package.go

package convert

import (
	"fmt"
	"go/token"
	"go/types"
	"log"

	goast "go/ast"

	"github.com/goplus/gogen"
	"github.com/goplus/llcppg/_xtool/llcppsymg/tool/name"
	"github.com/goplus/llcppg/ast"
	llcppg "github.com/goplus/llcppg/config"
	ctoken "github.com/goplus/llcppg/token"
	"github.com/goplus/mod/gopmod"
)

// In Processing Package
type Package struct {
	*PkgInfo
	p       *gogen.Package // package writer
	conf    *PackageConfig // package config
	cvt     *TypeConv      // package type convert
	curFile *HeaderFile    // current processing c header file.
	files   []*HeaderFile  // header files.
	locMap  *ThirdTypeLoc  // record third type's location

	// incomplete stores type declarations that are not fully defined yet, including:
	// - Forward declarations in C/C++
	// - Typedef declarations that reference incomplete types
	//
	// This is crucial for handling cases where:
	// 1. A type is referenced before its full definition (forward declaration)
	// 2. A typedef refers to a type that hasn't been fully defined yet
	//
	// These declarations are collected during the parsing phase and will be
	// properly initialized after all files have been processed, ensuring that
	// all type references can be correctly resolved.
	//
	// Note: In Go, when creating a new type via "type xxx xxx", the underlying
	// type must exist. This differs from C/C++ where incomplete types are allowed.
	// Therefore, we need this mechanism to defer type initialization until all
	// type definitions are available.
	incompleteTypes *IncompleteTypes

	symbols *ProcessSymbol // record the processed node
}

type PackageConfig struct {
	PkgBase
	Name           string // current package name
	OutputDir      string
	ConvSym        func(name *ast.Object, mangleName string) (goName string, err error)
	Symbols        *ProcessSymbol
	GenConf        *gogen.Config
	TrimPrefixes   []string
	LibCommand     string // use to gen link command like $(pkg-config --libs xxx)
	KeepUnderScore bool
}

// When creating a new package for conversion, a Go file named after the package is generated by default.
// If SetCurFile is not called, all type conversions will be written to this default Go file.
func NewPackage(config *PackageConfig) (*Package, error) {
	gogen.GeneratedHeader = ""
	if config.GenConf == nil {
		config.GenConf = &gogen.Config{
			EnableTypesalias: true,
		}
	}
	var symbols *ProcessSymbol
	if config.Symbols == nil {
		symbols = NewProcessSymbol()
	} else {
		symbols = config.Symbols
	}
	p := &Package{
		p:               gogen.NewPackage(config.PkgPath, config.Name, config.GenConf),
		conf:            config,
		incompleteTypes: NewIncompleteTypes(),
		locMap:          NewThirdTypeLoc(),
		symbols:         symbols,
	}

	// default have load llgo/c
	hasC := false
	for _, dep := range config.Deps {
		if dep == "c" || dep == "github.com/goplus/lib/c" {
			hasC = true
			break
		}
	}
	if !hasC {
		config.Deps = append([]string{"c"}, config.Deps...)
	}

	mod, err := gopmod.Load(config.OutputDir)
	if err != nil {
		return nil, fmt.Errorf("failed to load mod: %w", err)
	}

	p.PkgInfo = NewPkgInfo(config.PkgPath, config.Deps, config.Pubs)

	pkgManager := NewPkgDepLoader(mod, p.p)
	err = pkgManager.InitDeps(p.PkgInfo)
	if err != nil {
		return nil, fmt.Errorf("failed to init deps: %w", err)
	}
	err = p.initLink()
	if err != nil {
		return nil, fmt.Errorf("failed to init link: %w", err)
	}
	p.markUseDeps(pkgManager)
	p.cvt = NewConv(p)
	return p, nil
}

func (p *Package) Config() *PackageConfig {
	return p.conf
}

func (p *Package) Pkg() *gogen.Package {
	return p.p
}

func (p *Package) markUseDeps(pkgMgr *PkgDepLoader) {
	defer p.p.RestoreCurFile(p.p.CurFile())
	p.p.SetCurFile(p.autoLinkFile(), true)
	pkgs, err := pkgMgr.Imports(p.conf.Deps)
	if err != nil {
		log.Panicf("failed to import deps: %s", err.Error())
	}
	for _, pkg := range pkgs {
		depPkg := p.p.Import(pkg.PkgPath)
		depPkg.MarkForceUsed(p.p)
	}
}

func (p *Package) LookupFunc(fn *ast.FuncDecl) (*GoFuncSpec, error) {
	goName, err := p.conf.ConvSym(&fn.Object, fn.MangledName)
	if err != nil {
		return nil, err
	}
	return NewGoFuncSpec(goName), nil
}

func (p *Package) SetCurFile(hfile *HeaderFile) {
	var curFile *HeaderFile
	for _, f := range p.files {
		if f.File == hfile.File {
			curFile = f
			break
		}
	}

	if curFile == nil {
		curFile = hfile
		p.files = append(p.files, curFile)
	}

	p.curFile = curFile
	// for third hfile not register to gogen.Package
	if curFile.FileType != llcppg.Third {
		fileName := curFile.ToGoFileName(p.conf.Name)
		if debugLog {
			log.Printf("SetCurFile: %s File in Current Package: %v\n", fileName, curFile.FileType)
		}
		p.p.SetCurFile(fileName, true)
		p.p.Unsafe().MarkForceUsed(p.p)
	}
}

// todo(zzy):refine logic
func (p *Package) linkLib(lib string) error {
	if lib == "" {
		return fmt.Errorf("empty lib name")
	}
	linkString := fmt.Sprintf("link: %s;", lib)
	p.p.CB().NewConstStart(types.Typ[types.String], "LLGoPackage").Val(linkString).EndInit(1)
	return nil
}

func (p *Package) newReceiver(typ *ast.FuncType) (*types.Var, error) {
	recvField := typ.Params.List[0]
	recvType, err := p.ToType(recvField.Type)
	if err != nil {
		return nil, fmt.Errorf("newReceiver:failed to convert type: %w", err)
	}
	return p.p.NewParam(token.NoPos, "recv_", recvType), nil
}

func (p *Package) ToSigSignature(recv *types.Var, funcDecl *ast.FuncDecl) (*types.Signature, error) {
	var sig *types.Signature
	var err error
	sig, err = p.cvt.ToSignature(funcDecl.Type, recv)
	if err != nil {
		return nil, err
	}
	return sig, nil
}

func (p *Package) bodyStart(decl *gogen.Func, ret ast.Expr) error {
	if !Expr(ret).IsVoid() {
		retType, err := p.ToType(ret)
		if err != nil {
			return err
		}

		if asStruct(retType) {
			// use empty named struct type to return,without this solution,we will get a anonymous struct type
			// and it will cause a compile error,like following:
			// func (recv *Vector3) Vector3Barycenter(p Vector3, a Vector3, b Vector3, c Vector3) Vector3 {
			// 	return struct {
			// 		x c.Int
			// 		y c.Int
			// 		z c.Int
			// 	}{}
			// }
			// this result will cause the `c` in the return type is use the `c` in the parameter,which is not have the `Int`
			decl.BodyStart(p.p).StructLit(retType, 0, true).Return(1).End()
			return nil
		}
		decl.BodyStart(p.p).ZeroLit(retType).Return(1).End()
	} else {
		decl.BodyStart(p.p).End()
	}
	return nil
}

func (p *Package) handleFuncDecl(fnSpec *GoFuncSpec, sig *types.Signature, funcDecl *ast.FuncDecl) error {
	var decl *gogen.Func
	fnPubName := fnSpec.GoSymbName
	if fnSpec.IsMethod {
		decl = p.p.NewFuncDecl(token.NoPos, fnSpec.FnName, sig)
		err := p.bodyStart(decl, funcDecl.Type.Ret)
		if err != nil {
			return err
		}
		// we need to use the actual receiver name in link comment
		// both for value receiver and pointer receiver
		fnPubName = pubMethodName(sig.Recv().Type(), fnSpec)
	} else {
		decl = p.p.NewFuncDecl(token.NoPos, fnPubName, sig)
	}

	doc := NewCommentGroupFromC(funcDecl.Doc)
	doc.List = append(doc.List, NewFuncDocComment(funcDecl.Name.Name, fnPubName))
	decl.SetComments(p.p, doc)
	return nil
}

type TypeDefinedError struct {
	Name       string
	OriginName string
}

func (p *TypeDefinedError) Error() string {
	return "type " + p.Name + " already defined,original name is " + p.OriginName
}

func NewTypeDefinedError(name, originName string) *TypeDefinedError {
	return &TypeDefinedError{
		Name:       name,
		OriginName: originName,
	}
}

func getNamedType(recvType types.Type) *types.Named {
	switch t := recvType.(type) {
	case *types.Named:
		return t
	case *types.Pointer:
		if named, ok := t.Elem().(*types.Named); ok {
			return named
		}
	}
	return nil
}

// pubMethodName generates a public method name based on the receiver type and function name.
// It handles both pointer and value receivers.
//
// Parameters:
//   - recv: The receiver type from types.Signature
//   - fnName: The base function name
//
// Returns:
//   - For pointer receiver: "(*TypeName).FuncName"
//   - For value receiver: "TypeName.FuncName"
//   - For invalid/unknown receiver: just "FuncName"
func pubMethodName(recv types.Type, fnSpec *GoFuncSpec) string {
	if !fnSpec.IsMethod {
		return fnSpec.FnName
	}
	named := getNamedType(recv)
	if fnSpec.PtrRecv {
		return "(*" + named.Obj().Name() + ")." + fnSpec.FnName
	}
	return named.Obj().Name() + "." + fnSpec.FnName
}

func (p *Package) NewFuncDecl(funcDecl *ast.FuncDecl) error {
	isThird, _ := p.handleType(funcDecl.Name, funcDecl.Loc)
	if isThird {
		if debugLog {
			log.Printf("NewFuncDecl: %v is a function of third header file\n", funcDecl.Name)
		}
		return nil
	}
	if debugLog {
		log.Printf("NewFuncDecl: %v\n", funcDecl.Name)
	}

	fnSpec, err := p.LookupFunc(funcDecl)
	if err != nil {
		// not gen the function not in the symbolmap
		log.Printf("NewFuncDecl: %s not in the symbolmap: %s", funcDecl.Name.Name, err.Error())
		return nil
	}
	if fnSpec.IsIgnore() {
		log.Printf("NewFuncDecl: %v is ignored\n", funcDecl.Name)
		return nil
	}

	recv, exist, err := p.funcIsDefined(fnSpec, funcDecl)
	if err != nil {
		return fmt.Errorf("NewFuncDecl: %s fail: %w", funcDecl.Name.Name, err)
	}
	if exist {
		if debugLog {
			log.Printf("NewFuncDecl: %s is processed\n", funcDecl.Name.Name)
		}
		return nil
	}

	sig, err := p.ToSigSignature(recv, funcDecl)
	if err != nil {
		return fmt.Errorf("NewFuncDecl: fail convert signature %s: %w", funcDecl.Name.Name, err)
	}
	return p.handleFuncDecl(fnSpec, sig, funcDecl)
}

func (p *Package) funcIsDefined(fnSpec *GoFuncSpec, funcDecl *ast.FuncDecl) (recv *types.Var, exist bool, err error) {
	node := Node{
		name: funcDecl.Name.Name,
		kind: FuncDecl,
	}
	// if already processed,return
	_, exist = p.symbols.Lookup(node)
	if exist {
		return nil, true, nil
	}
	if fnSpec.IsMethod &&
		funcDecl.Type.Params.List != nil &&
		len(funcDecl.Type.Params.List) > 0 {
		recv, err = p.newReceiver(funcDecl.Type)
		if err != nil {
			return nil, false, err
		}
		var namedType = getNamedType(recv.Type())
		methodName := fnSpec.FnName
		for i := 0; i < namedType.NumMethods(); i++ {
			if namedType.Method(i).Name() == methodName { // unreachable,because if have the same method name,will return in p.symbols.Lookup(node)
				return nil, true, fmt.Errorf("NewFuncDecl: %s already defined", fnSpec.GoSymbName)
			}
		}
	} else {
		if obj := p.Lookup(fnSpec.FnName); obj != nil {
			return nil, true, fmt.Errorf("NewFuncDecl: %s already defined", fnSpec.GoSymbName)
		}
	}
	// register the function
	p.symbols.Register(node, fnSpec.FnName)
	return
}

func (p *Package) Lookup(name string) types.Object {
	return gogen.Lookup(p.p.Types.Scope(), name)
}

func (p *Package) lookupOrigin(name string, pubName string) types.Object {
	if obj := p.Lookup(name); obj != nil {
		return obj
	}
	if name != pubName {
		return p.Lookup(pubName)
	}
	return nil
}

func (p *Package) lookupPub(_ string, pubName string) types.Object {
	return p.Lookup(pubName)
}

// NewTypeDecl converts C/C++ type declarations to Go.
// Besides regular type declarations, it also supports:
// - Forward declarations: Pre-registers incomplete types for later definition
// - Self-referential types: Handles types that reference themselves (like linked lists)
func (p *Package) NewTypeDecl(typeDecl *ast.TypeDecl) error {
	skip, _ := p.handleType(typeDecl.Name, typeDecl.Loc)
	if skip {
		if debugLog {
			log.Printf("NewTypeDecl: %s type of third header\n", typeDecl.Name)
		}
		return nil
	}

	if debugLog {
		log.Printf("NewTypeDecl: %s\n", typeDecl.Name.Name)
	}

	cname := typeDecl.Name.Name
	isForward := p.cvt.inComplete(typeDecl.Type)
	name, changed, exist, err := p.RegisterNode(Node{name: cname, kind: TypeDecl}, p.declName, p.lookupOrigin)
	if err != nil {
		return fmt.Errorf("NewTypeDecl: %s fail: %w", typeDecl.Name.Name, err)
	}

	// if the type is already defined,we don't need to process again
	// but if the previous processed node is a forward declaration,we need to complete the type
	_, isIncom := p.incompleteTypes.Lookup(typeDecl.Name.Name)
	if exist && (isForward || !isIncom) {
		if debugLog {
			log.Printf("NewTypeDecl: %s is processed\n", typeDecl.Name.Name)
		}
		return nil
	}

	p.CollectNameMapping(cname, name)
	incom := p.handleTypeDecl(name, cname, typeDecl)
	if changed {
		substObj(p.p.Types, p.p.Types.Scope(), cname, incom.decl.Type().Obj())
	}

	if !isForward {
		if err := p.handleCompleteType(incom, typeDecl.Type, cname); err != nil {
			return fmt.Errorf("NewTypeDecl: fail to complete type %s: %w", typeDecl.Name.Name, err)
		}
	}
	return nil
}

// handleTypeDecl creates a new type declaration or retrieves existing one
func (p *Package) handleTypeDecl(pubname string, cname string, typeDecl *ast.TypeDecl) *Incomplete {
	if existDecl, exists := p.incompleteTypes.Lookup(cname); exists {
		return existDecl
	}
	decl := p.emptyTypeDecl(pubname, typeDecl.Doc)
	inc := &Incomplete{
		cname: cname,
		file:  p.curFile,
		decl:  decl,
		getType: func() (types.Type, error) {
			return types.NewStruct(p.cvt.defaultRecordField(), nil), nil
		},
	}
	p.incompleteTypes.Add(inc)
	return inc
}

func (p *Package) handleCompleteType(incom *Incomplete, typ *ast.RecordType, name string) error {
	// defer delete(p.incomplete, name)
	defer p.incompleteTypes.Complete(name)
	defer p.SetCurFile(p.curFile)
	p.SetCurFile(incom.file)
	structType, err := p.cvt.RecordTypeToStruct(typ)
	if err != nil {
		// For incomplete type's conerter error, we use default struct type
		return err
	}
	incom.decl.InitType(p.p, structType)
	return nil
}

// handleImplicitForwardDecl handles type references that cannot be found in the current scope.
// For such declarations, create a empty type decl and store it in the
// incomplete map, but not in the public symbol table.
func (p *Package) handleImplicitForwardDecl(name string) *gogen.TypeDecl {
	if decl, ok := p.incompleteTypes.Lookup(name); ok {
		return decl.decl
	}

	// Using TypeDecl as the node kind here because forward declarations in C/C++ typically
	// only occur with struct, class, and enum type declarations, not with typedefs or other declarations.
	// The TypeDecl node kind ensures these forward declarations are properly tracked and later completed.
	pubName, _, _, _ := p.RegisterNode(Node{name: name, kind: TypeDecl}, p.declName, p.lookupOrigin)
	decl := p.emptyTypeDecl(pubName, nil)
	inc := &Incomplete{
		cname: name,
		file:  p.curFile,
		decl:  decl,
		getType: func() (types.Type, error) {
			return types.NewStruct(p.cvt.defaultRecordField(), nil), nil
		},
	}
	p.incompleteTypes.Add(inc)
	return decl
}

func (p *Package) emptyTypeDecl(name string, doc *ast.CommentGroup) *gogen.TypeDecl {
	typeBlock := p.p.NewTypeDefs()
	typeBlock.SetComments(NewCommentGroupFromC(doc))
	return typeBlock.NewType(name)
}

func (p *Package) NewTypedefDecl(typedefDecl *ast.TypedefDecl) error {
	skip, _ := p.handleType(typedefDecl.Name, typedefDecl.Loc)
	if skip {
		if debugLog {
			log.Printf("NewTypedefDecl: %v is a typedef of third header file\n", typedefDecl.Name)
		}
		return nil
	}
	if debugLog {
		log.Printf("NewTypedefDecl: %s\n", typedefDecl.Name.Name)
	}

	node := Node{name: typedefDecl.Name.Name, kind: TypedefDecl}
	name, changed, exist, err := p.RegisterNode(node, p.declName, p.lookupOrigin)
	if err != nil {
		return fmt.Errorf("NewTypedefDecl: %s fail: %w", typedefDecl.Name.Name, err)
	}
	if exist {
		if debugLog {
			log.Printf("NewTypedefDecl: %s is processed\n", typedefDecl.Name.Name)
		}
		return nil
	}

	p.CollectNameMapping(typedefDecl.Name.Name, name)

	genDecl := p.p.NewTypeDefs()
	typeSpecdecl := genDecl.NewType(name)

	if changed {
		substObj(p.p.Types, p.p.Types.Scope(), typedefDecl.Name.Name, typeSpecdecl.Type().Obj())
	}

	deferInit := p.handleTyperefIncomplete(typedefDecl.Type, typeSpecdecl, typedefDecl.Name.Name)
	if deferInit {
		if debugLog {
			log.Printf("NewTypedefDecl: %s defer init\n", name)
		}
		return nil
	}

	typ, err := p.ToType(typedefDecl.Type)
	if err != nil {
		return fmt.Errorf("NewTypedefDecl:fail to convert type %v: %w", typedefDecl.Name.Name, err)
	}

	typeSpecdecl.InitType(p.p, typ)
	if _, ok := typ.(*types.Signature); ok {
		genDecl.SetComments(NewCommentGroup(NewTypecDocComment()))
	}

	return nil
}

func (p *Package) handleTyperefIncomplete(typeRef ast.Expr, typeSpecdecl *gogen.TypeDecl, namedName string) bool {
	var name string
	switch expr := typeRef.(type) {
	case *ast.TagExpr:
		if n, ok := expr.Name.(*ast.Ident); ok {
			name = n.Name
		} else {
			panic("todo:scoping expr not supported")
		}
	case *ast.Ident:
		name = expr.Name
	default:
		return false
	}

	_, inc := p.incompleteTypes.Lookup(name)
	if !inc {
		return false
	}

	p.incompleteTypes.Add(&Incomplete{
		cname: namedName,
		file:  p.curFile,
		decl:  typeSpecdecl,
		getType: func() (types.Type, error) {
			typ, err := p.ToType(typeRef)
			return typ, err
		},
	})
	return true
}

// Convert ast.Expr to types.Type
func (p *Package) ToType(expr ast.Expr) (types.Type, error) {
	return p.cvt.ToType(expr)
}

func (p *Package) NewTypedefs(name string, typ types.Type) *gogen.TypeDecl {
	def := p.p.NewTypeDefs()
	t := def.NewType(name)
	t.InitType(def.Pkg(), typ)
	def.Complete()
	return t
}

func (p *Package) NewEnumTypeDecl(enumTypeDecl *ast.EnumTypeDecl) error {
	skip, _ := p.handleType(enumTypeDecl.Name, enumTypeDecl.Loc)
	if skip {
		if debugLog {
			log.Printf("NewEnumTypeDecl: %v is a enum type of system header file\n", enumTypeDecl.Name)
		}
		return nil
	}
	if debugLog {
		log.Printf("NewEnumTypeDecl: %v\n", enumTypeDecl.Name)
	}
	enumType, exist, err := p.createEnumType(enumTypeDecl.Name)
	if err != nil {
		return fmt.Errorf("NewEnumTypeDecl: %v fail: %w", enumTypeDecl.Name, err)
	}
	if exist {
		if debugLog {
			log.Printf("NewEnumTypeDecl: %v is processed\n", enumTypeDecl.Name)
		}
		return nil
	}
	if len(enumTypeDecl.Type.Items) > 0 {
		err = p.createEnumItems(enumTypeDecl.Type.Items, enumType)
		if err != nil {
			return fmt.Errorf("NewEnumTypeDecl: %v fail: %w", enumTypeDecl.Name, err)
		}
	}
	return nil
}

func (p *Package) createEnumType(enumName *ast.Ident) (types.Type, bool, error) {
	var name string
	var changed bool
	var err error
	var exist bool
	var t *gogen.TypeDecl
	if enumName != nil {
		node := Node{name: enumName.Name, kind: EnumTypeDecl}
		name, changed, exist, err = p.RegisterNode(node, p.declName, p.lookupOrigin)
		if err != nil {
			return nil, false, err
		}
		if exist {
			return nil, true, nil
		}
		p.CollectNameMapping(enumName.Name, name)
	}
	enumType := p.cvt.ToDefaultEnumType()
	if name != "" {
		t = p.NewTypedefs(name, enumType)
		enumType = p.Lookup(name).Type()
	}
	if changed {
		substObj(p.p.Types, p.p.Types.Scope(), enumName.Name, t.Type().Obj())
	}
	return enumType, false, nil
}

func (p *Package) createEnumItems(items []*ast.EnumItem, enumType types.Type) error {
	defs := p.NewConstGroup()
	for _, item := range items {
		// The 'changed' parameter is intentionally ignored here because enum items are used as constant values, not type identifiers.
		// In C/C++ code, there are no type references to enum items, so there's no need to establish a cname->pubName mapping in the scope.
		// This is similar to how macro constants (Macro) are handled, as both are value-level symbols rather than type-level.
		name, _, exist, err := p.RegisterNode(Node{name: item.Name.Name, kind: EnumItem}, p.constName, p.lookupPub)
		if err != nil {
			return err
		}
		if exist {
			if debugLog {
				log.Printf("NewEnumTypeDecl: %v is processed\n", item.Name.Name)
			}
			continue
		}
		val, err := Expr(item.Value).ToInt()
		if err != nil {
			return fmt.Errorf("createEnumItems:fail to convert %T to int: %w", item.Value, err)
		}
		defs.New(val, enumType, name)
	}
	return nil
}

func (p *Package) NewMacro(macro *ast.Macro, goName string) error {
	// simple const macro define (#define NAME value)
	if len(macro.Tokens) == 2 && macro.Tokens[1].Token == ctoken.LITERAL {
		value := macro.Tokens[1].Lit
		defs := p.NewConstGroup()

		obj := p.lookupPub("", goName)
		if obj != nil {
			return fmt.Errorf("NewMacro: %s is already defined", macro.Name)
		}

		// node := Node{name: macro.Name, kind: Macro}

		// todo(zzy): remove this,current only to register name to ProcessSymbol,to keep other logic correct
		// _, _, exist, err := p.RegisterNode(node, p.constName, p.lookupPub)
		// if err != nil {
		// 	return fmt.Errorf("NewMacro: %s fail: %w", macro.Name, err)
		// }
		// if exist {
		// 	if debugLog {
		// 		log.Printf("NewMacro: %s is processed\n", macro.Name)
		// 	}
		// 	return nil
		// }
		if debugLog {
			log.Printf("NewMacro: %s = %s\n", goName, value)
		}
		if str, err := litToString(value); err == nil {
			defs.New(str, nil, goName)
		} else if _, err := litToUint(value); err == nil {
			defs.New(&goast.BasicLit{
				Kind:  token.INT,
				Value: value,
			}, nil, goName)
		} else if _, err := litToFloat(value, 64); err == nil {
			defs.New(&goast.BasicLit{
				Kind:  token.FLOAT,
				Value: value,
			}, nil, goName)
		}
	}
	return nil
}

func (p *Package) NewConstGroup() *ConstGroup {
	return NewConstGroup(p.p, p.p.Types.Scope())
}

func (p *Package) SetGoFile(fileName string) error {
	_, err := p.p.SetCurFile(fileName, true)
	// todo(zzy):avoid mark every time
	p.p.Unsafe().MarkForceUsed(p.p)
	return err
}

type ConstGroup struct {
	defs *gogen.ConstDefs
}

func NewConstGroup(pkg *gogen.Package, scope *types.Scope) *ConstGroup {
	return &ConstGroup{
		defs: pkg.NewConstDefs(scope),
	}
}

func (p *ConstGroup) New(val any, typ types.Type, name string) {
	p.defs.New(func(cb *gogen.CodeBuilder) int {
		cb.Val(val)
		return 1
	}, 0, token.NoPos, typ, name)
}

// Complete completes all incomplete type definitions,
// because some types may be implemented across multiple files.
func (p *Package) Complete() error {
	err := p.deferTypeBuild()
	if err != nil {
		return err
	}
	return nil
}

func (p *Package) autoLinkFile() string {
	return p.conf.Name + "_autogen_link.go"
}

func (p *Package) initLink() error {
	fileName := p.autoLinkFile()
	_, err := p.p.SetCurFile(fileName, true)
	if err != nil {
		return fmt.Errorf("failed to set current file: %w", err)
	}
	err = p.linkLib(p.conf.LibCommand)
	if err != nil {
		return err
	}
	return nil
}

func (p *Package) deferTypeBuild() error {
	err := p.incompleteTypes.IterateIncomplete(func(inc *Incomplete) error {
		p.SetCurFile(inc.file)
		typ, err := inc.getType()
		if typ != nil {
			inc.decl.InitType(p.p, typ)
		}
		if err != nil {
			return err
		}
		return nil
	})
	p.incompleteTypes.Clear()
	return err
}

type NameMethod func(name string) string

func (p *Package) RegisterNode(node Node, nameMethod NameMethod, lookup func(name string, pubName string) types.Object) (pubName string, changed bool, exist bool, err error) {
	pubName, exist = p.symbols.Lookup(node)
	if exist {
		return pubName, pubName != node.name, exist, nil
	}
	pubName, changed = p.GetUniqueName(node, nameMethod)
	obj := lookup(node.name, pubName)
	if obj != nil {
		return "", false, exist, NewTypeDefinedError(pubName, node.name)
	}
	return pubName, changed, exist, nil
}

// GetUniqueName generates a unique public name for a given node using the provided name transformation method.
// It ensures the generated name doesn't conflict with existing names by adding a numeric suffix if needed.
//
// Parameters:
//   - node: The node containing the original name to be transformed
//   - nameMethod: Function used to transform the original name (e.g., declName, constName)
//
// Returns:
//   - pubName: The generated unique public name
//   - changed: Whether the generated name differs from the original name
func (p *Package) GetUniqueName(node Node, nameMethod NameMethod) (pubName string, changed bool) {
	pubName = nameMethod(node.name)
	uniquePubName := p.symbols.Register(node, pubName)
	return uniquePubName, uniquePubName != node.name
}

// which is define in llcppg.cfg/typeMap
func (p *Package) definedName(name string) (string, bool) {
	definedName, ok := p.Pubs[name]
	if ok {
		if definedName == "" {
			return name, true
		}
		return definedName, true
	}
	return name, false
}

// transformName handles identifier name conversion following these rules:
// 1. First checks if the name exists in predefined mapping (in typeMap of llcppg.cfg)
// 2. If not in predefined mapping, applies the transform function
// 3. Before applying the transform function, removes specified prefixes (obtained via trimPrefixes)
//
// Parameters:
//   - name: Original C/C++ identifier name
//   - transform: Name transformation function (like names.PubName or names.ExportName)
//
// Returns:
//   - Transformed identifier name
func (p *Package) transformName(cname string, transform NameMethod) string {
	if definedName, ok := p.definedName(cname); ok {
		return definedName
	}
	return transform(name.RemovePrefixedName(cname, p.trimPrefixes()))
}

func (p *Package) declName(cname string) string {
	return p.transformName(cname, name.PubName)
}

func (p *Package) constName(cname string) string {
	return p.transformName(cname, name.ExportName)
}

func (p *Package) trimPrefixes() []string {
	if p.curFile.InCurPkg() {
		return p.conf.TrimPrefixes
	}
	return []string{}
}

// typedecl,enumdecl,funcdecl,funcdecl
// true determine continue execute the type gen
// if this type is in a third header,skip the type gen & collect the type info
func (p *Package) handleType(ident *ast.Ident, loc *ast.Location) (skip bool, anony bool) {
	anony = ident == nil
	if curPkg := p.curFile.InCurPkg(); curPkg || anony {
		return !curPkg, anony
	}
	if _, ok := p.locMap.Lookup(ident.Name); ok {
		// a third ident in multiple location is permit
		return true, anony
	}
	p.locMap.Add(ident, loc)
	return true, anony
}

// Collect the name mapping between origin name and pubname
// if in current package, it will be collected in public symbol table
func (p *Package) CollectNameMapping(originName, newName string) {
	value := ""
	if originName != newName {
		value = newName
	}
	if p.curFile.InCurPkg() {
		if !p.conf.KeepUnderScore && rune(originName[0]) == '_' {
			return
		}
		p.Pubs[originName] = value
	}
}

type ThirdTypeLoc struct {
	locMap map[string]string // type name from third package -> define location
}

func NewThirdTypeLoc() *ThirdTypeLoc {
	return &ThirdTypeLoc{
		locMap: make(map[string]string),
	}
}

func (p *ThirdTypeLoc) Add(ident *ast.Ident, loc *ast.Location) {
	p.locMap[ident.Name] = loc.File
}

func (p *ThirdTypeLoc) Lookup(name string) (string, bool) {
	loc, ok := p.locMap[name]
	return loc, ok
}

type IncompleteTypes struct {
	types    []*Incomplete          // ordered list of incomplete types
	typesMap map[string]*Incomplete // quick lookup by C name
}

type Incomplete struct {
	cname   string                     // origin name(in c)
	file    *HeaderFile                // the file where the type declaration is located
	decl    *gogen.TypeDecl            // the need to resolved later type declaration
	getType func() (types.Type, error) // will be executed after all incomplete types are initialized.
}

func NewIncompleteTypes() *IncompleteTypes {
	return &IncompleteTypes{
		types:    make([]*Incomplete, 0),
		typesMap: make(map[string]*Incomplete),
	}
}

func (it *IncompleteTypes) Add(inc *Incomplete) {
	it.types = append(it.types, inc)
	it.typesMap[inc.cname] = inc
}

func (it *IncompleteTypes) Lookup(cname string) (*Incomplete, bool) {
	inc, ok := it.typesMap[cname]
	return inc, ok
}

func (it *IncompleteTypes) Complete(cname string) {
	delete(it.typesMap, cname)
}

func (it *IncompleteTypes) Clear() {
	it.types = make([]*Incomplete, 0)
	it.typesMap = make(map[string]*Incomplete)
}

func (it *IncompleteTypes) IterateIncomplete(fn func(*Incomplete) error) error {
	for _, inc := range it.types {
		// skip the type that has been completed
		if _, ok := it.typesMap[inc.cname]; !ok {
			continue
		}
		if err := fn(inc); err != nil {
			return err
		}
	}
	return nil
}

type NodeKind int

const (
	FuncDecl NodeKind = iota + 1
	TypeDecl
	TypedefDecl
	EnumTypeDecl
	EnumItem
	Macro
)

type Node struct {
	name string
	kind NodeKind
}

func NewNode(name string, kind NodeKind) Node {
	return Node{name: name, kind: kind}
}

func (n Node) Name() string {
	return n.name
}

func (n Node) Kind() NodeKind {
	return n.kind
}

type ProcessSymbol struct {
	// not same node can have same name,so use the Node as key
	info  map[Node]string
	count map[string]int
}

func NewProcessSymbol() *ProcessSymbol {
	return &ProcessSymbol{
		info:  make(map[Node]string),
		count: make(map[string]int),
	}
}

func (p *ProcessSymbol) Lookup(node Node) (string, bool) {
	pubName, ok := p.info[node]
	return pubName, ok
}

func (p *ProcessSymbol) Register(node Node, pubName string) string {
	p.count[pubName]++
	count := p.count[pubName]
	pubName = name.SuffixCount(pubName, count)
	p.info[node] = pubName
	return pubName
}