#define MESSAGE_LENGTH 256
#define COMMAND_LENGTH 16

#define HEARTBEAT_INTERVAL 3 // in seconds
#define HEARTBEAT_TIMEOUT 10

typedef enum {
  Message = 1,
  Login,
  Logout,
  Hearbeat,
  List,
  JoinGroup,
  LeaveGroup,
  Mute,
  Unmute,
  Signal,
  Inbox
} Command_t;

typedef enum {
  ACK_ACCEPTED = 0,
  ACK_DELIVERED,
  ERR_UNKNOWN_COMMAND,
  ERR_NOT_LOGGED_IN,
  ERR_ALREADY_LOGGED_IN,
  ERR_ALREADY_IN_GROUP,
  ERR_USER_NOT_FOUND,
  ERR_USER_MUTED,
  ERR_INVALID_FORMAT
} Signal_t;

typedef struct {
  Command_t mtype;
  Signal_t stype; // Used with mtype = signal. Responses from the server - to
                  // specify errors or acks
  char sender[COMMAND_LENGTH];  // Who sent the message
  char command[COMMAND_LENGTH]; // Functions as an attribute to mtype -
                                // nicknames, id to send/mute to
  char message[MESSAGE_LENGTH]; // Actual message content
} msgbuf_t;