From b59c5a4488226254f3596587b9e5597596c97c06 Mon Sep 17 00:00:00 2001
From: Asim Aslam <asim@aslam.me>
Date: Sun, 13 Oct 2019 12:37:13 +0100
Subject: [PATCH] move network handler to service/handler

---
 network/service/handler/handler.go | 205 +++++++++++++++++++++++++++++
 1 file changed, 205 insertions(+)
 create mode 100644 network/service/handler/handler.go

diff --git a/network/service/handler/handler.go b/network/service/handler/handler.go
new file mode 100644
index 00000000..a4858308
--- /dev/null
+++ b/network/service/handler/handler.go
@@ -0,0 +1,205 @@
+// Package handler implements network RPC handler
+package handler
+
+import (
+	"context"
+
+	"github.com/micro/go-micro/errors"
+	"github.com/micro/go-micro/network"
+	pbNet "github.com/micro/go-micro/network/proto"
+	"github.com/micro/go-micro/router"
+	pbRtr "github.com/micro/go-micro/router/proto"
+)
+
+// Network implements network handler
+type Network struct {
+	Network network.Network
+}
+
+func flatten(n network.Node, visited map[string]bool) []network.Node {
+	// if node is nil runaway
+	if n == nil {
+		return nil
+	}
+
+	// set visisted
+	if visited == nil {
+		visited = make(map[string]bool)
+	}
+
+	// create new list of nodes
+	var nodes []network.Node
+
+	// check if already visited
+	if visited[n.Id()] == false {
+		// append the current node
+		nodes = append(nodes, n)
+	}
+
+	// set to visited
+	visited[n.Id()] = true
+
+	// visit the list of peers
+	for _, node := range n.Peers() {
+		nodes = append(nodes, flatten(node, visited)...)
+	}
+
+	return nodes
+}
+
+func (n *Network) Connect(ctx context.Context, req *pbNet.ConnectRequest, resp *pbNet.ConnectResponse) error {
+	if len(req.Nodes) == 0 {
+		return nil
+	}
+
+	// get list of existing nodes
+	nodes := n.Network.Options().Peers
+
+	// generate a node map
+	nodeMap := make(map[string]bool)
+
+	for _, node := range nodes {
+		nodeMap[node] = true
+	}
+
+	for _, node := range req.Nodes {
+		// TODO: we may have been provided a network only
+		// so process anad resolve node.Network
+		if len(node.Address) == 0 {
+			continue
+		}
+
+		// already exists
+		if _, ok := nodeMap[node.Address]; ok {
+			continue
+		}
+
+		nodeMap[node.Address] = true
+		nodes = append(nodes, node.Address)
+	}
+
+	// reinitialise the peers
+	n.Network.Init(
+		network.Peers(nodes...),
+	)
+
+	return nil
+}
+
+// Nodes returns the list of nodes
+func (n *Network) Nodes(ctx context.Context, req *pbNet.NodesRequest, resp *pbNet.NodesResponse) error {
+	depth := uint(req.Depth)
+	if depth <= 0 || depth > network.MaxDepth {
+		depth = network.MaxDepth
+	}
+
+	// root node
+	nodes := map[string]network.Node{}
+
+	// get peers encoded into protobuf
+	peers := flatten(n.Network, nil)
+
+	// walk all the peers
+	for _, peer := range peers {
+		if peer == nil {
+			continue
+		}
+		if _, ok := nodes[peer.Id()]; ok {
+			continue
+		}
+
+		// add to visited list
+		nodes[n.Network.Id()] = peer
+
+		resp.Nodes = append(resp.Nodes, &pbNet.Node{
+			Id:      peer.Id(),
+			Address: peer.Address(),
+		})
+	}
+
+	return nil
+}
+
+// Graph returns the network graph from this root node
+func (n *Network) Graph(ctx context.Context, req *pbNet.GraphRequest, resp *pbNet.GraphResponse) error {
+	depth := uint(req.Depth)
+	if depth <= 0 || depth > network.MaxDepth {
+		depth = network.MaxDepth
+	}
+
+	// get peers encoded into protobuf
+	peers := network.PeersToProto(n.Network, depth)
+
+	// set the root node
+	resp.Root = peers
+
+	return nil
+}
+
+// Routes returns a list of routing table routes
+func (n *Network) Routes(ctx context.Context, req *pbNet.RoutesRequest, resp *pbNet.RoutesResponse) error {
+	// build query
+
+	var qOpts []router.QueryOption
+
+	if q := req.Query; q != nil {
+		if len(q.Service) > 0 {
+			qOpts = append(qOpts, router.QueryService(q.Service))
+		}
+		if len(q.Address) > 0 {
+			qOpts = append(qOpts, router.QueryAddress(q.Address))
+		}
+		if len(q.Gateway) > 0 {
+			qOpts = append(qOpts, router.QueryGateway(q.Gateway))
+		}
+		if len(q.Router) > 0 {
+			qOpts = append(qOpts, router.QueryRouter(q.Router))
+		}
+		if len(q.Network) > 0 {
+			qOpts = append(qOpts, router.QueryNetwork(q.Network))
+		}
+	}
+
+	routes, err := n.Network.Options().Router.Table().Query(qOpts...)
+	if err != nil {
+		return errors.InternalServerError("go.micro.network", "failed to list routes: %s", err)
+	}
+
+	var respRoutes []*pbRtr.Route
+	for _, route := range routes {
+		respRoute := &pbRtr.Route{
+			Service: route.Service,
+			Address: route.Address,
+			Gateway: route.Gateway,
+			Network: route.Network,
+			Router:  route.Router,
+			Link:    route.Link,
+			Metric:  int64(route.Metric),
+		}
+		respRoutes = append(respRoutes, respRoute)
+	}
+
+	resp.Routes = respRoutes
+
+	return nil
+}
+
+// Services returns a list of services based on the routing table
+func (n *Network) Services(ctx context.Context, req *pbNet.ServicesRequest, resp *pbNet.ServicesResponse) error {
+	routes, err := n.Network.Options().Router.Table().List()
+	if err != nil {
+		return errors.InternalServerError("go.micro.network", "failed to list services: %s", err)
+	}
+
+	services := make(map[string]bool)
+
+	for _, route := range routes {
+		if _, ok := services[route.Service]; ok {
+			continue
+		}
+		services[route.Service] = true
+		resp.Services = append(resp.Services, route.Service)
+	}
+
+	return nil
+}