/**
 * @file        ui/overlay/install_wizard_overlay.cpp
 *
 * @brief       Generic pre-runtime installer dialog.
 */
#include <rex/ui/overlay/install_wizard_overlay.h>

#include <algorithm>
#include <utility>

#include <imgui.h>

namespace rex::ui {

InstallWizardDialog::InstallWizardDialog(ImGuiDrawer* drawer, std::string title,
                                         std::string intro, std::string install_directory,
                                         PickSourceCallback pick_source, InstallCallback install,
                                         CompleteCallback complete)
    : ImGuiDialog(drawer),
      title_(std::move(title)),
      intro_(std::move(intro)),
      install_directory_(std::move(install_directory)),
      pick_source_(std::move(pick_source)),
      install_(std::move(install)),
      complete_(std::move(complete)),
      status_(intro_) {}

void InstallWizardDialog::OnClose() {
  if (install_thread_.joinable()) {
    install_thread_.join();
  }
}

void InstallWizardDialog::PickSourceAndInstall() {
  if (!pick_source_) {
    return;
  }
  auto source_path = pick_source_();
  if (source_path.empty()) {
    return;
  }
  StartInstall(std::move(source_path));
}

void InstallWizardDialog::StartInstall(std::filesystem::path source_path) {
  if (install_thread_.joinable()) {
    install_thread_.join();
  }

  source_path_ = std::move(source_path);
  copied_bytes_ = 0;
  total_bytes_ = 0;
  install_done_ = false;
  install_ok_ = false;
  error_.clear();
  state_ = State::kInstalling;
  status_ = "Installing game files...";

  install_thread_ = std::thread([this]() {
    std::string error;
    const bool ok = install_ && install_(source_path_, copied_bytes_, total_bytes_, error);
    error_ = std::move(error);
    install_ok_ = ok;
    install_done_ = true;
  });
}

void InstallWizardDialog::FinishInstallIfNeeded() {
  if (state_ != State::kInstalling || !install_done_.load(std::memory_order_acquire)) {
    return;
  }

  if (install_thread_.joinable()) {
    install_thread_.join();
  }

  if (install_ok_.load(std::memory_order_acquire)) {
    state_ = State::kInstalled;
    status_ = "Installation complete.";
  } else {
    state_ = State::kFailed;
    status_ = "Installation failed.";
  }
}

void InstallWizardDialog::OnDraw(ImGuiIO& io) {
  FinishInstallIfNeeded();

  const float width = std::min(760.0f, std::max(460.0f, io.DisplaySize.x - 64.0f));
  ImGui::SetNextWindowPos(ImVec2(io.DisplaySize.x * 0.5f, io.DisplaySize.y * 0.5f),
                          ImGuiCond_Appearing, ImVec2(0.5f, 0.5f));
  ImGui::SetNextWindowSize(ImVec2(width, 0.0f), ImGuiCond_Always);

  ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(24.0f, 22.0f));
  ImGui::PushStyleVar(ImGuiStyleVar_FramePadding, ImVec2(14.0f, 9.0f));
  ImGui::PushStyleVar(ImGuiStyleVar_ItemSpacing, ImVec2(12.0f, 12.0f));
  ImGui::PushFont(nullptr, 18.0f);

  if (ImGui::Begin(title_.c_str(), nullptr,
                   ImGuiWindowFlags_NoCollapse | ImGuiWindowFlags_NoResize |
                       ImGuiWindowFlags_AlwaysAutoResize)) {
    ImGui::TextWrapped("%s", status_.c_str());
    ImGui::Spacing();
    ImGui::TextWrapped("Install directory: %s", install_directory_.c_str());

    if (!source_path_.empty()) {
      ImGui::TextWrapped("Source: %s", source_path_.string().c_str());
    }

    if (state_ == State::kInstalling) {
      const uint64_t total = total_bytes_.load(std::memory_order_relaxed);
      const uint64_t copied = copied_bytes_.load(std::memory_order_relaxed);
      const float progress =
          total == 0 ? 0.0f : std::clamp(static_cast<float>(double(copied) / double(total)), 0.0f, 1.0f);
      ImGui::ProgressBar(progress, ImVec2(-1.0f, 28.0f));
    } else if (state_ == State::kFailed) {
      ImGui::TextColored(ImVec4(0.95f, 0.28f, 0.24f, 1.0f), "%s", error_.c_str());
    }

    ImGui::Spacing();
    if (state_ == State::kWaitingForSource || state_ == State::kFailed) {
      if (ImGui::Button("Select ISO", ImVec2(160.0f, 42.0f))) {
        PickSourceAndInstall();
      }
    } else if (state_ == State::kInstalled) {
      if (ImGui::Button("Start Game", ImVec2(160.0f, 42.0f))) {
        auto complete = std::move(complete_);
        Close();
        if (complete) {
          complete();
        }
      }
    }

    ImGui::End();
  }

  ImGui::PopFont();
  ImGui::PopStyleVar(3);
}

}  // namespace rex::ui