third_party/libaddressinput/chromium/cpp/src/ruleset.h

// Copyright (C) 2014 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef I18N_ADDRESSINPUT_RULESET_H_
#define I18N_ADDRESSINPUT_RULESET_H_

#include <libaddressinput/address_field.h>
#include <libaddressinput/util/basictypes.h>
#include <libaddressinput/util/scoped_ptr.h>

#include <map>
#include <set>
#include <string>

#include "rule.h"
#include "util/canonicalize_string.h"
#include "util/trie.h"

namespace i18n {
namespace addressinput {

// A recursive data structure that stores a set of rules for a region. Can store
// the rules for a country, its administrative areas, localities, and dependent
// localities, in addition to the language-specific rules.
//
// Example for Canada and some of its provinces:
//                   CA-->fr
//                   |
// -------------------------------------
// |        |        |        |        |
// v        v        v        v        v
// AB-->fr  BC-->fr  MB-->fr  NB-->fr  NL-->fr
//
// The rules in Canada are in English by default. Each rule also has a French
// language version.
class Ruleset {
 public:
  // Builds a ruleset for |field| with a region-wide |rule| in the default
  // language of the country. The |field| should be between COUNTRY and
  // DEPENDENT_LOCALITY (inclusively). The |rule| should not be NULL.
  Ruleset(AddressField field, scoped_ptr<Rule> rule);

  ~Ruleset();

  // Returns the parent ruleset. This is NULL until this ruleset has been passed
  // into a AddSubRegionRuleset() method. Consequently, this is always NULL for
  // a country-level ruleset.
  Ruleset* parent() const { return parent_; }

  // Returns the field type for this ruleset.
  AddressField field() const { return field_; }

  // Returns the region-wide rule for this ruleset in the default language of
  // the country.
  const Rule& rule() const { return *rule_; }

  // Adds the |ruleset| for |sub_region| and sets this to be its parent. A
  // |sub_region| should be added at most once. The |ruleset| should not be
  // NULL.
  //
  // The field of the |ruleset| parameter must be exactly one smaller than the
  // field of this ruleset. For example, a COUNTRY ruleset can contain
  // ADMIN_AREA rulesets, but should not contain COUNTRY or LOCALITY rulesets.
  void AddSubRegionRuleset(const std::string& sub_region,
                           scoped_ptr<Ruleset> ruleset);

  // Adds a language-specific |rule| for |language_code| for this region. A
  // |language_code| should be added at most once. The |rule| should not be
  // NULL.
  void AddLanguageCodeRule(const std::string& language_code,
                           scoped_ptr<Rule> rule);

  // Returns the set of rules for |sub_region|. The result is NULL if there's no
  // such |sub_region|. The caller does not own the result.
  Ruleset* GetSubRegionRuleset(const std::string& sub_region) const;

  // If there's a language-specific rule for |language_code|, then returns this
  // rule. Otherwise returns the rule in the default language of the country.
  const Rule& GetLanguageCodeRule(const std::string& language_code) const;

  // Returns a mapping of sub-region keys to rulesets. The caller does now own
  // the result. The values are not NULL.
  const std::map<std::string, Ruleset*>& GetSubRegionRulesets() const {
    return sub_regions_;
  }

  // Enables using FindRulesetsByPrefix() method. Should be called only once and
  // on a COUNTRY level ruleset.
  void BuildPrefixSearchIndex();

  // Returns true if BuildPrefixSearchIndex() has been called.
  bool prefix_search_index_ready() const { return !tries_.empty(); }

  // Returns the deepest possible ruleset level for this country. Must be called
  // on a COUNTRY level ruleset. Must be called after BuildPrefixSearchIndex()
  // has been called.
  AddressField deepest_ruleset_level() const { return deepest_ruleset_level_; }

  // Finds all rulesets at |ruleset_level| where the rule for |language_code|
  // has the |identity_field| that starts with |prefix|. Ignores diacritics and
  // capitalization differences between the rule data and |prefix|.
  //
  // If there're no rules for |language_code| (or |language_code| is an empty
  // string), then the default language code is used.
  //
  // Should be called only on a COUNTRY level ruleset. Should be called only
  // after BuildPrefixSearchIndex() has been called.
  //
  // The |field| parameter should be only ADMIN_AREA, LOCALITY, or
  // DEPENDENT_LOCALITY. The result parameter should not be NULL.
  void FindRulesetsByPrefix(const std::string& language_code,
                            AddressField ruleset_level,
                            Rule::IdentityField identity_field,
                            const std::string& prefix,
                            std::set<const Ruleset*>* result) const;

 private:
  // The type that maps rule identity field to tries of rulesets.
  typedef std::map<Rule::IdentityField, Trie<const Ruleset*>*>
      IdentityFieldTries;

  // The type that maps address field to IdentityFieldTries.
  typedef std::map<AddressField, IdentityFieldTries*> AddressFieldTries;

  // The type that maps language code to AddressFieldTries.
  typedef std::map<std::string, AddressFieldTries*> LanguageCodeTries;

  // Adds all children of |parent_ruleset| into |tries_| of this ruleset. Should
  // be called only on a COUNTRY level ruleset.
  void AddSubRegionRulesetsToTrie(const Ruleset& parent_ruleset);

  // The tries to lookup rulesets by a prefix of key, name, or latin-name in a
  // rule. Has data only in a COUNTRY level ruleset. Owns the map and trie
  // objects. Does not own the ruleset objects.
  LanguageCodeTries tries_;

  // Canonicalizes region keys, names, and latin names when building a trie.
  scoped_ptr<StringCanonicalizer> canonicalizer_;

  // The parent ruleset of this object. The parent ruleset owns this object.
  Ruleset* parent_;

  // The field of this ruleset.
  const AddressField field_;

  // The deepest possible ruleset level for this country. Set in
  // BuildPrefixSearchIndex() method and, therefore, meaningful only on a
  // COUNTRY level ruleset.
  AddressField deepest_ruleset_level_;

  // The region-wide rule in the default language of the country.
  const scoped_ptr<const Rule> rule_;

  // Owned rulesets for sub-regions.
  std::map<std::string, Ruleset*> sub_regions_;

  // Owned language-specific rules for the region.
  std::map<std::string, const Rule*> language_codes_;

  DISALLOW_COPY_AND_ASSIGN(Ruleset);
};

}  // namespace addressinput
}  // namespace i18n

#endif  // I18N_ADDRESSINPUT_RULESET_H_