#ifndef CESSPOOL_H
#define CESSPOOL_H

#include <stddef.h>
#include <stdint.h>
#include "keys.h"
#include "dat_net.h"

// bootstrap node
// dht
// discovery
// lookup (key) ↳ lookup1
// announce
// ping
// holepunch udp

#define CESSPOOL_TOPIC_BYTES 32u
#define CESSPOOL_PEER_BYTES 32u

enum cesspool_message_type {
	CESSPOOL_LOOKUP = 0,
	CESSPOOL_ANNOUNCE = 1,
	CESSPOOL_UNANNOUNCE = 2,
	CESSPOOL_REPLY = 3,
	CESSPOOL_PING = 4,
	CESSPOOL_PONG = 5,
	CESSPOOL_HOLEPUNCH = 6
};

typedef struct cesspool_message {
	uint8_t type;
	uint8_t topic[CESSPOOL_TOPIC_BYTES];
	uint8_t peer_id[CESSPOOL_PEER_BYTES];
	uint16_t port;
	uint8_t payload[2048];
	size_t payload_len;
} cesspool_message_t;
typedef struct cesspool_request {
	uint32_t type;
	uint16_t port;
	uint8_t local_address[6];
	size_t local_address_len;
} cesspool_request_t;
typedef struct cesspool_response {
	uint8_t peers[1024];
	size_t peers_len;
	uint8_t local_peers[1024];
	size_t local_peers_len;
	/* Cesspool rendezvous records: IPv4(4), UDP port(2), peer key(32). */
	uint8_t peer_info[2048];
	size_t peer_info_len;
} cesspool_response_t;

#define CESSPOOL_MAX_BOOTSTRAP 16u
#define CESSPOOL_MAX_PEERS 256u
#define CESSPOOL_MAX_TOPICS 64u
#define CESSPOOL_MAX_ANNOUNCEMENTS 1024u
#define CESSPOOL_MAX_TRANSACTIONS 64u
typedef struct cesspool_peer {
	dat_peer_t address;
	uint8_t public_key[32];
	uint8_t discovery_topic[CESSPOOL_TOPIC_BYTES];
	uint64_t last_seen;
	unsigned failures;
	int local;
	int discovered;
} cesspool_peer_t;
typedef struct cesspool_topic {
	uint8_t key[32];
	uint16_t port;
	int announcing;
	int looking_up;
	uint64_t refresh_at;
} cesspool_topic_t;
typedef struct cesspool_transaction {
	uint16_t id;
	uint8_t target[32];
	uint8_t type;
	uint64_t expires_at;
	int active;
} cesspool_transaction_t;
typedef struct cesspool_announcement {
	uint8_t topic[CESSPOOL_TOPIC_BYTES];
	uint8_t peer_id[CESSPOOL_PEER_BYTES];
	dat_peer_t address;
	uint64_t last_seen;
} cesspool_announcement_t;
struct cesspool;
typedef void (*cesspool_transport_packet_fn)(struct cesspool *pool,
						 const dat_peer_t *source,
						 const uint8_t *packet,
						 size_t packet_len);
typedef struct cesspool {
	datnet_t net;
	dat_peer_t bootstrap_nodes[CESSPOOL_MAX_BOOTSTRAP];
	size_t bootstrap_count;
	uint16_t port;
	int ready;
	int bootstrap_server;
	cesspool_peer_t peers[CESSPOOL_MAX_PEERS];
	size_t peer_count;
	cesspool_topic_t topics[CESSPOOL_MAX_TOPICS];
	size_t topic_count;
	/* A peer may announce many topics; keep each membership independently. */
	cesspool_announcement_t announcements[CESSPOOL_MAX_ANNOUNCEMENTS];
	size_t announcement_count;
	uint64_t bootstrap_last_seen;
	uint64_t bootstrap_probe_at;
	int bootstrap_reachable;
	cesspool_transaction_t transactions[CESSPOOL_MAX_TRANSACTIONS];
	uint16_t next_transaction;
	void (*on_peer)(struct cesspool *, const cesspool_peer_t *);
	void (*on_holepunch)(struct cesspool *, const dat_peer_t *);
	cesspool_transport_packet_fn on_transport_packet;
	void *transport_context;
} cesspool_t;

int cesspool_discovery_key(const uint8_t public_key[32], uint8_t topic[32]);
int cesspool_encode(const cesspool_message_t *message, uint8_t *out,
		    size_t capacity, size_t *written);
int cesspool_decode(cesspool_message_t *message, const uint8_t *input,
		    size_t input_len);
int cesspool_request_encode(const cesspool_request_t *request, uint8_t *out,
			    size_t capacity, size_t *written);
int cesspool_request_decode(cesspool_request_t *request, const uint8_t *input,
			    size_t input_len);
int cesspool_response_encode(const cesspool_response_t *response, uint8_t *out,
			     size_t capacity, size_t *written);
int cesspool_response_decode(cesspool_response_t *response, const uint8_t *input,
			     size_t input_len);
int cesspool_process_response(cesspool_t *pool,
			      const cesspool_response_t *response,
			      const uint8_t local_prefix[2]);
int cesspool_init(cesspool_t *pool, const uint8_t peer_id[32]);
int cesspool_add_bootstrap(cesspool_t *pool, const char *host, uint16_t port);
/* Load Cesspool bootstrap endpoints from DDAT_BOOTSTRAP and the per-user
 * config/dat-gpt/bootstrap file. */
int cesspool_configure_bootstraps(cesspool_t *pool);
int cesspool_bootstrap_config_add(const char *endpoint);
int cesspool_bootstrap_config_set(const char *endpoint);
int cesspool_bootstrap_config_get(char *endpoint, size_t capacity);
int cesspool_bootstrap_config_list(char *contents, size_t capacity);
int cesspool_bootstrap(cesspool_t *pool);
int cesspool_listen(cesspool_t *pool, const char *host, uint16_t port);
int cesspool_set_bootstrap_server(cesspool_t *pool, int enabled);
int cesspool_announce(cesspool_t *pool, const uint8_t topic[32], uint16_t port);
int cesspool_lookup(cesspool_t *pool, const uint8_t topic[32]);
int cesspool_unannounce(cesspool_t *pool, const uint8_t topic[32], uint16_t port);
int cesspool_ping(cesspool_t *pool, const dat_peer_t *peer);
int cesspool_holepunch(cesspool_t *pool, const dat_peer_t *peer);
int cesspool_poll(cesspool_t *pool, int timeout_ms);
int cesspool_add_peer(cesspool_t *pool, const cesspool_peer_t *peer);
int cesspool_remove_peer(cesspool_t *pool, const uint8_t public_key[32]);
cesspool_peer_t *cesspool_find_peer(cesspool_t *pool, const uint8_t public_key[32]);
int cesspool_join(cesspool_t *pool, const uint8_t topic[32], uint16_t port,
		  int announce, int lookup);
int cesspool_leave(cesspool_t *pool, const uint8_t topic[32]);
int cesspool_tick(cesspool_t *pool, uint64_t now_ms);
size_t cesspool_closest(cesspool_t *pool, const uint8_t target[32],
			cesspool_peer_t **out, size_t capacity);
size_t cesspool_topic_peers(cesspool_t *pool,
			    const uint8_t topic[CESSPOOL_TOPIC_BYTES],
			    cesspool_peer_t **out, size_t capacity);
size_t cesspool_announced_peer_count(const cesspool_t *pool);
size_t cesspool_announced_topic_count(const cesspool_t *pool);
int cesspool_transaction_begin(cesspool_t *pool, uint8_t type,
			       const uint8_t target[32], uint64_t expires_at,
			       uint16_t *transaction_id);
int cesspool_transaction_finish(cesspool_t *pool, uint16_t transaction_id);
int cesspool_destroy(cesspool_t *pool);

#endif /* CESSPOOL_H */