text: /*
  Copyright 2017 The Kubernetes 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 strategicpatch
  
  import (
  	"errors"
  	"strings"
  
  	"k8s.io/apimachinery/pkg/util/mergepatch"
  	openapi "k8s.io/kube-openapi/pkg/util/proto"
  )
  
  const (
  	patchStrategyOpenapiextensionKey = "x-kubernetes-patch-strategy"
  	patchMergeKeyOpenapiextensionKey = "x-kubernetes-patch-merge-key"
  )
  
  type LookupPatchItem interface {
  	openapi.SchemaVisitor
  
  	Error() error
  	Path() *openapi.Path
  }
  
  type kindItem struct {
  	key          string
  	path         *openapi.Path
  	err          error
  	patchmeta    PatchMeta
  	subschema    openapi.Schema
  	hasVisitKind bool
  }
  
  func NewKindItem(key string, path *openapi.Path) *kindItem {
  	return &kindItem{
  		key:  key,
  		path: path,
  	}
  }
  
  var _ LookupPatchItem = &kindItem{}
  
  func (item *kindItem) Error() error {
  	return item.err
  }
  
  func (item *kindItem) Path() *openapi.Path {
  	return item.path
  }
  
  func (item *kindItem) VisitPrimitive(schema *openapi.Primitive) {
  	item.err = errors.New("expected kind, but got primitive")
  }
  
  func (item *kindItem) VisitArray(schema *openapi.Array) {
  	item.err = errors.New("expected kind, but got slice")
  }
  
  func (item *kindItem) VisitMap(schema *openapi.Map) {
  	item.err = errors.New("expected kind, but got map")
  }
  
  func (item *kindItem) VisitReference(schema openapi.Reference) {
  	if !item.hasVisitKind {
  		schema.SubSchema().Accept(item)
  	}
  }
  
  func (item *kindItem) VisitKind(schema *openapi.Kind) {
  	subschema, ok := schema.Fields[item.key]
  	if !ok {
  		item.err = FieldNotFoundError{Path: schema.GetPath().String(), Field: item.key}
  		return
  	}
  
  	mergeKey, patchStrategies, err := parsePatchMetadata(subschema.GetExtensions())
  	if err != nil {
  		item.err = err
  		return
  	}
  	item.patchmeta = PatchMeta{
  		patchStrategies: patchStrategies,
  		patchMergeKey:   mergeKey,
  	}
  	item.subschema = subschema
  }
  
  type sliceItem struct {
  	key          string
  	path         *openapi.Path
  	err          error
  	patchmeta    PatchMeta
  	subschema    openapi.Schema
  	hasVisitKind bool
  }
  
  func NewSliceItem(key string, path *openapi.Path) *sliceItem {
  	return &sliceItem{
  		key:  key,
  		path: path,
  	}
  }
  
  var _ LookupPatchItem = &sliceItem{}
  
  func (item *sliceItem) Error() error {
  	return item.err
  }
  
  func (item *sliceItem) Path() *openapi.Path {
  	return item.path
  }
  
  func (item *sliceItem) VisitPrimitive(schema *openapi.Primitive) {
  	item.err = errors.New("expected slice, but got primitive")
  }
  
  func (item *sliceItem) VisitArray(schema *openapi.Array) {
  	if !item.hasVisitKind {
  		item.err = errors.New("expected visit kind first, then visit array")
  	}
  	subschema := schema.SubType
  	item.subschema = subschema
  }
  
  func (item *sliceItem) VisitMap(schema *openapi.Map) {
  	item.err = errors.New("expected slice, but got map")
  }
  
  func (item *sliceItem) VisitReference(schema openapi.Reference) {
  	if !item.hasVisitKind {
  		schema.SubSchema().Accept(item)
  	} else {
  		item.subschema = schema.SubSchema()
  	}
  }
  
  func (item *sliceItem) VisitKind(schema *openapi.Kind) {
  	subschema, ok := schema.Fields[item.key]
  	if !ok {
  		item.err = FieldNotFoundError{Path: schema.GetPath().String(), Field: item.key}
  		return
  	}
  
  	mergeKey, patchStrategies, err := parsePatchMetadata(subschema.GetExtensions())
  	if err != nil {
  		item.err = err
  		return
  	}
  	item.patchmeta = PatchMeta{
  		patchStrategies: patchStrategies,
  		patchMergeKey:   mergeKey,
  	}
  	item.hasVisitKind = true
  	subschema.Accept(item)
  }
  
  func parsePatchMetadata(extensions map[string]interface{}) (string, []string, error) {
  	ps, foundPS := extensions[patchStrategyOpenapiextensionKey]
  	var patchStrategies []string
  	var mergeKey, patchStrategy string
  	var ok bool
  	if foundPS {
  		patchStrategy, ok = ps.(string)
  		if ok {
  			patchStrategies = strings.Split(patchStrategy, ",")
  		} else {
  			return "", nil, mergepatch.ErrBadArgType(patchStrategy, ps)
  		}
  	}
  	mk, foundMK := extensions[patchMergeKeyOpenapiextensionKey]
  	if foundMK {
  		mergeKey, ok = mk.(string)
  		if !ok {
  			return "", nil, mergepatch.ErrBadArgType(mergeKey, mk)
  		}
  	}
  	return mergeKey, patchStrategies, nil
  }
  