lorawan

type DataPayload struct {
	FHDR FHDR `json:"fhdr"`
	// FPort: 1 byte. nil when FRMPayload is empty.
	FPort *int `json:"f_port,omitempty"`
	// FRMPayloadHex is the encrypted application payload as hex.
	// Empty when no FRMPayload is present. We do not decrypt
	// (needs AppSKey / NwkSEncKey out-of-band).
	FRMPayloadHex string `json:"frm_payload_hex,omitempty"`
}

type FCtrl struct {
	Raw int  `json:"raw"`
	ADR bool `json:"adr"`
	// ADRACKReq is set on uplinks only.
	ADRACKReq bool `json:"adr_ack_req,omitempty"`
	ACK       bool `json:"ack"`
	// ClassB is set on uplinks only; FPending on downlinks only.
	ClassB   bool `json:"class_b,omitempty"`
	FPending bool `json:"f_pending,omitempty"`
	FOptsLen int  `json:"f_opts_len"`
}

type FHDR struct {
	// DevAddr is the 32-bit device address. Stored on the wire
	// little-endian; we render the big-endian hex form here so
	// it matches the form network servers / chirpstack use.
	DevAddrHex string `json:"dev_addr_hex"`
	DevAddr    uint32 `json:"dev_addr"`
	FCtrl      FCtrl  `json:"f_ctrl"`
	FCnt       int    `json:"f_cnt"`
	// FOptsHex is the optional MAC-command field (up to 15
	// bytes). Surfaced as hex; we don't dissect MAC commands
	// here (that's a follow-on Spec when a caller materialises).
	FOptsHex string `json:"f_opts_hex,omitempty"`
}

type JoinAccept struct {
	// AppNonce is the 3-byte network-supplied nonce.
	AppNonceHex string `json:"app_nonce_hex"`
	// NetID is the 3-byte network identifier.
	NetIDHex string `json:"net_id_hex"`
	// DevAddr is the 4-byte device address assigned to the
	// device for this session.
	DevAddrHex string `json:"dev_addr_hex"`
	DevAddr    uint32 `json:"dev_addr"`
	// DLSettings is the downlink-settings byte (RX1 DR offset +
	// RX2 data rate).
	DLSettings int `json:"dl_settings"`
	// RxDelay is the receive delay byte (0-15 seconds).
	RxDelay int `json:"rx_delay"`
	// CFListHex is the optional 16-byte channel-frequency list.
	// Empty when absent.
	CFListHex string `json:"cf_list_hex,omitempty"`
}

type JoinRequest struct {
	// JoinEUI is the 8-byte EUI-64 of the Join Server (LoRaWAN
	// 1.0.x called this AppEUI). Wire form is little-endian; we
	// render the big-endian hex here so it matches the form
	// printed on device labels.
	JoinEUIHex string `json:"join_eui_hex"`
	// DevEUI is the 8-byte EUI-64 of the device. Same little-
	// endian-on-wire convention.
	DevEUIHex string `json:"dev_eui_hex"`
	// DevNonce is the 2-byte little-endian device-supplied nonce.
	DevNonce int `json:"dev_nonce"`
}

type MHDR struct {
	Raw    int    `json:"raw"`
	MType  int    `json:"mtype"`
	Name   string `json:"mtype_name"`
	Major  int    `json:"major"`
	Uplink bool   `json:"uplink"`
}

type MType int

type PHYPayload struct {
	// MHDR is the parsed MAC header.
	MHDR MHDR `json:"mhdr"`
	// MIC is the 4-byte Message Integrity Code at the frame end.
	MICHex string `json:"mic_hex"`
	// Data is set for the data-frame MTypes (2-5).
	Data *DataPayload `json:"data,omitempty"`
	// JoinRequest is set when MType == 0.
	JoinRequest *JoinRequest `json:"join_request,omitempty"`
	// JoinAccept is set when MType == 1 (assumes operator has
	// decrypted the body).
	JoinAccept *JoinAccept `json:"join_accept,omitempty"`
	// RejoinRequestHex is set when MType == 6 (Rejoin Request).
	// We surface the raw bytes — Rejoin Type byte then variable
	// fields per LoRaWAN 1.1 §6.2.4.
	RejoinRequestHex string `json:"rejoin_request_hex,omitempty"`
	// ProprietaryHex is set when MType == 7.
	ProprietaryHex string `json:"proprietary_hex,omitempty"`
	// PayloadHex is the raw PHYPayload for callers that want to
	// re-render or audit.
	PayloadHex string `json:"payload_hex"`
}