// Copyright 2014 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.

#ifndef THIRD_PARTY_LIBADDRESSINPUT_CHROMIUM_CHROME_ADDRESS_VALIDATOR_H_
#define THIRD_PARTY_LIBADDRESSINPUT_CHROMIUM_CHROME_ADDRESS_VALIDATOR_H_

#include <stddef.h>

#include <map>
#include <memory>
#include <string>
#include <vector>

#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "base/time/time.h"
#include "third_party/libaddressinput/src/cpp/include/libaddressinput/address_field.h"
#include "third_party/libaddressinput/src/cpp/include/libaddressinput/address_validator.h"
#include "third_party/libaddressinput/src/cpp/include/libaddressinput/callback.h"
#include "third_party/libaddressinput/src/cpp/include/libaddressinput/preload_supplier.h"

namespace i18n {
namespace addressinput {
class AddressNormalizer;
class Source;
class Storage;
struct AddressData;
}
}

namespace autofill {

class InputSuggester;

// The object to be notified when loading of address validation rules is
// finished.
class LoadRulesListener {
 public:
  virtual ~LoadRulesListener() {}

  // Called when the validation rules for the |region_code| have been loaded.
  // The validation rules include the generic rules for the |region_code| and
  // specific rules for the country's administrative areas, localities, and
  // dependent localities. If a country has language-specific validation rules,
  // then these are also loaded.
  //
  // The |success| parameter is true when the rules were loaded successfully.
  virtual void OnAddressValidationRulesLoaded(const std::string& region_code,
                                              bool success) = 0;
};

// Interface to the libaddressinput AddressValidator for Chromium Autofill. The
// class is named AddressValidator to simplify switching between libaddressinput
// and this version.
//
// It's not possible to name this file address_validator.h because some
// compilers do not handle multiple files with the same name (although in
// different directories) gracefully. This class is a shim between upstream
// libaddressinput API and the API that Chrome expects, hence the file name
// chrome_address_validator.h.
class AddressValidator {
 public:
  // The status of address validation.
  enum Status {
    // Address validation completed successfully. Check |problems| to see if any
    // problems were found.
    SUCCESS,

    // The validation rules are not available, because LoadRules() was not
    // called or failed. Reload the rules.
    RULES_UNAVAILABLE,

    // The validation rules are being loaded. Try again later.
    RULES_NOT_READY
  };

  // Takes ownership of |source| and |storage|.
  AddressValidator(std::unique_ptr<::i18n::addressinput::Source> source,
                   std::unique_ptr<::i18n::addressinput::Storage> storage,
                   LoadRulesListener* load_rules_listener);

  virtual ~AddressValidator();

  // Loads the generic validation rules for |region_code| and specific rules
  // for the region's administrative areas, localities, and dependent
  // localities. A typical data size is 10KB. The largest is 250KB. If a region
  // has language-specific validation rules, then these are also loaded.
  //
  // Example rule:
  // https://i18napis.appspot.com/ssl-aggregate-address/data/US
  //
  // If the rules are already in progress of being loaded, it does nothing.
  // Invokes |load_rules_listener| when the loading has finished.
  virtual void LoadRules(const std::string& region_code);

  // Validates the |address| and populates |problems| with the validation
  // problems, filtered according to the |filter| parameter.
  //
  // If the |filter| is empty, then all discovered validation problems are
  // returned. If the |filter| contains problem elements, then only the problems
  // in the |filter| may be returned.
  virtual Status ValidateAddress(
      const ::i18n::addressinput::AddressData& address,
      const ::i18n::addressinput::FieldProblemMap* filter,
      ::i18n::addressinput::FieldProblemMap* problems) const;

  // Fills in |suggestions| for the partially typed in |user_input|, assuming
  // the user is typing in the |focused_field|. If the number of |suggestions|
  // is over the |suggestion_limit|, then returns no |suggestions| at all.
  //
  // If the |solutions| parameter is NULL, the checks whether the validation
  // rules are available, but does not fill in suggestions.
  //
  // Sample user input 1:
  //   country code = "US"
  //   postal code = "90066"
  //   focused field = POSTAL_CODE
  //   suggestions limit = 1
  // Suggestion:
  //   [{administrative_area: "CA"}]
  //
  // Sample user input 2:
  //   country code = "CN"
  //   dependent locality = "Zongyang"
  //   focused field = DEPENDENT_LOCALITY
  //   suggestions limit = 10
  // Suggestion:
  //   [{dependent_locality: "Zongyang Xian",
  //     locality: "Anqing Shi",
  //     administrative_area: "Anhui Sheng"}]
  virtual Status GetSuggestions(
      const ::i18n::addressinput::AddressData& user_input,
      ::i18n::addressinput::AddressField focused_field,
      size_t suggestion_limit,
      std::vector< ::i18n::addressinput::AddressData>* suggestions) const;

  // Canonicalizes the administrative area in |address_data|. For example,
  // "texas" changes to "TX". Returns true on success, otherwise leaves
  // |address_data| alone and returns false.
  virtual bool CanonicalizeAdministrativeArea(
      ::i18n::addressinput::AddressData* address) const;

 protected:
  // Constructor used only for MockAddressValidator.
  AddressValidator();

  // Returns the period of time to wait between the first attempt's failure and
  // the second attempt's initiation to load rules. Exposed for testing.
  virtual base::TimeDelta GetBaseRetryPeriod() const;

 private:
  // Verifies that |validator_| succeeded. Invoked by |validated_| callback.
  void Validated(bool success,
                 const ::i18n::addressinput::AddressData&,
                 const ::i18n::addressinput::FieldProblemMap&);

  // Invokes the |load_rules_listener_|, if it's not NULL. Called by
  // |rules_loaded_| callback.
  void RulesLoaded(bool success, const std::string& region_code, int);

  // Retries loading rules without resetting the retry counter.
  void RetryLoadRules(const std::string& region_code);

  // Loads and stores aggregate rules at COUNTRY level.
  const std::unique_ptr<::i18n::addressinput::PreloadSupplier> supplier_;

  // Suggests addresses based on user input.
  const std::unique_ptr<InputSuggester> input_suggester_;

  // Normalizes addresses into a canonical form.
  const std::unique_ptr<::i18n::addressinput::AddressNormalizer> normalizer_;

  // Validates addresses.
  const std::unique_ptr<const ::i18n::addressinput::AddressValidator>
      validator_;

  // The callback that |validator_| invokes when it finished validating an
  // address.
  const std::unique_ptr<const ::i18n::addressinput::AddressValidator::Callback>
      validated_;

  // The callback that |supplier_| invokes when it finished loading rules.
  const std::unique_ptr<const ::i18n::addressinput::PreloadSupplier::Callback>
      rules_loaded_;

  // Not owned delegate to invoke when |suppler_| finished loading rules. Can be
  // NULL.
  LoadRulesListener* const load_rules_listener_;

  // A mapping of region codes to the number of attempts to retry loading rules.
  std::map<std::string, int> attempts_number_;

  // Member variables should appear before the WeakPtrFactory, to ensure that
  // any WeakPtrs to AddressValidator are invalidated before its members
  // variable's destructors are executed, rendering them invalid.
  base::WeakPtrFactory<AddressValidator> weak_factory_;

  DISALLOW_COPY_AND_ASSIGN(AddressValidator);
};

}  // namespace autofill

#endif  // THIRD_PARTY_LIBADDRESSINPUT_CHROMIUM_CHROME_ADDRESS_VALIDATOR_H_