package violation

import (
	"errors"
	"fmt"
	"reflect"

	"github.com/golang/glog"
	v1alpha1 "github.com/nirmata/kyverno/pkg/apis/policy/v1alpha1"
	lister "github.com/nirmata/kyverno/pkg/client/listers/policy/v1alpha1"
	client "github.com/nirmata/kyverno/pkg/dclient"
	event "github.com/nirmata/kyverno/pkg/event"
	"github.com/nirmata/kyverno/pkg/info"
	"github.com/nirmata/kyverno/pkg/sharedinformer"
	"k8s.io/apimachinery/pkg/runtime"
)

//Generator to generate policy violation
type Generator interface {
	Add(infos ...*Info) error
	RemoveInactiveViolation(policy, rKind, rNs, rName string, ruleType info.RuleType) error
	ResourceRemoval(policy, rKind, rNs, rName string) error
}

type builder struct {
	client       *client.Client
	policyLister lister.PolicyLister
	eventBuilder event.Generator
}

//Builder is to build policy violations
type Builder interface {
	Generator
	processViolation(info *Info) error
	isActive(kind string, rname string, rnamespace string) (bool, error)
}

//NewPolicyViolationBuilder returns new violation builder
func NewPolicyViolationBuilder(client *client.Client,
	sharedInfomer sharedinformer.PolicyInformer,
	eventController event.Generator) Builder {

	builder := &builder{
		client:       client,
		policyLister: sharedInfomer.GetLister(),
		eventBuilder: eventController,
	}
	return builder
}

func (b *builder) Add(infos ...*Info) error {
	if infos == nil {
		return nil
	}
	for _, info := range infos {
		return b.processViolation(info)
	}
	return nil
}

func (b *builder) processViolation(info *Info) error {
	statusMap := map[string]interface{}{}
	violationsMap := map[string]interface{}{}
	violationMap := map[string]interface{}{}
	var violations interface{}
	var violation interface{}
	// Get Policy
	obj, err := b.client.GetResource("Policy", "", info.Policy, "status")
	if err != nil {
		return err
	}
	unstr := obj.UnstructuredContent()
	// get "status" subresource
	status, ok := unstr["status"]
	if ok {
		// status exists
		// status is already present then we append violations
		if statusMap, ok = status.(map[string]interface{}); !ok {
			return errors.New("Unable to parse status subresource")
		}
		// get policy violations
		violations, ok = statusMap["violations"]
		if !ok {
			return nil
		}
		violationsMap, ok = violations.(map[string]interface{})
		if !ok {
			return errors.New("Unable to get status.violations subresource")
		}
		// check if the resource has a violation
		violation, ok = violationsMap[info.getKey()]
		if !ok {
			// add resource violation
			violationsMap[info.getKey()] = info.Violation
			statusMap["violations"] = violationsMap
			unstr["status"] = statusMap
		} else {
			violationMap, ok = violation.(map[string]interface{})
			if !ok {
				return errors.New("Unable to get status.violations.violation subresource")
			}
			// we check if the new violation updates are different from stored violation info
			v := v1alpha1.Violation{}
			err := runtime.DefaultUnstructuredConverter.FromUnstructured(violationMap, &v)
			if err != nil {
				return err
			}
			// compare v & info.Violation
			if v.IsEqual(info.Violation) {
				// no updates to violation
				// do nothing
				return nil
			}
			// update the violation
			violationsMap[info.getKey()] = info.Violation
			statusMap["violations"] = violationsMap
			unstr["status"] = statusMap
		}
	} else {
		violationsMap[info.getKey()] = info.Violation
		statusMap["violations"] = violationsMap
		unstr["status"] = statusMap
	}

	obj.SetUnstructuredContent(unstr)
	// update the status sub-resource for policy
	_, err = b.client.UpdateStatusResource("Policy", "", obj, false)
	if err != nil {
		return err
	}
	return nil
}

func (b *builder) RemoveInactiveViolation(policy, rKind, rNs, rName string, ruleType info.RuleType) error {
	statusMap := map[string]interface{}{}
	violationsMap := map[string]interface{}{}
	violationMap := map[string]interface{}{}
	var violations interface{}
	var violation interface{}
	// Get Policy
	obj, err := b.client.GetResource("Policy", "", policy, "status")
	if err != nil {
		return err
	}
	unstr := obj.UnstructuredContent()
	// get "status" subresource
	status, ok := unstr["status"]
	if !ok {
		return nil
	}
	// status exists
	// status is already present then we append violations
	if statusMap, ok = status.(map[string]interface{}); !ok {
		return errors.New("Unable to parse status subresource")
	}
	// get policy violations
	violations, ok = statusMap["violations"]
	if !ok {
		return nil
	}
	violationsMap, ok = violations.(map[string]interface{})
	if !ok {
		return errors.New("Unable to get status.violations subresource")
	}
	// check if the resource has a violation
	violation, ok = violationsMap[BuildKey(rKind, rNs, rName)]
	if !ok {
		// no violation for this resource
		return nil
	}
	violationMap, ok = violation.(map[string]interface{})
	if !ok {
		return errors.New("Unable to get status.violations.violation subresource")
	}
	// check remove the rules of the given type
	// this is called when the policy is applied succesfully, so we can remove the previous failed rules
	// if all rules are to be removed, the deleted the violation
	v := v1alpha1.Violation{}
	err = runtime.DefaultUnstructuredConverter.FromUnstructured(violationMap, &v)
	if err != nil {
		return err
	}
	if !v.RemoveRulesOfType(ruleType.String()) {
		// no rule of given type found,
		// no need to remove rule
		return nil
	}
	// if there are no faile rules remove the violation
	if len(v.Rules) == 0 {
		delete(violationsMap, BuildKey(rKind, rNs, rName))
	} else {
		// update the rules
		violationsMap[BuildKey(rKind, rNs, rName)] = v
	}
	statusMap["violations"] = violationsMap
	unstr["status"] = statusMap

	obj.SetUnstructuredContent(unstr)
	// update the status sub-resource for policy
	_, err = b.client.UpdateStatusResource("Policy", "", obj, false)
	if err != nil {
		return err
	}
	return nil
}

func (b *builder) ResourceRemoval(policy, rKind, rNs, rName string) error {
	statusMap := map[string]interface{}{}
	violationsMap := map[string]interface{}{}
	var violations interface{}
	// Get Policy
	obj, err := b.client.GetResource("Policy", "", policy, "status")
	if err != nil {
		return err
	}
	unstr := obj.UnstructuredContent()
	// get "status" subresource
	status, ok := unstr["status"]
	if !ok {
		return nil
	}
	// status exists
	// status is already present then we append violations
	if statusMap, ok = status.(map[string]interface{}); !ok {
		return errors.New("Unable to parse status subresource")
	}
	// get policy violations
	violations, ok = statusMap["violations"]
	if !ok {
		return nil
	}
	violationsMap, ok = violations.(map[string]interface{})
	if !ok {
		return errors.New("Unable to get status.violations subresource")
	}

	// check if the resource has a violation
	_, ok = violationsMap[BuildKey(rKind, rNs, rName)]
	if !ok {
		// no violation for this resource
		return nil
	}
	// remove the pair from the map
	delete(violationsMap, BuildKey(rKind, rNs, rName))
	if len(violationsMap) == 0 {
		delete(statusMap, "violations")
	} else {
		statusMap["violations"] = violationsMap
	}
	unstr["status"] = statusMap

	obj.SetUnstructuredContent(unstr)
	// update the status sub-resource for policy
	_, err = b.client.UpdateStatusResource("Policy", "", obj, false)
	if err != nil {
		return err
	}
	return nil
}

// func (b *builder) processViolation(info *Info) error {
// 	currVs := map[string]interface{}{}
// 	statusMap := map[string]interface{}{}
// 	var ok bool
// 	//TODO: hack get from client
// 	p1, err := b.client.GetResource("Policy", "", info.Policy, "status")
// 	if err != nil {
// 		return err
// 	}
// 	unstr := p1.UnstructuredContent()
// 	// check if "status" field exists
// 	status, ok := unstr["status"]
// 	if ok {
// 		// status is already present then we append violations
// 		if statusMap, ok = status.(map[string]interface{}); !ok {
// 			return errors.New("Unable to parse status subresource")
// 		}
// 		violations, ok := statusMap["violations"]
// 		if !ok {
// 			glog.Info("violation not present")
// 		}
// 		// Violations map[string][]Violations
// 		glog.Info(reflect.TypeOf(violations))
// 		if currVs, ok = violations.(map[string]interface{}); !ok {
// 			return errors.New("Unable to parse violations")
// 		}
// 	}
// 	// Info:
// 	// Key - Kind, Namespace, Name
// 	// policy - Name
// 	//	violation, ok := currVs[info.getKey()]
// 	// Key -> resource
// 	// 1> Check if there were any previous violations for the given key
// 	// 2> If No, create a new one
// 	if !ok {
// 		currVs[info.getKey()] = info.Violation
// 	} else {
// 		currV := currVs[info.getKey()]
// 		glog.Info(reflect.TypeOf(currV))
// 		v, ok := currV.(map[string]interface{})
// 		if !ok {
// 			glog.Info("type not matching")
// 		}
// 		// get rules
// 		rules, ok := v["rules"]
// 		if !ok {
// 			glog.Info("rules not found")
// 		}
// 		glog.Info(reflect.TypeOf(rules))
// 		rs, ok := rules.([]interface{})
// 		if !ok {
// 			glog.Info("type not matching")
// 		}
// 		// check if rules are samre
// 		if isRuleNamesEqual(rs, info.Violation.Rules) {
// 			return nil
// 		}
// 		// else update the errors
// 		currVs[info.getKey()] = info.Violation
// 	}
// 	// newViolation := info.Violation
// 	// for _, violation := range currentViolations {
// 	// 	glog.Info(reflect.TypeOf(violation))
// 	// 	if v, ok := violation.(map[string]interface{}); ok {
// 	// 		if name, ok := v["name"].(string); ok {
// 	// 			if namespace, ok := v["namespace"].(string); ok {
// 	// 				ok, err := b.isActive(info.Kind, name, namespace)
// 	// 				if err != nil {
// 	// 					glog.Error(err)
// 	// 					continue
// 	// 				}
// 	// 				if !ok {
// 	// 					//TODO remove the violation as it corresponds to resource that does not exist
// 	// 					glog.Info("removed violation")
// 	// 				}
// 	// 			}
// 	// 		}
// 	// 	}
// 	// }
// 	// currentViolations = append(currentViolations, newViolation)
// 	// // update violations
// 	// set the updated status
// 	statusMap["violations"] = currVs
// 	unstr["status"] = statusMap
// 	p1.SetUnstructuredContent(unstr)
// 	_, err = b.client.UpdateStatusResource("Policy", "", p1, false)
// 	if err != nil {
// 		return err
// 	}
// 	return nil
// }

func (b *builder) isActive(kind, rname, rnamespace string) (bool, error) {
	// Generate Merge Patch
	_, err := b.client.GetResource(b.client.DiscoveryClient.GetGVRFromKind(kind).Resource, rnamespace, rname)
	if err != nil {
		glog.Errorf("unable to get resource %s/%s ", rnamespace, rname)
		return false, err
	}
	return true, nil
}

//NewViolation return new policy violation
func NewViolation(reason event.Reason, policyName, kind, rname, rnamespace, msg string) *Info {
	return &Info{Policy: policyName,
		Violation: v1alpha1.Violation{
			Kind:      kind,
			Name:      rname,
			Namespace: rnamespace,
			Reason:    reason.String(),
		},
	}
}

// //NewViolationFromEvent returns violation info from event
// func NewViolationFromEvent(e *event.Info, pName, rKind, rName, rnamespace string) *Info {
// 	return &Info{
// 		Policy: pName,
// 		Violation: types.Violation{
// 			Kind:      rKind,
// 			Name:      rName,
// 			Namespace: rnamespace,
// 			Reason:    e.Reason,
// 			Message:   e.Message,
// 		},
// 	}
// }
// Build a new Violation
func BuldNewViolation(pName string, rKind string, rNs string, rName string, reason string, frules []v1alpha1.FailedRule) *Info {
	return &Info{
		Policy: pName,
		Violation: v1alpha1.Violation{
			Kind:      rKind,
			Namespace: rNs,
			Name:      rName,
			Reason:    reason,
			Rules:     frules,
		},
	}
}

func removeRuleTypes(currRules []interface{}, ruleType info.RuleType) ([]interface{}, error) {
	//rules := []v1alpha1.FailedRule{}
	var rules []interface{}
	// removedRuleCount := 0
	for _, r := range currRules {
		glog.Info(reflect.TypeOf(r))
		rfule, ok := r.(map[string]interface{})
		if !ok {
			return nil, fmt.Errorf("incorrect type")
		}
		glog.Info(reflect.TypeOf(rfule["type"]))
		rtype, ok := rfule["type"].(string)
		if !ok {
			return nil, fmt.Errorf("incorrect type")
		}
		name, ok := rfule["name"].(string)
		if !ok {
			return nil, fmt.Errorf("incorrect type")
		}
		if rtype != ruleType.String() {
			rules = append(rules, v1alpha1.FailedRule{Name: name, Type: rtype})
		}
	}
	return rules, nil
}

func isRuleNamesEqual(currRules []interface{}, newRules []v1alpha1.FailedRule) bool {
	if len(currRules) != len(newRules) {
		return false
	}
	for i, r := range currRules {
		glog.Info(reflect.TypeOf(r))
		rfule, ok := r.(map[string]interface{})
		if !ok {
			return false
		}
		glog.Info(reflect.TypeOf(rfule["name"]))
		// name
		name, ok := rfule["name"].(string)
		if !ok {
			return false
		}
		if name != newRules[i].Name {
			return false
		}
		// type

		rtype, ok := rfule["type"].(string)
		if !ok {
			return false
		}
		if rtype != newRules[i].Type {
			return false
		}

	}
	return true
}

// //RemoveViolation will remove the violation for the resource if there was one
// func (b *builder) RemoveInactiveViolation(policy, rKind, rNs, rName string, ruleType info.RuleType) error {
// 	// Remove the <resource, Violation> pair from map
// 	statusMap := map[string]interface{}{}
// 	currVs := map[string]interface{}{}
// 	// Get the policy
// 	p, err := b.client.GetResource("Policy", "", policy, "status")
// 	if err != nil {
// 		glog.Infof("policy %s not found", policy)
// 		return err
// 	}
// 	unstr := p.UnstructuredContent()

// 	// check if "status" field exists
// 	status, ok := unstr["status"]
// 	if ok {
// 		// status is already present then we append violations
// 		if statusMap, ok = status.(map[string]interface{}); !ok {
// 			return errors.New("Unable to parse status subresource")
// 		}
// 		violations, ok := statusMap["violations"]
// 		if !ok {
// 			glog.Info("violation not present")
// 		}
// 		glog.Info(reflect.TypeOf(violations))
// 		if currVs, ok = violations.(map[string]interface{}); !ok {
// 			return errors.New("Unable to parse violations")
// 		}
// 		currV, ok := currVs[BuildKey(rKind, rNs, rName)]
// 		if !ok {
// 			// No Violation present
// 			return nil
// 		}
// 		glog.Info(reflect.TypeOf(currV))
// 		v, ok := currV.(map[string]interface{})
// 		if !ok {
// 			glog.Info("type not matching")
// 		}
// 		// get rules
// 		rules, ok := v["rules"]
// 		if !ok {
// 			glog.Info("rules not found")
// 		}
// 		glog.Info(reflect.TypeOf(rules))
// 		rs, ok := rules.([]interface{})
// 		if !ok {
// 			glog.Info("type not matching")
// 		}
// 		// Remove rules of defined type
// 		newrs, err := removeRuleTypes(rs, ruleType)
// 		if err != nil {
// 			glog.Info(err)
// 		}
// 		if newrs == nil {
// 			// all records are removed and is empty
// 			glog.Info("can remove the record")
// 			delete(currVs, BuildKey(rKind, rNs, rName))
// 		} else {
// 			v["rules"] = newrs
// 			// update the violation with new rule
// 			currVs[BuildKey(rKind, rNs, rName)] = v
// 		}
// 		// update violations
// 		statusMap["violations"] = currVs
// 		// update status
// 		unstr["status"] = statusMap
// 		p.SetUnstructuredContent(unstr)
// 		_, err = b.client.UpdateStatusResource("Policy", "", p, false)
// 		if err != nil {
// 			return err
// 		}
// 	}
// 	return nil
// }

// func (b *builder) ResourceRemoval(policy, rKind, rNs, rName string) error {
// 	// Remove the <resource, Violation> pair from map
// 	statusMap := map[string]interface{}{}
// 	currVs := map[string]interface{}{}
// 	// Get the policy
// 	p, err := b.client.GetResource("Policy", "", policy, "status")
// 	if err != nil {
// 		glog.Infof("policy %s not found", policy)
// 		return err
// 	}
// 	unstr := p.UnstructuredContent()
// 	// check if "status" field exists
// 	status, ok := unstr["status"]
// 	if ok {
// 		// status is already present then we append violations
// 		if statusMap, ok = status.(map[string]interface{}); !ok {
// 			return errors.New("Unable to parse status subresource")
// 		}
// 		violations, ok := statusMap["violations"]
// 		if !ok {
// 			glog.Info("violation not present")
// 		}
// 		glog.Info(reflect.TypeOf(violations))
// 		if currVs, ok = violations.(map[string]interface{}); !ok {
// 			return errors.New("Unable to parse violations")
// 		}
// 		_, ok = currVs[BuildKey(rKind, rNs, rName)]
// 		if !ok {
// 			// No Violation for this resource
// 			return nil
// 		}
// 		// remove the pair from the map
// 		delete(currVs, BuildKey(rKind, rNs, rName))
// 		glog.Info("Removed Violation")
// 		// update violations
// 		statusMap["violations"] = currVs
// 		// update status
// 		unstr["status"] = statusMap
// 		p.SetUnstructuredContent(unstr)
// 		_, err = b.client.UpdateStatusResource("Policy", "", p, false)
// 		if err != nil {
// 			return err
// 		}
// 	}
// 	return nil
// }