github.com/galaxyobe/gen@v0.0.0-20220910125335-392fa8f0990f/cmd/option-gen/generators/generator.go

/*
 Copyright 2022 Galaxyobe.

 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 generators

import (
	"io"
	"strings"

	"k8s.io/gengo/generator"
	"k8s.io/gengo/namer"
	"k8s.io/gengo/types"
	"k8s.io/klog/v2"

	"github.com/galaxyobe/gen/pkg/util"
	tpgenerator "github.com/galaxyobe/gen/third_party/gengo/generator"

	"github.com/galaxyobe/gen/third_party/gengo/parser"
)

type GenType struct {
	*types.Type
	AllowFields  []string
	OptionName   string
	OptionSuffix string
}

func NewGenTypes(pkg *types.Package) (pkgEnabled bool, genTypes GenTypes) {
	for _, t := range pkg.Types {
		ut := util.UnderlyingType(t)
		switch ut.Kind {
		case types.Struct:
		case types.Func:
			genTypes.Functions = append(genTypes.Functions, ut.Name.Name)
		default:
			continue
		}
		comments := t.CommentLines
		setTag, enabled := util.GetTagBoolStatus(tagName, comments)
		setName, name := util.GetTagValueStatus(tagTypeName, comments)
		setSuffix, suffix := util.GetTagValueStatus(tagSuffixName, comments)
		allowedFields := util.GetTagValues(tagSelectFieldsName, comments)
		if len(allowedFields) > 0 || setName || setSuffix {
			setTag = true
			enabled = true
		}
		if !setTag || !enabled {
			continue // ignore type
		}
		optionName := getOptionName(t.Name.Name)
		if !setName {
			name = optionName
		}
		if !setSuffix {
			suffix = name
		}
		pkgEnabled = true
		genTypes.Types = append(genTypes.Types, &GenType{
			Type:         t,
			AllowFields:  allowedFields,
			OptionName:   name,
			OptionSuffix: suffix,
		})
	}
	if len(genTypes.Types) == 0 {
		pkgEnabled = false
		return
	}
	for name := range pkg.Functions {
		genTypes.Functions = append(genTypes.Functions, name)
	}
	return
}

type GenTypes struct {
	Types     []*GenType
	Functions []string
}

func (g GenTypes) find(t *types.Type) *GenType {
	for _, item := range g.Types {
		if item.Name.Name == t.Name.Name && item.Name.Package == t.Name.Package {
			return item
		}
	}
	return nil
}

func (g GenTypes) allowed(t *types.Type) bool {
	return g.find(t) != nil
}

// allowedField allowed type's field to generate Option func.
// will be ignored field enabled status when it's in +gen:option:fields allowed fields.
func (g GenTypes) allowedField(t *types.Type, m int) bool {
	for _, item := range g.Types {
		if item.Name.Name == t.Name.Name && item.Name.Package == t.Name.Package {
			if len(t.Members) == 0 {
				return true
			}
			field := t.Members[m]
			set, enable := util.GetTagBoolStatus(tagFieldName, field.CommentLines)
			if set && !enable && len(item.AllowFields) == 0 {
				return false
			}
			if len(item.AllowFields) == 0 {
				return true
			}
			return util.Exist(item.AllowFields, field.Name)
		}
	}
	return false
}

func (g GenTypes) existMethod(funcName string) bool {
	for _, item := range g.Functions {
		if item == funcName {
			return true
		}
	}
	return false
}

type genOption struct {
	generator.DefaultGen
	build         *parser.Builder
	targetPackage string
	boundingDirs  []string
	imports       namer.ImportTracker
	genTypes      GenTypes
	packageTypes  util.PackageTypes
}

func NewGenOption(build *parser.Builder, sanitizedName, targetPackage string, boundingDirs []string, genTypes GenTypes, sourcePath string) generator.Generator {
	return &genOption{
		DefaultGen: generator.DefaultGen{
			OptionalName: sanitizedName,
		},
		build:         build,
		targetPackage: targetPackage,
		boundingDirs:  boundingDirs,
		imports:       generator.NewImportTracker(),
		genTypes:      genTypes,
		packageTypes:  util.NewPackageTypes(build),
	}
}

func (g *genOption) Name() string {
	return "option"
}

func (g *genOption) Filter(c *generator.Context, t *types.Type) bool {
	ok := g.genTypes.allowed(t)
	if !ok {
		klog.V(5).Infof("Ignore generate option function for type %v", t)
	}
	return ok
}

func (g *genOption) Namers(c *generator.Context) namer.NameSystems {
	// Have the raw namer for this file track what it imports.
	return namer.NameSystems{
		"raw": namer.NewRawNamer(g.targetPackage, g.imports),
	}
}

func (g *genOption) Init(c *generator.Context, w io.Writer) error {
	return nil
}

func (g *genOption) GenerateType(c *generator.Context, t *types.Type, w io.Writer) error {
	klog.V(5).Infof("Generating option function for type %v", t)
	sw := tpgenerator.NewSnippetWriter(w, c, "", "")
	sw.AddFunc("slice", func(s string) string {
		if strings.HasPrefix(s, "[]") {
			return strings.ReplaceAll(s, "[]", "...")
		}
		return s
	})
	g.genOptionType(sw, t)
	g.genWithFieldFunc(sw, t)
	sw.Do("\n", nil)

	return sw.Error()
}

func (g *genOption) isOtherPackage(pkg string) bool {
	if pkg == g.targetPackage {
		return false
	}
	if strings.HasSuffix(pkg, "\""+g.targetPackage+"\"") {
		return false
	}
	return true
}

func (g *genOption) Imports(c *generator.Context) (imports []string) {
	var importLines []string
	for _, singleImport := range g.imports.ImportLines() {
		if g.isOtherPackage(singleImport) {
			importLines = append(importLines, singleImport)
		}
	}
	return importLines
}

func getOptionName(typeName string) string {
	if strings.HasSuffix(typeName, "Option") {
		return typeName
	}
	return typeName + "Option"
}

func (g *genOption) getOptionSuffixName(t *types.Type) string {
	suffix := getOptionName(t.Name.Name)
	if v := g.genTypes.find(t); v != nil {
		suffix = v.OptionSuffix
	}
	return suffix
}

func (g *genOption) getOptionTypeName(t *types.Type) string {
	name := getOptionName(t.Name.Name)
	if v := g.genTypes.find(t); v != nil {
		name = v.OptionName
	}
	return name
}

func (g *genOption) genOptionType(sw *tpgenerator.SnippetWriter, t *types.Type) {
	name := g.getOptionTypeName(t)
	if g.genTypes.existMethod(name) {
		return
	}
	args := generator.Args{
		"type": t,
		"name": name,
	}
	sw.Do("type {{.name}} func(* {{.type|public}})\n", args)
}

func (g *genOption) genWithFieldFunc(sw *tpgenerator.SnippetWriter, t *types.Type) {
	isExternalType := g.packageTypes.IsExternalType(t.Name.Package, t.Name.Name)
	option := g.getOptionTypeName(t)
	suffix := g.getOptionSuffixName(t)
	methodGen := util.NewMethodGenerate(util.GenName("With", suffix))
	for idx, m := range t.Members {
		if util.IsLower(m.Name) && isExternalType {
			continue
		}
		if !g.genTypes.allowedField(t, idx) {
			continue
		}
		method := methodGen.GenName(m.Name)
		if g.genTypes.existMethod(method) {
			continue
		}
		args := generator.Args{
			"type":   t,
			"option": option,
			"field":  m,
			"method": method,
		}
		sw.Do("func {{.method}} (val {{.field.Type|raw|slice}}) {{.option}} {\n", args)
		sw.Do("return func(object * {{.type|public}}) {\n", args)
		sw.Do("object.{{.field.Name}} = val\n", args)
		sw.Do("}\n", nil)
		sw.Do("}\n\n", nil)
	}
}