dht

type Bep44Return struct {
	V   bencode.Bytes `bencode:"v,omitempty"`
	K   [32]byte      `bencode:"k,omitempty"`
	Sig [64]byte      `bencode:"sig,omitempty"`
	Seq *int64        `bencode:"seq,omitempty"`
}

type Bep51Return struct {
	Interval *int64 `bencode:"interval,omitempty"`
	Num      *int64 `bencode:"num,omitempty"`
	// Nodes supporting this extension should always include the samples field in the response, even
	// when it is zero-length. This lets indexing nodes to distinguish nodes supporting this
	// extension from those that respond to unknown query types which contain a target field [2].
	Samples *CompactInfohashes `bencode:"samples,omitempty"`
}

type CompactIPv4NodeInfo []NodeInfo

type CompactIPv6NodeInfo []NodeInfo

type CompactInfohashes []ID

type Error struct {
	Code int
	Msg  string
}

type ID = protocol.ID

type Msg struct {
	Q        string   `bencode:"q,omitempty"` // Query method (one of 4: "ping", "find_node", "get_peers", "announce_peer")
	A        *MsgArgs `bencode:"a,omitempty"` // named arguments sent with a query
	T        string   `bencode:"t"`           // required: transaction ID
	Y        string   `bencode:"y"`           // required: type of the message: q for QUERY, r for RESPONSE, e for ERROR
	R        *Return  `bencode:"r,omitempty"` // RESPONSE type only
	E        *Error   `bencode:"e,omitempty"` // ERROR type only
	IP       NodeAddr `bencode:"ip,omitempty"`
	ReadOnly bool     `bencode:"ro,omitempty"` // BEP 43. Sender does not respond to queries.
	// https://www.libtorrent.org/dht_extensions.html
	ClientId string `bencode:"v,omitempty"`
}

type MsgArgs struct {
	ID       ID `bencode:"id"`                  // ID of the querying Node
	InfoHash ID `bencode:"info_hash,omitempty"` // InfoHash of the torrent
	Target   ID `bencode:"target,omitempty"`    // ID of the node sought
	// Token received from an earlier get_peers query. Also used in a BEP 44 put.
	Token       string `bencode:"token,omitempty"`
	Port        *int   `bencode:"port,omitempty"`         // Sender's torrent port
	ImpliedPort bool   `bencode:"implied_port,omitempty"` // Use senders apparent DHT port
	Want        []Want `bencode:"want,omitempty"`         // Contains strings like "n4" and "n6" from BEP 32.
	NoSeed      int    `bencode:"noseed,omitempty"`       // BEP 33
	Scrape      int    `bencode:"scrape,omitempty"`       // BEP 33

	// I don't know if we should use bencode.Bytes for this. If we unmarshalled bytes that didn't
	// marshal back the same, our hashes will not match. But this might also serve to prevent abuse.
	V interface{} `bencode:"v,omitempty"`
	// Why is this optional? Because I think we need to know if it wasn't set rather than use a
	// default value.
	Seq  *int64   `bencode:"seq,omitempty"`
	Cas  int64    `bencode:"cas,omitempty"`
	K    [32]byte `bencode:"k,omitempty"`
	Salt []byte   `bencode:"salt,omitempty"`
	Sig  [64]byte `bencode:"sig,omitempty"`
}

type NodeAddr struct {
	IP   net.IP
	Port int
}

type NodeInfo struct {
	ID   protocol.ID
	Addr NodeAddr
}

type RecvMsg struct {
	Msg  Msg
	From netip.AddrPort
}

type Return struct {
	// All returns are supposed to contain an ID, but what if they don't?
	ID ID `bencode:"id"` // ID of the queried (and responding) node

	// k closest nodes to the requested target. Included in responses to queries that imply
	// traversal, for example get_peers, find_nodes, get, sample_infohashes.
	Nodes  CompactIPv4NodeInfo `bencode:"nodes,omitempty"`
	Nodes6 CompactIPv6NodeInfo `bencode:"nodes6,omitempty"`

	Token  *string    `bencode:"token,omitempty"`  // Token for future announce_peer or put (BEP 44)
	Values []NodeAddr `bencode:"values,omitempty"` // Torrent peers

	// BEP 33 (scrapes)
	BFsd *ScrapeBloomFilter `bencode:"BFsd,omitempty"`
	BFpe *ScrapeBloomFilter `bencode:"BFpe,omitempty"`

	Bep51Return

	// BEP 44
	Bep44Return
}

type ScrapeBloomFilter [256]byte

type Want string