package render

import (
	"github.com/weaveworks/scope/probe/docker"
	"github.com/weaveworks/scope/probe/endpoint"
	"github.com/weaveworks/scope/probe/process"
	"github.com/weaveworks/scope/report"
)

// Constants are used in the tests.
const (
	InboundMajor  = "The Internet"
	OutboundMajor = "The Internet"
	InboundMinor  = "Inbound connections"
	OutboundMinor = "Outbound connections"

	// Topology for pseudo-nodes and IPs so we can differentiate them at the end
	Pseudo = "pseudo"
)

func renderProcesses(rpt report.Report) bool {
	return len(rpt.Process.Nodes) >= 1
}

// EndpointRenderer is a Renderer which produces a renderable endpoint graph.
var EndpointRenderer = SelectEndpoint

// ProcessRenderer is a Renderer which produces a renderable process
// graph by merging the endpoint graph and the process topology. It
// also colors connected nodes. Since the process topology views only
// show connected processes, we need this info to determine whether
// processes appearing in a details panel are linkable.
var ProcessRenderer = Memoise(ColorConnected(endpoints2Processes{}))

// processWithContainerNameRenderer is a Renderer which produces a process
// graph enriched with container names where appropriate
type processWithContainerNameRenderer struct {
	Renderer
}

func (r processWithContainerNameRenderer) Render(rpt report.Report) Nodes {
	processes := r.Renderer.Render(rpt)
	containers := SelectContainer.Render(rpt)

	outputs := make(report.Nodes, len(processes.Nodes))
	for id, p := range processes.Nodes {
		outputs[id] = p
		containerID, timestamp, ok := p.Latest.LookupEntry(docker.ContainerID)
		if !ok {
			continue
		}
		container, ok := containers.Nodes[report.MakeContainerNodeID(containerID)]
		if !ok {
			continue
		}
		p.Latest = p.Latest.Set(docker.ContainerID, timestamp, containerID)
		if containerName, timestamp, ok := container.Latest.LookupEntry(docker.ContainerName); ok {
			p.Latest = p.Latest.Set(docker.ContainerName, timestamp, containerName)
		}
		outputs[id] = p
	}
	return Nodes{Nodes: outputs, Filtered: processes.Filtered}
}

// ProcessWithContainerNameRenderer is a Renderer which produces a process
// graph enriched with container names where appropriate
//
// not memoised
var ProcessWithContainerNameRenderer = processWithContainerNameRenderer{ProcessRenderer}

// ProcessNameRenderer is a Renderer which produces a renderable process
// name graph by munging the progess graph.
//
// not memoised
var ProcessNameRenderer = CustomRenderer{RenderFunc: processes2Names, Renderer: ProcessRenderer}

// endpoints2Processes joins the endpoint topology to the process
// topology, matching on hostID and pid.
type endpoints2Processes struct {
}

func (e endpoints2Processes) Render(rpt report.Report) Nodes {
	if len(rpt.Process.Nodes) == 0 {
		return Nodes{}
	}
	local := LocalNetworks(rpt)
	processes := SelectProcess.Render(rpt)
	endpoints := SelectEndpoint.Render(rpt)
	ret := newJoinResults(processes.Nodes)

	for _, n := range endpoints.Nodes {
		// Nodes without a hostid are treated as pseudo nodes
		if hostNodeID, ok := n.Latest.Lookup(report.HostNodeID); !ok {
			if id, ok := pseudoNodeID(n, local); ok {
				ret.addChild(n, id, newPseudoNode)
			}
		} else {
			pid, timestamp, ok := n.Latest.LookupEntry(process.PID)
			if !ok {
				continue
			}
			if hasMoreThanOneConnection(n, endpoints.Nodes) {
				continue
			}

			hostID, _ := report.ParseHostNodeID(hostNodeID)
			id := report.MakeProcessNodeID(hostID, pid)
			ret.addChild(n, id, func(id string) report.Node {
				// we have a pid, but no matching process node;
				// create a new one rather than dropping the data
				return report.MakeNode(id).WithTopology(report.Process).
					WithLatest(process.PID, timestamp, pid)
			})
		}
	}
	return ret.result(endpoints)
}

// When there is more than one connection originating from a source
// endpoint, we cannot be sure that its pid is associated with all of
// them, since the source endpoint may have been re-used by a
// different process. See #2665. It is better to drop such an endpoint
// than risk rendering bogus connections.  Aliased connections - when
// all the remote endpoints represent the same logical endpoint, due
// to NATing - are fine though.
func hasMoreThanOneConnection(n report.Node, endpoints report.Nodes) bool {
	if len(n.Adjacency) < 2 {
		return false
	}
	firstRealEndpointID := ""
	for _, endpointID := range n.Adjacency {
		if ep, ok := endpoints[endpointID]; ok {
			if copyID, _, ok := ep.Latest.LookupEntry(endpoint.CopyOf); ok {
				endpointID = copyID
			}
		}
		if firstRealEndpointID == "" {
			firstRealEndpointID = endpointID
		} else if firstRealEndpointID != endpointID {
			return true
		}
	}
	return false
}

// processes2Names maps process Nodes to Nodes for each process name.
func processes2Names(processes Nodes) Nodes {
	ret := newJoinResults(nil)

	for _, n := range processes.Nodes {
		if n.Topology == Pseudo {
			ret.passThrough(n)
		} else if name, timestamp, ok := n.Latest.LookupEntry(process.Name); ok {
			ret.addChildAndChildren(n, name, func(id string) report.Node {
				return report.MakeNode(id).WithTopology(MakeGroupNodeTopology(n.Topology, process.Name)).
					WithLatest(process.Name, timestamp, name)
			})
		}
	}
	return ret.result(processes)
}