#pragma once

#include <core/color.h>
#include <core/rect.h>
#include <core/types.h>
#include <core/vec2.h>
#include <graphics/font.h>
#include <graphics/opengl/gl_texture.h>
#include <graphics/texture.h>
#include <memory>
#include <stb/stb_rect_pack.h>
#include <stb/stb_truetype.h>
#include <unordered_map>
#include <vector>

namespace extra2d {

// ============================================================================
// OpenGL 字体图集实现 - 使用 stb_rect_pack 进行矩形打包
// ============================================================================
class GLFontAtlas : public FontAtlas {
public:
  GLFontAtlas(const std::string &filepath, int fontSize, bool useSDF = false);
  ~GLFontAtlas();

  // FontAtlas 接口实现
  const Glyph *getGlyph(char32_t codepoint) const override;
  Texture *getTexture() const override { return texture_.get(); }
  int getFontSize() const override { return fontSize_; }
  float getAscent() const override { return ascent_; }
  float getDescent() const override { return descent_; }
  float getLineGap() const override { return lineGap_; }
  float getLineHeight() const override { return ascent_ - descent_ + lineGap_; }
  Vec2 measureText(const std::string &text) override;
  bool isSDF() const override { return useSDF_; }

private:
  // 图集配置 - 增大尺寸以支持更多字符
  static constexpr int ATLAS_WIDTH = 1024;
  static constexpr int ATLAS_HEIGHT = 1024;
  static constexpr int PADDING = 2; // 字形之间的间距

  int fontSize_;
  bool useSDF_;
  mutable std::unique_ptr<GLTexture> texture_;
  mutable std::unordered_map<char32_t, Glyph> glyphs_;

  // stb_rect_pack 上下文
  mutable stbrp_context packContext_;
  mutable std::vector<stbrp_node> packNodes_;
  mutable int currentY_;

  std::vector<unsigned char> fontData_;
  stbtt_fontinfo fontInfo_;
  float scale_;
  float ascent_;
  float descent_;
  float lineGap_;
  
  // 预分配字形位图缓冲区，避免每次动态分配
  mutable std::vector<uint8_t> glyphBitmapCache_;
  mutable std::vector<uint8_t> glyphRgbaCache_;

  void createAtlas();
  void cacheGlyph(char32_t codepoint) const;
};

} // namespace extra2d