/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef WEBGL_BUFFER_H_
#define WEBGL_BUFFER_H_

#include <map>

#include "CacheInvalidator.h"
#include "GLDefs.h"
#include "mozilla/LinkedList.h"
#include "nsWrapperCache.h"
#include "WebGLObjectModel.h"
#include "WebGLTypes.h"

namespace mozilla {

class WebGLBuffer final : public nsWrapperCache,
                          public WebGLRefCountedObject<WebGLBuffer>,
                          public LinkedListElement<WebGLBuffer> {
  friend class WebGLContext;
  friend class WebGL2Context;
  friend class WebGLTexture;

 public:
  enum class Kind { Undefined, ElementArray, OtherData };

  WebGLBuffer(WebGLContext* webgl, GLuint buf);

  void SetContentAfterBind(GLenum target);
  Kind Content() const { return mContent; }

  void Delete();

  size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;

  GLenum Usage() const { return mUsage; }
  size_t ByteLength() const { return mByteLength; }

  Maybe<uint32_t> GetIndexedFetchMaxVert(GLenum type, uint64_t byteOffset,
                                         uint32_t indexCount) const;
  bool ValidateRange(size_t byteOffset, size_t byteLen) const;

  WebGLContext* GetParentObject() const { return mContext; }

  virtual JSObject* WrapObject(JSContext* cx,
                               JS::Handle<JSObject*> givenProto) override;

  bool ValidateCanBindToTarget(GLenum target);
  void BufferData(GLenum target, uint64_t size, const void* data, GLenum usage);
  void BufferSubData(GLenum target, uint64_t dstByteOffset, uint64_t dataLen,
                     const void* data) const;

  ////

  static void AddBindCount(GLenum target, WebGLBuffer* buffer, int8_t addVal) {
    if (!buffer) return;

    if (target == LOCAL_GL_TRANSFORM_FEEDBACK_BUFFER) {
      MOZ_ASSERT_IF(addVal < 0, buffer->mTFBindCount >= size_t(-addVal));
      buffer->mTFBindCount += addVal;
      buffer->mFetchInvalidator.InvalidateCaches();
    } else {
      MOZ_ASSERT_IF(addVal < 0, buffer->mNonTFBindCount >= size_t(-addVal));
      buffer->mNonTFBindCount += addVal;
    }
  }

  static void SetSlot(GLenum target, WebGLBuffer* newBuffer,
                      WebGLRefPtr<WebGLBuffer>* const out_slot) {
    WebGLBuffer* const oldBuffer = *out_slot;
    AddBindCount(target, oldBuffer, -1);
    AddBindCount(target, newBuffer, +1);
    *out_slot = newBuffer;
  }

  bool IsBoundForTF() const { return bool(mTFBindCount); }
  bool IsBoundForNonTF() const { return bool(mNonTFBindCount); }

  ////

  const GLenum mGLName;

  NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(WebGLBuffer)
  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(WebGLBuffer)

 protected:
  ~WebGLBuffer();

  void InvalidateCacheRange(uint64_t byteOffset, uint64_t byteLength) const;

  Kind mContent;
  GLenum mUsage;
  size_t mByteLength;
  size_t mTFBindCount;
  size_t mNonTFBindCount;
  mutable uint64_t mLastUpdateFenceId = 0;

  struct IndexRange final {
    GLenum type;
    uint64_t byteOffset;
    uint32_t indexCount;

    bool operator<(const IndexRange& x) const {
      if (type != x.type) return type < x.type;

      if (byteOffset != x.byteOffset) return byteOffset < x.byteOffset;

      return indexCount < x.indexCount;
    }
  };

  UniqueBuffer mIndexCache;
  mutable std::map<IndexRange, Maybe<uint32_t>> mIndexRanges;

 public:
  CacheInvalidator mFetchInvalidator;

  void ResetLastUpdateFenceId() const;
};

}  // namespace mozilla

#endif  // WEBGL_BUFFER_H_