/*
Copyright 2021 The KubeVela Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package appfile

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

	"github.com/kubevela/pkg/multicluster"
	"github.com/pkg/errors"
	kerrors "k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/api/meta"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
	"k8s.io/apimachinery/pkg/runtime"
	"sigs.k8s.io/controller-runtime/pkg/client"

	"github.com/oam-dev/kubevela/pkg/cue/definition/health"
	"github.com/oam-dev/kubevela/pkg/cue/upgrade"

	"github.com/oam-dev/kubevela/apis/core.oam.dev/common"
	"github.com/oam-dev/kubevela/apis/core.oam.dev/v1beta1"
	"github.com/oam-dev/kubevela/apis/types"
	oamutil "github.com/oam-dev/kubevela/pkg/oam/util"
)

const (
	// UsageTag is usage comment annotation
	UsageTag = "+usage="
	// ShortTag is the short alias annotation
	ShortTag = "+short"
	// ImmutableTag marks a parameter field as immutable
	ImmutableTag = "+immutable"
)

// Template is a helper struct for processing capability including
// ComponentDefinition, TraitDefinition.
// It mainly collects schematic and status data of a capability definition.
type Template struct {
	TemplateStr        string
	Health             string
	CustomStatus       string
	Details            string
	CapabilityCategory types.CapabilityCategory
	Reference          common.WorkloadTypeDescriptor
	Terraform          *common.Terraform

	ComponentDefinition *v1beta1.ComponentDefinition
	WorkloadDefinition  *v1beta1.WorkloadDefinition
	TraitDefinition     *v1beta1.TraitDefinition

	PolicyDefinition       *v1beta1.PolicyDefinition
	WorkflowStepDefinition *v1beta1.WorkflowStepDefinition
}

// LoadTemplate gets the capability definition from cluster and resolve it.
// It returns a helper struct, Template, which will be used for further
// processing.
func LoadTemplate(ctx context.Context, cli client.Client, capName string, capType types.CapType, annotations map[string]string) (*Template, error) {
	ctx = multicluster.WithCluster(ctx, multicluster.Local)
	// Application Controller only loads template from ComponentDefinition and TraitDefinition
	switch capType {
	case types.TypeComponentDefinition, types.TypeWorkload:
		cd := new(v1beta1.ComponentDefinition)
		err := oamutil.GetCapabilityDefinition(ctx, cli, cd, capName, annotations)
		if err != nil {
			if kerrors.IsNotFound(err) {
				wd := new(v1beta1.WorkloadDefinition)
				if err := oamutil.GetDefinition(ctx, cli, wd, capName); err != nil {
					return nil, errors.WithMessagef(err, "load template from component definition [%s] ", capName)
				}
				tmpl, err := newTemplateOfWorkloadDefinition(wd)
				if err != nil {
					return nil, err
				}
				gvk, err := oamutil.GetGVKFromDefinition(cli.RESTMapper(), wd.Spec.Reference)
				if err != nil {
					return nil, errors.WithMessagef(err, "get group version kind from component definition [%s]", capName)
				}
				tmpl.Reference = common.WorkloadTypeDescriptor{
					Definition: common.WorkloadGVK{
						APIVersion: metav1.GroupVersion{
							Group:   gvk.Group,
							Version: gvk.Version,
						}.String(),
						Kind: gvk.Kind,
					},
				}
				return tmpl, nil
			}
			return nil, errors.WithMessagef(err, "load template from component definition [%s] ", capName)
		}
		tmpl, err := newTemplateOfCompDefinition(cd)
		if err != nil {
			return nil, err
		}
		return tmpl, nil

	case types.TypeTrait:
		td := new(v1beta1.TraitDefinition)
		err := oamutil.GetCapabilityDefinition(ctx, cli, td, capName, annotations)
		if err != nil {
			return nil, errors.WithMessagef(err, "load template from trait definition [%s] ", capName)
		}
		tmpl, err := newTemplateOfTraitDefinition(td)
		if err != nil {
			return nil, err
		}
		return tmpl, nil
	case types.TypePolicy:
		d := new(v1beta1.PolicyDefinition)
		err := oamutil.GetCapabilityDefinition(ctx, cli, d, capName, annotations)
		if err != nil {
			return nil, errors.WithMessagef(err, "load template from policy definition [%s] ", capName)
		}
		tmpl, err := newTemplateOfPolicyDefinition(d)
		if err != nil {
			return nil, err
		}
		return tmpl, nil
	case types.TypeWorkflowStep:
		d := new(v1beta1.WorkflowStepDefinition)
		err := oamutil.GetCapabilityDefinition(ctx, cli, d, capName, annotations)
		if err != nil {
			return nil, errors.WithMessagef(err, "load template from workflow step definition  [%s] ", capName)
		}
		tmpl, err := newTemplateOfWorkflowStepDefinition(d)
		if err != nil {
			return nil, err
		}
		return tmpl, nil
	}
	return nil, fmt.Errorf("kind(%s) of %s not supported", capType, capName)
}

// LoadTemplateFromRevision will load Definition template from app revision
func LoadTemplateFromRevision(capName string, capType types.CapType, apprev *v1beta1.ApplicationRevision, mapper meta.RESTMapper) (*Template, error) {
	if apprev == nil {
		return nil, errors.Errorf("fail to find template for %s as app revision is empty", capName)
	}
	capName = verifyRevisionName(capName, capType, apprev)
	switch capType {
	case types.TypeComponentDefinition:
		cd, ok := apprev.Spec.ComponentDefinitions[capName]
		if !ok {
			wd, ok := apprev.Spec.WorkloadDefinitions[capName]
			if !ok {
				return nil, errors.Errorf("component definition [%s] not found in app revision %s", capName, apprev.Name)
			}
			tmpl, err := newTemplateOfWorkloadDefinition(&wd)
			if err != nil {
				return nil, err
			}
			gvk, err := oamutil.GetGVKFromDefinition(mapper, wd.Spec.Reference)
			if err != nil {
				return nil, errors.WithMessagef(err, "Get group version kind from component definition [%s]", capName)
			}
			tmpl.Reference = common.WorkloadTypeDescriptor{
				Definition: common.WorkloadGVK{
					APIVersion: metav1.GroupVersion{
						Group:   gvk.Group,
						Version: gvk.Version,
					}.String(),
					Kind: gvk.Kind,
				},
			}
			return tmpl, nil
		}
		tmpl, err := newTemplateOfCompDefinition(cd.DeepCopy())
		if err != nil {
			return nil, err
		}
		return tmpl, nil

	case types.TypeTrait:
		td, ok := apprev.Spec.TraitDefinitions[capName]
		if !ok {
			return nil, errors.Errorf("TraitDefinition [%s] not found in app revision %s", capName, apprev.Name)
		}
		tmpl, err := newTemplateOfTraitDefinition(td.DeepCopy())
		if err != nil {
			return nil, err
		}
		return tmpl, nil
	case types.TypePolicy:
		d, ok := apprev.Spec.PolicyDefinitions[capName]
		if !ok {
			return nil, errors.Errorf("PolicyDefinition [%s] not found in app revision %s", capName, apprev.Name)
		}
		tmpl, err := newTemplateOfPolicyDefinition(d.DeepCopy())
		if err != nil {
			return nil, err
		}
		return tmpl, nil
	case types.TypeWorkflowStep:
		w, ok := apprev.Spec.WorkflowStepDefinitions[capName]
		if !ok {
			return nil, errors.Errorf("WorkflowStepDefinition [%s] not found in app revision %s", capName, apprev.Name)
		}
		tmpl, err := newTemplateOfWorkflowStepDefinition(w.DeepCopy())
		if err != nil {
			return nil, err
		}
		return tmpl, nil
	default:
		return nil, fmt.Errorf("kind(%s) of %s not supported", capType, capName)
	}
}

// IsNotFoundInAppRevision check if the error is `not found in app revision`
func IsNotFoundInAppRevision(err error) bool {
	return err != nil && strings.Contains(err.Error(), "not found in app revision")
}

func verifyRevisionName(capName string, capType types.CapType, apprev *v1beta1.ApplicationRevision) string {
	if strings.Contains(capName, "@") {
		splitName := capName[0:strings.LastIndex(capName, "@")]
		ok := false

		switch capType {
		case types.TypeComponentDefinition:
			_, ok = apprev.Spec.ComponentDefinitions[splitName]
		case types.TypeTrait:
			_, ok = apprev.Spec.TraitDefinitions[splitName]
		case types.TypePolicy:
			_, ok = apprev.Spec.PolicyDefinitions[splitName]
		case types.TypeWorkflowStep:
			_, ok = apprev.Spec.WorkflowStepDefinitions[splitName]
		default:
			return capName
		}

		if ok {
			return splitName
		}
	}

	return capName
}

// DryRunTemplateLoader return a function that do the same work as
// LoadTemplate, but load template from provided ones before loading from
// cluster through LoadTemplate
func DryRunTemplateLoader(defs []*unstructured.Unstructured) TemplateLoaderFn {
	return func(ctx context.Context, r client.Client, capName string, capType types.CapType, annotations map[string]string) (*Template, error) {
		// retrieve provided cap definitions
		for _, def := range defs {
			if def.GetKind() == v1beta1.ComponentDefinitionKind &&
				capType == types.TypeComponentDefinition && def.GetName() == capName {
				compDef := &v1beta1.ComponentDefinition{}
				if err := runtime.DefaultUnstructuredConverter.FromUnstructured(def.Object, compDef); err != nil {
					return nil, errors.Wrap(err, "invalid component definition")
				}
				tmpl, err := newTemplateOfCompDefinition(compDef)
				if err != nil {
					return nil, errors.WithMessagef(err, "cannot load template of component definition %q", capName)
				}
				return tmpl, nil
			}
			if def.GetKind() == v1beta1.TraitDefinitionKind &&
				capType == types.TypeTrait && def.GetName() == capName {
				traitDef := &v1beta1.TraitDefinition{}
				if err := runtime.DefaultUnstructuredConverter.FromUnstructured(def.Object, traitDef); err != nil {
					return nil, errors.Wrap(err, "invalid trait definition")
				}
				tmpl, err := newTemplateOfTraitDefinition(traitDef)
				if err != nil {
					return nil, errors.WithMessagef(err, "cannot load template of trait definition %q", capName)
				}
				return tmpl, nil
			}
		}
		// not found in provided cap definitions
		// then try to retrieve from cluster
		tmpl, err := LoadTemplate(ctx, r, capName, capType, annotations)
		if err != nil {
			return nil, errors.WithMessagef(err, "cannot load template %q from cluster and provided ones", capName)
		}
		return tmpl, nil
	}
}

func newTemplateOfCompDefinition(compDef *v1beta1.ComponentDefinition) (*Template, error) {
	tmpl := &Template{
		Reference:           compDef.Spec.Workload,
		ComponentDefinition: compDef,
	}
	if err := loadSchematicToTemplate(tmpl, compDef.Spec.Status, compDef.Spec.Schematic, compDef.Spec.Extension); err != nil {
		return nil, errors.WithMessage(err, "cannot load template")
	}
	if compDef.Annotations["type"] == string(types.TerraformCategory) {
		tmpl.CapabilityCategory = types.TerraformCategory
	}
	return tmpl, nil
}

func newTemplateOfTraitDefinition(traitDef *v1beta1.TraitDefinition) (*Template, error) {
	tmpl := &Template{
		TraitDefinition: traitDef,
	}
	if err := loadSchematicToTemplate(tmpl, traitDef.Spec.Status, traitDef.Spec.Schematic, traitDef.Spec.Extension); err != nil {
		return nil, errors.WithMessage(err, "cannot load template")
	}
	return tmpl, nil
}

func newTemplateOfWorkloadDefinition(wlDef *v1beta1.WorkloadDefinition) (*Template, error) {
	tmpl := &Template{
		Reference:          common.WorkloadTypeDescriptor{Type: wlDef.Spec.Reference.Name},
		WorkloadDefinition: wlDef,
	}
	if err := loadSchematicToTemplate(tmpl, wlDef.Spec.Status, wlDef.Spec.Schematic, wlDef.Spec.Extension); err != nil {
		return nil, errors.WithMessage(err, "cannot load template")
	}
	return tmpl, nil
}

func newTemplateOfPolicyDefinition(def *v1beta1.PolicyDefinition) (*Template, error) {
	tmpl := &Template{
		PolicyDefinition: def,
	}
	if err := loadSchematicToTemplate(tmpl, nil, def.Spec.Schematic, nil); err != nil {
		return nil, errors.WithMessage(err, "cannot load template")
	}
	return tmpl, nil
}

func newTemplateOfWorkflowStepDefinition(def *v1beta1.WorkflowStepDefinition) (*Template, error) {
	tmpl := &Template{
		WorkflowStepDefinition: def,
	}
	if err := loadSchematicToTemplate(tmpl, nil, def.Spec.Schematic, nil); err != nil {
		return nil, errors.WithMessage(err, "cannot load template")
	}
	return tmpl, nil
}

// loadSchematicToTemplate loads common data that all kind definitions have.
func loadSchematicToTemplate(tmpl *Template, status *common.Status, schematic *common.Schematic, ext *runtime.RawExtension) error {
	if status != nil {
		tmpl.CustomStatus = status.CustomStatus
		tmpl.Health = status.HealthPolicy
		tmpl.Details = status.Details
	}

	if schematic != nil {
		if schematic.CUE != nil {
			tmpl.CapabilityCategory = types.CUECategory
			tmpl.TemplateStr = schematic.CUE.Template
		}
		if schematic.Terraform != nil {
			tmpl.CapabilityCategory = types.TerraformCategory
			tmpl.Terraform = schematic.Terraform
			return nil
		}
	}

	if tmpl.TemplateStr == "" && ext != nil {
		tmpl.CapabilityCategory = types.CUECategory
		extension := map[string]interface{}{}
		if err := json.Unmarshal(ext.Raw, &extension); err != nil {
			return errors.Wrap(err, "cannot parse capability extension")
		}
		if extTemplate, ok := extension["template"]; ok {
			if tmpStr, ok := extTemplate.(string); ok {
				tmpl.TemplateStr = tmpStr
			}
		}
	}
	return nil
}

// ConvertTemplateJSON2Object convert spec.extension or spec.schematic to object
func ConvertTemplateJSON2Object(capabilityName string, in *runtime.RawExtension, schematic *common.Schematic) (types.Capability, error) {
	var t types.Capability
	t.Name = capabilityName
	if in != nil && in.Raw != nil {
		err := json.Unmarshal(in.Raw, &t)
		if err != nil {
			return t, errors.Wrapf(err, "parse extension fail")
		}
	}
	capTemplate := &Template{}
	if err := loadSchematicToTemplate(capTemplate, nil, schematic, in); err != nil {
		return t, errors.WithMessage(err, "cannot resolve schematic")
	}
	if capTemplate.TemplateStr != "" {
		t.CueTemplate = capTemplate.TemplateStr
	}
	return t, nil
}

// definitionKind returns the upgrade.DefinitionKind for this template, derived from
// whichever definition pointer is populated. Defaults to ComponentKind.
func (t *Template) definitionKind() upgrade.DefinitionKind {
	switch {
	case t.TraitDefinition != nil:
		return upgrade.TraitKind
	case t.PolicyDefinition != nil:
		return upgrade.PolicyKind
	case t.WorkflowStepDefinition != nil:
		return upgrade.WorkflowStepKind
	default:
		return upgrade.ComponentKind
	}
}

func (t *Template) AsStatusRequest(parameter map[string]interface{}) *health.StatusRequest {
	kind := t.definitionKind()
	healthCUE, _ := upgrade.EnsureCueVersionCompatibility(t.Health, "health", kind, upgrade.TemplateAreaHealth)
	customCUE, _ := upgrade.EnsureCueVersionCompatibility(t.CustomStatus, "customStatus", kind, upgrade.TemplateAreaCustomStatus)
	detailsCUE, _ := upgrade.EnsureCueVersionCompatibility(t.Details, "statusDetails", kind, upgrade.TemplateAreaStatusDetail)
	return &health.StatusRequest{
		Health:    healthCUE,
		Custom:    customCUE,
		Details:   detailsCUE,
		Parameter: parameter,
	}
}