/*
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 context

import (
	"context"
	"encoding/json"
	"time"

	"cuelang.org/go/cue"
	runtimev1alpha1 "github.com/crossplane/crossplane-runtime/apis/core/v1alpha1"
	"github.com/pkg/errors"
	corev1 "k8s.io/api/core/v1"
	kerrors "k8s.io/apimachinery/pkg/api/errors"
	"sigs.k8s.io/controller-runtime/pkg/client"

	"github.com/oam-dev/kubevela/pkg/cue/model"
	"github.com/oam-dev/kubevela/pkg/cue/model/value"
	"github.com/oam-dev/kubevela/pkg/oam/util"
)

const (
	// ConfigMapKeyComponents is the key in ConfigMap Data field for containing data of components
	ConfigMapKeyComponents = "components"
	// ConfigMapKeyVars is the key in ConfigMap Data field for containing data of variable
	ConfigMapKeyVars = "vars"
	// AnnotationStartTimestamp is the annotation key of the workflow start  timestamp
	AnnotationStartTimestamp = "vela.io/startTime"
)

// WorkflowContext is workflow context.
type WorkflowContext struct {
	cli        client.Client
	store      corev1.ConfigMap
	components map[string]*ComponentManifest
	vars       *value.Value
}

// GetComponent Get ComponentManifest from workflow context.
func (wf *WorkflowContext) GetComponent(name string) (*ComponentManifest, error) {
	component, ok := wf.components[name]
	if !ok {
		return nil, errors.Errorf("component %s not found in application", name)
	}
	return component, nil
}

// PatchComponent patch component with value.
func (wf *WorkflowContext) PatchComponent(name string, patchValue *value.Value) error {
	component, err := wf.GetComponent(name)
	if err != nil {
		return err
	}
	return component.Patch(patchValue)
}

// GetVar get variable from workflow context.
func (wf *WorkflowContext) GetVar(paths ...string) (*value.Value, error) {
	return wf.vars.LookupValue(paths...)
}

// SetVar set variable to workflow context.
func (wf *WorkflowContext) SetVar(v *value.Value, paths ...string) error {
	str, err := v.String()
	if err != nil {
		return errors.WithMessage(err, "compile var")
	}
	return wf.vars.FillRaw(str, paths...)
}

// MakeParameter make 'value' with map[string]interface{}
func (wf *WorkflowContext) MakeParameter(parameter map[string]interface{}) (*value.Value, error) {
	var s = "{}"
	if parameter != nil {
		s = string(util.MustJSONMarshal(parameter))
	}

	return wf.vars.MakeValue(s)
}

// Commit the workflow context and persist it's content.
func (wf *WorkflowContext) Commit() error {
	if err := wf.writeToStore(); err != nil {
		return err
	}
	if err := wf.sync(); err != nil {
		return errors.WithMessagef(err, "save context to configMap(%s/%s)", wf.store.Namespace, wf.store.Name)
	}
	return nil
}

func (wf *WorkflowContext) writeToStore() error {
	varStr, err := wf.vars.String()
	if err != nil {
		return err
	}
	jsonObject := map[string]string{}
	for name, comp := range wf.components {
		s, err := comp.string()
		if err != nil {
			return errors.WithMessagef(err, "encode component %s ", name)
		}
		jsonObject[name] = s
	}

	wf.store.Data = map[string]string{
		ConfigMapKeyComponents: string(util.MustJSONMarshal(jsonObject)),
		ConfigMapKeyVars:       varStr,
	}
	return nil
}

func (wf *WorkflowContext) sync() error {
	ctx := context.Background()
	if err := wf.cli.Update(ctx, &wf.store); err != nil {
		if kerrors.IsNotFound(err) {
			return wf.cli.Create(ctx, &wf.store)
		}
		return err
	}
	return nil
}

// LoadFromConfigMap recover workflow context from configMap.
func (wf *WorkflowContext) LoadFromConfigMap(cm corev1.ConfigMap) error {
	data := cm.Data
	componentsJs := map[string]string{}

	if err := json.Unmarshal([]byte(data[ConfigMapKeyComponents]), &componentsJs); err != nil {
		return errors.WithMessage(err, "decode components")
	}
	wf.components = map[string]*ComponentManifest{}
	for name, compJs := range componentsJs {
		cm := new(ComponentManifest)
		if err := cm.unmarshal(compJs); err != nil {
			return errors.WithMessagef(err, "unmarshal component(%s) manifest", name)
		}
		wf.components[name] = cm
	}
	var err error
	wf.vars, err = value.NewValue(data[ConfigMapKeyVars], nil)
	if err != nil {
		return errors.WithMessage(err, "decode vars")
	}
	return nil
}

// StoreRef return the store reference of workflow context.
func (wf *WorkflowContext) StoreRef() *runtimev1alpha1.TypedReference {
	return &runtimev1alpha1.TypedReference{
		APIVersion: wf.store.APIVersion,
		Kind:       wf.store.Kind,
		Name:       wf.store.Name,
		UID:        wf.store.UID,
	}
}

// ComponentManifest contains resources rendered from an application component.
type ComponentManifest struct {
	Workload    model.Instance
	Auxiliaries []model.Instance
}

// Patch the ComponentManifest with value
func (comp *ComponentManifest) Patch(patchValue *value.Value) error {
	pInst, err := model.NewOther(patchValue.CueValue())
	if err != nil {
		return err
	}
	return comp.Workload.Unify(pInst)
}

type componentMould struct {
	StandardWorkload string
	Traits           []string
}

func (comp *ComponentManifest) string() (string, error) {
	cm := componentMould{
		StandardWorkload: comp.Workload.String(),
	}
	for _, aux := range comp.Auxiliaries {
		cm.Traits = append(cm.Traits, aux.String())
	}
	js, err := json.Marshal(cm)
	return string(js), err
}

func (comp *ComponentManifest) unmarshal(v string) error {

	cm := componentMould{}
	if err := json.Unmarshal([]byte(v), &cm); err != nil {
		return err
	}
	var r cue.Runtime
	wlInst, err := r.Compile("workload", cm.StandardWorkload)
	if err != nil {
		return err
	}
	wl, err := model.NewBase(wlInst.Value())
	if err != nil {
		return err
	}

	comp.Workload = wl
	for _, s := range cm.Traits {
		auxInst, err := r.Compile("-", s)
		if err != nil {
			return err
		}
		aux, err := model.NewOther(auxInst.Value())
		if err != nil {
			return err
		}
		comp.Auxiliaries = append(comp.Auxiliaries, aux)
	}

	return nil
}

// NewContext new workflow context.
func NewContext(cli client.Client, ns, rev string) (Context, error) {

	var (
		ctx        = context.Background()
		manifestCm corev1.ConfigMap
	)

	if err := cli.Get(ctx, client.ObjectKey{
		Namespace: ns,
		Name:      rev,
	}, &manifestCm); err != nil {
		return nil, errors.WithMessagef(err, "Get manifest ConfigMap %s/%s ", ns, rev)
	}

	wfCtx, err := newContext(cli, ns, rev)
	if err != nil {
		return nil, err
	}
	if err := wfCtx.LoadFromConfigMap(manifestCm); err != nil {
		return nil, errors.WithMessagef(err, "load from ConfigMap  %s/%s", ns, rev)
	}

	return wfCtx, wfCtx.Commit()
}

func newContext(cli client.Client, ns, rev string) (*WorkflowContext, error) {
	var (
		ctx   = context.Background()
		store corev1.ConfigMap
	)
	store.Name = generateStoreName(rev)
	store.Namespace = ns
	if err := cli.Get(ctx, client.ObjectKey{Name: store.Name, Namespace: store.Namespace}, &store); err != nil {
		if kerrors.IsNotFound(err) {
			if err := cli.Create(ctx, &store); err != nil {
				return nil, err
			}
		} else {
			return nil, err
		}
	}
	store.Annotations = map[string]string{
		AnnotationStartTimestamp: time.Now().String(),
	}
	wfCtx := &WorkflowContext{
		cli:        cli,
		store:      store,
		components: map[string]*ComponentManifest{},
	}
	var err error
	wfCtx.vars, err = value.NewValue("", nil)

	return wfCtx, err
}

// LoadContext load workflow context from store.
func LoadContext(cli client.Client, ns, rev string) (Context, error) {
	var store corev1.ConfigMap
	if err := cli.Get(context.Background(), client.ObjectKey{
		Namespace: ns,
		Name:      generateStoreName(rev),
	}, &store); err != nil {
		return nil, err
	}
	ctx := &WorkflowContext{
		cli:   cli,
		store: store,
	}
	if err := ctx.LoadFromConfigMap(store); err != nil {
		return nil, err
	}
	return ctx, nil
}

func generateStoreName(rev string) string {
	return "workflow-" + rev
}