#define ECP_RBUF_FLAG_IN_RBUF       0x01
#define ECP_RBUF_FLAG_IN_MSGQ       0x02
#define ECP_RBUF_FLAG_IN_TIMER      0x04
#define ECP_RBUF_FLAG_SKIP          0x08

#define ECP_RBUF_FLAG_CCONTROL      0x01
#define ECP_RBUF_FLAG_RELIABLE      0x02
#define ECP_RBUF_FLAG_MSGQ          0x04

#define ECP_MTYPE_RBACK             0x04
#define ECP_MTYPE_RBFLUSH           0x05
#define ECP_MTYPE_RBTIMER           0x06
#define ECP_MTYPE_NOP               0x07

#define ECP_ERR_RBUF_DUP            -100

typedef uint32_t ecp_win_t;

/* size must be power of 2 */
#define ECP_RBUF_IDX_MASK(idx, size)    ((idx) & ((size) - 1))
#define ecp_rbuf_skip(mtype)            ((mtype & ECP_MTYPE_MASK) < ECP_MTYPE_NOP ? 1 : 0)

#ifdef ECP_WITH_MSGQ
#include "msgq.h"
#endif

typedef struct ECPRBTimerItem {
    ECPTimerItem item;
    unsigned char empty;
} ECPRBTimerItem;

typedef struct ECPRBTimer {
    ECPRBTimerItem item[ECP_MAX_TIMER];
    unsigned short idx_w;
#ifdef ECP_WITH_PTHREAD
    pthread_mutex_t mutex;
#endif
} ECPRBTimer;

typedef struct ECPRBMessage {
    unsigned char buf[ECP_MAX_MSG];
    size_t size;
    unsigned char flags;
} ECPRBMessage;

typedef struct ECPRBPacket {
    unsigned char buf[ECP_MAX_PKT];
    size_t size;
    unsigned char flags;
    ECPRBTimerItem *timer;
} ECPRBPacket;

typedef struct ECPRBuffer {
    ecp_seq_t seq_start;
    ecp_seq_t seq_max;
    unsigned short arr_size;
    unsigned short idx_start;
    union {
        ECPRBMessage *msg;
        ECPRBPacket *pkt;
    } arr;
} ECPRBuffer;

typedef struct ECPRBRecv {
    unsigned char flags;
    ecp_cts_t deliver_delay;
    unsigned short hole_max;
    unsigned short ack_rate;
    unsigned short ack_pkt;
    ecp_seq_t seq_ack;
    ecp_ack_t ack_map;
    ECPRBuffer rbuf;
#ifdef ECP_WITH_MSGQ
    ECPConnMsgQ msgq;
#endif
    struct ECPFragIter *frag_iter;
} ECPRBRecv;

typedef struct ECPRBSend {
    unsigned char flags;
    ecp_win_t win_size;
    ecp_win_t in_transit;
    ecp_win_t cnt_cc;
    ecp_seq_t seq_cc;
    ecp_seq_t seq_flush;
    ecp_seq_t seq_nack;
    unsigned char flush;
    unsigned int nack_rate;
    ECPRBuffer rbuf;
    ECPRBTimer *timer;
#ifdef ECP_WITH_PTHREAD
    pthread_mutex_t mutex;
#endif
} ECPRBSend;

typedef struct ECPConnRBuffer {
    ECPRBRecv *recv;
    ECPRBSend *send;
} ECPConnRBuffer;

int _ecp_rbuf_start(ECPRBuffer *rbuf, ecp_seq_t seq);
int _ecp_rbuf_msg_idx(ECPRBuffer *rbuf, ecp_seq_t seq, unsigned short *idx);

int ecp_rbuf_create(struct ECPConnection *conn, ECPRBSend *buf_s, ECPRBPacket *msg_s, unsigned int msg_s_size, ECPRBRecv *buf_r, ECPRBMessage *msg_r, unsigned int msg_r_size);
void ecp_rbuf_destroy(struct ECPConnection *conn);
ssize_t ecp_rbuf_pld_send(struct ECPConnection *conn, struct ECPBuffer *packet, struct ECPBuffer *payload, size_t pld_size, unsigned char flags, ecp_seq_t seq);
int ecp_rbuf_handle_seq(struct ECPConnection *conn, unsigned char mtype);
int ecp_rbuf_set_seq(struct ECPConnection *conn, struct ECPSeqItem *si, unsigned char *payload, size_t pld_size);
ssize_t ecp_rbuf_pkt_send(struct ECPConnection *conn, struct ECPSocket *sock, ECPNetAddr *addr, struct ECPBuffer *packet, size_t pkt_size, unsigned char flags, ECPTimerItem *ti, struct ECPSeqItem *si);

int ecp_rbuf_recv_create(struct ECPConnection *conn, ECPRBRecv *buf, ECPRBMessage *msg, unsigned short msg_size);
void ecp_rbuf_recv_destroy(struct ECPConnection *conn);
int ecp_rbuf_recv_start(struct ECPConnection *conn, ecp_seq_t seq);
int ecp_rbuf_set_hole(struct ECPConnection *conn, unsigned short hole_max);
int ecp_rbuf_set_delay(struct ECPConnection *conn, ecp_cts_t delay);

ssize_t ecp_rbuf_store(struct ECPConnection *conn, ecp_seq_t seq, unsigned char *msg, size_t msg_size, struct ECP2Buffer *b);
struct ECPFragIter *ecp_rbuf_get_frag_iter(struct ECPConnection *conn);

int ecp_rbuf_send_create(struct ECPConnection *conn, ECPRBSend *buf, ECPRBPacket *msg, unsigned short msg_size);
void ecp_rbuf_send_destroy(struct ECPConnection *conn);
int ecp_rbuf_send_start(struct ECPConnection *conn);
int ecp_rbuf_flush(struct ECPConnection *conn);
int ecp_rbuf_set_wsize(struct ECPConnection *conn, ecp_win_t size);

ssize_t ecp_rbuf_handle_ack(struct ECPConnection *conn, ecp_seq_t seq, unsigned char mtype, unsigned char *msg, ssize_t size, struct ECP2Buffer *b);
ssize_t ecp_rbuf_handle_flush(struct ECPConnection *conn, ecp_seq_t seq, unsigned char mtype, unsigned char *msg, ssize_t size, struct ECP2Buffer *b);
ssize_t ecp_rbuf_handle_timer(struct ECPConnection *conn, ecp_seq_t seq, unsigned char mtype, unsigned char *msg, ssize_t size, struct ECP2Buffer *b);