acds.h

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#include <ascii-chat/network/acip/acds_sizes.h>
#include <ascii-chat/crypto/sizes.h>
#include <ascii-chat/common.h>
 
#pragma once
 
#include <stdint.h>
#include <stdbool.h>
#include "../../options/options.h"
#include "../../network/packet/packet.h"
#include "../../network/acip/protocol.h"
#include "../../network/webrtc/stun.h"
#include "../../network/webrtc/turn.h"
 
#ifdef __cplusplus
extern "C" {
#endif
 
// Pack network protocol structures tightly for wire format
#ifdef _WIN32
#pragma pack(push, 1)
#endif

typedef enum {
  SESSION_TYPE_DIRECT_TCP = 0, 
  SESSION_TYPE_WEBRTC = 1      
} acds_session_type_t;


typedef struct __attribute__((packed)) {
  uint8_t identity_pubkey[ED25519_PUBLIC_KEY_SIZE]; 
  uint8_t signature[ED25519_SIGNATURE_SIZE];        
  uint64_t timestamp;                               
 
  uint8_t capabilities;     
  uint8_t max_participants; 
  uint8_t session_type;     
 
  uint8_t has_password;                           
  uint8_t password_hash[ACIP_PASSWORD_HASH_SIZE]; 
  uint8_t expose_ip_publicly; 
 
  uint8_t reserved_string_len; 
  // char  reserved_string[];        ///< Variable length, follows if len > 0
 
  // Multi-key protocol: tracks which key in sequence this is
  uint8_t total_keys; 
  uint8_t key_index;  
 
  // Server connection information (where clients should connect)
  // For DIRECT_TCP: server_address and server_port specify where to connect
  // For WEBRTC: these fields are ignored, signaling happens through ACDS
  char server_address[ACIP_ADDRESS_SIZE]; 
  uint16_t server_port;                   
} acip_session_create_t;

typedef struct __attribute__((packed)) {
  uint8_t session_string_len;                       
  char session_string[ACIP_MAX_SESSION_STRING_LEN]; 
  uint8_t session_id[SESSION_ID_SIZE];              
  uint8_t participant_id[SESSION_ID_SIZE];          
  uint64_t expires_at;                              
 
  uint8_t stun_count; 
  uint8_t turn_count; 
  // Followed by: stun_server_t[stun_count], turn_server_t[turn_count]
} acip_session_created_t;


typedef struct __attribute__((packed)) {
  uint8_t session_string_len;
  char session_string[ACIP_MAX_SESSION_STRING_LEN];
} acip_session_lookup_t;

typedef struct __attribute__((packed)) {
  uint8_t found;                                
  uint8_t session_id[SESSION_ID_SIZE];          
  uint8_t host_pubkey[ED25519_PUBLIC_KEY_SIZE]; 
  uint8_t capabilities;                         
  uint8_t max_participants;
  uint8_t current_participants;
  uint8_t session_type; 
  uint8_t has_password; 
  uint64_t created_at;  
  uint64_t expires_at;  
 
  // ACDS Policy Flags (enforced by discovery server)
  uint8_t require_server_verify; 
  uint8_t require_client_verify; 
} acip_session_info_t;

typedef struct __attribute__((packed)) {
  uint8_t session_string_len;
  char session_string[ACIP_MAX_SESSION_STRING_LEN];
  uint8_t identity_pubkey[ED25519_PUBLIC_KEY_SIZE]; 
  uint8_t signature[ED25519_SIGNATURE_SIZE];        
  uint64_t timestamp;                               
 
  uint8_t has_password;
  char password[ACIP_PASSWORD_SIZE]; 
} acip_session_join_t;

typedef struct __attribute__((packed)) {
  uint8_t success;                             
  uint8_t error_code;                          
  char error_message[ACIP_ERROR_MESSAGE_SIZE]; 
 
  uint8_t participant_id[SESSION_ID_SIZE]; 
  uint8_t session_id[SESSION_ID_SIZE];     
  uint8_t initiator_id[SESSION_ID_SIZE];   
 
  // Host status for discovery mode negotiation
  uint8_t host_established;         
  uint8_t host_id[SESSION_ID_SIZE]; 
 
  // Peer information for host negotiation (only relevant if host_established == 0)
  uint8_t peer_count; 
  // Followed by: uint8_t peer_ids[peer_count][16] (variable length)
 
  // Server connection information (ONLY if success == 1 AND host_established == 1)
  uint8_t session_type;                   
  char server_address[ACIP_ADDRESS_SIZE]; 
  uint16_t server_port;                   
 
  // TURN credentials for WebRTC NAT traversal (ONLY if session_type == SESSION_TYPE_WEBRTC)
  // Generated by ACDS server using HMAC-SHA1 with shared secret
  // Format follows RFC 5766 time-limited TURN authentication
  char turn_username[ACIP_TURN_AUTH_SIZE]; 
  char turn_password[ACIP_PASSWORD_SIZE];  
} acip_session_joined_t;

typedef struct __attribute__((packed)) {
  uint8_t session_id[SESSION_ID_SIZE];                     
  uint8_t new_participant_id[SESSION_ID_SIZE];             
  uint8_t new_participant_pubkey[ED25519_PUBLIC_KEY_SIZE]; 
  uint8_t current_participant_count;                       
} acip_participant_joined_t;

typedef struct __attribute__((packed)) {
  uint8_t session_id[SESSION_ID_SIZE];          
  uint8_t left_participant_id[SESSION_ID_SIZE]; 
  uint8_t was_host;                             
  uint8_t remaining_count;                      
} acip_participant_left_t;

typedef struct __attribute__((packed)) {
  uint8_t session_id[SESSION_ID_SIZE];
  uint8_t participant_id[SESSION_ID_SIZE];
} acip_session_leave_t;

typedef struct __attribute__((packed)) {
  uint8_t session_id[SESSION_ID_SIZE];
  uint8_t signature[ED25519_SIGNATURE_SIZE]; 
} acip_session_end_t;

typedef struct __attribute__((packed)) {
  uint8_t session_id[SESSION_ID_SIZE];
  uint8_t participant_id[SESSION_ID_SIZE];
  uint8_t signature[ED25519_SIGNATURE_SIZE]; 
} acip_session_reconnect_t;



typedef struct __attribute__((packed)) {
  uint8_t session_id[SESSION_ID_SIZE];   
  uint8_t sender_id[SESSION_ID_SIZE];    
  uint8_t recipient_id[SESSION_ID_SIZE]; 
  uint8_t sdp_type;                      
  uint16_t sdp_len;                      
  // char  sdp_data[];               ///< Variable length SDP string
} acip_webrtc_sdp_t;

typedef struct __attribute__((packed)) {
  uint8_t session_id[SESSION_ID_SIZE];
  uint8_t sender_id[SESSION_ID_SIZE];
  uint8_t recipient_id[SESSION_ID_SIZE];
  uint16_t candidate_len;
  // char  candidate[];              ///< Variable length ICE candidate
} acip_webrtc_ice_t;



typedef struct __attribute__((packed)) {
  uint8_t identity_pubkey[ED25519_PUBLIC_KEY_SIZE];
  uint8_t signature[ED25519_SIGNATURE_SIZE];
  uint64_t timestamp;
  uint8_t string_len;
  char string[ACIP_MAX_SESSION_STRING_LEN];
  uint32_t duration_days; 
} acip_string_reserve_t;

typedef struct __attribute__((packed)) {
  uint8_t success;
  uint8_t error_code;
  char error_message[ACIP_ERROR_MESSAGE_SIZE];
  uint64_t expires_at; 
} acip_string_reserved_t;

typedef struct __attribute__((packed)) {
  uint8_t identity_pubkey[ED25519_PUBLIC_KEY_SIZE];
  uint8_t signature[ED25519_SIGNATURE_SIZE];
  uint64_t timestamp;
  uint8_t string_len;
  char string[ACIP_MAX_SESSION_STRING_LEN];
  uint32_t duration_days;
} acip_string_renew_t;

typedef struct __attribute__((packed)) {
  uint8_t identity_pubkey[ED25519_PUBLIC_KEY_SIZE];
  uint8_t signature[ED25519_SIGNATURE_SIZE];
  uint64_t timestamp;
  uint8_t string_len;
  char string[ACIP_MAX_SESSION_STRING_LEN];
} acip_string_release_t;



typedef struct __attribute__((packed)) {
  uint8_t session_id[SESSION_ID_SIZE];
  uint8_t num_participants; 
  // Followed by: participant_entry_t[num_participants] (variable length)
  // participant_entry_t {
  //   uint8_t participant_id[16];
  //   char address[ACIP_ADDRESS_SIZE];
  //   uint16_t port;
  //   uint8_t connection_type;
  // }
} acip_participant_list_t;

typedef struct __attribute__((packed)) {
  uint8_t participant_id[SESSION_ID_SIZE];
  char address[ACIP_ADDRESS_SIZE]; 
  uint16_t port;                   
  uint8_t connection_type;         
} acip_participant_entry_t;

typedef struct __attribute__((packed)) {
  uint8_t session_id[SESSION_ID_SIZE];
  uint8_t from_participant_id[SESSION_ID_SIZE]; 
  uint8_t to_participant_id[SESSION_ID_SIZE];   
  uint64_t round_number;                        
} acip_ring_collect_t;



typedef enum {
  ACIP_NAT_TYPE_OPEN = 0,            
  ACIP_NAT_TYPE_FULL_CONE = 1,       
  ACIP_NAT_TYPE_RESTRICTED = 2,      
  ACIP_NAT_TYPE_PORT_RESTRICTED = 3, 
  ACIP_NAT_TYPE_SYMMETRIC = 4        
} acip_nat_type_t;

typedef enum {
  ACIP_CONNECTION_TYPE_DIRECT_PUBLIC = 0, 
  ACIP_CONNECTION_TYPE_UPNP = 1,          
  ACIP_CONNECTION_TYPE_STUN = 2,          
  ACIP_CONNECTION_TYPE_TURN = 3           
} acip_connection_type_t;

typedef struct __attribute__((packed)) {
  uint8_t session_id[SESSION_ID_SIZE];
  uint8_t participant_id[SESSION_ID_SIZE];
 
  // NAT detection results
  uint8_t has_public_ip;       
  uint8_t upnp_available;      
  uint8_t upnp_mapped_port[2]; 
  uint8_t stun_nat_type;       
  uint8_t lan_reachable;       
  uint32_t stun_latency_ns;    
 
  // Bandwidth measurements (critical for host selection)
  uint32_t upload_kbps;    
  uint32_t download_kbps;  
  uint32_t rtt_to_acds_ns; 
  uint32_t jitter_ns;      
  uint8_t packet_loss_pct; 
 
  // Connection info
  char public_address[ACIP_ADDRESS_SIZE]; 
  uint16_t public_port;                   
 
  // ICE candidate summary
  uint8_t ice_candidate_types; 
} acip_nat_quality_t;

typedef struct __attribute__((packed)) {
  uint8_t session_id[SESSION_ID_SIZE];
  uint8_t host_id[SESSION_ID_SIZE];     
  char host_address[ACIP_ADDRESS_SIZE]; 
  uint16_t host_port;                   
  uint8_t connection_type;              
  uint32_t generation;                  
  uint32_t sequence;                    
} acip_host_announcement_t;

typedef struct __attribute__((packed)) {
  uint8_t session_id[SESSION_ID_SIZE];
  uint8_t host_id[SESSION_ID_SIZE];
  char host_address[ACIP_ADDRESS_SIZE];
  uint16_t host_port;
  uint8_t connection_type; 
  uint32_t generation;     
  uint32_t sequence;       
} acip_host_designated_t;

typedef struct __attribute__((packed)) {
  uint8_t session_id[SESSION_ID_SIZE];
  uint8_t participant_id[SESSION_ID_SIZE]; 
  uint8_t last_host_id[SESSION_ID_SIZE];   
  uint32_t disconnect_reason;              
  uint64_t disconnect_time_ms;             
} acip_host_lost_t;

typedef struct __attribute__((packed)) {
  uint8_t session_id[SESSION_ID_SIZE];
  uint8_t future_host_id[SESSION_ID_SIZE];     
  char future_host_address[ACIP_ADDRESS_SIZE]; 
  uint16_t future_host_port;                   
  uint8_t connection_type;                     
  uint64_t elected_at_round;                   
} acip_future_host_elected_t;



typedef struct __attribute__((packed)) {
  uint8_t error_code;                                 
  char error_message[ACIP_SIGNAL_ERROR_MESSAGE_SIZE]; 
} acip_error_t;

typedef struct __attribute__((packed)) {
  uint8_t session_id[SESSION_ID_SIZE];     
  uint8_t participant_id[SESSION_ID_SIZE]; 
  uint32_t test_size_bytes;                
  uint64_t client_send_time_ns;            
} acip_bandwidth_test_t;

typedef struct __attribute__((packed)) {
  uint32_t measured_upload_kbps;   
  uint32_t measured_download_kbps; 
  uint32_t rtt_ns;                 
  uint32_t jitter_ns;              
  uint8_t packet_loss_pct;         
} acip_bandwidth_result_t;

typedef struct __attribute__((packed)) {
  uint8_t session_id[SESSION_ID_SIZE];     
  uint8_t participant_id[SESSION_ID_SIZE]; 
  uint64_t broadcast_id;                   
  uint16_t packet_type;                    
} acip_broadcast_ack_t;

typedef enum {
  ACIP_ERROR_NONE = 0,              
  ACIP_ERROR_SESSION_NOT_FOUND = 1, 
  ACIP_ERROR_SESSION_FULL = 2,      
  ACIP_ERROR_INVALID_PASSWORD = 3,  
  ACIP_ERROR_INVALID_SIGNATURE = 4, 
  ACIP_ERROR_RATE_LIMITED = 5,      
  ACIP_ERROR_STRING_TAKEN = 6,      
  ACIP_ERROR_STRING_INVALID = 7,    
  ACIP_ERROR_INTERNAL = 255         
} acip_error_code_t;




#define ACIP_SESSION_EXPIRATION_MS (24ULL * 60 * 60 * 1000)

#define ACIP_DISCOVERY_DEFAULT_PORT OPT_ACDS_PORT_INT_DEFAULT

#define ACIP_HOST_DEFAULT_PORT OPT_PORT_INT_DEFAULT

#define ACDS_OFFICIAL_SERVER_HOSTNAME "discovery-service.ascii-chat.com"

 
#ifdef _WIN32
#pragma pack(pop)
#endif
 
#ifdef __cplusplus
}
#endif
 /* acds */