// Copyright 2026 Dolphin Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
// Local qualification only: synthetic ARM code/data, synthetic NAND journal, no
// firmware/profile.
#include <array>
#include <chrono>
#include <cstdio>
#include <filesystem>
#include <stdexcept>
#include <string>
#include <thread>
#include <vector>

#include <winsock2.h>

#include "Common/Network.h"
#include "Common/PerformanceTrace.h"
#include "Core/IOS/Starlet/ARMCore.h"
#include "Core/IOS/Starlet/AX88772.h"
#include "Core/IOS/Starlet/NANDJournal.h"
#include "Core/IOS/Starlet/SlirpNetwork.h"
#include "PrivateETW.h"

namespace Trace = Common::PerformanceTrace;
using namespace IOS::LLE;
class ProbeBus final : public ARMBus
{
public:
  u8 Read8(u32 address) override { return bytes.at(address); }
  void Write8(u32 address, u8 value) override { bytes.at(address) = value; }
  const u8* GetDirectMemoryPointer(u32 address, u32 size) const override
  {
    return address < bytes.size() && size <= bytes.size() - address ? bytes.data() + address :
                                                                      nullptr;
  }
  void Op(u32 offset, u16 op)
  {
    bytes[offset] = static_cast<u8>(op >> 8);
    bytes[offset + 1] = static_cast<u8>(op);
  }
  std::array<u8, 8192> bytes{};
};
void Check(bool value)
{
  if (!value)
    throw std::runtime_error("P1 local probe validation failed");
}
void LocalNAT(const std::string& directory)
{
  SlirpNetwork network;
  AX88772 device([&](std::span<const u8> frame) { network.Input(frame); });
  std::string error;
  if (!network.Start(
          directory, [&](std::span<const u8> frame) { device.ReceiveFrame(frame); }, &error))
    throw std::runtime_error(error);
  const auto control = [&](u8 type, u8 request, u16 value) {
    std::array<u8, 8> setup{
        type, request, static_cast<u8>(value), static_cast<u8>(value >> 8), 0, 0, 0, 0};
    size_t actual = 0;
    Check(device.Transfer(0, 0, setup, &actual) == AX88772::Result::Completed);
    Check(device.Transfer(0, 2, {}, &actual) == AX88772::Result::Completed);
  };
  control(0, 9, 1);
  control(0x40, 0x10, 0x88);
  control(0x40, 0x1b, 0x306);
  device.SetLink(true);
  // ARP reaches only libslirp's virtual gateway: no DNS, Internet or remote server.
  Common::MACAddress mac{2, 0x44, 0x4f, 0x4c, 0, 1};
  Common::ARPPacket request(Common::MACAddress{255, 255, 255, 255, 255, 255}, mac);
  request.arp_header.opcode = htons(1);
  request.arp_header.sender_address = mac;
  request.arp_header.sender_ip = htonl(0x0a00020f);
  request.arp_header.target_ip = htonl(0x0a000202);
  const auto frame = request.Build();
  const u16 length = static_cast<u16>(frame.size());
  std::vector<u8> framed{static_cast<u8>(length), static_cast<u8>(length >> 8),
                         static_cast<u8>(~length), static_cast<u8>(~length >> 8)};
  framed.insert(framed.end(), frame.begin(), frame.end());
  Trace::Marker("LocalNATBegin");
  for (u32 i = 0; i < 32; ++i)
  {
    Trace::SampleRoot root(true);
    size_t actual = 0;
    Check(device.Transfer(3, 1, framed, &actual) == AX88772::Result::Completed);
    network.Poll(243000);
    device.TraceQueue();
    std::array<u8, 2048> response{};
    Check(device.Transfer(2, 2, response, &actual) == AX88772::Result::Completed);
    Check(actual >= 46);
    const auto arp =
        Common::PacketView(response.data() + 4, response[0] | (response[1] << 8)).GetARPPacket();
    Check(arp && ntohs(arp->arp_header.opcode) == 2 &&
          arp->arp_header.sender_ip == htonl(0x0a000202));
    device.TraceQueue();
  }
  Trace::Marker("LocalNATEnd");
}
int main(int argc, char** argv)
{
  try
  {
    if (argc != 3 && argc != 4)
      throw std::runtime_error("Usage: TraceProbeP1.exe NEW-synthetic-journal-path "
                               "libslirp-runtime-directory [NEW-private-ETL]");
    const std::string journal_path = argv[1];
    Check(!std::filesystem::exists(journal_path));
    PrivateETW private_trace(argc == 4 ? argv[3] : nullptr);
    Trace::Marker("ProbeBegin");
    ProbeBus bus;
    bus.Op(0, 0x6810);  // ldr r0,[r2]
    bus.Op(2, 0x6851);  // ldr r1,[r2,#4]
    bus.Op(4, 0x46c0);  // nop
    bus.Op(6, 0xe7fb);  // b 0
    bus.Write32(4096, 0x12345678);
    bus.Write32(4100, 0x87654321);
    ARMCore cpu(bus);
    cpu.SetCPSR(static_cast<u32>(ARMCore::Mode::Supervisor) | ARMCore::CPSR_T);
    cpu.SetRegister(2, 4096);
    cpu.SetJitEnabled(true);
    Trace::Marker("ARMWorkBegin");
    const auto start = std::chrono::steady_clock::now();
    // Fixed work, not a duration-based loop: suitable for ON/OFF cost
    // comparisons.
    constexpr u64 slices = 160000;
    for (u64 i = 0; i < slices; ++i)
    {
      Trace::SampleRoot root;
      Check(cpu.RunCycles(4096) == 4096);
      if ((i & 1023) == 0)
        Trace::Snapshot(cpu.GetTraceGeneration(), cpu.GetExecutedInstructions(),
                        cpu.GetJitNativeExecutedInstructions(), cpu.GetJitSlowReadCount(),
                        cpu.GetJitSlowWriteCount(), cpu.GetJitLifetimeCompiledBlockCount(),
                        cpu.GetJitFallbackInstructionCount(), cpu.GetRegister(15), false);
    }
    const double ms =
        std::chrono::duration<double, std::milli>(std::chrono::steady_clock::now() - start).count();
    Check(cpu.GetRegister(0) == 0x12345678 && cpu.GetRegister(1) == 0x87654321);
    Check(cpu.GetExecutedInstructions() == slices * 4096);
    Trace::Marker("ARMWorkEnd");
    Trace::Marker("KnownSleepBegin");
    std::this_thread::sleep_for(std::chrono::milliseconds(750));
    Trace::Marker("KnownSleepEnd");
    {
      Trace::Marker("SyntheticJournalBegin");
      NANDJournal journal;
      NANDJournal::Pages pages;
      Common::SHA1::Digest synthetic_identity{};
      std::string error;
      Check(journal.Open(journal_path, synthetic_identity, &pages, &error));
      for (u32 i = 0; i < 128; ++i)
      {
        Trace::SampleRoot root(true);
        NANDJournal::Pages update;
        update[i].fill(static_cast<u8>(i));
        Check(journal.Append(update));
      }
      Trace::Marker("SyntheticJournalEnd");
    }
    {
      NANDJournal verifier;
      NANDJournal::Pages pages;
      Common::SHA1::Digest synthetic_identity{};
      std::string error;
      Check(verifier.Open(journal_path, synthetic_identity, &pages, &error));
      Check(pages.size() == 128);
      for (u32 i = 0; i < 128; ++i)
        for (u8 value : pages.at(i))
          Check(value == static_cast<u8>(i));
    }
    LocalNAT(std::filesystem::absolute(argv[2]).string());
    cpu.Reset();
    std::this_thread::sleep_for(std::chrono::milliseconds(1100));
    Trace::Snapshot(cpu.GetTraceGeneration(), cpu.GetExecutedInstructions(),
                    cpu.GetJitNativeExecutedInstructions(), cpu.GetJitSlowReadCount(),
                    cpu.GetJitSlowWriteCount(), cpu.GetJitLifetimeCompiledBlockCount(),
                    cpu.GetJitFallbackInstructionCount(), cpu.GetRegister(15), false);
    Trace::Marker("ProbeEnd");
    const bool trace_enabled = Trace::Enabled();
    Check(private_trace.Close());
    std::printf("P1Probe exact=OK trace-requested=%d trace-enabled=%d "
                "arm-ms=%.3f instructions=%llu journal-pages=128 nat-arp-replies=32\n",
                Trace::Requested(), trace_enabled, ms, slices * 4096);
    return 0;
  }
  catch (const std::exception& error)
  {
    std::fprintf(stderr, "%s\n", error.what());
    return 1;
  }
}