package nstd

import (
	"git.noahlan.cn/noahlan/ntool/nstr"
	"reflect"
	"runtime"
	"strings"
)

// FullFcName struct.
type FullFcName struct {
	// FullName eg: git.noahlan.cn/noahlan/ntool/nstd.IsNil
	FullName string
	pkgPath  string
	pkgName  string
	funcName string
}

// Parse the full func name.
func (ffn *FullFcName) Parse() {
	if ffn.funcName != "" {
		return
	}

	i := strings.LastIndex(ffn.FullName, "/")

	ffn.pkgPath = ffn.FullName[:i+1]
	// spilt get pkg and func name
	ffn.pkgName, ffn.funcName = nstr.MustCut(ffn.FullName[i+1:], ".")

	ffn.pkgPath += ffn.pkgName
}

// PkgPath string get. eg: git.noahlan.cn/noahlan/ntool/nstd
func (ffn *FullFcName) PkgPath() string {
	ffn.Parse()
	return ffn.pkgPath
}

// PkgName string get. eg: nstd
func (ffn *FullFcName) PkgName() string {
	ffn.Parse()
	return ffn.pkgName
}

// FuncName get short func name. eg: IsNil
func (ffn *FullFcName) FuncName() string {
	ffn.Parse()
	return ffn.funcName
}

// String get full func name string.
func (ffn *FullFcName) String() string {
	return ffn.FullName
}

// FuncName get full func name, contains pkg path.
//
// eg:
//
//	// OUTPUT: git.noahlan.cn/noahlan/ntool/nstd.IsNil
//	nstd.FuncName(nstd.PkgName)
func FuncName(fn any) string {
	return runtime.FuncForPC(reflect.ValueOf(fn).Pointer()).Name()
}

// CutFuncName get pkg path and short func name
func CutFuncName(fullFcName string) (pkgPath, shortFnName string) {
	ffn := FullFcName{FullName: fullFcName}
	return ffn.PkgPath(), ffn.FuncName()
}

// PkgName get current package name
//
// Usage:
//
//	fullFcName := nstd.FuncName(fn)
//	pgkName := nstd.PkgName(fullFcName)
func PkgName(fullFcName string) string {
	for {
		lastPeriod := strings.LastIndex(fullFcName, ".")
		lastSlash := strings.LastIndex(fullFcName, "/")
		if lastPeriod > lastSlash {
			fullFcName = fullFcName[:lastPeriod]
		} else {
			break
		}
	}
	return fullFcName
}