#include "modules/sni/host.hpp"

#include <spdlog/spdlog.h>

#include <algorithm>

#include "modules/sni/item.hpp"
#include "util/scope_guard.hpp"

namespace waybar::modules::SNI {

static const unsigned RETRY_DELAY_MS = 200;
static const unsigned MAX_RETRIES = 10;

Host::Host(std::size_t id, const Json::Value& config, const Bar& bar,
           const std::vector<std::string>& ignore_list,
           const std::function<void(std::unique_ptr<Item>&)>& on_add,
           const std::function<void(std::unique_ptr<Item>&)>& on_remove,
           const std::function<void()>& on_reorder, const std::function<void()>& on_update)
    : bus_name_("org.kde.StatusNotifierHost-" + std::to_string(getpid()) + "-" +
                std::to_string(id)),
      object_path_("/StatusNotifierHost/" + std::to_string(id)),
      bus_name_id_(Gio::DBus::own_name(Gio::DBus::BusType::BUS_TYPE_SESSION, bus_name_,
                                       sigc::mem_fun(*this, &Host::busAcquired))),
      config_(config),
      bar_(bar),
      ignore_list_(ignore_list),
      on_add_(on_add),
      on_remove_(on_remove),
      on_reorder_(on_reorder),
      on_update_(on_update) {
  auto orders = config["orders"];
  if (!orders.isNull()) {
    for (auto itr = orders.begin(); itr != orders.end(); ++itr) {
      auto key = itr.name();
      auto& value = *itr;
      assert(value.isInt());

      orders_[key] = value.asInt();
    }
  }
}

Host::~Host() {
  retry_connection_.disconnect();
  if (bus_name_id_ > 0) {
    Gio::DBus::unown_name(bus_name_id_);
    bus_name_id_ = 0;
  }
  if (watcher_id_ > 0) {
    Gio::DBus::unwatch_name(watcher_id_);
    watcher_id_ = 0;
  }
  g_cancellable_cancel(cancellable_);
  g_clear_object(&cancellable_);
  g_clear_object(&watcher_);
}

void Host::checkIgnoreList(const std::vector<std::string>& ignore_list,
                           const std::function<void(std::unique_ptr<Item>&)>& on_remove) {
  spdlog::debug("Host::checkIgnoreList - checking {} items against {} patterns", items_.size(),
                ignore_list.size());

  for (auto it = items_.begin(); it != items_.end();) {
    auto& item = *it;
    spdlog::debug("  Checking item: bus_name='{}', category='{}', icon_name='{}', title='{}'",
                  item->bus_name, item->category, item->icon_name, item->title);

    bool should_remove = false;

    for (const auto& ignored : ignore_list) {
      if (item->bus_name.find(ignored) != std::string::npos ||
          item->category.find(ignored) != std::string::npos ||
          item->icon_name.find(ignored) != std::string::npos ||
          item->id.find(ignored) != std::string::npos ||
          item->title.find(ignored) != std::string::npos) {
        spdlog::info(
            "Host: Ignoring item bus_name='{}', category='{}', icon_name='{}', title='{}' - "
            "matched pattern '{}'",
            item->bus_name, item->category, item->icon_name, item->title, ignored);
        on_remove(item);
        should_remove = true;
        break;
      }
    }

    if (should_remove) {
      it = items_.erase(it);
    } else {
      ++it;
    }
  }
}

void Host::busAcquired(const Glib::RefPtr<Gio::DBus::Connection>& conn, const Glib::ustring& name) {
  watcher_id_ = Gio::DBus::watch_name(conn, "org.kde.StatusNotifierWatcher",
                                      sigc::mem_fun(*this, &Host::nameAppeared),
                                      sigc::mem_fun(*this, &Host::nameVanished));
}

void Host::nameAppeared(const Glib::RefPtr<Gio::DBus::Connection>& conn, const Glib::ustring& name,
                        const Glib::ustring& name_owner) {
  if (cancellable_ != nullptr) {
    // TODO
    return;
  }
  cancellable_ = g_cancellable_new();
  sn_watcher_proxy_new(conn->gobj(), G_DBUS_PROXY_FLAGS_NONE, "org.kde.StatusNotifierWatcher",
                       "/StatusNotifierWatcher", cancellable_, &Host::proxyReady, this);
}

void Host::nameVanished(const Glib::RefPtr<Gio::DBus::Connection>& conn,
                        const Glib::ustring& name) {
  retry_connection_.disconnect();
  retry_count_ = 0;
  g_cancellable_cancel(cancellable_);
  g_clear_object(&cancellable_);
  g_clear_object(&watcher_);
  clearItems();
}

void Host::proxyReady(GObject* src, GAsyncResult* res, gpointer data) {
  GError* error = nullptr;
  waybar::util::ScopeGuard error_deleter([&error]() {
    if (error != nullptr) {
      g_error_free(error);
    }
  });
  SnWatcher* watcher = sn_watcher_proxy_new_finish(res, &error);
  if (g_error_matches(error, G_IO_ERROR, G_IO_ERROR_CANCELLED) != 0) {
    spdlog::error("Host: {}", error->message);
    return;
  }
  auto* host = static_cast<SNI::Host*>(data);
  if (error != nullptr) {
    spdlog::error("Host: {}", error->message);
    g_clear_object(&host->cancellable_);
    if (host->retry_count_ >= MAX_RETRIES) {
      spdlog::warn("Host: giving up on watcher proxy creation after {} retries",
                   host->retry_count_);
      return;
    }
    host->retry_count_ += 1;
    // Store the timeout connection so it is disconnected in ~Host, avoiding a
    // use-after-free if the Host is destroyed before the retry fires.
    host->retry_connection_ = Glib::signal_timeout().connect(
        [host]() -> bool {
          if (host->watcher_ != nullptr) {
            return false;
          }
          try {
            auto conn = Gio::DBus::Connection::get_sync(Gio::DBus::BusType::BUS_TYPE_SESSION);
            host->nameAppeared(conn, "org.kde.StatusNotifierWatcher", "");
          } catch (const Glib::Error& e) {
            spdlog::error("Host: retry get_sync failed: {}", static_cast<std::string>(e.what()));
            if (host->retry_count_ < MAX_RETRIES) {
              host->retry_count_ += 1;
              return true;  // re-arm this timer; never let the exception escape
            }
            spdlog::warn("Host: giving up on watcher proxy creation after {} retries",
                         host->retry_count_);
          } catch (const std::exception& e) {
            spdlog::error("Host: retry failed: {}", e.what());
          }
          return false;
        },
        RETRY_DELAY_MS);
    return;
  }
  host->retry_count_ = 0;
  host->watcher_ = watcher;
  sn_watcher_call_register_host(host->watcher_, host->object_path_.c_str(), host->cancellable_,
                                &Host::registerHost, data);
}

void Host::registerHost(GObject* src, GAsyncResult* res, gpointer data) {
  GError* error = nullptr;
  waybar::util::ScopeGuard error_deleter([&error]() {
    if (error != nullptr) {
      g_error_free(error);
    }
  });
  sn_watcher_call_register_host_finish(SN_WATCHER(src), res, &error);
  if (g_error_matches(error, G_IO_ERROR, G_IO_ERROR_CANCELLED) != 0) {
    spdlog::error("Host: {}", error->message);
    return;
  }
  auto* host = static_cast<SNI::Host*>(data);
  if (error != nullptr) {
    spdlog::error("Host: {}", error->message);
    return;
  }
  g_signal_connect(host->watcher_, "item-registered", G_CALLBACK(&Host::itemRegistered), data);
  g_signal_connect(host->watcher_, "item-unregistered", G_CALLBACK(&Host::itemUnregistered), data);
  auto* items = sn_watcher_dup_registered_items(host->watcher_);
  if (items != nullptr) {
    spdlog::info("Host: Found {} pre-registered SNI items", g_strv_length(items));
    for (uint32_t i = 0; items[i] != nullptr; i += 1) {
      spdlog::info("Host: Processing pre-registered item: {}", items[i]);
      host->addRegisteredItem(items[i]);
    }
  }
  g_strfreev(items);
}

void Host::itemRegistered(SnWatcher* watcher, const gchar* service, gpointer data) {
  auto* host = static_cast<SNI::Host*>(data);
  spdlog::info("Host::itemRegistered called with service: {}", service);
  host->addRegisteredItem(service);
  // host->checkIgnoreList(host->ignore_list_, std::bind(&Host::itemUnregistered, host,
  // std::placeholders::_1, std::placeholders::_2, data));
}

void Host::itemUnregistered(SnWatcher* watcher, const gchar* service, gpointer data) {
  auto* host = static_cast<SNI::Host*>(data);
  auto [bus_name, object_path] = waybar::modules::SNI::Host::getBusNameAndObjectPath(service);
  for (auto it = host->items_.begin(); it != host->items_.end(); ++it) {
    if ((*it)->bus_name == bus_name && (*it)->object_path == object_path) {
      host->removeItem(it);
      break;
    }
  }
}

void Host::itemReady(Item& item) {
  auto it = std::find_if(items_.begin(), items_.end(),
                         [&item](const auto& candidate) { return candidate.get() == &item; });
  if (it != items_.end() && (*it)->isReady()) {
    on_add_(*it);
  }
}

void Host::itemInvalidated(Item& item) {
  auto it = std::find_if(items_.begin(), items_.end(),
                         [&item](const auto& candidate) { return candidate.get() == &item; });
  if (it != items_.end()) {
    removeItem(it);
  }
}

void Host::removeItem(std::vector<std::unique_ptr<Item>>::iterator it) {
  if ((*it)->isReady()) {
    on_remove_(*it);
  }
  items_.erase(it);
}

void Host::clearItems() {
  bool removed_ready_item = false;
  for (auto& item : items_) {
    if (item->isReady()) {
      on_remove_(item);
      removed_ready_item = true;
    }
  }
  bool had_items = !items_.empty();
  items_.clear();
  if (had_items && !removed_ready_item) {
    on_update_();
  }
}

std::tuple<std::string, std::string> Host::getBusNameAndObjectPath(const std::string& service) {
  auto it = service.find('/');
  if (it != std::string::npos) {
    return {service.substr(0, it), service.substr(it)};
  }
  return {service, "/StatusNotifierItem"};
}

void Host::addRegisteredItem(const std::string& service) {
  // Check service string directly before parsing
  for (const auto& ignored : ignore_list_) {
    if (service.find(ignored) != std::string::npos) {
      spdlog::info("Host: Ignoring service '{}' - matched pattern '{}'", service, ignored);
      return;
    }
  }
  std::string bus_name;
  std::string object_path;
  std::tie(bus_name, object_path) = getBusNameAndObjectPath(service);
  spdlog::debug("SNI item registered: bus_name={}, object_path={}, full_service={}", bus_name,
                object_path, service);
  auto it = std::ranges::find_if(items_, [&bus_name, &object_path](const auto& item) {
    return bus_name == item->bus_name && object_path == item->object_path;
  });
  if (it == items_.end()) {
    spdlog::debug("Adding SNI item: {}", bus_name);
    items_.emplace_back(std::make_unique<Item>(
        bus_name, object_path, config_, bar_, [this](Item& item) { itemReady(item); },
        [this](Item& item) { itemInvalidated(item); }, on_update_, *this, orders_));
  }
}

void Host::reorderItems() {
  // Re-apply the configured ordering to the tray. This is invoked while an
  // item's Id/order is first resolved (from Item::setCustomIcon), which happens
  // *before* the item is marked ready and added. It must therefore only reorder
  // the widgets that have already been added; re-running the full add path here
  // would (a) re-parent widgets and reconnect signals for every item and (b)
  // mutate items_ from within checkIgnoreList while it is being iterated,
  // invalidating iterators/pointers. Delegating to on_reorder_ keeps this to a
  // pure reordering of existing children.
  on_reorder_();
}

}  // namespace waybar::modules::SNI