//===-- runtime/tools.cpp ---------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "tools.h"
#include <algorithm>
#include <cstring>

namespace Fortran::runtime {

std::size_t TrimTrailingSpaces(const char *s, std::size_t n) {
  while (n > 0 && s[n - 1] == ' ') {
    --n;
  }
  return n;
}

OwningPtr<char> SaveDefaultCharacter(
    const char *s, std::size_t length, const Terminator &terminator) {
  if (s) {
    auto *p{static_cast<char *>(AllocateMemoryOrCrash(terminator, length + 1))};
    std::memcpy(p, s, length);
    p[length] = '\0';
    return OwningPtr<char>{p};
  } else {
    return OwningPtr<char>{};
  }
}

static bool CaseInsensitiveMatch(
    const char *value, std::size_t length, const char *possibility) {
  for (; length-- > 0; ++possibility) {
    char ch{*value++};
    if (ch >= 'a' && ch <= 'z') {
      ch += 'A' - 'a';
    }
    if (*possibility != ch) {
      if (*possibility != '\0' || ch != ' ') {
        return false;
      }
      // Ignore trailing blanks (12.5.6.2 p1)
      while (length-- > 0) {
        if (*value++ != ' ') {
          return false;
        }
      }
      return true;
    }
  }
  return *possibility == '\0';
}

int IdentifyValue(
    const char *value, std::size_t length, const char *possibilities[]) {
  if (value) {
    for (int j{0}; possibilities[j]; ++j) {
      if (CaseInsensitiveMatch(value, length, possibilities[j])) {
        return j;
      }
    }
  }
  return -1;
}

void ToFortranDefaultCharacter(
    char *to, std::size_t toLength, const char *from) {
  std::size_t len{std::strlen(from)};
  std::memcpy(to, from, std::max(toLength, len));
  if (len < toLength) {
    std::memset(to + len, ' ', toLength - len);
  }
}

} // namespace Fortran::runtime