package protocolctl

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

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

func NewProtocolStructure() *protocol.ProtocolStructure {
	p := protocol.ProtocolStructure{}
	return &p
}

func UpdateMetaData(
	prot *protocol.ProtocolStructure,
	name string,
	version string,
	tcpiplayer uint,
	osilayer uint,
	extensionTo string,
	desc string,
	requiredJSfunctions []string,
	lowerLayerIdent map[string]string,
) {
	prot.Metadata.Name = name
	prot.Metadata.Description = desc
	prot.Metadata.ExtensionTo = extensionTo
	prot.Metadata.Version = version
	prot.Metadata.OSILayer = osilayer
	prot.Metadata.TCPIPLayer = tcpiplayer
	prot.Metadata.RequiredJSFunctions = requiredJSfunctions
	prot.Metadata.LowerLayerIdentification = lowerLayerIdent
}

func NewField(
	name string,
	desc string,
	regex string,
	size uint,
	subfields []protocol.Field,
	optional bool,
	payload bool,
) *protocol.Field {
	f := protocol.Field{
		Name:      name,
		Desc:      desc,
		Regex:     regex,
		Size:      size,
		SubFields: subfields,
		Optional:  optional,
		Payload:   payload,
	}
	return &f
}

func AppendField(prot *protocol.ProtocolStructure, field *protocol.Field) {
	prot.Structure = append(prot.Structure, *field)
}

func UpdateFieldByName(prot *protocol.ProtocolStructure, name string, field *protocol.Field) {
	var fnd int = -1
	for i, f := range prot.Structure {
		if f.Name == name {
			fnd = i
		}
	}
	if fnd != -1 {
		prot.Structure[fnd] = *field
	}
}

func UpdateFieldByElement(prot *protocol.ProtocolStructure, element int, field *protocol.Field) {
	prot.Structure[element] = *field
}

func RemoveFieldByName(prot *protocol.ProtocolStructure, name string) {
	element := -1
	for i, f := range prot.Structure {
		if f.Name == name {
			element = i
		}
	}
	if element == -1 {
		return
	}
	RemoveFieldByElement(prot, element)
}

func RemoveFieldByElement(prot *protocol.ProtocolStructure, field int) {
	ret := make([]protocol.Field, 0)
	ret = append(ret, prot.Structure[:field]...)
	ret = append(ret, prot.Structure[field+1:]...)
	prot.Structure = ret
}

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

func LoadNew(path string) (*protocol.ProtocolStructure, error) {
	prot := NewProtocolStructure()
	err := Load(prot, path)
	return prot, err
}

func ToJson(prot *protocol.ProtocolStructure) string {
	data, err := json.Marshal(*prot)
	if err != nil {
		return ""
	}
	return string(data)
}

func Save(prot *protocol.ProtocolStructure, path string) error {
	data, err := json.Marshal(*prot)
	if err != nil {
		return err
	}
	err = os.WriteFile(path, data, fs.ModeAppend)
	return err
}