#include "cru/ui/controls/text_common.hpp"

#include "cru/common/logger.hpp"
#include "cru/platform/graph/font.hpp"
#include "cru/platform/graph/painter.hpp"
#include "cru/platform/native/ui_application.hpp"
#include "cru/ui/control.hpp"
#include "cru/ui/render/canvas_render_object.hpp"
#include "cru/ui/render/text_render_object.hpp"

#include <cassert>

namespace cru::ui::controls {
using platform::graph::ITextLayout;

constexpr float caret_width = 2;
constexpr long long caret_blink_duration = 500;

TextControlService::TextControlService(Control* control,
                                       ITextControl* text_control)
    : control_(control), text_control_(text_control) {
  event_revoker_guards_.push_back(
      EventRevokerGuard{control->MouseDownEvent()->Direct()->AddHandler(
          [this](event::MouseButtonEventArgs& args) {
            if (this->select_down_button_.has_value()) {
              return;
            } else {
              if (!this->control_->CaptureMouse()) return;
              const auto text_render_object =
                  this->text_control_->GetTextRenderObject();
              this->select_down_button_ = args.GetButton();
              const auto result = text_render_object->TextHitTest(
                  text_render_object->FromRootToContent(args.GetPoint()));
              const auto position = result.position + (result.trailing ? 1 : 0);
              this->select_start_position_ = position;
              log::Debug("Begin to select text. Position: {}", position);
            }
          })});

  event_revoker_guards_.push_back(
      EventRevokerGuard{control->MouseMoveEvent()->Direct()->AddHandler(
          [this](event::MouseEventArgs& args) {
            if (this->select_down_button_.has_value()) {
              const auto text_render_object =
                  this->text_control_->GetTextRenderObject();
              const auto result = text_render_object->TextHitTest(
                  text_render_object->FromRootToContent(args.GetPoint()));
              const auto position = result.position + (result.trailing ? 1 : 0);
              this->caret_position_ = position;
              log::Debug("Text select range: {} : {}.", position,
                         this->select_start_position_);
              this->text_control_->GetTextRenderObject()->SetSelectionRange(
                  TextRange::FromTwoSides(
                      static_cast<unsigned>(position),
                      static_cast<unsigned>(this->select_start_position_)));
              this->text_control_->GetTextRenderObject()->InvalidatePaint();
              this->text_control_->GetCaretRenderObject()->InvalidatePaint();
            }
          })});

  event_revoker_guards_.push_back(
      EventRevokerGuard{control->MouseUpEvent()->Direct()->AddHandler(
          [this](event::MouseButtonEventArgs& args) {
            if (this->select_down_button_.has_value() &&
                this->select_down_button_.value() == args.GetButton()) {
              this->control_->ReleaseMouse();
              this->select_down_button_ = std::nullopt;
              log::Debug("End selecting text.");
            }
          })});
}

TextControlService::~TextControlService() { TearDownCaretTimer(); }

void TextControlService::SetCaretVisible(bool visible) {
  if (visible) {
    SetupCaretTimer();
  } else {
    TearDownCaretTimer();
  }
}

void TextControlService::DrawCaret(platform::graph::IPainter* painter) {
  if (caret_show_) {
    const auto text_render_object = text_control_->GetTextRenderObject();
    const auto point = text_render_object->TextSingleRect(
        caret_position_, false);  // Maybe cache the result???
    painter->FillRectangle(
        Rect{point,
             Size{caret_width, text_render_object->GetFont()->GetFontSize()}},
        text_control_->GetCaretBrush());
  }
}

void TextControlService::SetupCaretTimer() {
  if (caret_visible_) return;

  caret_visible_ = true;
  caret_timer_tag_ =
      platform::native::IUiApplication::GetInstance()->SetInterval(
          std::chrono::milliseconds(caret_blink_duration), [this] {
            this->caret_show_ = !this->caret_show_;
            this->text_control_->GetCaretRenderObject()->InvalidatePaint();
          });
}

void TextControlService::TearDownCaretTimer() {
  if (!caret_visible_) return;
  caret_visible_ = false;
  platform::native::IUiApplication::GetInstance()->CancelTimer(
      caret_timer_tag_);
}
}  // namespace cru::ui::controls