#include "flutter_window.h"

#include <optional>

#include <flutter/event_channel.h>
#include <flutter/event_sink.h>
#include <flutter/event_stream_handler_functions.h>
#include <flutter/method_channel.h>
#include <flutter/standard_method_codec.h>

#include "flutter/generated_plugin_registrant.h"

FlutterWindow::FlutterWindow(const flutter::DartProject& project)
    : project_(project) {}

FlutterWindow::~FlutterWindow() {}

bool FlutterWindow::OnCreate() {
  if (!Win32Window::OnCreate()) {
    return false;
  }

  RECT frame = GetClientArea();

  flutter_controller_ = std::make_unique<flutter::FlutterViewController>(
      frame.right - frame.left, frame.bottom - frame.top, project_);
  if (!flutter_controller_->engine() || !flutter_controller_->view()) {
    return false;
  }
  RegisterPlugins(flutter_controller_->engine());

  static bool im_initialized = false;
  im_channel_ = std::make_unique<flutter::MethodChannel<flutter::EncodableValue>>(
      flutter_controller_->engine()->messenger(), "com.fysxkj.oa/im",
      &flutter::StandardMethodCodec::GetInstance());
  im_channel_->SetMethodCallHandler(
      [](const flutter::MethodCall<flutter::EncodableValue>& call,
         std::unique_ptr<flutter::MethodResult<flutter::EncodableValue>> result) {
        if (call.method_name() == "init") {
          im_initialized = true;
          flutter::EncodableMap map;
          map[flutter::EncodableValue("ok")] = flutter::EncodableValue(true);
          map[flutter::EncodableValue("initialized")] =
              flutter::EncodableValue(true);
          map[flutter::EncodableValue("engine")] =
              flutter::EncodableValue("dart-tcp");
          result->Success(flutter::EncodableValue(map));
        } else if (call.method_name() == "release") {
          im_initialized = false;
          flutter::EncodableMap map;
          map[flutter::EncodableValue("ok")] = flutter::EncodableValue(true);
          result->Success(flutter::EncodableValue(map));
        } else if (call.method_name() == "engine") {
          result->Success(flutter::EncodableValue(
              im_initialized ? "dart-tcp" : "idle"));
        } else {
          result->NotImplemented();
        }
      });

  ota_channel_ = std::make_unique<flutter::MethodChannel<flutter::EncodableValue>>(
      flutter_controller_->engine()->messenger(), "com.fysxkj.oa/ota",
      &flutter::StandardMethodCodec::GetInstance());
  ota_channel_->SetMethodCallHandler(
      [](const flutter::MethodCall<flutter::EncodableValue>& call,
         std::unique_ptr<flutter::MethodResult<flutter::EncodableValue>> result) {
        if (call.method_name() == "startScreenshotWatch" ||
            call.method_name() == "stopScreenshotWatch" ||
            call.method_name() == "preferMaxRefresh") {
          result->Success(flutter::EncodableValue(true));
        } else {
          result->NotImplemented();
        }
      });

  device_channel_ = std::make_unique<flutter::EventChannel<flutter::EncodableValue>>(
      flutter_controller_->engine()->messenger(), "com.fysxkj.oa/device",
      &flutter::StandardMethodCodec::GetInstance());
  device_channel_->SetStreamHandler(
      std::make_unique<flutter::StreamHandlerFunctions<flutter::EncodableValue>>(
          [this](const flutter::EncodableValue*,
                 std::unique_ptr<flutter::EventSink<flutter::EncodableValue>>&& events)
              -> std::unique_ptr<flutter::StreamHandlerError<flutter::EncodableValue>> {
            screenshot_sink_ = std::move(events);
            return nullptr;
          },
          [this](const flutter::EncodableValue*)
              -> std::unique_ptr<flutter::StreamHandlerError<flutter::EncodableValue>> {
            screenshot_sink_.reset();
            return nullptr;
          }));

  SetChildContent(flutter_controller_->view()->GetNativeWindow());

  AddClipboardFormatListener(GetHandle());

  flutter_controller_->engine()->SetNextFrameCallback([&]() {
    this->Show();
  });

  flutter_controller_->ForceRedraw();

  return true;
}

void FlutterWindow::EmitScreenshot() {
  const ULONGLONG now = GetTickCount64();
  if (now - last_shot_at_ < 1500) return;
  last_shot_at_ = now;
  if (screenshot_sink_) {
    screenshot_sink_->Success(flutter::EncodableValue("screenshot"));
  }
}

void FlutterWindow::OnDestroy() {
  if (GetHandle()) {
    RemoveClipboardFormatListener(GetHandle());
  }
  if (flutter_controller_) {
    flutter_controller_ = nullptr;
  }

  Win32Window::OnDestroy();
}

LRESULT
FlutterWindow::MessageHandler(HWND hwnd, UINT const message,
                              WPARAM const wparam,
                              LPARAM const lparam) noexcept {
  // Give Flutter, including plugins, an opportunity to handle window messages.
  if (flutter_controller_) {
    std::optional<LRESULT> result =
        flutter_controller_->HandleTopLevelWindowProc(hwnd, message, wparam,
                                                      lparam);
    if (result) {
      return *result;
    }
  }

  switch (message) {
    case WM_FONTCHANGE:
      flutter_controller_->engine()->ReloadSystemFonts();
      break;
    case WM_CLIPBOARDUPDATE: {
      if (OpenClipboard(nullptr)) {
        const bool image = IsClipboardFormatAvailable(CF_BITMAP) ||
                             IsClipboardFormatAvailable(CF_DIB) ||
                             IsClipboardFormatAvailable(
                                 RegisterClipboardFormatW(L"PNG"));
        CloseClipboard();
        if (image) EmitScreenshot();
      }
      break;
    }
    case WM_KEYUP:
    case WM_SYSKEYUP:
      if (wparam == VK_SNAPSHOT) {
        EmitScreenshot();
      }
      break;
  }

  return Win32Window::MessageHandler(hwnd, message, wparam, lparam);
}