#include "guard.h"
#ifndef OPENSSL_NO_QUIC
#include <env-inl.h>
#include <memory_tracker-inl.h>
#include <ngtcp2/ngtcp2.h>
#include <node_sockaddr-inl.h>
#include <openssl/ssl.h>
#include <string_bytes.h>
#include <v8.h>
#include <algorithm>
#include "bindingdata.h"
#include "data.h"
#include "defs.h"
#include "simdutf.h"
#include "util.h"

namespace node {

using v8::Array;
using v8::ArrayBuffer;
using v8::ArrayBufferView;
using v8::BackingStore;
using v8::BackingStoreInitializationMode;
using v8::BackingStoreOnFailureMode;
using v8::BigInt;
using v8::Isolate;
using v8::Just;
using v8::Local;
using v8::Maybe;
using v8::MaybeLocal;
using v8::Nothing;
using v8::Uint8Array;
using v8::Undefined;
using v8::Value;

namespace quic {
// NOLINTNEXTLINE(runtime/thread_local)
thread_local int DebugIndentScope::indent_ = 0;

Path::Path(const SocketAddress& local, const SocketAddress& remote) {
  ngtcp2_addr_init(&this->local, local.data(), local.length());
  ngtcp2_addr_init(&this->remote, remote.data(), remote.length());
}

std::string Path::ToString() const {
  DebugIndentScope indent;
  auto prefix = indent.Prefix();

  const sockaddr* local_in = reinterpret_cast<const sockaddr*>(local.addr);
  auto local_addr = SocketAddress::GetAddress(local_in);
  auto local_port = SocketAddress::GetPort(local_in);

  const sockaddr* remote_in = reinterpret_cast<const sockaddr*>(remote.addr);
  auto remote_addr = SocketAddress::GetAddress(remote_in);
  auto remote_port = SocketAddress::GetPort(remote_in);

  std::string res("{");
  res += prefix + "local: " + local_addr + ":" + std::to_string(local_port);
  res += prefix + "remote: " + remote_addr + ":" + std::to_string(remote_port);
  res += indent.Close();
  return res;
}

PathStorage::PathStorage() {
  Reset();
}

void PathStorage::Reset() {
  ngtcp2_path_storage_zero(this);
}

void PathStorage::CopyTo(PathStorage* path) const {
  ngtcp2_path_copy(&path->path, &this->path);
}

bool PathStorage::operator==(const PathStorage& other) const {
  return ngtcp2_path_eq(&path, &other.path) != 0;
}

bool PathStorage::operator!=(const PathStorage& other) const {
  return ngtcp2_path_eq(&path, &other.path) == 0;
}

// ============================================================================

Store::Store(std::shared_ptr<BackingStore> store, size_t length, size_t offset)
    : store_(std::move(store)), length_(length), offset_(offset) {
  CHECK_LE(offset_, store_->ByteLength());
  CHECK_LE(length_, store_->ByteLength() - offset_);
}

Store::Store(std::unique_ptr<BackingStore> store, size_t length, size_t offset)
    : store_(std::move(store)), length_(length), offset_(offset) {
  CHECK_LE(offset_, store_->ByteLength());
  CHECK_LE(length_, store_->ByteLength() - offset_);
}

Maybe<Store> Store::From(Local<ArrayBuffer> buffer) {
  Isolate* isolate = Isolate::GetCurrent();
  Environment* env = Environment::GetCurrent(isolate->GetCurrentContext());
  auto length = buffer->ByteLength();
  auto dest = ArrayBuffer::NewBackingStore(
      isolate,
      length,
      BackingStoreInitializationMode::kUninitialized,
      BackingStoreOnFailureMode::kReturnNull);
  if (!dest) {
    THROW_ERR_MEMORY_ALLOCATION_FAILED(env);
    return Nothing<Store>();
  }
  if (length > 0) {
    memcpy(dest->Data(), buffer->Data(), length);
  }
  return Just(Store(std::move(dest), length, 0));
}

Maybe<Store> Store::From(Local<ArrayBufferView> view) {
  Isolate* isolate = Isolate::GetCurrent();
  Environment* env = Environment::GetCurrent(isolate->GetCurrentContext());
  auto length = view->ByteLength();
  auto offset = view->ByteOffset();
  auto dest = ArrayBuffer::NewBackingStore(
      isolate,
      length,
      BackingStoreInitializationMode::kUninitialized,
      BackingStoreOnFailureMode::kReturnNull);
  if (!dest) {
    THROW_ERR_MEMORY_ALLOCATION_FAILED(env);
    return Nothing<Store>();
  }
  if (length > 0) {
    memcpy(dest->Data(),
           static_cast<const uint8_t*>(view->Buffer()->Data()) + offset,
           length);
  }
  return Just(Store(std::move(dest), length, 0));
}

Store Store::CopyFrom(Local<ArrayBuffer> buffer) {
  Isolate* isolate = Isolate::GetCurrent();
  auto backing = buffer->GetBackingStore();
  auto length = buffer->ByteLength();
  auto dest = ArrayBuffer::NewBackingStore(
      isolate,
      length,
      BackingStoreInitializationMode::kUninitialized,
      BackingStoreOnFailureMode::kReturnNull);
  if (!dest) {
    THROW_ERR_MEMORY_ALLOCATION_FAILED(Environment::GetCurrent(isolate));
    return Store();
  }
  // copy content
  memcpy(dest->Data(), backing->Data(), length);
  return Store(std::move(dest), length, 0);
}

Store Store::CopyFrom(Local<ArrayBufferView> view) {
  Isolate* isolate = Isolate::GetCurrent();
  auto backing = view->Buffer()->GetBackingStore();
  auto length = view->ByteLength();
  auto offset = view->ByteOffset();
  auto dest = ArrayBuffer::NewBackingStore(
      isolate,
      length,
      BackingStoreInitializationMode::kUninitialized,
      BackingStoreOnFailureMode::kReturnNull);
  // copy content
  if (!dest) {
    THROW_ERR_MEMORY_ALLOCATION_FAILED(Environment::GetCurrent(isolate));
    return Store();
  }
  memcpy(dest->Data(), static_cast<char*>(backing->Data()) + offset, length);
  return Store(std::move(dest), length, 0);
}

Local<Uint8Array> Store::ToUint8Array(Environment* env) const {
  return !store_
             ? Uint8Array::New(ArrayBuffer::New(env->isolate(), 0), 0, 0)
             : Uint8Array::New(
                   ArrayBuffer::New(env->isolate(), store_), offset_, length_);
}

Store::operator bool() const {
  return store_ != nullptr;
}
size_t Store::length() const {
  return length_;
}

size_t Store::total_length() const {
  return store_ ? store_->ByteLength() : 0;
}

template <typename T, OneByteType N>
T Store::convert() const {
  // We can only safely convert to T if we have a valid store.
  CHECK(store_);
  T buf;
  buf.base = static_cast<N*>(store_->Data()) + offset_;
  buf.len = length_;
  return buf;
}

Store::operator uv_buf_t() const {
  return convert<uv_buf_t, char>();
}

Store::operator ngtcp2_vec() const {
  return convert<ngtcp2_vec, uint8_t>();
}

Store::operator nghttp3_vec() const {
  return convert<nghttp3_vec, uint8_t>();
}

void Store::MemoryInfo(MemoryTracker* tracker) const {
  tracker->TrackField("store", store_);
}

// ============================================================================

namespace {

constexpr size_t kMaxConnectionCloseReasonLength = 256;

constexpr std::string_view TypeName(QuicError::Type type) {
  switch (type) {
    case QuicError::Type::APPLICATION:
      return "application";
    case QuicError::Type::TRANSPORT:
      return "transport";
    case QuicError::Type::VERSION_NEGOTIATION:
      return "version_negotiation";
    case QuicError::Type::IDLE_CLOSE:
      return "idle_close";
    case QuicError::Type::DROP_CONNECTION:
      return "drop_connection";
    case QuicError::Type::RETRY:
      return "retry";
    default:
      return "<unknown>";
  }
}
}  // namespace

QuicError::QuicError(const std::string& reason)
    : reason_(reason), error_(), ptr_(&error_) {
  ngtcp2_ccerr_default(&error_);
}

// Keep in mind that reason_ in each of the constructors here will copy
// the string from the ngtcp2_ccerr input.
QuicError::QuicError(const ngtcp2_ccerr* ptr)
    : reason_(reinterpret_cast<const char*>(ptr->reason), ptr->reasonlen),
      error_(),
      ptr_(ptr) {}

QuicError::QuicError(const ngtcp2_ccerr& error)
    : reason_(reinterpret_cast<const char*>(error.reason), error.reasonlen),
      error_(error),
      ptr_(&error_) {}

QuicError::QuicError(QuicError&& other) noexcept
    : reason_(std::move(other.reason_)),
      error_(other.error_),
      ptr_(other.ptr_ == &other.error_ ? &error_ : other.ptr_) {
  // Fix up the internal reason pointer after moving.
  error_.reason = reason_c_str();
  error_.reasonlen = reason_.length();
}

QuicError& QuicError::operator=(QuicError&& other) noexcept {
  if (this != &other) {
    reason_ = std::move(other.reason_);
    error_ = other.error_;
    ptr_ = (other.ptr_ == &other.error_) ? &error_ : other.ptr_;
    error_.reason = reason_c_str();
    error_.reasonlen = reason_.length();
  }
  return *this;
}

QuicError::QuicError(const QuicError& other)
    : reason_(other.reason_),
      error_(other.error_),
      ptr_(other.ptr_ == &other.error_ ? &error_ : other.ptr_) {
  error_.reason = reason_c_str();
  error_.reasonlen = reason_.length();
}

QuicError& QuicError::operator=(const QuicError& other) {
  if (this != &other) {
    reason_ = other.reason_;
    error_ = other.error_;
    ptr_ = (other.ptr_ == &other.error_) ? &error_ : other.ptr_;
    error_.reason = reason_c_str();
    error_.reasonlen = reason_.length();
  }
  return *this;
}

const uint8_t* QuicError::reason_c_str() const {
  return reinterpret_cast<const uint8_t*>(reason_.c_str());
}

bool QuicError::operator!=(const QuicError& other) const {
  return !(*this == other);
}

bool QuicError::operator==(const QuicError& other) const {
  if (this == &other) return true;
  return type() == other.type() && code() == other.code() &&
         frame_type() == other.frame_type();
}

QuicError::Type QuicError::type() const {
  return static_cast<Type>(ptr_->type);
}

error_code QuicError::code() const {
  return ptr_->error_code;
}

uint64_t QuicError::frame_type() const {
  return ptr_->frame_type;
}

const std::string_view QuicError::reason() const {
  return reason_;
}

QuicError::operator const ngtcp2_ccerr&() const {
  return *ptr_;
}

QuicError::operator const ngtcp2_ccerr*() const {
  return ptr_;
}

ngtcp2_ccerr QuicError::ToNgtcp2ConnectionCloseError() const {
  ngtcp2_ccerr error = *ptr_;
  error.reason = reason_c_str();

  const size_t reasonlen =
      std::min(reason_.size(), kMaxConnectionCloseReasonLength);

  error.reasonlen = simdutf::trim_partial_utf8(reason_.data(), reasonlen);

  return error;
}

std::string QuicError::reason_for_liberr(int liberr) {
  return ngtcp2_strerror(liberr);
}

std::string QuicError::reason_for_h3_liberr(int liberr) {
  return nghttp3_strerror(liberr);
}

bool QuicError::is_fatal_liberror(int liberr) {
  return ngtcp2_err_is_fatal(liberr) != 0;
}

bool QuicError::is_fatal_h3_liberror(int liberr) {
  return nghttp3_err_is_fatal(liberr) != 0;
}

error_code QuicError::liberr_to_code(int liberr) {
  return ngtcp2_err_infer_quic_transport_error_code(liberr);
}

error_code QuicError::h3_liberr_to_code(int liberr) {
  return nghttp3_err_infer_quic_app_error_code(liberr);
}

bool QuicError::is_crypto_error() const {
  const auto error_code = code();
  return type() == Type::TRANSPORT && error_code >= NGTCP2_CRYPTO_ERROR &&
         error_code < NGTCP2_CRYPTO_ERROR + 0x100U;
}

std::optional<int> QuicError::get_crypto_error() const {
  if (!is_crypto_error()) return std::nullopt;
  return static_cast<int>(code() - NGTCP2_CRYPTO_ERROR);
}

const char* QuicError::name() const {
  // Application error codes are
  // opaque to QUIC, so we only decode for transport.
  if (type() != Type::TRANSPORT) return nullptr;
  // CRYPTO_ERROR carries a TLS alert in its low byte (RFC 9001 sec. 4.8).
  // OpenSSL's SSL_alert_desc_string_long owns a stable string for every
  // alert it knows about; we filter out the "unknown" placeholder so the
  // JS side can present `errorName` as undefined for unrecognised alerts.
  if (auto alert = get_crypto_error()) {
    const char* n = SSL_alert_desc_string_long(*alert);
    if (n != nullptr && std::string_view(n) != "unknown") return n;
    return nullptr;
  }
  // Named transport-layer error codes from RFC 9000 sec. 20.1 and the
  // RFC 9368 version-negotiation extension.
  switch (code()) {
    case NGTCP2_NO_ERROR:
      return "NO_ERROR";
    case NGTCP2_INTERNAL_ERROR:
      return "INTERNAL_ERROR";
    case NGTCP2_CONNECTION_REFUSED:
      return "CONNECTION_REFUSED";
    case NGTCP2_FLOW_CONTROL_ERROR:
      return "FLOW_CONTROL_ERROR";
    case NGTCP2_STREAM_LIMIT_ERROR:
      return "STREAM_LIMIT_ERROR";
    case NGTCP2_STREAM_STATE_ERROR:
      return "STREAM_STATE_ERROR";
    case NGTCP2_FINAL_SIZE_ERROR:
      return "FINAL_SIZE_ERROR";
    case NGTCP2_FRAME_ENCODING_ERROR:
      return "FRAME_ENCODING_ERROR";
    case NGTCP2_TRANSPORT_PARAMETER_ERROR:
      return "TRANSPORT_PARAMETER_ERROR";
    case NGTCP2_CONNECTION_ID_LIMIT_ERROR:
      return "CONNECTION_ID_LIMIT_ERROR";
    case NGTCP2_PROTOCOL_VIOLATION:
      return "PROTOCOL_VIOLATION";
    case NGTCP2_INVALID_TOKEN:
      return "INVALID_TOKEN";
    case NGTCP2_APPLICATION_ERROR:
      return "APPLICATION_ERROR";
    case NGTCP2_CRYPTO_BUFFER_EXCEEDED:
      return "CRYPTO_BUFFER_EXCEEDED";
    case NGTCP2_KEY_UPDATE_ERROR:
      return "KEY_UPDATE_ERROR";
    case NGTCP2_AEAD_LIMIT_REACHED:
      return "AEAD_LIMIT_REACHED";
    case NGTCP2_NO_VIABLE_PATH:
      return "NO_VIABLE_PATH";
    case NGTCP2_VERSION_NEGOTIATION_ERROR:
      return "VERSION_NEGOTIATION_ERROR";
    default:
      return nullptr;
  }
}

MaybeLocal<Value> QuicError::ToV8Value(Environment* env) const {
  if ((type() == Type::TRANSPORT && code() == NGTCP2_NO_ERROR) ||
      (type() == Type::APPLICATION &&
       (code() == 0 || code() == NGHTTP3_H3_NO_ERROR)) ||
      type() == Type::IDLE_CLOSE) {
    // Application code 0 is the default no-error code for raw QUIC
    // applications (DefaultApplication::GetNoErrorCode() returns 0).
    // NGHTTP3_H3_NO_ERROR (0x100) is the HTTP/3 no-error code.
    // Idle close is always clean — the session timed out normally.
    return Undefined(env->isolate());
  }

  Local<Value> type_str;
  if (!node::ToV8Value(env->context(), TypeName(type())).ToLocal(&type_str)) {
    return {};
  }

  Local<Value> argv[] = {
      type_str,
      BigInt::NewFromUnsigned(env->isolate(), code()),
      Undefined(env->isolate()),
      Undefined(env->isolate()),
  };

  // Note that per the QUIC specification, the reason, if present, is
  // expected to be UTF-8 encoded. The spec uses the term "SHOULD" here,
  // which means that is is entirely possible that some QUIC implementation
  // could choose a different encoding, in which case the conversion here
  // will produce garbage. That's ok though, we're going to use the default
  // assumption that the impl is following the guidelines.
  if (reason_.length() > 0 &&
      !node::ToV8Value(env->context(), reason()).ToLocal(&argv[2])) {
    return {};
  }

  // Attach a human-readable name for known wire codes (RFC 9000 sec. 20.1
  // names and OpenSSL TLS alert descriptions for CRYPTO_ERROR). Unknown
  // codes leave the slot as undefined.
  if (const char* n = name()) {
    argv[3] = BindingData::Get(env).error_name_string(n);
  }

  return Array::New(env->isolate(), argv, arraysize(argv)).As<Value>();
}

std::string QuicError::ToString() const {
  std::string str = "QuicError(";
  str += TypeName(type());
  str += ") ";
  str += std::to_string(code());
  if (!reason_.empty()) str += ": " + reason_;
  return str;
}

void QuicError::MemoryInfo(MemoryTracker* tracker) const {
  tracker->TrackField("reason", reason_.length());
}

QuicError QuicError::ForTransport(TransportError code, std::string reason) {
  return ForTransport(static_cast<error_code>(code), std::move(reason));
}

QuicError QuicError::ForTransport(error_code code, std::string reason) {
  QuicError error(std::move(reason));
  ngtcp2_ccerr_set_transport_error(
      &error.error_, code, error.reason_c_str(), error.reason().length());
  return error;
}

QuicError QuicError::ForApplication(Http3Error code, std::string reason) {
  return ForApplication(static_cast<error_code>(code), std::move(reason));
}

QuicError QuicError::ForApplication(error_code code, std::string reason) {
  QuicError error(std::move(reason));
  ngtcp2_ccerr_set_application_error(
      &error.error_, code, error.reason_c_str(), error.reason().length());
  return error;
}

QuicError QuicError::ForVersionNegotiation(std::string reason) {
  return ForNgtcp2Error(NGTCP2_ERR_RECV_VERSION_NEGOTIATION, std::move(reason));
}

QuicError QuicError::ForIdleClose(std::string reason) {
  return ForNgtcp2Error(NGTCP2_ERR_IDLE_CLOSE, std::move(reason));
}

QuicError QuicError::ForDropConnection(std::string reason) {
  return ForNgtcp2Error(NGTCP2_ERR_DROP_CONN, std::move(reason));
}

QuicError QuicError::ForRetry(std::string reason) {
  return ForNgtcp2Error(NGTCP2_ERR_RETRY, std::move(reason));
}

QuicError QuicError::ForNgtcp2Error(int code, std::string reason) {
  QuicError error(std::move(reason));
  ngtcp2_ccerr_set_liberr(
      &error.error_, code, error.reason_c_str(), error.reason().length());
  return error;
}

QuicError QuicError::ForTlsAlert(int code, std::string reason) {
  QuicError error(std::move(reason));
  ngtcp2_ccerr_set_tls_alert(
      &error.error_, code, error.reason_c_str(), error.reason().length());
  return error;
}

QuicError QuicError::FromConnectionClose(ngtcp2_conn* session) {
  return QuicError(ngtcp2_conn_get_ccerr(session));
}

#define V(name)                                                                \
  const QuicError QuicError::TRANSPORT_##name =                                \
      ForTransport(TransportError::name);
QUIC_TRANSPORT_ERRORS(V)
#undef V

const QuicError QuicError::TRANSPORT_NO_ERROR =
    ForTransport(TransportError::NO_ERROR_);
const QuicError QuicError::HTTP3_NO_ERROR = ForApplication(NGHTTP3_H3_NO_ERROR);
const QuicError QuicError::VERSION_NEGOTIATION = ForVersionNegotiation();
const QuicError QuicError::IDLE_CLOSE = ForIdleClose();
const QuicError QuicError::DROP_CONNECTION = ForDropConnection();
const QuicError QuicError::RETRY = ForRetry();
const QuicError QuicError::INTERNAL_ERROR = ForNgtcp2Error(NGTCP2_ERR_INTERNAL);

}  // namespace quic
}  // namespace node

#endif  // OPENSSL_NO_QUIC