/* Copyright 2023 The TensorFlow Authors. All Rights Reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
==============================================================================*/
#include "xprof/convert/trace_viewer/trace_events_to_json.h"

#include <cstddef>
#include <cstdint>
#include <string>
#include <string_view>
#include <utility>

#include "absl/container/btree_map.h"
#include "absl/strings/match.h"
#include "absl/strings/str_format.h"
#include "absl/strings/string_view.h"
#include "plugin/xprof/protobuf/trace_events.pb.h"
#include "plugin/xprof/protobuf/trace_events_raw.pb.h"

namespace tensorflow {
namespace profiler {

std::string JsonEscape(absl::string_view raw) {
  std::string escaped_string;
  const size_t length = raw.length();
  escaped_string.reserve((length + 1) * 2);
  escaped_string.push_back('"');
  for (size_t i = 0; i < length; ++i) {
    const unsigned char c = raw[i];
    if (c < 0x20) {
      // Not printable.
      escaped_string.push_back('\\');
      switch (c) {
        case '\b':
          escaped_string.push_back('b');
          break;
        case '\f':
          escaped_string.push_back('f');
          break;
        case '\n':
          escaped_string.push_back('n');
          break;
        case '\r':
          escaped_string.push_back('r');
          break;
        case '\t':
          escaped_string.push_back('t');
          break;
        default:
          absl::StrAppendFormat(&escaped_string, "u%04x",
                                static_cast<unsigned int>(c));
      }
      continue;
    }

    switch (c) {
      case '\"':
        escaped_string.append("\\\"");
        continue;
      case '\\':
        escaped_string.append("\\\\");
        continue;

      case '<':
      case '>':
      case '&': {
        absl::StrAppendFormat(&escaped_string, "\\u%04x",
                              static_cast<unsigned int>(c));
        continue;
      }
      case '\xe2': {
        if ((i + 2 < length) && (raw[i + 1] == '\x80')) {
          if (raw[i + 2] == '\xa8') {
            escaped_string.append("\\u2028");
            i += 2;
            continue;
          } else if (raw[i + 2] == '\xa9') {
            escaped_string.append("\\u2029");
            i += 2;
            continue;
          }
        }
        escaped_string.push_back(c);
        continue;
      }
    }

    // Character should not be escaped.
    escaped_string.push_back(c);
  }

  escaped_string.push_back('"');
  return escaped_string;
}

// Converts the given proto to text format and escapes it for JSON.
std::string ProtoString(const tsl::protobuf::Message& pb) {
  return JsonEscape(pb.DebugString());
}

absl::btree_map<uint64_t, uint64_t> BuildStackFrameReferences(
    const Trace& trace) {
  const auto& name_table = trace.name_table();
  absl::btree_map<uint64_t, uint64_t> output;
  for (const auto& [fp, name] : name_table) {
    if (!absl::StartsWith(name, "@@")) continue;
    output[fp] = 0;
  }
  uint64_t sf = 1;
  for (auto& it : output) {
    it.second = sf++;
  }
  return output;
}

}  // namespace profiler
}  // namespace tensorflow
