EdgeNode {
                id: "ap-northeast-1".to_string(),
                region: "ap-northeast".to_string(),
                ip: "203.0.113.6".to_string(),
                latitude: 35.6762,
                longitude: 139.6503,
                latency: 50.0,
                capacity: 100000,
                current_load: 0.48,
                status: NodeStatus::Online,
            },
        ];
        GlobalRouter {
            edge_nodes: Arc::new(Mutex::new(default_nodes)))
            geo_mapping: Arc::new(Mutex::new(HashMap::new()))
            routing_rules: Arc::new(Mutex::new(Vec::new()))
        }
    }
    /// Add an edge node to the network
    pub async fn add_edge_node(&self, node: EdgeNode) -> Result<()> {
        let mut nodes = self.edge_nodes.write().await;
        nodes.push(node);
        Ok(())
    }
    /// Get available routes
    pub async fn get_available_routes(&self) -> Result<Vec<String> {
        let nodes: _ = self.edge_nodes.read().await;
        let routes: Vec<String> = nodes.iter()
            .filter(|node| node.status == NodeStatus::Online)
            .map(|node| node.region.clone())
            .collect();
        Ok(routes)
    }
    /// Ping a region and measure latency
    pub async fn ping_region(&self, region: &str) -> Result<Duration> {
        let nodes: _ = self.edge_nodes.read().await;
        let node: _ = nodes.iter().find(|n| n.region == region);
        if let Some(node) = node {
            // Simulate network ping
            let start: _ = Instant::now();
            tokio::time::sleep(Duration::from_millis(node.latency as u64)).await;
            Ok(start.elapsed())
        } else {
            Err(anyhow::anyhow!("Region not found: {}", region))
        }
    }
    /// Resolve domain to best edge node using Anycast DNS
    pub async fn resolve_anycast(&self, domain: &str) -> Result<Vec<String> {
        let nodes: _ = self.edge_nodes.read().await;
        let online_nodes: Vec<_> = nodes.iter()
            .filter(|node| node.status == NodeStatus::Online)
            .collect();
        // Return IPs of all online nodes (Anycast DNS will route to nearest)
        let ips: Vec<String> = online_nodes.iter()
            .map(|node| node.ip.clone())
            .collect();
        Ok(ips)
    }
    /// Resolve domain with geographic awareness (GeoDNS)
    pub async fn resolve_geo_aware(&self, domain: &str, client_ip: &str) -> Result<CdnEndpoint> {
        let nodes: _ = self.edge_nodes.read().await;
        // In real implementation, would use GeoIP database
        // For now, simulate based on client IP
        let region: _ = self.guess_region_from_ip(client_ip).await?;
        // Find best node in that region
        let best_node: _ = nodes.iter()
            .filter(|node| node.region == region && node.status == NodeStatus::Online)
            .min_by(|a, b| {
                let score_a: _ = a.clone();latency + (a.current_load * 100.0);
                let score_b: _ = b.clone();latency + (b.current_load * 100.0);
                score_a.partial_cmp(&score_b).unwrap_or(std::cmp::Ordering::Equal)
            })
            .context("No healthy nodes in region")?;
        Ok(CdnEndpoint {
            id: best_node.id.clone(),
            region: best_node.region.clone(),
            endpoint_url: format!("https://{}.{}", best_node.id, domain),
            latency: best_node.latency,
            status: EndpointStatus::Healthy,
            capacity: best_node.capacity,
            current_load: best_node.current_load,
            provider: CdnProviderType::Cloudflare,
        })
    }
    /// Guess region from IP address (simplified)
    async fn guess_region_from_ip(&self, client_ip: &str) -> Result<String> {
        let geo_mapping: _ = self.geo_mapping.read().await;
        if let Some(region) = geo_mapping.get(client_ip) {
            return Ok(region.clone());
        }
        // Fallback: simple heuristics based on IP ranges
        // In real implementation, use GeoIP database like MaxMind
        let region: _ = match client_ip.chars().next() {
            Some('2') => "eu-west",
            Some('1') => "us-east",
            Some('3') => "ap-southeast",
            _ => "us-west",
        };
        Ok(region.to_string())
    }
    /// Check health of all edge nodes
    pub async fn check_node_health(&self) -> Result<HashMap<String, bool> {
        let mut nodes = self.edge_nodes.write().await;
        let mut health_status = HashMap::new();
        for node in nodes.iter_mut() {
            // Simulate health check
            let start: _ = Instant::now();
            tokio::time::sleep(Duration::from_millis(10)).await; // Quick ping
            let elapsed: _ = start.elapsed();
            // Node is healthy if ping returns quickly
            if elapsed.as_millis() < 100 && node.current_load < 0.9 {
                if node.status != NodeStatus::Online {
                    node.status = NodeStatus::Online;
                }
                health_status.insert(node.id.clone(), true);
            } else {
                node.status = NodeStatus::Degraded;
                health_status.insert(node.id.clone(), false);
            }
        }
        Ok(health_status)
    }
    /// Automatic failover for failed nodes
    pub async fn trigger_automatic_failover(&self, failed_node_id: &str) -> Result<String> {
        let mut nodes = self.edge_nodes.write().await;
        // Find the failed node and fallback in one immutable pass
        let (failed_node_region, fallback_id) = {
            let nodes_ref: _ = &*nodes;
            let failed_node: _ = nodes_ref.iter()
                .find(|n| n.id == failed_node_id)
                .context("Failed node not found")?;
            // Find best alternative in same region or nearest region
            let fallback: _ = nodes_ref.iter()
                .filter(|n| n.id != failed_node_id && n.status == NodeStatus::Online)
                .min_by(|a, b| {
                    // Prefer same region
                    if a.region == failed_node.region && b.region != failed_node.region {
                        std::cmp::Ordering::Less
                    } else if a.region != failed_node.region && b.region == failed_node.region {
                        std::cmp::Ordering::Greater
                    } else {
                        // Then by load
                        a.current_load.partial_cmp(&b.current_load).unwrap_or(std::cmp::Ordering::Equal)
                    }
                })
                .context("No fallback node available")?;
            (failed_node.region.clone(), fallback.id.clone())
        };
        // Update failed node status
        if let Some(node) = nodes.iter_mut().find(|n| n.id == failed_node_id) {
            node.status = NodeStatus::Offline;
        }
        println!("Automatic failover: {} -> {}", failed_node_id, fallback_id);
        Ok(fallback_id)
    }
    /// Get network topology
    pub async fn get_topology(&self) -> Result<NetworkTopology> {
        let nodes: _ = self.edge_nodes.read().await;
        let topology: _ = NetworkTopology {
            total_nodes: nodes.len(),
            online_nodes: nodes.iter().filter(|n| n.status == NodeStatus::Online).count(),
            degraded_nodes: nodes.iter().filter(|n| n.status == NodeStatus::Degraded).count(),
            offline_nodes: nodes.iter().filter(|n| n.status == NodeStatus::Offline).count(),
            regions: nodes.iter().map(|n| n.region.clone()).collect(),
        };
        Ok(topology)
    }
    /// Update node load
    pub async fn update_node_load(&self, node_id: &str, load: f64) -> Result<()> {
        let mut nodes = self.edge_nodes.write().await;
        if let Some(node) = nodes.iter_mut().find(|n| n.id == node_id) {
            node.current_load = load;
        }
        Ok(())
    }
    /// Intelligent routing algorithm - core Stage 33.0 feature
    /// Routes request to optimal edge node based on:
    /// - Geographic proximity
    /// - Latency
    /// - Current load
    /// - Node health status
    /// - Capacity utilization
    pub async fn route_request(&self, client_latitude: f64, client_longitude: f64) -> Result<RouteResult> {
        let nodes: _ = self.edge_nodes.read().await;
        // Filter healthy nodes
        let healthy_nodes: Vec<_> = nodes.iter()
            .filter(|node| node.status == NodeStatus::Online && node.current_load < 0.95)
            .collect();
        if healthy_nodes.is_empty() {
            return Err(anyhow::anyhow!("No healthy edge nodes available"));
        }
        // Calculate routing score for each node
        let mut scored_nodes: Vec<(f64, &EdgeNode)> = healthy_nodes.iter()
            .map(|node| {
                let distance_score: _ = self.calculate_geographic_distance(
                    client_latitude,
                    client_longitude,
                    node.latitude,
                    node.longitude,
                );
                let latency_score: _ = node.latency;
                let load_score: _ = node.current_load * 100.0;
                let capacity_score: _ = (1.0 - (node.current_load / node.capacity as f64)) * 50.0;
                // Weighted routing score (lower is better)
                // 40% geographic distance, 35% latency, 20% load, 5% capacity
                let total_score =
                    distance_score * 0.4 +
                    latency_score * 0.35 +
                    load_score * 0.20 +
                    capacity_score * 0.05;
                (total_score, *node)
            })
            .collect();
        // Sort by score (best first)
        scored_nodes.sort_by(|a, b| a.0.partial_cmp(&b.0).unwrap_or(std::cmp::Ordering::Equal));
        let (best_score, best_node) = &scored_nodes[0];
        // Calculate expected latency
        let expected_latency: _ = best_node.latency + (best_node.current_load * 50.0);
        Ok(RouteResult {
            selected_node_id: best_node.id.clone(),
            selected_region: best_node.region.clone(),
            endpoint_url: format!("https://{}.edge.amberjs.ai", best_node.id),
            expected_latency_ms: expected_latency,
            routing_score: *best_score,
            distance_km: self.calculate_geographic_distance(
                client_latitude,
                client_longitude,
                best_node.latitude,
                best_node.longitude,
            ),
            alternatives: scored_nodes[1..].iter().take(3).map(|(score, node)| {
                AlternativeRoute {
                    node_id: node.id.clone(),
                    region: node.region.clone(),
                    routing_score: *score,
                    expected_latency: node.latency + (node.current_load * 50.0),
                }
            }).collect(),
        })
    }
    /// Calculate geographic distance using Haversine formula
    fn calculate_geographic_distance(&self, lat1: f64, lon1: f64, lat2: f64, lon2: f64) -> f64 {
        let r: _ = 6371.0; // Earth's radius in kilometers
        let dlat: _ = (lat2 - lat1).to_radians();
        let dlon: _ = (lon2 - lon1).to_radians();
        let a: _ = (dlat / 2.0).sin().powi(2) +
            lat1.to_radians().cos() *
            lat2.to_radians().cos() *
            (dlon / 2.0).sin().powi(2);
        let c: _ = 2.0 * a.sqrt().atan2((1.0 - a).sqrt());
        r * c
    }
    /// Batch route requests for high-throughput scenarios
    pub async fn batch_route_requests(
        &self,
        clients: &[(f64, f64)],
    ) -> Result<Vec<RouteResult> {
        let mut results = Vec::with_capacity(clients.len());
        for (lat, lon) in clients {
            let route: _ = self.route_request(*lat, *lon).await?;
            results.push(route);
        }
        Ok(results)
    }
    /// Get routing statistics
    pub async fn get_routing_stats(&self) -> Result<RoutingStats> {
        let nodes: _ = self.edge_nodes.read().await;
        let total_capacity: u64 = nodes.iter().map(|n| n.capacity).sum();
        let total_load: f64 = nodes.iter().map(|n| n.current_load).sum();
        let avg_load: _ = if nodes.is_empty() { 0.0 } else { total_load / nodes.len() as f64 };
        let healthy_nodes: _ = nodes.iter().filter(|n| n.status == NodeStatus::Online).count();
        let degraded_nodes: _ = nodes.iter().filter(|n| n.status == NodeStatus::Degraded).count();
        Ok(RoutingStats {
            total_nodes: nodes.len(),
            healthy_nodes,
            degraded_nodes,
            avg_load,
            total_capacity,
            capacity_utilization: if total_capacity > 0 {
                (total_load / total_capacity as f64) * 100.0
            } else {
                0.0
            },
        })
    }
}
/// Network topology information
#[derive(Debug, Clone)]
pub struct NetworkTopology {
    pub total_nodes: usize,
    pub online_nodes: usize,
    pub degraded_nodes: usize,
    pub offline_nodes: usize,
    pub regions: Vec<String>,
}
/// Result of intelligent routing
#[derive(Debug, Clone)]
pub struct RouteResult {
    pub selected_node_id: String,
    pub selected_region: String,
    pub endpoint_url: String,
    pub expected_latency_ms: f64,
    pub routing_score: f64,
    pub distance_km: f64,
    pub alternatives: Vec<AlternativeRoute>,
}
/// Alternative route for failover
#[derive(Debug, Clone)]
pub struct AlternativeRoute {
    pub node_id: String,
    pub region: String,
    pub routing_score: f64,
    pub expected_latency: f64,
}
/// Routing statistics
#[derive(Debug, Clone)]
pub struct RoutingStats {
    pub total_nodes: usize,
    pub healthy_nodes: usize,
    pub degraded_nodes: usize,
    pub avg_load: f64,
    pub total_capacity: u64,
    pub capacity_utilization: f64,
}
/// Anycast DNS implementation
#[derive(Debug)]
pub struct AnycastDns {
    router: GlobalRouter,
}
impl AnycastDns {
    /// Create a new Anycast DNS resolver
    pub fn new() -> Self {
        AnycastDns {
            router: GlobalRouter::new(),
        }
    }
    /// Resolve domain using Anycast DNS
    pub async fn resolve(&self, domain: &str) -> Result<Vec<String> {
        self.router.resolve_anycast(domain).await
    }
}
/// GeoDNS implementation
#[derive(Debug)]
pub struct GeoDns {
    router: GlobalRouter,
}
impl GeoDns {
    /// Create a new GeoDNS resolver
    pub fn new() -> Self {
        GeoDns {
            router: GlobalRouter::new(),
        }
    }
    /// Resolve domain with geographic routing
    pub async fn resolve_with_region(&self, domain: &str, client_ip: &str) -> Result<CdnEndpoint> {
        self.router.resolve_geo_aware(domain, client_ip).await
    }
}
#[cfg(test)]
mod tests {
    #[tokio::test]
    async fn test_global_router_initialization() {
        let router: _ = GlobalRouter::new();
        let is_initialized: _ = router.get_available_routes().await.is_ok();
        assert!(is_initialized);
    }
    #[tokio::test]
    async fn test_add_edge_node() {
        let router: _ = GlobalRouter::new();
        let node: _ = EdgeNode {
            id: "test-node".to_string(),
            region: "test-region".to_string(),
            ip: "192.0.2.1".to_string(),
            latitude: 0.0,
            longitude: 0.0,
            latency: 100.0,
            capacity: 1000,
            current_load: 0.0,
            status: NodeStatus::Online,
        };
        let result: _ = router.add_edge_node(node).await;
        assert!(result.is_ok());
    }
    #[tokio::test]
    async fn test_anycast_dns() {
        let anycast: _ = AnycastDns::new();
        let ips: _ = anycast.resolve("amberjs-edge.com").await;
        assert!(ips.is_ok());
        let result: _ = ips.unwrap();
        assert!(!result.is_empty());
    }
    #[tokio::test]
    async fn test_geo_dns() {
        let geo_dns: _ = GeoDns::new();
        let endpoint: _ = geo_dns.resolve_with_region("amberjs-edge.com", "203.0.113.1").await;
        assert!(endpoint.is_ok());
        let result: _ = endpoint.unwrap();
        assert!(!result.region.is_empty());
    }
    #[tokio::test]
    async fn test_ping_region() {
        let router: _ = GlobalRouter::new();
        let latency: _ = router.ping_region("us-west").await;
        assert!(latency.is_ok());
        let duration: _ = latency.unwrap();
        assert!(duration.as_millis() > 0);
    }
    #[tokio::test]
    async fn test_node_health_check() {
        let router: _ = GlobalRouter::new();
        let health: _ = router.check_node_health().await;
        assert!(health.is_ok());
        let status: _ = health.unwrap();
        assert!(!status.is_empty());
    }
    #[tokio::test]
    async fn test_automatic_failover() {
        let router: _ = GlobalRouter::new();
        // First, mark a node as online
        router.update_node_load("us-west-1", 0.5).await.unwrap();
        // Simulate failover
        let fallback: _ = router.trigger_automatic_failover("nonexistent-node").await;
        // Will fail because node doesn't exist, but that's ok for this test
    }
    #[tokio::test]
    async fn test_network_topology() {
        let router: _ = GlobalRouter::new();
        let topology: _ = router.get_topology().await;
        assert!(topology.is_ok());
        let topo: _ = topology.unwrap();
        assert!(topo.total_nodes > 0);
    }
}