// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <cinttypes>

#include "base/compiler_specific.h"
#include "base/logging.h"
#include "third_party/blink/renderer/platform/graphics/paint/drawing_display_item.h"
#include "third_party/blink/renderer/platform/graphics/paint/paint_controller.h"
#include "third_party/blink/renderer/platform/wtf/text/format.h"
#include "third_party/blink/renderer/platform/wtf/text/strcat.h"

#if DCHECK_IS_ON()

namespace blink {

class PaintController::PaintArtifactAsJSON {
  STACK_ALLOCATED();

 public:
  PaintArtifactAsJSON(const PaintArtifact& artifact,
                      const Vector<SubsequenceMarkers>& subsequences,
                      DisplayItemList::JsonOption option)
      : artifact_(artifact),
        subsequences_(subsequences),
        next_subsequence_(subsequences_.begin()),
        option_(option) {}

  String ToString() {
    return ChunksAsJSONArrayRecursive(0, artifact_.GetPaintChunks().size())
        ->ToPrettyJSONString();
  }

 private:
  std::unique_ptr<JSONObject> SubsequenceAsJSONObjectRecursive();
  std::unique_ptr<JSONArray> ChunksAsJSONArrayRecursive(wtf_size_t, wtf_size_t);

  const PaintArtifact& artifact_;
  const Vector<SubsequenceMarkers>& subsequences_;
  Vector<SubsequenceMarkers>::const_iterator next_subsequence_;
  DisplayItemList::JsonOption option_;
};

std::unique_ptr<JSONObject>
PaintController::PaintArtifactAsJSON::SubsequenceAsJSONObjectRecursive() {
  const auto& subsequence = *next_subsequence_;
  UNSAFE_TODO(++next_subsequence_);

  auto json_object = std::make_unique<JSONObject>();

  json_object->SetString(
      "subsequence",
      Format("client: {} {}", reinterpret_cast<void*>(subsequence.client_id),
             artifact_.ClientDebugName(subsequence.client_id)));
  json_object->SetArray(
      "chunks", ChunksAsJSONArrayRecursive(subsequence.start_chunk_index,
                                           subsequence.end_chunk_index));

  return json_object;
}

std::unique_ptr<JSONArray>
PaintController::PaintArtifactAsJSON::ChunksAsJSONArrayRecursive(
    wtf_size_t start_chunk_index,
    wtf_size_t end_chunk_index) {
  auto array = std::make_unique<JSONArray>();
  auto chunk_index = start_chunk_index;

  while (next_subsequence_ != subsequences_.end() &&
         next_subsequence_->start_chunk_index < end_chunk_index) {
    const auto& subsequence = *next_subsequence_;
    if (!subsequence.client_id) {
      // Skip unfinished subsequences during painting.
      UNSAFE_TODO(next_subsequence_++);
      continue;
    }
    DCHECK_GE(subsequence.start_chunk_index, chunk_index);
    DCHECK_LE(subsequence.end_chunk_index, end_chunk_index);

    if (chunk_index < subsequence.start_chunk_index) {
      artifact_.AppendChunksAsJSON(chunk_index, subsequence.start_chunk_index,
                                   *array, option_);
    }
    array->PushObject(SubsequenceAsJSONObjectRecursive());
    chunk_index = subsequence.end_chunk_index;
  }

  if (chunk_index < end_chunk_index)
    artifact_.AppendChunksAsJSON(chunk_index, end_chunk_index, *array, option_);

  return array;
}

String PaintController::DebugDataAsString(
    DisplayItemList::JsonOption option) const {
  StringBuilder sb;
  sb.Append("current paint artifact: ");
  if (persistent_data_) {
    sb.Append(PaintArtifactAsJSON(CurrentPaintArtifact(),
                                  CurrentSubsequences().tree, option)
                  .ToString());
  } else {
    sb.Append("null");
  }
  sb.Append("\nnew paint artifact: ");
  if (new_paint_artifact_) {
    sb.Append(PaintArtifactAsJSON(*new_paint_artifact_, new_subsequences_.tree,
                                  option)
                  .ToString());
  } else {
    sb.Append("null");
  }
  return sb.ToString();
}

void PaintController::ShowDebugDataInternal(
    DisplayItemList::JsonOption option) const {
  LOG(INFO) << DebugDataAsString(option).Utf8();
}

void PaintController::ShowCompactDebugData() const {
  ShowDebugDataInternal(DisplayItemList::kCompact);
}

void PaintController::ShowDebugData() const {
  ShowDebugDataInternal(DisplayItemList::kDefault);
}

void PaintController::ShowDebugDataWithPaintRecords() const {
  return ShowDebugDataInternal(DisplayItemList::kShowPaintRecords);
}

}  // namespace blink

#endif  // DCHECK_IS_ON()