Files
snoop_device/src/Services/WhipClient.h
2025-10-13 20:01:16 +03:00

238 lines
9.1 KiB
C++

// src/Services/WhipClient.h
#pragma once
#define CPPHTTPLIB_OPENSSL_SUPPORT
#include <memory>
#include <string>
#include <string_view>
#include <atomic>
#include <mutex>
#include <optional>
#include <filesystem>
#include <vector>
#include <regex>
#include <array>
#include <random>
#include <cstdint>
#include <cstring>
#include <spdlog/spdlog.h>
#include <nlohmann/json.hpp>
#include <httplib.h> // build with CPPHTTPLIB_OPENSSL_SUPPORT
#include <rtc/rtc.hpp>
#include <rtc/peerconnection.hpp>
#include <rtc/description.hpp>
#include <rtc/track.hpp>
namespace snoop
{
class WhipClient
{
public:
struct Params
{
std::string whipUrl; // full WHIP endpoint (may include ?token=...)
std::string caPath; // CA chain
std::string crtPath; // client cert
std::string keyPath; // client key (temp extracted from keyctl)
int sampleRate = 48000;
int channels = 1; // 1 or 2; timestamp advance uses PCM frames per channel
};
explicit WhipClient(Params p) : m_p(std::move(p)) {}
~WhipClient() { Stop(); }
void Start()
{
std::lock_guard lk(m_mtx);
if (m_started)
return;
rtc::Configuration cfg;
m_pc = std::make_shared<rtc::PeerConnection>(cfg);
m_pc->onStateChange([this](rtc::PeerConnection::State s)
{ spdlog::info("WHIP pc state: {}", (int)s); });
m_pc->onGatheringStateChange([this](rtc::PeerConnection::GatheringState s)
{ spdlog::info("WHIP gathering state: {}", (int)s); });
m_pc->onLocalDescription([this](rtc::Description desc)
{
try {
const std::string offer = std::string(desc);
auto [answer, resourceUrl] = PostOfferWHIP(offer);
m_resourceUrl = resourceUrl;
m_pc->setRemoteDescription(rtc::Description(answer, "answer"));
spdlog::info("WHIP remote description set");
} catch (const std::exception& e) {
spdlog::error("WHIP POST offer failed: {}", e.what());
} });
m_pc->onLocalCandidate([this](rtc::Candidate c)
{
if (!m_resourceUrl) return;
try { PatchCandidateWHIP(c); }
catch (const std::exception& e) { spdlog::warn("WHIP PATCH candidate failed: {}", e.what()); } });
// Create a sendonly audio track
rtc::Description::Audio audioDesc("audio", rtc::Description::Direction::SendOnly);
// Opus PT typically negotiated to 111 by browsers; we'll use 111 in RTP header
m_track = m_pc->addTrack(audioDesc);
// Initialize RTP state (random SSRC/seq)
std::mt19937 rng{std::random_device{}()};
m_ssrc = std::uniform_int_distribution<uint32_t>()(rng);
m_seq = std::uniform_int_distribution<uint16_t>()(rng);
m_ts = 0; // RTP clock for Opus is 48kHz
// Create SDP offer (triggers onLocalDescription)
m_pc->setLocalDescription();
m_started = true;
}
void Stop()
{
std::lock_guard lk(m_mtx);
if (!m_started)
return;
m_track.reset();
m_pc.reset();
m_resourceUrl.reset();
m_started = false;
}
// Call this from your Opus encoder callback.
// opusData: encoded Opus frame bytes
// opusBytes: length
// pcmFramesPerChannel: number of PCM samples per channel represented by this Opus frame (e.g., 960 for 20ms @48k).
void PushOpus(const unsigned char *opusData, size_t opusBytes, int pcmFramesPerChannel)
{
std::lock_guard lk(m_mtx);
if (!m_track || !m_started)
return;
// Build RTP header (12 bytes)
std::array<uint8_t, 12> rtp{};
rtp[0] = 0x80; // V=2, P=0, X=0, CC=0
rtp[1] = 0x80 | (m_pt & 0x7F); // M=1 (end of frame), PT
rtp[2] = uint8_t(m_seq >> 8);
rtp[3] = uint8_t(m_seq & 0xFF);
rtp[4] = uint8_t(m_ts >> 24);
rtp[5] = uint8_t((m_ts >> 16) & 0xFF);
rtp[6] = uint8_t((m_ts >> 8) & 0xFF);
rtp[7] = uint8_t(m_ts & 0xFF);
rtp[8] = uint8_t(m_ssrc >> 24);
rtp[9] = uint8_t((m_ssrc >> 16) & 0xFF);
rtp[10] = uint8_t((m_ssrc >> 8) & 0xFF);
rtp[11] = uint8_t(m_ssrc & 0xFF);
// Concatenate header + payload
rtc::binary packet;
packet.resize(rtp.size() + opusBytes);
std::memcpy(packet.data(), rtp.data(), rtp.size());
std::memcpy(packet.data() + rtp.size(), opusData, opusBytes);
// Send RTP on the media track
m_track->send(packet); // libdatachannel expects RTP bytes on tracks
// Advance RTP state
++m_seq;
// For Opus @ 48k clock, timestamp increments by the PCM frame count per channel
// (do not multiply by channels)
m_ts += static_cast<uint32_t>(pcmFramesPerChannel);
}
private:
Params m_p;
std::shared_ptr<rtc::PeerConnection> m_pc;
std::shared_ptr<rtc::Track> m_track;
std::optional<std::string> m_resourceUrl;
std::mutex m_mtx;
std::atomic<bool> m_started{false};
// RTP state
uint32_t m_ssrc = 0;
uint16_t m_seq = 0;
uint32_t m_ts = 0;
uint8_t m_pt = 111; // dynamic payload type commonly used for Opus
// --- WHIP HTTP helpers (mTLS-capable) ---
static std::tuple<std::string, std::string> ExtractAnswerAndLocation(const httplib::Result &r)
{
if (!r)
throw std::runtime_error("No HTTP result");
if (r->status != 201 && r->status != 200)
throw std::runtime_error("Unexpected WHIP status: " + std::to_string(r->status));
std::string answer = r->body;
std::string resourceUrl;
if (r->has_header("Location"))
resourceUrl = r->get_header_value("Location");
return {answer, resourceUrl};
}
std::pair<std::string, std::string> PostOfferWHIP(const std::string &sdpOffer)
{
auto [cli, path] = MakeClientForUrl(sdpOffer, m_p.whipUrl);
auto res = cli->Post(path.c_str(), sdpOffer, "application/sdp");
auto [answer, resUrl] = ExtractAnswerAndLocation(res);
return {answer, resUrl};
}
void PatchCandidateWHIP(const rtc::Candidate &cand)
{
if (!m_resourceUrl)
return;
auto [cli, path] = MakeClientForUrl(std::string(""), *m_resourceUrl);
std::string frag = "a=" + std::string(cand);
auto res = cli->Patch(path.c_str(), frag, "application/trickle-ice-sdpfrag");
if (!res || (res->status < 200 || res->status >= 300))
{
spdlog::warn("WHIP PATCH {} -> {}", path, res ? res->status : -1);
}
}
// Build client + path for URL; uses mTLS when https
std::pair<std::unique_ptr<httplib::SSLClient>, std::string>
MakeClientForUrl(const std::string &body, const std::string &url)
{
(void)body;
static const std::regex re(R"(^(https?)://([^/:]+)(?::(\d+))?(/.*)?$)");
std::smatch m;
if (!std::regex_match(url, m, re))
throw std::runtime_error("Invalid URL: " + url);
std::string scheme = m[1].str();
std::string host = m[2].str();
int port = m[3].matched ? std::stoi(m[3].str()) : (scheme == "https" ? 443 : 80);
std::string path = m[4].matched ? m[4].str() : "/";
if (scheme == "https")
{
#ifndef CPPHTTPLIB_OPENSSL_SUPPORT
throw std::runtime_error("https URL but CPPHTTPLIB_OPENSSL_SUPPORT not enabled");
#else
auto cli = std::make_unique<httplib::SSLClient>(host.c_str(), port, m_p.crtPath, m_p.keyPath, std::string());
cli->enable_server_certificate_verification(true);
cli->set_ca_cert_path(m_p.caPath.c_str());
cli->set_connection_timeout(10);
cli->set_read_timeout(60);
cli->set_write_timeout(60);
return {std::move(cli), path};
#endif
}
// else
// {
// auto cli = std::make_unique<httplib::Client>(host.c_str(), port);
// cli->set_connection_timeout(10);
// cli->set_read_timeout(60);
// cli->set_write_timeout(60);
// return {std::move(cli), path};
// }
}
};
} // namespace snoop