package netproto

import (
	"encoding/base64"
)

type MainHeader struct {
	Version          uint8             `json:"version"`
	Meta             map[string]string `json:"meta"`
	ExtensionHeaders []ExtensionHeader `json:"extension_headers"`
}

const (
	MainHeaderVersion1 = 1
)

const (
	ExtensionHeaderType_Source            uint8 = 1 /* https://git.send.nrw/sendnrw/sendnrwlib/issues/1 */
	ExtensionHeaderType_Destination       uint8 = 2 /* https://git.send.nrw/sendnrw/sendnrwlib/issues/1 */
	ExtensionHeaderType_PayloadDefinition uint8 = 3
	ExtensionHeaderType_Protocol          uint8 = 4
	ExtensionHeaderType_Control           uint8 = 5 /*Syn/SynAck/Ack/AckFin/Fin*/
	ExtensionHeaderType_Crypto            uint8 = 6 /*Hinweis auf eine Verschlüsselung*/
	ExtensionHeaderType_Validation        uint8 = 7 /*Hinweis auf eine Validierung oder Checksum*/
	ExtensionHeaderType_Routing           uint8 = 8 /*Hinweis auf eine Routing-Information*/
)

const (
	ControlFlag_Flow_SYN                string = "SYN"
	ControlFlag_Flow_SYNACK             string = "SYNACK"
	ControlFlag_Flow_ACK                string = "ACK"
	ControlFlag_Flow_ACKFIN             string = "ACKFIN"
	ControlFlag_Flow_FIN                string = "FIN"
	ControlFlag_Encryption_INSECURE     string = "INSECURE"
	ControlFlag_Encryption_STAYINSECURE string = "STAYINSECURE"
	ControlFlag_Encryption_SECURESTART  string = "SECURESTART"
	ControlFlag_Encryption_SECUREACCEPT string = "SECUREACCEPT"
	ControlFlag_Encryption_SECUREFAIL   string = "SECUREFAIL"
)

func GenerateEHT1(IPv4, IPv6, Port string) ExtensionHeader {
	return ExtensionHeader{
		Type: ExtensionHeaderType_Source,
		Meta: map[string]string{"version": "1.0"},
		Data: map[string]string{"ipv4": IPv4, "ipv6": IPv6, "port": Port},
	}
}

func GenerateEHT2(IPv4, IPv6, Port string) ExtensionHeader {
	return ExtensionHeader{
		Type: ExtensionHeaderType_Destination,
		Meta: map[string]string{"version": "1.0"},
		Data: map[string]string{"ipv4": IPv4, "ipv6": IPv6, "port": Port},
	}
}

func GenerateEHT3(PayloadMime, PayloadLength, PayloadChecksum string) ExtensionHeader {
	return ExtensionHeader{
		Type: ExtensionHeaderType_PayloadDefinition,
		Meta: map[string]string{"version": "1.0"},
		Data: map[string]string{"payloadmime": PayloadMime, "payloadlength": PayloadLength, "payloadchecksum": PayloadChecksum},
	}
}

func GenerateEHT4(ProtocolName, ProtocolVersion, ProtocolOID string) ExtensionHeader {
	return ExtensionHeader{
		Type: ExtensionHeaderType_Protocol,
		Meta: map[string]string{"version": "1.0"},
		Data: map[string]string{"protocolname": ProtocolName, "protocolversion": ProtocolVersion, "protocoloid": ProtocolOID},
	}
}

func GenerateEHT5(ControlFlagFlow, ControlFlagEncryption string) ExtensionHeader {
	return ExtensionHeader{
		Type: ExtensionHeaderType_Control,
		Meta: map[string]string{"version": "1.0"},
		Data: map[string]string{"controlflagflow": ControlFlagFlow, "controlflagencryption": ControlFlagEncryption},
	}
}

func GenerateEHT6(PublicKey string) ExtensionHeader {
	return ExtensionHeader{
		Type: ExtensionHeaderType_Crypto,
		Meta: map[string]string{"version": "1.0"},
		Data: map[string]string{"publickey": PublicKey},
	}
}

func GenerateEHT7(Checksum string) ExtensionHeader {
	return ExtensionHeader{
		Type: ExtensionHeaderType_Validation,
		Meta: map[string]string{"version": "1.0"},
		Data: map[string]string{"checksum": Checksum},
	}
}

func GenerateMainHeader(Version uint8, Flag string, ExH ...ExtensionHeader) MainHeader {
	return MainHeader{
		Version:          Version,
		Meta:             map[string]string{"version": "1.0", "flag": Flag},
		ExtensionHeaders: ExH,
	}
}

func GenerateNetworkProtocol(mainheader MainHeader, payload string) NetworkProtocol {
	return NetworkProtocol{
		Header:  mainheader,
		Payload: payload,
	}
}

func EncodeBase64(input string) (string, error) {
	return base64.StdEncoding.EncodeToString([]byte(input)), nil
}

func DecodeBase64(input string) (string, error) {
	d, err := base64.StdEncoding.DecodeString(input)
	if err != nil {
		return "", err
	}
	return string(d), nil
}

type ExtensionHeader struct {
	Type uint8             `json:"type"`
	Meta map[string]string `json:"meta"`
	Data map[string]string `json:"data"`
}

type NetworkProtocol struct {
	Header  MainHeader `json:"header"`
	Payload string     `json:"payload"`
}