// SPDX-License-Identifier: Apache-2.0
// Copyright Authors of Cilium

package v2

import (
	"fmt"
	"log/slog"

	v1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"

	"github.com/cilium/cilium/pkg/comparator"
	k8sCiliumUtils "github.com/cilium/cilium/pkg/k8s/apis/cilium.io/utils"
	slimv1 "github.com/cilium/cilium/pkg/k8s/slim/k8s/apis/meta/v1"
	k8sUtils "github.com/cilium/cilium/pkg/k8s/utils"
	"github.com/cilium/cilium/pkg/labels"
	"github.com/cilium/cilium/pkg/policy/api"
)

// +genclient
// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
// +deepequal-gen:private-method=true
// +kubebuilder:resource:categories={cilium,ciliumpolicy},singular="ciliumnetworkpolicy",path="ciliumnetworkpolicies",scope="Namespaced",shortName={cnp,ciliumnp}
// +kubebuilder:printcolumn:JSONPath=".metadata.creationTimestamp",name="Age",type=date
// +kubebuilder:printcolumn:JSONPath=".status.conditions[?(@.type=='Valid')].status",name="Valid",type=string
// +kubebuilder:subresource:status
// +kubebuilder:storageversion

// CiliumNetworkPolicy is a Kubernetes third-party resource with an extended
// version of NetworkPolicy.
type CiliumNetworkPolicy struct {
	// +deepequal-gen=false
	metav1.TypeMeta `json:",inline"`
	// +deepequal-gen=false
	metav1.ObjectMeta `json:"metadata"`

	// Spec is the desired Cilium specific rule specification.
	Spec *api.Rule `json:"spec,omitempty"`

	// Specs is a list of desired Cilium specific rule specification.
	Specs api.Rules `json:"specs,omitempty"`

	// Status is the status of the Cilium policy rule
	//
	// +deepequal-gen=false
	// +kubebuilder:validation:Optional
	Status CiliumNetworkPolicyStatus `json:"status"`
}

// DeepEqual compares 2 CNPs.
func (in *CiliumNetworkPolicy) DeepEqual(other *CiliumNetworkPolicy) bool {
	return objectMetaDeepEqual(in.ObjectMeta, other.ObjectMeta) && in.deepEqual(other)
}

// objectMetaDeepEqual performs an equality check for metav1.ObjectMeta that
// ignores the LastAppliedConfigAnnotation. This function's usage is shared
// among CNP and CCNP as they have the same structure.
func objectMetaDeepEqual(in, other metav1.ObjectMeta) bool {
	if !(in.Name == other.Name && in.Namespace == other.Namespace) {
		return false
	}

	return comparator.MapStringEqualsIgnoreKeys(
		in.GetAnnotations(),
		other.GetAnnotations(),
		// Ignore v1.LastAppliedConfigAnnotation annotation
		[]string{v1.LastAppliedConfigAnnotation})
}

// +deepequal-gen=true

// CiliumNetworkPolicyStatus is the status of a Cilium policy rule.
type CiliumNetworkPolicyStatus struct {

	// DerivativePolicies is the status of all policies derived from the Cilium
	// policy
	DerivativePolicies map[string]CiliumNetworkPolicyNodeStatus `json:"derivativePolicies,omitempty"`

	// +optional
	// +patchMergeKey=type
	// +patchStrategy=merge
	// +listType=map
	// +listMapKey=type
	Conditions []NetworkPolicyCondition `json:"conditions,omitempty"`
}

// +deepequal-gen=true

// CiliumNetworkPolicyNodeStatus is the status of a Cilium policy rule for a
// specific node.
type CiliumNetworkPolicyNodeStatus struct {
	// OK is true when the policy has been parsed and imported successfully
	// into the in-memory policy repository on the node.
	OK bool `json:"ok,omitempty"`

	// Error describes any error that occurred when parsing or importing the
	// policy, or realizing the policy for the endpoints to which it applies
	// on the node.
	Error string `json:"error,omitempty"`

	// LastUpdated contains the last time this status was updated
	LastUpdated slimv1.Time `json:"lastUpdated,omitempty"`

	// Revision is the policy revision of the repository which first implemented
	// this policy.
	Revision uint64 `json:"localPolicyRevision,omitempty"`

	// Enforcing is set to true once all endpoints present at the time the
	// policy has been imported are enforcing this policy.
	Enforcing bool `json:"enforcing,omitempty"`

	// Annotations corresponds to the Annotations in the ObjectMeta of the CNP
	// that have been realized on the node for CNP. That is, if a CNP has been
	// imported and has been assigned annotation X=Y by the user,
	// Annotations in CiliumNetworkPolicyNodeStatus will be X=Y once the
	// CNP that was imported corresponding to Annotation X=Y has been realized on
	// the node.
	Annotations map[string]string `json:"annotations,omitempty"`
}

// CreateCNPNodeStatus returns a CiliumNetworkPolicyNodeStatus created from the
// provided fields.
func CreateCNPNodeStatus(enforcing, ok bool, cnpError error, rev uint64, annotations map[string]string) CiliumNetworkPolicyNodeStatus {
	cnpns := CiliumNetworkPolicyNodeStatus{
		Enforcing:   enforcing,
		Revision:    rev,
		OK:          ok,
		LastUpdated: slimv1.Now(),
		Annotations: annotations,
	}
	if cnpError != nil {
		cnpns.Error = cnpError.Error()
	}
	return cnpns
}

func (r *CiliumNetworkPolicy) String() string {
	result := ""
	result += fmt.Sprintf("TypeMeta: %s, ", r.TypeMeta.String())
	result += fmt.Sprintf("ObjectMeta: %s, ", r.ObjectMeta.String())
	if r.Spec != nil {
		result += fmt.Sprintf("Spec: %v", *(r.Spec))
	}
	if r.Specs != nil {
		result += fmt.Sprintf("Specs: %v", r.Specs)
	}
	result += fmt.Sprintf("Status: %v", r.Status)
	return result
}

// SetDerivedPolicyStatus set the derivative policy status for the given
// derivative policy name.
func (r *CiliumNetworkPolicy) SetDerivedPolicyStatus(derivativePolicyName string, status CiliumNetworkPolicyNodeStatus) {
	if r.Status.DerivativePolicies == nil {
		r.Status.DerivativePolicies = map[string]CiliumNetworkPolicyNodeStatus{}
	}
	r.Status.DerivativePolicies[derivativePolicyName] = status
}

// Parse parses a CiliumNetworkPolicy and returns a list of cilium policy
// rules.
func (r *CiliumNetworkPolicy) Parse(logger *slog.Logger, clusterName string) (api.Rules, error) {
	if r.ObjectMeta.Name == "" {
		return nil, NewErrParse("CiliumNetworkPolicy must have name")
	}

	namespace := k8sUtils.ExtractNamespace(&r.ObjectMeta)
	// Temporary fix for CCNPs. See #12834.
	// TL;DR. CCNPs are converted into SlimCNPs and end up here so we need to
	// convert them back to CCNPs to allow proper parsing.
	if namespace == "" {
		ccnp := CiliumClusterwideNetworkPolicy{
			TypeMeta:   r.TypeMeta,
			ObjectMeta: r.ObjectMeta,
			Spec:       r.Spec,
			Specs:      r.Specs,
			Status:     r.Status,
		}
		return ccnp.Parse(logger, clusterName)
	}
	name := r.ObjectMeta.Name
	uid := r.ObjectMeta.UID

	retRules := api.Rules{}

	if r.Spec == nil && r.Specs == nil {
		return nil, ErrEmptyCNP
	}

	if r.Spec != nil {
		if err := r.Spec.Sanitize(); err != nil {
			return nil, NewErrParse(fmt.Sprintf("Invalid CiliumNetworkPolicy spec: %s", err))
		}
		if r.Spec.NodeSelector.LabelSelector != nil {
			return nil, NewErrParse("Invalid CiliumNetworkPolicy spec: rule cannot have NodeSelector")
		}
		cr := k8sCiliumUtils.ParseToCiliumRule(logger, clusterName, namespace, name, uid, r.Spec)
		retRules = append(retRules, cr)
	}
	if r.Specs != nil {
		for _, rule := range r.Specs {
			if err := rule.Sanitize(); err != nil {
				return nil, NewErrParse(fmt.Sprintf("Invalid CiliumNetworkPolicy specs: %s", err))
			}
			if rule.NodeSelector.LabelSelector != nil {
				return nil, NewErrParse("Invalid CiliumNetworkPolicy spec: rule cannot have NodeSelector")
			}
			cr := k8sCiliumUtils.ParseToCiliumRule(logger, clusterName, namespace, name, uid, rule)
			retRules = append(retRules, cr)
		}
	}

	return retRules, nil
}

// GetIdentityLabels returns all rule labels in the CiliumNetworkPolicy.
func (r *CiliumNetworkPolicy) GetIdentityLabels() labels.LabelArray {
	namespace := k8sUtils.ExtractNamespace(&r.ObjectMeta)
	name := r.ObjectMeta.Name
	uid := r.ObjectMeta.UID

	// Even though the struct represents CiliumNetworkPolicy, we use it both for
	// CiliumNetworkPolicy and CiliumClusterwideNetworkPolicy, so here we check for namespace
	// to send correct derivedFrom label to get the correct policy labels.
	derivedFrom := k8sCiliumUtils.ResourceTypeCiliumNetworkPolicy
	if namespace == "" {
		derivedFrom = k8sCiliumUtils.ResourceTypeCiliumClusterwideNetworkPolicy
	}
	return k8sCiliumUtils.GetPolicyLabels(namespace, name, uid, derivedFrom)
}

// RequiresDerivative return true if the CNP has any rule that will create a new
// derivative rule.
func (r *CiliumNetworkPolicy) RequiresDerivative() bool {
	if r.Spec != nil {
		if r.Spec.RequiresDerivative() {
			return true
		}
	}
	if r.Specs != nil {
		for _, rule := range r.Specs {
			if rule.RequiresDerivative() {
				return true
			}
		}
	}
	return false
}

// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
// +k8s:openapi-gen=false
// +deepequal-gen=false

// CiliumNetworkPolicyList is a list of CiliumNetworkPolicy objects.
type CiliumNetworkPolicyList struct {
	metav1.TypeMeta `json:",inline"`
	metav1.ListMeta `json:"metadata"`

	// Items is a list of CiliumNetworkPolicy
	Items []CiliumNetworkPolicy `json:"items"`
}

type PolicyConditionType string

const (
	PolicyConditionValid PolicyConditionType = "Valid"
)

type NetworkPolicyCondition struct {
	// The type of the policy condition
	Type PolicyConditionType `json:"type"`
	// The status of the condition, one of True, False, or Unknown
	Status v1.ConditionStatus `json:"status"`
	// The last time the condition transitioned from one status to another.
	// +optional
	LastTransitionTime slimv1.Time `json:"lastTransitionTime,omitempty"`
	// The reason for the condition's last transition.
	// +optional
	Reason string `json:"reason,omitempty"`
	// A human readable message indicating details about the transition.
	// +optional
	Message string `json:"message,omitempty"`
}
