package packetctl

import (
	"encoding/json"
	"io/fs"
	"os"

	"gitea.mmo.to/ProtocolPacketForger/ppf/packet"
)

func NewPacketStructure() *packet.Structure {
	p := packet.Structure{}
	return &p
}

func UpdateMetaData(
	pack *packet.Structure,
) {
	// still empty
}

func NewPacketLayer() *packet.Layer {
	p := packet.Layer{}
	return &p
}

func NewEmptyFieldValue() *packet.FieldValue {
	f := packet.FieldValue{}
	return &f
}

func NewFieldValue(
	value string,
) *packet.FieldValue {
	f := packet.FieldValue{
		Value: value,
	}
	return &f
}

func AppendField(pack *packet.Layer, field *packet.FieldValue) int {
	i := len(pack.Values)
	pack.Values = append(pack.Values, *field)
	return i + 1
}

func AddField(pack *packet.Layer, index int, field *packet.FieldValue) {
	if len(pack.Values) == index {
		AppendField(pack, field)
		return
	}
	ret := make([]packet.FieldValue, 0)
	ret = append(ret, pack.Values[:index]...)
	ret = append(ret, *field)
	ret = append(ret, pack.Values[index:]...)
	pack.Values = ret
}

func AppendLayer(pack *packet.Structure, layer *packet.Layer) {
	pack.Layers = append(pack.Layers, *layer)
}

func Addlayer(pack *packet.Structure, index int, layer *packet.Layer) {
	if len(pack.Layers) == index {
		AppendLayer(pack, layer)
		return
	}
	ret := make([]packet.Layer, 0)
	ret = append(ret, pack.Layers[:index]...)
	ret = append(ret, *layer)
	ret = append(ret, pack.Layers[index:]...)
	pack.Layers = ret
}

func UpdateField(pack *packet.Layer, e int, field *packet.FieldValue) {
	pack.Values[e] = *field
}

func UpdateLayer(pack *packet.Structure, e int, layer *packet.Layer) {
	pack.Layers[e] = *layer
}

func RemoveField(pack *packet.Layer, e int) {
	l := len(pack.Values) - 1
	ret := make([]packet.FieldValue, l)
	ret = append(ret, pack.Values[:e]...)
	ret = append(ret, pack.Values[e+1:]...)
	pack.Values = ret
}

func RemoveLayer(pack *packet.Structure, e int) {
	l := len(pack.Layers) - 1
	ret := make([]packet.Layer, l)
	ret = append(ret, pack.Layers[:e]...)
	ret = append(ret, pack.Layers[e+1:]...)
	pack.Layers = ret
}

func Load(pack *packet.Structure, path string) error {
	data, err := os.ReadFile(path)
	if err != nil {
		return err
	}
	err = json.Unmarshal(data, pack)
	return err
}

func ToJson(pack *packet.Structure) string {
	data, err := json.MarshalIndent(*pack, "", "  ")
	if err != nil {
		return ""
	}
	return string(data)
}

func Save(pack *packet.Structure, path string) error {
	data, err := json.MarshalIndent(*pack, "", "  ")
	if err != nil {
		return err
	}
	err = os.WriteFile(path, data, fs.ModeAppend)
	return err
}