#ifndef _rtcp_header_h_
#define _rtcp_header_h_

#include <stdint.h>

#define RTCP_V(v)   ((v >> 30) & 0x03) // rtcp version
#define RTCP_P(v)   ((v >> 29) & 0x01) // rtcp padding
#define RTCP_RC(v)  ((v >> 24) & 0x1F) // rtcp reception report count
#define RTCP_PT(v)  ((v >> 16) & 0xFF) // rtcp packet type
#define RTCP_LEN(v) (v & 0xFFFF)       // rtcp packet length

// https://www.iana.org/assignments/rtp-parameters/rtp-parameters.xhtml
enum rtcp_type_t {
    RTCP_FIR = 192,     // RFC2032, Reserved (Historic-FIR)
    RTCP_NACK = 193,    // RFC2032, Reserved (Historic-NACK)
    RTCP_SMPTETC = 194, // RFC5484
    RTCP_IJ = 195,      // RFC5450

    RTCP_SR = 200,
    RTCP_RR = 201,
    RTCP_SDES = 202,
    RTCP_BYE = 203,
    RTCP_APP = 204,

    RTCP_RTPFB = 205, // RFC4585
    RTCP_PSFB = 206,  // RFC4585
    RTCP_XR = 207,    // RFC3611
    RTCP_AVB = 208,
    RTCP_RSI = 209,   // RFC5760
    RTCP_TOKEN = 210, // RFC6284
    RTCP_IDMS = 211,  // RFC7272
    RTCP_RGRS = 212,  // RFC8861

    RTCP_LIMIT = 223, // RFC5761 RTCP packet types in the ranges 1-191 and 224-254 SHOULD only be used when other values
                      // have been exhausted.
};

// https://www.iana.org/assignments/rtp-parameters/rtp-parameters.xhtml#rtp-parameters-5
enum rtcp_sdes_type_t {
    RTCP_SDES_END = 0,     // RFC3550
    RTCP_SDES_CNAME = 1,   // RFC3550
    RTCP_SDES_NAME = 2,    // RFC3550
    RTCP_SDES_EMAIL = 3,   // RFC3550
    RTCP_SDES_PHONE = 4,   // RFC3550
    RTCP_SDES_LOC = 5,     // RFC3550
    RTCP_SDES_TOOL = 6,    // RFC3550
    RTCP_SDES_NOTE = 7,    // RFC3550
    RTCP_SDES_PRIVATE = 8, // RFC3550
    RTCP_SDES_CADDR = 9,   // H.323 callable address
    RTCP_SDES_APSI = 10,   // RFC6776
    RTCP_SDES_RGRP = 11,   // RFC8861
    RTCP_SDES_RID = 12,    // RFC8852
    RTCP_SDES_RRID = 13,   // RFC8852
    RTCP_SDES_CCID = 14,   // RFC8849
    RTCP_SDES_MID = 15,    // RFC8843
};

// https://www.iana.org/assignments/rtp-parameters/rtp-parameters.xhtml#rtp-parameters-8
enum rtcp_rtpfb_type_t {
    RTCP_RTPFB_NACK = 1,   // RFC4585, Generic NACK
    RTCP_RTPFB_TMMBR = 3,  // RFC5104, Temporary Maximum Media Stream Bit Rate Request (TMMBR)
    RTCP_RTPFB_TMMBN = 4,  // RFC5104, Temporary Maximum Media Stream Bit Rate Notification (TMMBN)
    RTCP_RTPFB_SRREQ = 5,  // RFC6051, RTCP Rapid Resynchronisation Request(RTCP-SR-REQ)
    RTCP_RTPFB_RAMS = 6,   // RFC6285, Rapid Acquisition of Multicast Sessions
    RTCP_RTPFB_TLLEI = 7,  // RFC6642, Transport-Layer Third-Party Loss Early Indication
    RTCP_RTPFB_ECN = 8,    // RFC6679, RTCP ECN Feedback
    RTCP_RTPFB_PS = 9,     // RFC7728, Media Pause/Resume
    RTCP_RTPFB_DBI = 10,   // 3GPP TS 26.114 v16.3.0, Delay Budget Information (DBI)
    RTCP_RTPFB_CCFB = 11,  // RFC8888, RTP Congestion Control Feedback
    RTCP_RTPFB_TCC01 = 15, // draft-holmer-rmcat-transport-wide-cc-extensions-01

    RTCP_RTPFB_EXT = 31,
};

// https://www.iana.org/assignments/rtp-parameters/rtp-parameters.xhtml#rtp-parameters-9
enum rtcp_psfb_type_t {
    RTCP_PSFB_PLI = 1,   // RFC4585, Picture Loss Indication (PLI)
    RTCP_PSFB_SLI = 2,   // RFC4585, Slice Loss Indication (SLI)
    RTCP_PSFB_RPSI = 3,  // RFC4585, Reference Picture Selection Indication (RPSI)
    RTCP_PSFB_FIR = 4,   // RFC5104, Full Intra Request (FIR)
    RTCP_PSFB_TSTR = 5,  // RFC5104, Temporal-Spatial Trade-off Request
    RTCP_PSFB_TSTN = 6,  // RFC5104, Temporal-Spatial Trade-off Notification
    RTCP_PSFB_VBCM = 7,  // RFC5104, Video Back Channel Message
    RTCP_PSFB_PSLEI = 8, // RFC6642, Payload-Specific Third-Party Loss Early Indication
    RTCP_PSFB_ROI = 9,   // 3GPP TS 26.114 v16.3.0, Video region-of-interest (ROI)
    RTCP_PSFB_LRR = 10,  // RFC-ietf-avtext-lrr-07, Layer Refresh Request Command
    RTCP_PSFB_AFB = 15,  // RFC4585, Application layer FB (AFB) message
    RTCP_PSFB_REMB = 15, // https://datatracker.ietf.org/doc/html/draft-alvestrand-rmcat-remb-03#section-2.2

    RTCP_PSFB_EXT = 31,
};

// https://www.iana.org/assignments/rtcp-xr-block-types/rtcp-xr-block-types.xhtml
enum rtcp_xr_type_t {
    RTCP_XR_LRLE = 1, // RFC3611, Loss RLE Report Block
    RTCP_XR_DRLE = 2, // RFC3611, Duplicate RLE Report Block
    RTCP_XR_PRT = 3,  // RFC3611, Packet Receipt Times Report Block
    RTCP_XR_RRT = 4,  // RFC3611, Receiver Reference Time Report Block
    RTCP_XR_DLRR = 5, // RFC3611, DLRR Report Block
    RTCP_XR_SS = 6,   // RFC3611, Statistics Summary Report Block
    RTCP_XR_VM = 7,   // RFC3611, VoIP Metrics Report Block
    RTCP_XR_RTCP = 8, // RFC5093, RTCP XR

    RTCP_XR_IDMS = 12, // RFC7272, IDMS Report Block
    RTCP_XR_ECN = 13,  // RFC6679, ECN Summary Report

    RTCP_XR_DISRLE = 25, // RFC7097, DRLE (Discard RLE Report)
    RTCP_XR_BDR = 26,    // RFC7243, BDR (Bytes Discarded Report)
    RTCP_XR_RFISD = 27,  // RFC7244, RFISD (RTP Flows Initial Synchronization Delay)
    RTCP_XR_RFSO = 28,   // RFC7244, RFSO (RTP Flows Synchronization Offset Metrics Block)
};

typedef struct _rtcp_header_t {
    uint32_t v : 2;       // version
    uint32_t p : 1;       // padding
    uint32_t rc : 5;      // reception report count
    uint32_t pt : 8;      // packet type
    uint32_t length : 16; /* pkt len in words, w/o this word */
} rtcp_header_t;

typedef struct _rtcp_sr_t // sender report
{
    uint32_t ssrc;
    uint32_t ntpmsw; // ntp timestamp MSW(in second)
    uint32_t ntplsw; // ntp timestamp LSW(in picosecond)
    uint32_t rtpts;  // rtp timestamp
    uint32_t spc;    // sender packet count
    uint32_t soc;    // sender octet count
} rtcp_sr_t;

typedef struct _rtcp_rr_t // receiver report
{
    uint32_t ssrc;
} rtcp_rr_t;

typedef struct _rtcp_rb_t // report block
{
    uint32_t ssrc;
    uint32_t fraction : 8;    // fraction lost
    uint32_t cumulative : 24; // cumulative number of packets lost
    uint32_t exthsn;          // extended highest sequence number received
    uint32_t jitter;          // interarrival jitter
    uint32_t lsr;             // last SR
    uint32_t dlsr;            // delay since last SR
} rtcp_rb_t;

// source description RTCP packet
typedef struct _rtcp_sdes_item_t {
    uint8_t pt; // chunk type
    uint8_t len;
    uint8_t *data;
} rtcp_sdes_item_t;

typedef struct _rtcp_bye_t {
    const void *reason;
    int bytes; // reason length
} rtcp_bye_t;

typedef struct _rtcp_app_t {
    uint8_t subtype;
    char name[4];
    void *data;
    int bytes; // data length
} rtcp_app_t;

// Slice Loss Indication (SLI)
typedef struct _rtcp_sli_t {
    uint32_t first : 13;  // The macroblock (MB) address of the first lost macroblock.
    uint32_t number : 13; // The number of lost macroblocks, in scan order
    uint32_t picture_id : 6;
} rtcp_sli_t;

// Full Intra Request (FIR)
typedef struct _rtcp_fir_t {
    uint32_t ssrc;
    uint32_t sn : 8; // Command sequence number
    uint32_t reserved : 19;
    uint32_t index : 5; // for TSTR
} rtcp_fir_t;

// Video Back Channel Message (VBCM)
typedef struct _rtcp_vbcm_t {
    uint32_t ssrc;
    uint32_t sn : 8; // Command sequence number
    uint32_t reserved : 1;
    uint32_t pt : 7;
    uint32_t len : 16;
    void *payload;
} rtcp_vbcm_t;

// Layer Refresh Request
typedef struct _rtcp_lrr_t {
    uint32_t ssrc;

    uint32_t sn : 8; // Command sequence number
    uint32_t c : 1;
    uint32_t payload : 7;
    uint32_t reserved : 16; // Reserved

    uint32_t res1 : 5; // reserved
    uint32_t ttid : 3; // Target Temporal Layer ID (TTID) (3 bits)
    uint32_t tlid : 8; // Target Layer ID (TLID) (8 bits)
    uint32_t res2 : 5; // reserved
    uint32_t ctid : 3; // Current Temporal Layer ID (CTID) (3 bits)
    uint32_t clid : 8; // Current Layer ID (CLID) (8 bits)
} rtcp_lrr_t;

// Generic NACK
typedef struct _rtcp_nack_t {
    uint16_t pid; // Packet ID (PID)
    uint16_t blp; // bitmask of following lost packets (BLP)
} rtcp_nack_t;

// Temporary Maximum Media Stream Bit Rate Request (TMMBR)
typedef struct _rtcp_tmmbr_t {
    uint32_t ssrc;
    uint32_t exp : 6;       // MxTBR Exp (6 bits)
    uint32_t mantissa : 17; // MxTBR Mantissa (17 bits)
    uint32_t overhead : 9;  // Measured Overhead (9 bits)

    // maximum total media bit rate(MxTBR)
    // MxTBR = mantissa * 2^exp
} rtcp_tmmbr_t;

// RTP/AVPF Transport-Layer ECN Feedback Packet(ECN)
typedef struct _rtcp_ecn_t {
    uint32_t ext_highest_seq; // 32-bit extended highest sequence number received
    uint32_t ect[2];          // The 32-bit cumulative number of RTP packets received from this SSRC.
    uint16_t ect_ce_counter;
    uint16_t not_ect_counter;
    uint16_t lost_packets_counter;
    uint16_t duplication_counter;
} rtcp_ecn_t;

typedef struct _rtcp_remb_t {
    uint32_t ssrc;
    uint32_t exp : 6;       // BR Exp (6 bits)
    uint32_t mantissa : 18; // BR Mantissa (18 bits) in bps

    // maximum total media bit rate(MxTBR)
    // MxTBR = mantissa * 2^exp
} rtcp_remb_t;

// RTP Congestion Control Feedback
typedef struct _rtcp_ccfb_t {
    uint32_t seq : 16;
    uint32_t received : 1;
    uint32_t ecn : 2; // 00 if not received or if ECN is not used
    // uint32_t ato : 13;

    int16_t ato; // ms * 1024, Arrival time offset (ATO, 13 bits) & (TCC-01 16 bits)
} rtcp_ccfb_t;

// DLRR Report Block
typedef struct _rtcp_dlrr_t {
    uint32_t ssrc;
    uint32_t lrr;
    uint32_t dlrr;
} rtcp_dlrr_t;

typedef struct _rtcp_rtpfb_t {
    uint32_t media; // media ssrc

    union {
        // RTCP_RTPFB | (RTCP_RTPFB_NACK << 8)
        // RTCP_RTPFB | (RTCP_RTPFB_TLLEI << 8)
        struct {
            rtcp_nack_t *nack;
            int count;
        } nack;

        // RTCP_RTPFB | (RTCP_RTPFB_TMMBR << 8)
        // RTCP_RTPFB | (RTCP_RTPFB_TMMBN << 8)
        struct {
            rtcp_tmmbr_t *tmmbr;
            int count;
        } tmmbr;

        // RTCP_RTPFB | (RTCP_RTPFB_CCFB << 8)
        // RTCP_RTPFB | (RTCP_RTPFB_TCC01 << 8)
        struct {
            rtcp_ccfb_t *ccfb;
            int count;

            int32_t timestamp;
            uint32_t begin : 16;
            uint32_t cc : 8; // TCC01 only

            uint32_t ssrc; // ccfb only
        } tcc01;

        // RTCP_RTPFB | (RTCP_RTPFB_PS << 8)
        struct {
            uint32_t target;
            uint32_t cmd : 8;
            uint32_t len : 8;
            uint32_t id : 16;
            void *payload;
        } ps;

        // RTCP_RTPFB | (RTCP_RTPFB_ECN << 8)
        rtcp_ecn_t ecn;

        // RTCP_RTPFB | (RTCP_RTPFB_DBI << 8)
        struct {
            uint32_t delay : 16;
            uint32_t s : 1;
            uint32_t q : 1;
        } dbi;
    } u;
} rtcp_rtpfb_t;

typedef struct _rtcp_psfb_t {
    uint32_t media; // media ssrc

    union {
        // RTCP_PSFB | (RTCP_PSFB_PLI << 8)

        // RTCP_PSFB | (RTCP_PSFB_SLI << 8)
        struct {
            rtcp_sli_t *sli;
            int count;
        } sli;

        // RTCP_PSFB | (RTCP_PSFB_FIR << 8)
        // RTCP_PSFB | (RTCP_PSFB_TSTR << 8)
        // RTCP_PSFB | (RTCP_PSFB_TSTN << 8)
        struct {
            rtcp_fir_t *fir;
            int count;
        } fir;

        // RTCP_PSFB | (RTCP_PSFB_VBCM << 8)
        struct {
            uint8_t pt;
            uint32_t len; // length in bit
            void *payload;
        } rpsi;

        // RTCP_PSFB | (RTCP_PSFB_VBCM << 8)
        rtcp_vbcm_t vbcm;

        // RTCP_PSFB | (RTCP_PSFB_PSLEI << 8)
        struct {
            uint32_t *ssrc;
            int count;
        } pslei;

        // RTCP_PSFB | (RTCP_PSFB_LRR << 8)
        struct {
            rtcp_lrr_t *lrr;
            int count;
        } lrr;

        // RTCP_PSFB | (RTCP_PSFB_AFB << 8)
        struct {
            rtcp_remb_t *remb;
            int count;
        } afb;
    } u;
} rtcp_psfb_t;

typedef struct _rtcp_xr_t {
    union {
        // RTCP_XR | (RTCP_XR_LRLE << 8)
        // RTCP_XR | (RTCP_XR_DRLE << 8)
        struct {
            uint32_t source;     // SSRC of source
            uint32_t begin : 16; // begin_seq
            uint32_t end : 16;   // end_seq
            uint8_t *chunk;
            int count;
        } rle; // lrle/drle

        // RTCP_XR | (RTCP_XR_PRT << 8)
        struct {
            uint32_t source;     // SSRC of source
            uint32_t begin : 16; // begin_seq
            uint32_t end : 16;   // end_seq
            uint32_t *timestamp;
            int count;
        } prt;

        // RTCP_XR | (RTCP_XR_RRT << 8)
        uint64_t rrt;

        // RTCP_XR | (RTCP_XR_DLRR << 8)
        struct {
            rtcp_dlrr_t *dlrr;
            int count;
        } dlrr;

        // RTCP_XR | (RTCP_XR_ECN << 8)
        rtcp_ecn_t ecn;
    } u;
} rtcp_xr_t;

#endif /* !_rtcp_header_h_ */