package analyzer

import (
	"encoding/json"
	"fmt"
	"strings"

	"github.com/pkg/errors"
	troubleshootv1beta2 "github.com/replicatedhq/troubleshoot/pkg/apis/troubleshoot/v1beta2"
	"github.com/replicatedhq/troubleshoot/pkg/constants"
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/klog/v2"
)

type providers struct {
	microk8s        bool
	dockerDesktop   bool
	eks             bool
	gke             bool
	digitalOcean    bool
	openShift       bool
	tanzu           bool
	kurl            bool
	aks             bool
	ibm             bool
	minikube        bool
	rke2            bool
	k3s             bool
	oke             bool
	kind            bool
	k0s             bool
	embeddedCluster bool
}

type Provider int

const (
	unknown         Provider = iota
	microk8s        Provider = iota
	dockerDesktop   Provider = iota
	eks             Provider = iota
	gke             Provider = iota
	digitalOcean    Provider = iota
	openShift       Provider = iota
	tanzu           Provider = iota
	kurl            Provider = iota
	aks             Provider = iota
	ibm             Provider = iota
	minikube        Provider = iota
	rke2            Provider = iota
	k3s             Provider = iota
	oke             Provider = iota
	kind            Provider = iota
	k0s             Provider = iota
	embeddedCluster Provider = iota
)

type AnalyzeDistribution struct {
	analyzer *troubleshootv1beta2.Distribution
}

func (a *AnalyzeDistribution) Title() string {
	title := a.analyzer.CheckName
	if title == "" {
		title = "Kubernetes Distribution"
	}

	return title
}

func (a *AnalyzeDistribution) IsExcluded() (bool, error) {
	return isExcluded(a.analyzer.Exclude)
}

func (a *AnalyzeDistribution) Analyze(getFile getCollectedFileContents, findFiles getChildCollectedFileContents) ([]*AnalyzeResult, error) {
	result, err := a.analyzeDistribution(a.analyzer, getFile)
	if err != nil {
		klog.Errorf("failed to analyze distribution: %v", err)
		return nil, errors.Wrapf(err, "failed to analyze distribution")
	}
	result.Strict = a.analyzer.Strict.BoolOrDefaultFalse()
	return []*AnalyzeResult{result}, nil
}

func CheckApiResourcesForProviders(foundProviders *providers, apiResources []*metav1.APIResourceList, provider string) string {
	for _, resource := range apiResources {
		if strings.HasPrefix(resource.GroupVersion, "apps.openshift.io/") {
			foundProviders.openShift = true
			return "openShift"
		}
		if strings.HasPrefix(resource.GroupVersion, "run.tanzu.vmware.com/") {
			foundProviders.tanzu = true
			return "tanzu"
		}
	}

	return provider
}

func ParseNodesForProviders(nodes []corev1.Node) (providers, string) {
	foundProviders := providers{}
	foundMaster := false
	stringProvider := ""

	for _, node := range nodes {
		for k, v := range node.ObjectMeta.Labels {

			if k == "kurl.sh/cluster" && v == "true" {
				foundProviders.kurl = true
				stringProvider = "kurl"
			} else if k == "microk8s.io/cluster" && v == "true" {
				foundProviders.microk8s = true
				stringProvider = "microk8s"
			}
			if k == "node-role.kubernetes.io/master" {
				foundMaster = true
			}
			if k == "node-role.kubernetes.io/control-plane" {
				foundMaster = true
			}
			if k == "kubernetes.azure.com/role" {
				foundProviders.aks = true
				stringProvider = "aks"
			}
			if k == "minikube.k8s.io/version" {
				foundProviders.minikube = true
				stringProvider = "minikube"
			}
			if k == "node.kubernetes.io/instance-type" && v == "k3s" {
				foundProviders.k3s = true
				stringProvider = "k3s"
			}
			if k == "beta.kubernetes.io/instance-type" && v == "k3s" {
				foundProviders.k3s = true
				stringProvider = "k3s"
			}
			if k == "oci.oraclecloud.com/fault-domain" {
				// Based on: https://docs.oracle.com/en-us/iaas/Content/ContEng/Reference/contengsupportedlabelsusecases.htm
				foundProviders.oke = true
				stringProvider = "oke"
			}
			if k == "node.k0sproject.io/role" {
				foundProviders.k0s = true
				stringProvider = "k0s"
			}

			if k == "kots.io/embedded-cluster-role" {
				foundProviders.embeddedCluster = true
				stringProvider = "embedded-cluster"
			}

			if k == "run.tanzu.vmware.com/kubernetesDistributionVersion" {
				foundProviders.tanzu = true
				stringProvider = "tanzu"
			}
		}

		for k := range node.ObjectMeta.Annotations {
			if k == "rke2.io/node-args" {
				foundProviders.rke2 = true
				stringProvider = "rke2"
			}
		}

		if node.Status.NodeInfo.OSImage == "Docker Desktop" {
			foundProviders.dockerDesktop = true
			stringProvider = "dockerDesktop"
		}

		if strings.HasPrefix(node.Spec.ProviderID, "digitalocean:") {
			foundProviders.digitalOcean = true
			stringProvider = "digitalOcean"
		}
		if strings.HasPrefix(node.Spec.ProviderID, "aws:") {
			foundProviders.eks = true
			stringProvider = "eks"
		}
		if strings.HasPrefix(node.Spec.ProviderID, "gce:") {
			foundProviders.gke = true
			stringProvider = "gke"
		}
		if strings.HasPrefix(node.Spec.ProviderID, "ibm:") {
			foundProviders.ibm = true
			stringProvider = "ibm"
		}
		if strings.HasPrefix(node.Spec.ProviderID, "kind:") {
			foundProviders.kind = true
			stringProvider = "kind"
		}
	}

	if foundMaster {
		// eks does not have masters within the node list
		foundProviders.eks = false
		if stringProvider == "eks" {
			stringProvider = ""
		}
	}

	// If k0s and embedded-cluster are both found, prefer embedded-cluster
	if foundProviders.k0s && foundProviders.embeddedCluster {
		stringProvider = "embedded-cluster"
	}

	return foundProviders, stringProvider
}

func (a *AnalyzeDistribution) analyzeDistribution(analyzer *troubleshootv1beta2.Distribution, getCollectedFileContents func(string) ([]byte, error)) (*AnalyzeResult, error) {
	var unknownDistribution string
	collected, err := getCollectedFileContents(fmt.Sprintf("%s/%s.json", constants.CLUSTER_RESOURCES_DIR, constants.CLUSTER_RESOURCES_NODES))
	if err != nil {
		return nil, errors.Wrap(err, fmt.Sprintf("failed to get contents of %s.json", constants.CLUSTER_RESOURCES_NODES))
	}

	var nodes corev1.NodeList
	if err := json.Unmarshal(collected, &nodes); err != nil {
		return nil, errors.Wrap(err, "failed to unmarshal node list")
	}

	foundProviders, _ := ParseNodesForProviders(nodes.Items)

	apiResourcesBytes, err := getCollectedFileContents(fmt.Sprintf("%s/%s.json", constants.CLUSTER_RESOURCES_DIR, constants.CLUSTER_RESOURCES_RESOURCES))
	// if the file is not found, that is not a fatal error
	// troubleshoot 0.9.15 and earlier did not collect that file
	if err == nil {
		var apiResources []*metav1.APIResourceList
		if err := json.Unmarshal(apiResourcesBytes, &apiResources); err != nil {
			return nil, errors.Wrap(err, "failed to unmarshal api resource list")
		}
		_ = CheckApiResourcesForProviders(&foundProviders, apiResources, "")
	}

	result := &AnalyzeResult{
		Title:   a.Title(),
		IconKey: "kubernetes_distribution",
		IconURI: "https://troubleshoot.sh/images/analyzer-icons/distribution.svg?w=20&h=14",
	}

	// ordering is important for passthrough
	for _, outcome := range analyzer.Outcomes {
		if outcome.Fail != nil {
			if outcome.Fail.When == "" {
				result.IsFail = true
				result.Message = outcome.Fail.Message
				result.URI = outcome.Fail.URI

				return result, nil
			}

			isMatch, err := compareDistributionConditionalToActual(outcome.Fail.When, foundProviders, &unknownDistribution)
			if err != nil {
				return result, errors.Wrap(err, "failed to compare distribution conditional")
			}

			if isMatch {
				result.IsFail = true
				result.Message = outcome.Fail.Message
				result.URI = outcome.Fail.URI

				return result, nil
			}
		} else if outcome.Warn != nil {
			if outcome.Warn.When == "" {
				result.IsWarn = true
				result.Message = outcome.Warn.Message
				result.URI = outcome.Warn.URI

				return result, nil
			}

			isMatch, err := compareDistributionConditionalToActual(outcome.Warn.When, foundProviders, &unknownDistribution)
			if err != nil {
				return result, errors.Wrap(err, "failed to compare distribution conditional")
			}

			if isMatch {
				result.IsWarn = true
				result.Message = outcome.Warn.Message
				result.URI = outcome.Warn.URI

				return result, nil
			}
		} else if outcome.Pass != nil {
			if outcome.Pass.When == "" {
				result.IsPass = true
				result.Message = outcome.Pass.Message
				result.URI = outcome.Pass.URI

				return result, nil
			}

			isMatch, err := compareDistributionConditionalToActual(outcome.Pass.When, foundProviders, &unknownDistribution)
			if err != nil {
				return result, errors.Wrap(err, "failed to compare distribution conditional")
			}

			if isMatch {
				result.IsPass = true
				result.Message = outcome.Pass.Message
				result.URI = outcome.Pass.URI

				return result, nil
			}

		}
	}

	result.IsWarn = true
	if unknownDistribution != "" {
		result.Message = unknownDistribution
	} else {
		result.Message = "None of the conditionals were met"
	}

	return result, nil
}

func compareDistributionConditionalToActual(conditional string, actual providers, unknownDistribution *string) (bool, error) {
	parts := strings.Split(strings.TrimSpace(conditional), " ")

	// we can make this a lot more flexible
	if len(parts) == 1 {
		parts = []string{
			"=",
			parts[0],
		}
	}

	if len(parts) != 2 {
		return false, errors.New("unable to parse conditional")
	}

	normalizedName := mustNormalizeDistributionName(parts[1])

	if normalizedName == unknown {
		*unknownDistribution += fmt.Sprintf("- Unknown distribution: %s ", parts[1])
		return false, nil
	}

	isMatch := false
	switch normalizedName {
	case microk8s:
		isMatch = actual.microk8s
	case dockerDesktop:
		isMatch = actual.dockerDesktop
	case eks:
		isMatch = actual.eks
	case gke:
		isMatch = actual.gke
	case digitalOcean:
		isMatch = actual.digitalOcean
	case openShift:
		isMatch = actual.openShift
	case kurl:
		isMatch = actual.kurl
	case aks:
		isMatch = actual.aks
	case ibm:
		isMatch = actual.ibm
	case minikube:
		isMatch = actual.minikube
	case rke2:
		isMatch = actual.rke2
	case k3s:
		isMatch = actual.k3s
	case oke:
		isMatch = actual.oke
	case kind:
		isMatch = actual.kind
	case k0s:
		isMatch = actual.k0s
	case embeddedCluster:
		isMatch = actual.embeddedCluster
	}

	switch parts[0] {
	case "=", "==", "===":
		return isMatch, nil
	case "!=", "!==":
		return !isMatch, nil
	}

	return false, nil
}

func mustNormalizeDistributionName(raw string) Provider {
	switch strings.ReplaceAll(strings.TrimSpace(strings.ToLower(raw)), "-", "") {
	case "microk8s":
		return microk8s
	case "dockerdesktop", "docker desktop", "docker-desktop":
		return dockerDesktop
	case "eks":
		return eks
	case "gke":
		return gke
	case "digitalocean":
		return digitalOcean
	case "openshift":
		return openShift
	case "tanzu":
		return tanzu
	case "kurl":
		return kurl
	case "aks":
		return aks
	case "ibm", "ibmcloud", "ibm cloud":
		return ibm
	case "minikube":
		return minikube
	case "rke2":
		return rke2
	case "k3s":
		return k3s
	case "oke":
		return oke
	case "kind":
		return kind
	case "k0s":
		return k0s
	case "embeddedcluster":
		return embeddedCluster
	}

	return unknown
}