#include "json_utils.h"

namespace node {

std::string EscapeJsonChars(std::string_view str) {

  // 'static constexpr' is slightly better than static const

  // since the initialization occurs at compile time.

  // See https://lemire.me/blog/I3Cah

  static constexpr std::string_view control_symbols[0x20] = {

      "\\u0000", "\\u0001", "\\u0002", "\\u0003", "\\u0004", "\\u0005",

      "\\u0006", "\\u0007", "\\b",     "\\t",     "\\n",     "\\u000b",

      "\\f",     "\\r",     "\\u000e", "\\u000f", "\\u0010", "\\u0011",

      "\\u0012", "\\u0013", "\\u0014", "\\u0015", "\\u0016", "\\u0017",

      "\\u0018", "\\u0019", "\\u001a", "\\u001b", "\\u001c", "\\u001d",

      "\\u001e", "\\u001f"};

  std::string ret;

  size_t last_pos = 0;

  size_t pos = 0;

  for (; pos < str.size(); ++pos) {

    std::string replace;

    char ch = str[pos];

    if (ch == '\\') {

      replace = "\\\\";

    } else if (ch == '\"') {

      replace = "\\\"";

    } else {

      size_t num = static_cast<size_t>(ch);

      if (num < 0x20) replace = control_symbols[num];

    }

    if (!replace.empty()) {

      if (pos > last_pos) {

        ret += str.substr(last_pos, pos - last_pos);

      }

      last_pos = pos + 1;

      ret += replace;

    }

  }

  // Append any remaining symbols.

  if (last_pos < str.size()) {

    ret += str.substr(last_pos, pos - last_pos);

  }

  return ret;

}

std::string Reindent(const std::string& str, int indent_depth) {

  if (indent_depth <= 0) return str;

  const std::string indent(indent_depth, ' ');

  std::string out;

  std::string::size_type pos = 0;

  for (;;) {

    std::string::size_type prev_pos = pos;

    pos = str.find('\n', pos);

    out.append(indent);

    if (pos == std::string::npos) {

      out.append(str, prev_pos, std::string::npos);

      break;

    } else {

      pos++;

      out.append(str, prev_pos, pos - prev_pos);

    }

  }

  return out;

}

}  // namespace node