#include "shared/elements/__ELEMENT_CLASS_NAME__.h"

#import <Cocoa/Cocoa.h>

namespace {

NSString* NSStringFromStdString(const std::string& value) {
  NSString* result = [NSString stringWithUTF8String:value.c_str()];
  return result != nil ? result : @"";
}

class __ELEMENT_SYMBOL_NAME__NativeUIView : public __ELEMENT_SYMBOL_NAME__View {
 public:
  explicit __ELEMENT_SYMBOL_NAME__NativeUIView(void* opaque)
      : __ELEMENT_SYMBOL_NAME__View(opaque) {
    RunOnMainThreadSync(^{
      label_ = [NSTextField labelWithString:NSStringFromStdString(value())];
      label_.textColor = [NSColor blackColor];
    });
  }

  ~__ELEMENT_SYMBOL_NAME__NativeUIView() override {
    RunOnMainThreadSync(^{
      [label_ removeFromSuperview];
      label_ = nil;
    });
  }

  bool IsSurfaceEnabled() override { return false; }

  void OnAttach() override {
    RunOnMainThreadSync(^{
      AttachToParent();
    });
  }

  void OnDetach() override {
    RunOnMainThreadSync(^{
      [label_ removeFromSuperview];
    });
  }

  void OnLayoutChanged(
      float left,
      float top,
      float width,
      float height,
      float pixel_ratio) override {
    (void)pixel_ratio;
    RunOnMainThreadSync(^{
      NSView* lynx_parent = ParentView();
      NSView* parent = AttachToParent(lynx_parent);
      if (lynx_parent == nil || parent == nil) {
        return;
      }

      const NSRect frame_in_lynx = NSMakeRect(left, top, width, height);
      label_.frame = [lynx_parent convertRect:frame_in_lynx toView:parent];
    });
  }

 private:
  using MainThreadBlock = void (^)(void);

  void OnValueChanged(const std::string& value) override {
    std::string text = value;
    RunOnMainThreadSync(^{
      if (label_ != nil) {
        label_.stringValue = NSStringFromStdString(text);
      }
    });
  }

  static void RunOnMainThreadSync(MainThreadBlock block) {
    if ([NSThread isMainThread]) {
      block();
      return;
    }
    dispatch_sync(dispatch_get_main_queue(), block);
  }

  NSView* ParentView() {
    if (lynx_view() == nullptr) {
      return nil;
    }
    return (__bridge NSView*)lynx_view_get_native_window(lynx_view());
  }

  NSView* AttachToParent() { return AttachToParent(ParentView()); }

  NSView* AttachToParent(NSView* lynx_parent) {
    if (label_ == nil || lynx_parent == nil) {
      return nil;
    }
    NSView* parent =
        lynx_parent.window.contentView != nil ? lynx_parent.window.contentView
                                              : lynx_parent;
    if (label_.superview != parent) {
      [label_ removeFromSuperview];
      [parent addSubview:label_ positioned:NSWindowAbove relativeTo:nil];
    }
    return parent;
  }

  NSTextField* label_ = nil;
};

}  // namespace

lynx_native_view_t* Create__ELEMENT_SYMBOL_NAME__NativeUINativeView(void* opaque) {
  auto* view = new __ELEMENT_SYMBOL_NAME__NativeUIView(opaque);
  return view->native_view();
}