// Copyright 2018 Google LLC. All Rights Reserved. This file and proprietary
// source code may only be used and distributed under the Widevine Master
// License Agreement.
#include "test_host.h"

#include <gtest/gtest.h>
#include <chrono>

#include "device_cert.h"
#include "log.h"

using namespace widevine;

namespace {

constexpr char kCertificateFilename[] = "cert.bin";

}  // namespace

TestHost::TestHost() { Reset(); }
TestHost::~TestHost() { wvcdm::TestSleep::set_callback(nullptr); }

void TestHost::Reset() {
  auto now = std::chrono::steady_clock().now();
  now_ = now.time_since_epoch() / std::chrono::milliseconds(1);
  wvcdm::TestSleep::set_callback(this);

  save_device_cert_ = false;

  // Surprisingly, std::priority_queue has no clear().
  while (!timers_.empty()) {
    timers_.pop();
  }

  files_.clear();
  files_[kCertificateFilename] =
      (device_cert_.size() > 0)
          ? device_cert_
          : std::string((const char*)kDeviceCert, kDeviceCertSize);
}

void TestHost::ElapseTime(int64_t milliseconds) {
  // Note that, during the time rollback tests, milliseconds will be negative,
  // so we cannot assume goal_time > now_.
  int64_t goal_time = now_ + milliseconds;

  // Walk forward from now_ to goal_time, stepping at each timer along the way
  // to fire its callback.
  while (!timers_.empty() && now_ < goal_time) {
    Timer t = timers_.top();
    ASSERT_GE(t.expiry_time(), now_);
    if (t.expiry_time() <= goal_time) {
      timers_.pop();
      now_ = t.expiry_time();
      t.client()->onTimerExpired(t.context());
    } else {
      // The next timer is further in the future than goal_time, so we are done
      // processing the timers.
      break;
    }
  }

  // No matter what happened with the timers, update now_ to the goal_time.
  now_ = goal_time;
}

int TestHost::NumTimers() const { return timers_.size(); }

bool TestHost::read(const std::string& name, std::string* data) {
  StorageMap::iterator it = files_.find(name);
  bool ok = it != files_.end();
  LOGV("read file: %s: %s", name.c_str(), ok ? "ok" : "fail");
  if (!ok) return false;
  *data = it->second;
  return true;
}

bool TestHost::write(const std::string& name, const std::string& data) {
  LOGV("write file: %s", name.c_str());
  files_[name] = data;
  if (save_device_cert_ && name.compare(kCertificateFilename) == 0) {
    device_cert_ = data;
    save_device_cert_ = false;
  }
  return true;
}

bool TestHost::exists(const std::string& name) {
  StorageMap::iterator it = files_.find(name);
  bool ok = it != files_.end();
  LOGV("exists? %s: %s", name.c_str(), ok ? "true" : "false");
  return ok;
}

bool TestHost::remove(const std::string& name) {
  LOGV("remove: %s", name.c_str());
  if (name.empty()) {
    // If no name, delete all files (see DeviceFiles::DeleteAllFiles())
    files_.clear();
    return true;
  }

  return files_.erase(name) > 0;
}

int32_t TestHost::size(const std::string& name) {
  StorageMap::iterator it = files_.find(name);
  if (it == files_.end()) return -1;
  return it->second.size();
}

bool TestHost::list(std::vector<std::string>* names) {
  names->clear();
  for (StorageMap::iterator it = files_.begin(); it != files_.end(); it++) {
    names->push_back(it->first);
  }
  return true;
}

int64_t TestHost::now() { return now_; }

void TestHost::setTimeout(int64_t delay_ms, IClient* client, void* context) {
  int64_t expiry_time = now_ + delay_ms;
  timers_.push(Timer(expiry_time, client, context));
}

void TestHost::cancel(IClient* client) {
  // Filter out the timers for this client and put the rest into |others|.
  std::priority_queue<Timer> others;

  while (timers_.size()) {
    Timer t = timers_.top();
    timers_.pop();

    if (t.client() != client) {
      others.push(t);
    }
  }

  // Now swap the queues.
  std::swap(timers_, others);
}