#include "hecl/ClientProcess.hpp"

#include <algorithm>

#include "hecl/Blender/Connection.hpp"
#include "hecl/Database.hpp"
#include "hecl/MultiProgressPrinter.hpp"

#include <athena/FileReader.hpp>
#include <boo/IApplication.hpp>
#include <logvisor/logvisor.hpp>

#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#include <Windows.h>
#else
#include <sys/wait.h>
#endif

#define HECL_MULTIPROCESSOR 1

namespace hecl {
static logvisor::Module CP_Log("hecl::ClientProcess");

ThreadLocalPtr<ClientProcess::Worker> ClientProcess::ThreadWorker;

int CpuCountOverride = 0;

void SetCpuCountOverride(int argc, char** argv) {
  bool threadArg = false;
  for (int i = 1; i < argc; ++i) {
    if (threadArg) {
      if (int count = int(hecl::StrToUl(argv[i], nullptr, 0))) {
        CpuCountOverride = count;
        return;
      }
    }
    if (!hecl::StrNCmp(argv[i], "-j", 2)) {
      if (int count = int(hecl::StrToUl(argv[i] + 2, nullptr, 0))) {
        CpuCountOverride = count;
        return;
      }
      threadArg = true;
    }
  }
}

static int GetCPUCount() {
  if (CpuCountOverride > 0) {
    return CpuCountOverride;
  }

  int ret;
#if _WIN32
  SYSTEM_INFO sysinfo;
  GetSystemInfo(&sysinfo);
  ret = sysinfo.dwNumberOfProcessors;
#else
  ret = sysconf(_SC_NPROCESSORS_ONLN);
#endif

  return ret;
}

void ClientProcess::BufferTransaction::run(blender::Token& btok) {
  athena::io::FileReader r(m_path.getAbsolutePath(), 32 * 1024, false);
  if (r.hasError()) {
    CP_Log.report(logvisor::Fatal, FMT_STRING("unable to background-buffer '{}'"), m_path.getAbsolutePath());
    return;
  }
  if (m_offset)
    r.seek(m_offset, athena::SeekOrigin::Begin);
  r.readBytesToBuf(m_targetBuf, m_maxLen);
  m_complete = true;
}

void ClientProcess::CookTransaction::run(blender::Token& btok) {
  m_dataSpec->setThreadProject();
  m_returnResult = m_parent.syncCook(m_path, m_dataSpec, btok, m_force, m_fast);
  std::unique_lock lk{m_parent.m_mutex};
  ++m_parent.m_completedCooks;
  m_parent.m_progPrinter->setMainFactor(m_parent.m_completedCooks / float(m_parent.m_addedCooks));
  m_complete = true;
}

void ClientProcess::LambdaTransaction::run(blender::Token& btok) {
  m_func(btok);
  m_complete = true;
}

ClientProcess::Worker::Worker(ClientProcess& proc, int idx) : m_proc(proc), m_idx(idx) {
  m_thr = std::thread(std::bind(&Worker::proc, this));
}

void ClientProcess::Worker::proc() {
  ClientProcess::ThreadWorker.reset(this);

  std::string thrName = fmt::format(FMT_STRING("HECL Worker {}"), m_idx);
  logvisor::RegisterThreadName(thrName.c_str());

  std::unique_lock lk{m_proc.m_mutex};
  while (m_proc.m_running) {
    if (!m_didInit) {
      m_proc.m_initCv.notify_one();
      m_didInit = true;
    }
    while (m_proc.m_running && m_proc.m_pendingQueue.size()) {
      std::shared_ptr<Transaction> trans = std::move(m_proc.m_pendingQueue.front());
      ++m_proc.m_inProgress;
      m_proc.m_pendingQueue.pop_front();
      lk.unlock();
      trans->run(m_blendTok);
      lk.lock();
      m_proc.m_completedQueue.push_back(std::move(trans));
      --m_proc.m_inProgress;
    }
    m_proc.m_waitCv.notify_one();
    if (!m_proc.m_running)
      break;
    m_proc.m_cv.wait(lk);
  }
  lk.unlock();
  m_blendTok.shutdown();
}

ClientProcess::ClientProcess(const MultiProgressPrinter* progPrinter) : m_progPrinter(progPrinter) {
#if HECL_MULTIPROCESSOR
  const int cpuCount = GetCPUCount();
#else
  constexpr int cpuCount = 1;
#endif
  m_workers.reserve(cpuCount);
  for (int i = 0; i < cpuCount; ++i) {
    std::unique_lock lk{m_mutex};
    m_workers.emplace_back(*this, m_workers.size());
    m_initCv.wait(lk);
  }
}

std::shared_ptr<const ClientProcess::BufferTransaction> ClientProcess::addBufferTransaction(const ProjectPath& path,
                                                                                            void* target, size_t maxLen,
                                                                                            size_t offset) {
  std::unique_lock lk{m_mutex};
  auto ret = std::make_shared<BufferTransaction>(*this, path, target, maxLen, offset);
  m_pendingQueue.emplace_back(ret);
  m_cv.notify_one();
  return ret;
}

std::shared_ptr<const ClientProcess::CookTransaction> ClientProcess::addCookTransaction(const hecl::ProjectPath& path,
                                                                                        bool force, bool fast,
                                                                                        Database::IDataSpec* spec) {
  std::unique_lock lk{m_mutex};
  auto ret = std::make_shared<CookTransaction>(*this, path, force, fast, spec);
  m_pendingQueue.emplace_back(ret);
  m_cv.notify_one();
  ++m_addedCooks;
  m_progPrinter->setMainFactor(m_completedCooks / float(m_addedCooks));
  return ret;
}

std::shared_ptr<const ClientProcess::LambdaTransaction>
ClientProcess::addLambdaTransaction(std::function<void(blender::Token&)>&& func) {
  std::unique_lock lk{m_mutex};
  auto ret = std::make_shared<LambdaTransaction>(*this, std::move(func));
  m_pendingQueue.emplace_back(ret);
  m_cv.notify_one();
  return ret;
}

bool ClientProcess::syncCook(const hecl::ProjectPath& path, Database::IDataSpec* spec, blender::Token& btok, bool force,
                             bool fast) {
  if (spec->canCook(path, btok)) {
    const Database::DataSpecEntry* specEnt = spec->overrideDataSpec(path, spec->getDataSpecEntry());
    if (specEnt) {
      hecl::ProjectPath cooked = path.getCookedPath(*specEnt);
      if (fast)
        cooked = cooked.getWithExtension(".fast");
      cooked.makeDirChain(false);
      if (force || cooked.getPathType() == ProjectPath::Type::None || path.getModtime() > cooked.getModtime()) {
        if (m_progPrinter) {
          std::string str;
          if (path.getAuxInfo().empty())
            str = fmt::format(FMT_STRING("Cooking {}"), path.getRelativePath());
          else
            str = fmt::format(FMT_STRING("Cooking {}|{}"), path.getRelativePath(), path.getAuxInfo());
          m_progPrinter->print(str, std::nullopt, -1.f, hecl::ClientProcess::GetThreadWorkerIdx());
          m_progPrinter->flush();
        } else {
          if (path.getAuxInfo().empty())
            LogModule.report(logvisor::Info, FMT_STRING("Cooking {}"), path.getRelativePath());
          else
            LogModule.report(logvisor::Info, FMT_STRING("Cooking {}|{}"), path.getRelativePath(), path.getAuxInfo());
        }
        spec->doCook(path, cooked, false, btok, [](const char*) {});
        if (m_progPrinter) {
          std::string str;
          if (path.getAuxInfo().empty())
            str = fmt::format(FMT_STRING("Cooked  {}"), path.getRelativePath());
          else
            str = fmt::format(FMT_STRING("Cooked  {}|{}"), path.getRelativePath(), path.getAuxInfo());
          m_progPrinter->print(str, std::nullopt, -1.f, hecl::ClientProcess::GetThreadWorkerIdx());
          m_progPrinter->flush();
        }
      }
      return true;
    }
  }
  return false;
}

void ClientProcess::swapCompletedQueue(std::list<std::shared_ptr<Transaction>>& queue) {
  std::unique_lock lk{m_mutex};
  queue.swap(m_completedQueue);
}

void ClientProcess::waitUntilComplete() {
  std::unique_lock lk{m_mutex};
  while (isBusy())
    m_waitCv.wait(lk);
}

void ClientProcess::shutdown() {
  if (!m_running)
    return;
  std::unique_lock lk{m_mutex};
  m_pendingQueue.clear();
  m_running = false;
  m_cv.notify_all();
  lk.unlock();
  for (Worker& worker : m_workers)
    if (worker.m_thr.joinable())
      worker.m_thr.join();
}

} // namespace hecl