/*
 * Copyright (c) 2016-present The ZLMediaKit project authors. All Rights Reserved.
 *
 * This file is part of ZLMediaKit(https://github.com/ZLMediaKit/ZLMediaKit).
 *
 * Use of this source code is governed by MIT-like license that can be found in the
 * LICENSE file in the root of the source tree. All contributing project authors
 * may be found in the AUTHORS file in the root of the source tree.
 */

#ifndef ZLMEDIAKIT_RTCPFCI_H
#define ZLMEDIAKIT_RTCPFCI_H

#include "Rtcp.h"

namespace mediakit {
#pragma pack(push, 1)

/////////////////////////////////////////// PSFB ////////////////////////////////////////////////////

// PSFB fmt = 2
// https://tools.ietf.org/html/rfc4585#section-6.3.2.2
//     0                   1                   2                   3
//     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
//    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//    |            First        |        Number           | PictureID |
//    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// First: 13 bits
//       The macroblock (MB) address of the first lost macroblock.  The MB
//       numbering is done such that the macroblock in the upper left
//       corner of the picture is considered macroblock number 1 and the
//       number for each macroblock increases from left to right and then
//       from top to bottom in raster-scan order (such that if there is a
//       total of N macroblocks in a picture, the bottom right macroblock
//       is considered macroblock number N).
//
//    Number: 13 bits
//       The number of lost macroblocks, in scan order as discussed above.
//
//    PictureID: 6 bits
//       The six least significant bits of the codec-specific identifier
//       that is used to reference the picture in which the loss of the
//       macroblock(s) has occurred.  For many video codecs, the PictureID
//       is identical to the Temporal Reference.
class FCI_SLI {
public:
    static size_t constexpr kSize = 4;

    FCI_SLI(uint16_t first, uint16_t number, uint8_t pic_id);

    void check(size_t size);
    uint16_t getFirst() const;
    uint16_t getNumber() const;
    uint8_t getPicID() const;
    std::string dumpString() const;

private:
    uint32_t data;
};

#if 0
//PSFB fmt = 3
//https://tools.ietf.org/html/rfc4585#section-6.3.3.2
//    0                   1                   2                   3
//    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   |      PB       |0| Payload Type|    Native RPSI bit string     |
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   |   defined per codec          ...                | Padding (0) |
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
class FCI_RPSI {
public:
    //The number of unused bits required to pad the length of the RPSI
    //      message to a multiple of 32 bits.
    uint8_t pb;

#if __BYTE_ORDER == __BIG_ENDIAN
    //0:  1 bit
    //      MUST be set to zero upon transmission and ignored upon reception.
    uint8_t zero : 1;
    //Payload Type: 7 bits
    //      Indicates the RTP payload type in the context of which the native
    //      RPSI bit string MUST be interpreted.
    uint8_t pt : 7;
#else
    uint8_t pt: 7;
    uint8_t zero: 1;
#endif

    // Native RPSI bit string: variable length
    //      The RPSI information as natively defined by the video codec.
    char bit_string[5];

    //Padding: #PB bits
    //      A number of bits set to zero to fill up the contents of the RPSI
    //      message to the next 32-bit boundary.  The number of padding bits
    //      MUST be indicated by the PB field.
    uint8_t padding;

    static size_t constexpr kSize = 8;
};
#endif

// PSFB fmt = 4
// https://tools.ietf.org/html/rfc5104#section-4.3.1.1
//     0                   1                   2                   3
//     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
//    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//    |                              SSRC                             |
//    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//    | Seq nr.       |    Reserved                                   |
//    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
class FCI_FIR {
public:
    static size_t constexpr kSize = 8;

    FCI_FIR(uint32_t ssrc, uint8_t seq_number, uint32_t reserved = 0);

    void check(size_t size);
    uint32_t getSSRC() const;
    uint8_t getSeq() const;
    uint32_t getReserved() const;
    std::string dumpString() const;

private:
    uint32_t ssrc;
    uint8_t seq_number;
    uint8_t reserved[3];
};

#if 0
//PSFB fmt = 5
//https://tools.ietf.org/html/rfc5104#section-4.3.2.1
// 0                   1                   2                   3
//    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   |                              SSRC                             |
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   |  Seq nr.      |  Reserved                           | Index   |
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
class FCI_TSTR {
public:
    static size_t constexpr kSize = 8;

    void check(size_t size) {
        CHECK(size == kSize);
    }

private:
    uint8_t data[kSize];
};

//PSFB fmt = 6
//https://tools.ietf.org/html/rfc5104#section-4.3.2.1
// 0                   1                   2                   3
//    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   |                              SSRC                             |
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   |  Seq nr.      |  Reserved                           | Index   |
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
class FCI_TSTN : public FCI_TSTR{

};

//PSFB fmt = 7
//https://tools.ietf.org/html/rfc5104#section-4.3.4.1
//0                   1                   2                   3
//    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   |                              SSRC                             |
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   | Seq nr.       |0| Payload Type| Length                        |
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   |                    VBCM Octet String....      |    Padding    |
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
class FCI_VBCM {
public:
    static size_t constexpr kSize = 12;

    void check(size_t size) {
        CHECK(size == kSize);
    }

private:
    uint8_t data[kSize];
};

#endif

// PSFB fmt = 15
// https://tools.ietf.org/html/draft-alvestrand-rmcat-remb-03
//     0                   1                   2                   3
//     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
//    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//    |  Unique identifier 'R' 'E' 'M' 'B'                            |
//    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//    |  Num SSRC     | BR Exp    |  BR Mantissa                      |
//    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//    |   SSRC feedback                                               |
//    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//    |  ...                                                          |
//  Num SSRC (8 bits):  Number of SSRCs in this message.
//
//    BR Exp (6 bits):   The exponential scaling of the mantissa for the
//                maximum total media bit rate value, ignoring all packet
//                overhead.  The value is an unsigned integer [0..63], as
//                in RFC 5104 section 4.2.2.1.
//
//    BR Mantissa (18 bits):   The mantissa of the maximum total media bit
//                rate (ignoring all packet overhead) that the sender of
//                the REMB estimates.  The BR is the estimate of the
//                traveled path for the SSRCs reported in this message.
//                The value is an unsigned integer in number of bits per
//                second.
//
//    SSRC feedback (32 bits)  Consists of one or more SSRC entries which
//                this feedback message applies to.
class FCI_REMB {
public:
    static size_t constexpr kSize = 8;

    static std::string create(const std::vector<uint32_t> &ssrcs, uint32_t bitrate);
    void check(size_t size);
    std::string dumpString() const;
    uint32_t getBitRate() const;
    std::vector<uint32_t> getSSRC();

private:
    // Unique identifier 'R' 'E' 'M' 'B'
    char magic[4];
    // Num SSRC (8 bits)/BR Exp (6 bits)/ BR Mantissa (18 bits)
    uint8_t bitrate[4];
    // SSRC feedback (32 bits)  Consists of one or more SSRC entries which
    //               this feedback message applies to.
    uint32_t ssrc_feedback[1];
};

/////////////////////////////////////////// RTPFB ////////////////////////////////////////////////////

// RTPFB fmt = 1
// https://tools.ietf.org/html/rfc4585#section-6.2.1
//  0                   1                   2                   3
//     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
//    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//    |            PID                |             BLP               |
//    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
class FCI_NACK {
public:
    static constexpr size_t kSize = 4;
    static constexpr size_t kBitSize = 16;

    FCI_NACK(uint16_t pid_h, const std::vector<bool> &type);

    void check(size_t size);
    uint16_t getPid() const;
    uint16_t getBlp() const;
    // 返回丢包列表，总长度17，第一个包必丢  [AUTO-TRANSLATED:5d5cd4b8]
    // Return the list of lost packets, total length 17, the first packet must be lost
    //  TODO: replace std::bitset
    std::vector<bool> getBitArray() const;
    std::string dumpString() const;

private:
    // The PID field is used to specify a lost packet.  The PID field
    //      refers to the RTP sequence number of the lost packet.
    uint16_t pid;
    // bitmask of following lost packets (BLP): 16 bits
    uint16_t blp;
};

#if 0
//RTPFB fmt = 3
//https://tools.ietf.org/html/rfc5104#section-4.2.1.1
//    0                   1                   2                   3
//    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   |                              SSRC                             |
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   | MxTBR Exp |  MxTBR Mantissa                 |Measured Overhead|
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
class FCI_TMMBR {
public:
    static size_t constexpr kSize = 8;

    void check(size_t size) {
        CHECK(size == kSize);
    }

private:
    //SSRC (32 bits): The SSRC value of the media sender that is
    //              requested to obey the new maximum bit rate.
    uint32_t ssrc;

    //     MxTBR Exp (6 bits): The exponential scaling of the mantissa for the
    //              maximum total media bit rate value.  The value is an
    //              unsigned integer [0..63].
    //     MxTBR Mantissa (17 bits): The mantissa of the maximum total media
    //              bit rate value as an unsigned integer.
    //     Measured Overhead (9 bits): The measured average packet overhead
    //              value in bytes.  The measurement SHALL be done according
    //              to the description in section 4.2.1.2. The value is an
    //              unsigned integer [0..511].
    uint32_t max_tbr;
};

//RTPFB fmt = 4
// https://tools.ietf.org/html/rfc5104#section-4.2.2.1
// 0                   1                   2                   3
//    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   |                              SSRC                             |
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   | MxTBR Exp |  MxTBR Mantissa                 |Measured Overhead|
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
class FCI_TMMBN : public FCI_TMMBR{
public:

};
#endif

enum class SymbolStatus : uint8_t {
    // Packet not received
    not_received = 0,
    // Packet received, small delta （所谓small detal是指能用一个字节表示的数值）  [AUTO-TRANSLATED:50af3beb]
    // Packet received, small delta (so-called small delta refers to a value that can be represented by one byte)
    small_delta = 1,
    // Packet received, large ornegative delta （large即是能用两个字节表示的数值）  [AUTO-TRANSLATED:7a16594d]
    // Packet received, large or negative delta (large is a value that can be represented by two bytes)
    large_delta = 2,
    // Reserved
    reserved = 3
};

// RTPFB fmt = 15
// https://tools.ietf.org/html/draft-holmer-rmcat-transport-wide-cc-extensions-01#section-3.1
// https://zhuanlan.zhihu.com/p/206656654
//    0                   1                   2                   3
//    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   |      base sequence number     |      packet status count      |
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   |                 reference time                | fb pkt. count |
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   |          packet chunk         |         packet chunk          |
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   .                                                               .
//   .                                                               .
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   |         packet chunk          |  recv delta   |  recv delta   |
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   .                                                               .
//   .                                                               .
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   |           recv delta          |  recv delta   | zero padding  |
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
class FCI_TWCC {
public:
    static size_t constexpr kSize = 8;
    using TwccPacketStatus
        = std::map<uint16_t /*rtp ext seq*/, std::pair<SymbolStatus, int16_t /*recv delta,单位为250us*/>>;
    void check(size_t size);
    std::string dumpString(size_t total_size) const;
    uint16_t getBaseSeq() const;
    // 单位64ms  [AUTO-TRANSLATED:992ffed7]
    // Unit 64ms
    uint32_t getReferenceTime() const;
    uint16_t getPacketCount() const;
    TwccPacketStatus getPacketChunkList(size_t total_size) const;

    static std::string create(uint32_t ref_time, uint8_t fb_pkt_count, TwccPacketStatus &status);

private:
    // base sequence number,基础序号,本次反馈的第一个包的序号;也就是RTP扩展头的序列号  [AUTO-TRANSLATED:4e43ffcc]
    // base sequence number, basic sequence number, the sequence number of the first packet in this feedback; that is, the sequence number of the RTP extension header
    uint16_t base_seq;
    // packet status count, 包个数,本次反馈包含多少个包的状态;从基础序号开始算  [AUTO-TRANSLATED:533efb94]
    // packet status count, number of packets, how many packet statuses are included in this feedback; counted from the base sequence number
    uint16_t pkt_status_count;
    // reference time,基准时间,绝对时间;计算该包中每个媒体包的到达时间都要基于这个基准时间计算  [AUTO-TRANSLATED:5265d98e]
    // reference time, reference time, absolute time; the arrival time of each media packet in this packet is calculated based on this reference time
    uint8_t ref_time[3];
    // feedback packet count,反馈包号,本包是第几个transport-cc包，每次加1                          |  [AUTO-TRANSLATED:1ff6d73e]
    // feedback packet count, feedback packet number, this packet is the nth transport-cc packet, incremented by 1 each time                          |
    uint8_t fb_pkt_count;
};
#pragma pack(pop)
} // namespace mediakit
#endif // ZLMEDIAKIT_RTCPFCI_H