#include "common/gui_file.hh"

#include <cassert>

#include <imgui.h>
#include <imgui_stdlib.h>

#include "common/dir_item.hh"
#include "common/generic_context.hh"


using namespace std::literals;

namespace nf7::gui {

static nf7::DirItem* GetDirItem(nf7::FileHolder& h, nf7::DirItem::Flags f) noexcept
try {
  auto& d = h.GetFileOrThrow().interfaceOrThrow<nf7::DirItem>();
  return d.flags() & f? &d: nullptr;
} catch (nf7::Exception&) {
  return nullptr;
}


bool FileFactory::Update() noexcept {
  const auto em = ImGui::GetFontSize();

  ImGui::PushItemWidth(16*em);
  if (ImGui::IsWindowAppearing()) {
    name_        = "new_file";
    type_filter_ = "";
  }

  bool submit = false;
  ImGui::InputTextWithHint("##type_filter", "search...", &type_filter_);
  if (ImGui::BeginListBox("type", {16*em, 8*em})) {
    for (const auto& reg : nf7::File::registry()) {
      const auto& t = *reg.second;

      const bool match =
          t.flags().contains("nf7::File::TypeInfo::Factory") &&
          (type_filter_.empty() ||
           t.name().find(type_filter_) != std::string::npos) &&
          filter_(t);

      const bool sel = (type_ == &t);
      if (!match) {
        if (sel) type_ = nullptr;
        continue;
      }

      constexpr auto kSelectableFlags =
          ImGuiSelectableFlags_SpanAllColumns |
          ImGuiSelectableFlags_AllowItemOverlap;
      if (ImGui::Selectable(t.name().c_str(), sel, kSelectableFlags)) {
        type_ = &t;
      }
      if (ImGui::IsItemHovered()) {
        ImGui::BeginTooltip();
        t.UpdateTooltip();
        ImGui::EndTooltip();

        if (ImGui::IsMouseDoubleClicked(ImGuiMouseButton_Left)) {
          submit = true;
        }
      }
    }
    ImGui::EndListBox();
  }
  ImGui::PopItemWidth();
  ImGui::Spacing();

  if (flags_ & kNameInput) {
    if (ImGui::IsWindowAppearing()) ImGui::SetKeyboardFocusHere();
    ImGui::InputText("name", &name_);
    ImGui::Spacing();
  }

  // input validation
  bool err = false;
  if (type_ == nullptr) {
    ImGui::Bullet(); ImGui::TextUnformatted("type is not selected");
    err = true;
  }
  if (flags_ & kNameInput) {
    try {
      nf7::File::Path::ValidateTerm(name_);
    } catch (Exception& e) {
      ImGui::Bullet(); ImGui::Text("invalid name: %s", e.msg().c_str());
      err = true;
    }
    if (flags_ & kNameDupCheck) {
      if (owner_->Find(name_)) {
        ImGui::Bullet(); ImGui::Text("name duplicated");
        err = true;
      }
    }
  }

  if (!err) {
    if (ImGui::Button("ok")) {
      submit = true;
    }
    if (ImGui::IsItemHovered()) {
      const auto path = owner_->abspath().Stringify();
      if (flags_ & kNameInput) {
        ImGui::SetTooltip(
            "create %s as '%s' on '%s'", type_->name().c_str(), name_.c_str(), path.c_str());
      } else {
        ImGui::SetTooltip("create %s on '%s'", type_->name().c_str(), path.c_str());
      }
    }
  }
  return submit && !err;
}


std::string FileHolderEditor::GetDisplayText() const noexcept {
  std::string text;
  if (holder_->own()) {
    text = "[OWN] " + holder_->GetFile()->type().name();
  } else if (holder_->ref()) {
    text = "[REF] "s + holder_->path().Stringify();
  } else if (holder_->empty()) {
    text = "(empty)";
  } else {
    assert(false);
  }
  return text;
}

void FileHolderEditor::Button(float w, bool small) noexcept {
  ImGui::PushID(this);
  ImGui::BeginGroup();
  const auto text = GetDisplayText();

  const bool open = small?
      ImGui::SmallButton(text.c_str()):
      ImGui::Button(text.c_str(), {w, 0});
  if (open) {
    ImGui::OpenPopup("FileHolderEmplacePopup_FromButton");
  }
  if (ImGui::IsItemHovered()) {
    ImGui::BeginTooltip();
    Tooltip();
    ImGui::EndTooltip();
  }
  ImGui::EndGroup();

  UpdateEmplacePopup("FileHolderEmplacePopup_FromButton");
  ImGui::PopID();
}
void FileHolderEditor::ButtonWithLabel(const char* name) noexcept {
  ImGui::PushID(this);
  ImGui::BeginGroup();
  Button(ImGui::CalcItemWidth());
  ImGui::SameLine(0, ImGui::GetStyle().ItemInnerSpacing.x);
  ImGui::TextUnformatted(name);
  ImGui::EndGroup();
  ImGui::PopID();
}
void FileHolderEditor::Tooltip() noexcept {
  ImGui::TextUnformatted(GetDisplayText().c_str());
  ImGui::Indent();
  if (auto a = GetDirItem(*holder_, nf7::DirItem::kTooltip)) {
    a->UpdateTooltip();
  }
  ImGui::Unindent();
}
void FileHolderEditor::ItemWidget(const char* title) noexcept {
  if (auto d = GetDirItem(*holder_, nf7::DirItem::kWidget)) {
    if (ImGui::CollapsingHeader(title, ImGuiTreeNodeFlags_DefaultOpen)) {
      ImGui::PushID(d);
      ImGui::Indent();
      d->UpdateWidget();
      ImGui::Unindent();
      ImGui::PopID();
    }
  }
}

void FileHolderEditor::Update() noexcept {
  ImGui::PushID(this);
  if (std::exchange(open_emplace_, false)) {
    ImGui::OpenPopup("FileHolderEmplacePopup_FromMenu");
  }
  UpdateEmplacePopup("FileHolderEmplacePopup_FromMenu");
  ImGui::PopID();
}
void FileHolderEditor::UpdateEmplacePopup(const char* id) noexcept {
  if (ImGui::BeginPopup(id)) {
    if (ImGui::IsWindowAppearing()) {
      if (holder_->ref()) {
        type_ = kRef;
        path_ = holder_->path().Stringify();
      } else {
        type_ = kOwn;
        path_ = {};
      }
    }

    if (ImGui::RadioButton("own", type_ == kOwn)) { type_ = kOwn; }
    ImGui::SameLine();
    if (ImGui::RadioButton("ref", type_ == kRef)) { type_ = kRef; }

    switch (type_) {
    case kOwn:
      if (factory_.Update()) {
        ImGui::CloseCurrentPopup();

        auto& f = holder_->owner();
        f.env().ExecMain(
            std::make_shared<nf7::GenericContext>(f),
            [this]() {
              holder_->Emplace(factory_.Create(holder_->owner().env()));
            });
      }
      break;

    case kRef:
      ImGui::InputText("path", &path_);

      bool missing = false;
      try {
        auto path = nf7::File::Path::Parse(path_);
        try {
          holder_->owner().ResolveOrThrow(path);
        } catch (nf7::File::NotFoundException&) {
          missing = true;
        }
        if (ImGui::Button("apply")) {
          ImGui::CloseCurrentPopup();
          auto& f = holder_->owner();
          f.env().ExecMain(
              std::make_shared<nf7::GenericContext>(f),
              [this, p = std::move(path)]() mutable {
                holder_->Emplace(std::move(p));
              });
        }
      } catch (nf7::Exception& e) {
        ImGui::Bullet(); ImGui::TextUnformatted(e.msg().c_str());
      }
      if (missing) {
        ImGui::Bullet(); ImGui::TextUnformatted("the file is missing :(");
      }
      break;
    }
    ImGui::EndPopup();
  }
}

}  // namespace nf7::gui