// Copyright 2018 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

#include "UICommon/AutoUpdate.h"

#include <picojson/picojson.h>

#include "Common/CommonPaths.h"
#include "Common/FileUtil.h"
#include "Common/HttpRequest.h"
#include "Common/Logging/Log.h"
#include "Common/StringUtil.h"
#include "Common/scmrev.h"
#include "Core/ConfigManager.h"

#ifdef _WIN32
#include <Windows.h>
#endif

namespace
{
bool SystemSupportsAutoUpdates()
{
#ifdef _WIN32
  return true;
#else
  return false;
#endif
}

#ifdef _WIN32

const char UPDATER_FILENAME[] = "Updater.exe";
const char UPDATER_RELOC_FILENAME[] = "Updater.2.exe";
const char UPDATER_LOG_FILE[] = "Updater.log";

std::wstring MakeUpdaterCommandLine(const std::map<std::string, std::string>& flags)
{
  std::wstring cmdline = UTF8ToUTF16(UPDATER_FILENAME) + L" ";  // Start with a fake argv[0].
  for (const auto& pair : flags)
  {
    std::string value = "--" + pair.first + "=" + pair.second;
    value = ReplaceAll(value, "\"", "\\\"");  // Escape double quotes.
    value = "\"" + value + "\" ";
    cmdline += UTF8ToUTF16(value);
  }
  return cmdline;
}

// Used to remove the relocated updater file once we don't need it anymore.
void CleanupFromPreviousUpdate()
{
  std::string reloc_updater_path = File::GetExeDirectory() + DIR_SEP + UPDATER_RELOC_FILENAME;
  File::Delete(reloc_updater_path);
}
#endif
}  // namespace

void AutoUpdateChecker::CheckForUpdate()
{
  // Don't bother checking if updates are not supported or not enabled.
  if (SConfig::GetInstance().m_auto_update_track.empty() || !SystemSupportsAutoUpdates())
    return;

#ifdef _WIN32
  CleanupFromPreviousUpdate();
#endif

  std::string version_hash = SConfig::GetInstance().m_auto_update_hash_override.empty() ?
                                 SCM_REV_STR :
                                 SConfig::GetInstance().m_auto_update_hash_override;
  std::string url = "https://dolphin-emu.org/update/check/v0/" +
                    SConfig::GetInstance().m_auto_update_track + "/" + version_hash;

  Common::HttpRequest req{std::chrono::seconds{10}};
  auto resp = req.Get(url);
  if (!resp)
  {
    ERROR_LOG(COMMON, "Auto-update request failed");
    return;
  }
  std::string contents(reinterpret_cast<char*>(resp->data()), resp->size());
  INFO_LOG(COMMON, "Auto-update JSON response: %s", contents.c_str());

  picojson::value json;
  std::string err = picojson::parse(json, contents);
  if (!err.empty())
  {
    ERROR_LOG(COMMON, "Invalid JSON received from auto-update service: %s", err.c_str());
    return;
  }
  picojson::object obj = json.get<picojson::object>();

  if (obj["status"].get<std::string>() != "outdated")
  {
    INFO_LOG(COMMON, "Auto-update status: we are up to date.");
    return;
  }

  NewVersionInformation nvi;
  nvi.this_manifest_url = obj["old"].get<picojson::object>()["manifest"].get<std::string>();
  nvi.next_manifest_url = obj["new"].get<picojson::object>()["manifest"].get<std::string>();
  nvi.content_store_url = obj["content-store"].get<std::string>();
  nvi.new_shortrev = obj["new"].get<picojson::object>()["name"].get<std::string>();
  nvi.new_hash = obj["new"].get<picojson::object>()["hash"].get<std::string>();
  // TODO: generate the HTML changelog from the JSON information.
  OnUpdateAvailable(nvi);
}

void AutoUpdateChecker::TriggerUpdate(const AutoUpdateChecker::NewVersionInformation& info)
{
#ifdef _WIN32
  std::map<std::string, std::string> updater_flags;
  updater_flags["this-manifest-url"] = info.this_manifest_url;
  updater_flags["next-manifest-url"] = info.next_manifest_url;
  updater_flags["content-store-url"] = info.content_store_url;
  updater_flags["parent-pid"] = std::to_string(GetCurrentProcessId());
  updater_flags["install-base-path"] = File::GetExeDirectory();
  updater_flags["log-file"] = File::GetExeDirectory() + DIR_SEP + UPDATER_LOG_FILE;

  // Copy the updater so it can update itself if needed.
  std::string updater_path = File::GetExeDirectory() + DIR_SEP + UPDATER_FILENAME;
  std::string reloc_updater_path = File::GetExeDirectory() + DIR_SEP + UPDATER_RELOC_FILENAME;
  File::Copy(updater_path, reloc_updater_path);

  // Run the updater!
  std::wstring command_line = MakeUpdaterCommandLine(updater_flags);
  STARTUPINFO sinfo = {sizeof(info)};
  PROCESS_INFORMATION pinfo;
  INFO_LOG(COMMON, "Updater command line: %s", UTF16ToUTF8(command_line).c_str());
  if (!CreateProcessW(UTF8ToUTF16(reloc_updater_path).c_str(),
                      const_cast<wchar_t*>(command_line.c_str()), nullptr, nullptr, FALSE, 0,
                      nullptr, nullptr, &sinfo, &pinfo))
  {
    ERROR_LOG(COMMON, "Could not start updater process: error=%d", GetLastError());
  }
#endif
}