package client

import (
	"strings"

	protocolnnet "git.noahlan.cn/noahlan/nnet/v2/internal/protocol/nnet"
	protocolpkg "git.noahlan.cn/noahlan/nnet/v2/pkg/protocol"
	unpackerpkg "git.noahlan.cn/noahlan/nnet/v2/pkg/unpacker"
)

type unpackingProtocol interface {
	Unpacker() unpackerpkg.Unpacker
}

func newApplicationProtocol(name string) protocolpkg.Protocol {
	switch strings.ToLower(strings.TrimSpace(name)) {
	case "", "none", "raw":
		return nil
	case "nnet":
		return protocolnnet.NewNNetProtocol("1.0")
	default:
		return nil
	}
}

func newApplicationUnpacker(protocol protocolpkg.Protocol) unpackerpkg.Unpacker {
	if protocol == nil {
		return nil
	}
	if provider, ok := protocol.(unpackingProtocol); ok {
		return provider.Unpacker()
	}
	return nil
}

func encodeApplicationMessage(protocol protocolpkg.Protocol, data []byte) ([]byte, error) {
	if protocol == nil {
		return data, nil
	}
	return protocol.Encode(data, nil)
}

func decodeApplicationMessage(protocol protocolpkg.Protocol, frame []byte) ([]byte, error) {
	if protocol == nil {
		msg := make([]byte, len(frame))
		copy(msg, frame)
		return msg, nil
	}
	_, body, err := protocol.Decode(frame)
	if err != nil {
		return nil, err
	}
	msg := make([]byte, len(body))
	copy(msg, body)
	return msg, nil
}