package prune

import (
	"fmt"
	"strings"

	"k8s.io/apimachinery/pkg/api/meta"
	"k8s.io/apimachinery/pkg/runtime/schema"
)

type Resource struct {
	group      string
	version    string
	kind       string
	namespaced bool
}

func (pr Resource) String() string {
	return fmt.Sprintf("%v/%v, Kind=%v, Namespaced=%v", pr.group, pr.version, pr.kind, pr.namespaced)
}

func GetRESTMappings(mapper meta.RESTMapper, pruneResources *[]Resource) (namespaced, nonNamespaced []*meta.RESTMapping, err error) {
	if len(*pruneResources) == 0 {
		// default allowlist
		*pruneResources = []Resource{
			{"", "v1", "ConfigMap", true},
			{"", "v1", "Endpoints", true},
			{"", "v1", "Namespace", false},
			{"", "v1", "PersistentVolumeClaim", true},
			{"", "v1", "PersistentVolume", false},
			{"", "v1", "Pod", true},
			{"", "v1", "ReplicationController", true},
			{"", "v1", "Secret", true},
			{"", "v1", "Service", true},
			{"batch", "v1", "Job", true},
			{"batch", "v1", "CronJob", true},
			{"networking.k8s.io", "v1", "Ingress", true},
			{"apps", "v1", "DaemonSet", true},
			{"apps", "v1", "Deployment", true},
			{"apps", "v1", "ReplicaSet", true},
			{"apps", "v1", "StatefulSet", true},
		}
	}

	for _, resource := range *pruneResources {
		addedMapping, err := mapper.RESTMapping(schema.GroupKind{Group: resource.group, Kind: resource.kind}, resource.version)
		if err != nil {
			return nil, nil, fmt.Errorf("invalid resource %v: %v", resource, err)
		}
		if resource.namespaced {
			namespaced = append(namespaced, addedMapping)
		} else {
			nonNamespaced = append(nonNamespaced, addedMapping)
		}
	}

	return namespaced, nonNamespaced, nil
}

func ParseResources(mapper meta.RESTMapper, gvks []string) ([]Resource, error) {
	pruneResources := []Resource{}
	for _, groupVersionKind := range gvks {
		gvk := strings.Split(groupVersionKind, "/")
		if len(gvk) != 3 {
			return nil, fmt.Errorf("invalid GroupVersionKind format: %v, please follow <group/version/kind>", groupVersionKind)
		}

		if gvk[0] == "core" {
			gvk[0] = ""
		}
		mapping, err := mapper.RESTMapping(schema.GroupKind{Group: gvk[0], Kind: gvk[2]}, gvk[1])
		if err != nil {
			return pruneResources, err
		}
		var namespaced bool
		namespaceScope := mapping.Scope.Name()
		switch namespaceScope {
		case meta.RESTScopeNameNamespace:
			namespaced = true
		case meta.RESTScopeNameRoot:
			namespaced = false
		default:
			return pruneResources, fmt.Errorf("Unknown namespace scope: %q", namespaceScope)
		}

		pruneResources = append(pruneResources, Resource{gvk[0], gvk[1], gvk[2], namespaced})
	}
	return pruneResources, nil
}