// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "components/autofill/core/common/autofill_regexes.h"

#include <utility>

#include "base/containers/scoped_ptr_hash_map.h"
#include "base/logging.h"
#include "base/macros.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/singleton.h"
#include "base/strings/string16.h"
#include "third_party/icu/source/i18n/unicode/regex.h"

namespace {

// A singleton class that serves as a cache of compiled regex patterns.
class AutofillRegexes {
 public:
  static AutofillRegexes* GetInstance();

  // Returns the compiled regex matcher corresponding to |pattern|.
  icu::RegexMatcher* GetMatcher(const base::string16& pattern);

 private:
  AutofillRegexes();
  ~AutofillRegexes();
  friend struct base::DefaultSingletonTraits<AutofillRegexes>;

  // Maps patterns to their corresponding regex matchers.
  base::ScopedPtrHashMap<base::string16, scoped_ptr<icu::RegexMatcher>>
      matchers_;

  DISALLOW_COPY_AND_ASSIGN(AutofillRegexes);
};

// static
AutofillRegexes* AutofillRegexes::GetInstance() {
  return base::Singleton<AutofillRegexes>::get();
}

AutofillRegexes::AutofillRegexes() {
}

AutofillRegexes::~AutofillRegexes() {
}

icu::RegexMatcher* AutofillRegexes::GetMatcher(const base::string16& pattern) {
  auto it = matchers_.find(pattern);
  if (it == matchers_.end()) {
    const icu::UnicodeString icu_pattern(pattern.data(), pattern.length());

    UErrorCode status = U_ZERO_ERROR;
    scoped_ptr<icu::RegexMatcher> matcher(
        new icu::RegexMatcher(icu_pattern, UREGEX_CASE_INSENSITIVE, status));
    DCHECK(U_SUCCESS(status));

    auto result = matchers_.add(pattern, std::move(matcher));
    DCHECK(result.second);
    it = result.first;
  }
  return it->second;
}

}  // namespace

namespace autofill {

bool MatchesPattern(const base::string16& input,
                    const base::string16& pattern) {
  icu::RegexMatcher* matcher =
      AutofillRegexes::GetInstance()->GetMatcher(pattern);
  icu::UnicodeString icu_input(input.data(), input.length());
  matcher->reset(icu_input);

  UErrorCode status = U_ZERO_ERROR;
  UBool match = matcher->find(0, status);
  DCHECK(U_SUCCESS(status));
  return match == TRUE;
}

}  // namespace autofill