#pragma once
#include <plot/core/status.hpp>
#include <plot/core/types.hpp>
#include <plot/gl/handle.hpp>
#include <plot/render/buffer.hpp>

namespace plot::render {

/// Vertex array plus instance buffer of the line pipeline.
///
/// The attribute layout is fixed by the line shader (see shaders.hpp): `a_p0` at
/// location 0 and `a_p1` at location 1, two floats each, advancing once per
/// instance. A caller never writes a location, stride or offset; it stages a
/// `LineBatch` and uploads its `data()`.
class LineVertexArray {
 public:
  /// Creates the vertex array, the instance buffer and the attribute layout.
  bool create(Status* st = nullptr) noexcept;

  /// Uploads `segments` instances from interleaved `x0,y0,x1,y1` floats and
  /// records how many the next draw should rasterise.
  void upload(const f32* interleaved, u32 segments) noexcept;

  void bind() const noexcept { vao_.bind(); }
  bool valid() const noexcept { return vao_.id() != 0; }
  u32 instance_count() const noexcept { return instances_; }

 private:
  LineBuffer buffer_;
  gl::VertexArray vao_;
  u32 instances_ = 0;
};

/// Vertex array plus instance buffer of the text pipeline: `a_pos` at location 0
/// and the glyph's atlas texel origin `a_uv` at location 1, two floats each,
/// advancing once per instance.
class TextVertexArray {
 public:
  bool create(Status* st = nullptr) noexcept;

  /// Uploads `glyphs` instances from interleaved `x,y,u,v` floats.
  void upload(const f32* interleaved, u32 glyphs) noexcept;

  void bind() const noexcept { vao_.bind(); }
  bool valid() const noexcept { return vao_.id() != 0; }
  u32 instance_count() const noexcept { return instances_; }

 private:
  TextBuffer buffer_;
  gl::VertexArray vao_;
  u32 instances_ = 0;
};

}  // namespace plot::render