// Copyright (c) 2023 Dominic Masters
// 
// This software is released under the MIT License.
// https://opensource.org/licenses/MIT

#pragma once
#include "scene/components/ui/UIComponentRenderable.hpp"
#include "display/mesh/QuadMesh.hpp"
#include "asset/assets/TrueTypeAsset.hpp"
#include "util/Xml.hpp"

#define UI_LABEL_MAX_WIDTH_NONE -1

namespace Dawn {
  struct UILabelStyle {
    struct Color color = COLOR_WHITE;
    flag_t style = 0;
    flag_t decorations = 0;
    uint32_t size = 16;
    TrueTypeAsset *font = nullptr;
  };

  struct UILabelText {
    std::string text;
    struct UILabelStyle style;
    int32_t lineStart = 0;
    int32_t lineCount = 0;
    usagelockid_t lockId = -1;
    struct TrueTypeFaceTexture *texture = nullptr;
  };

  struct UILabelLine {
    float_t width = 0.0f;
    float_t height = 0.0f;
    glm::vec2 position;
    int32_t quadStart = -1;
    int32_t quadCount = 0;
  };

  enum UILabelVerticalAlign {
    UI_LABEL_VERTICAL_ALIGN_TOP,
    UI_LABEL_VERTICAL_ALIGN_MIDDLE,
    UI_LABEL_VERTICAL_ALIGN_BOTTOM
  };

  enum UILabelTextAlign {
    UI_LABEL_TEXT_ALIGN_LEFT,
    UI_LABEL_TEXT_ALIGN_CENTER,
    UI_LABEL_TEXT_ALIGN_RIGHT
    // TODO: Add justify
  };

  class UILabel : public UIComponentRenderable {
    private:
      Mesh mesh;
      Mesh meshDecorations;
      FontShaderBuffer shaderBuffer;
      std::map<TrueTypeFaceTexture*, int32_t> textureMap;
      bool_t ignoreAlignmentUpdate = false;
      bool_t hasDecorations = false;

      void updateTextAlignments();

    public:
      int32_t quadStart = 0;
      int32_t quadCount = -1;
      int32_t quadCountTotal = -1;

      glm::vec2 textOffset = glm::vec2(0.0f, 0.0f);

      std::vector<struct UILabelText> texts;
      std::vector<struct UILabelText> textsBuffered;
      std::vector<struct UILabelLine> lines;
      
      StateEvent<> eventTextChanged;

      // @optional
      StateProperty<float_t> lineHeight;

      // @optional
      StateProperty<enum UILabelTextAlign> textAlign;

      UILabel(SceneItem *item);

      void onStart() override;
      std::vector<struct ShaderPassItem> getUIRenderPasses() override;
      float_t getContentWidth() override;
      float_t getContentHeight() override;

      /**
       * Rebuffer the quads for this label. This method will perform all the
       * necessary difference calculations from where the current state of this text is.
       * 
       * @param texts Texts to buffer.
       */
      void rebufferQuads(std::vector<struct UILabelText> texts);
  };
}