#include "str.hh"

#include <cstddef>
#include <string_view>
#include <vector>

namespace str {

namespace {

[[nodiscard]]
inline bool is_space(char c) {
  return c == ' ' || c == '\t' || c == '\r' || c == '\n';
}

}  // namespace

void split(std::string_view str, std::vector<std::string_view>& out,
           char separator, bool keep_empty) {
  out.clear();

  size_t offset = 0;
  while (true) {
    auto next = str.find(separator, offset);
    if (next == std::string_view::npos) {
      if (keep_empty || offset < str.size())
        out.push_back(str.substr(offset));
      break;
    }
    if (keep_empty || offset < next)
      out.push_back(str.substr(offset, next - offset));
    offset = next + 1;
  }
}

std::vector<std::string_view> split(std::string_view str, char separator,
                                    bool keep_empty) {
  std::vector<std::string_view> vec;
  split(str, vec, separator, keep_empty);
  return vec;
}

std::string_view trim(std::string_view str) {
  size_t s = 0;
  size_t e = str.size();
  while (s < e && is_space(str[s]))
    ++s;
  while (e > s && is_space(str[e - 1]))
    --e;
  return str.substr(s, e - s);
}

}  // namespace str