#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