package multus

import (
	"fmt"
	"os"

	nadutils "github.com/k8snetworkplumbingwg/network-attachment-definition-client/pkg/utils"
	core "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/types"
)

// Logger defines the log types that this library will use for outputting status information to the
// user. Because this library may be called interactively by a user or programmatically by another
// application, we allow the calling application to make a very simple Logger type that will be
// compatible with this library.
type Logger interface {
	Infof(format string, args ...interface{})
	Debugf(format string, args ...interface{})
	Warningf(format string, args ...interface{})
}

type SimpleStderrLogger struct{}

func (*SimpleStderrLogger) Infof(format string, args ...interface{}) {
	fmt.Fprintf(os.Stderr, " INFO: "+format+"\n", args...)
}

func (*SimpleStderrLogger) Debugf(format string, args ...interface{}) {
	fmt.Fprintf(os.Stderr, "DEBUG: "+format+"\n", args...)
}

func (*SimpleStderrLogger) Warningf(format string, args ...interface{}) {
	fmt.Fprintf(os.Stderr, " WARN: "+format+"\n", args...)
}

func getNetworksFromPod(
	pod *core.Pod,
	desiredPublicNet, desiredClusterNet *types.NamespacedName,
) (
	publicAddr, clusterAddr string, suggestions []string, err error,
) {
	nets, err := nadutils.GetNetworkStatus(pod)
	if err != nil {
		return "", "", unableToProvideAddressSuggestions,
			fmt.Errorf("pod has no network status yet: %w", err)
	}
	if len(nets) == 0 {
		return "", "", unableToProvideAddressSuggestions,
			fmt.Errorf("pod has no attached networks yet")
	}

	// if the pod has networks attached, parse all of them, and report any debugging suggestions
	// associated for each one
	publicAddr, clusterAddr = "", ""
	suggestions = []string{}
	for _, net := range nets {
		nsName, err := networkNamespacedName(net.Name, pod.Namespace)
		if err != nil {
			suggestions = append(suggestions,
				fmt.Sprintf("pod has an attached network with an un-parse-able network name [%s]; "+
					"not sure what to do; this is unlikely to resolve", net.Name),
			)
		}
		if len(net.IPs) == 0 {
			suggestions = append(suggestions,
				fmt.Sprintf("pod has an attached network [%s] with no IP; "+
					"could this be an IPAM issue?", net.Name))
		}

		ip := net.IPs[0] // any IP should work
		if desiredPublicNet != nil && nsName == *desiredPublicNet {
			// FOUND DESIRED PUBLIC ADDR
			publicAddr = ip
		}
		if desiredClusterNet != nil && nsName == *desiredClusterNet {
			// FOUND DESIRED CLUSTER ADDR
			clusterAddr = ip
		}
	}

	if desiredPublicNet != nil && publicAddr == "" {
		suggestions = append(suggestions, "pod does not have a public network attachment")
	}
	if desiredClusterNet != nil && clusterAddr == "" {
		suggestions = append(suggestions, "pod does not have a cluster network attachment")
	}

	// if there are any suggestions, something isn't right
	if len(suggestions) > 0 {
		suggestions = append(suggestions, unableToProvideAddressSuggestions...)
		return publicAddr, clusterAddr, suggestions, fmt.Errorf("did not find all desired networks")
	}

	// found what we were looking for
	return publicAddr, clusterAddr, []string{}, nil
}

func podIsRunning(pod core.Pod) bool {
	return pod.Status.Phase == core.PodRunning
}

func podIsReady(pod core.Pod) bool {
	for _, c := range pod.Status.Conditions {
		if c.Type == core.PodReady {
			return c.Status == core.ConditionTrue
		}
	}
	return false
}

func networkNamespacedName(netName, podNamespace string) (types.NamespacedName, error) {
	nsName := types.NamespacedName{}
	// what we really want is the result of parsePodNetworkObjectText(), a private method.
	// because the network name is in the same format as network annotations, we can at
	// at least use ParseNetworkAnnotation() to parse the network name
	netSelections, err := nadutils.ParseNetworkAnnotation(netName, podNamespace)
	if err != nil {
		return nsName, fmt.Errorf("failed to parse network name %q into namespaced name: %w", netName, err)
	}

	if len(netSelections) != 1 {
		return nsName, fmt.Errorf("failed to parse network name %q into a single namespaced network name, instead: %v", netName, netSelections)
	}

	net := netSelections[0]
	nsName.Namespace = net.Namespace
	nsName.Name = net.Name
	return nsName, nil
}