// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/new_tab_page/one_google_bar/one_google_bar_service.h"

#include <utility>

#include "base/functional/bind.h"
#include "base/functional/callback.h"
#include "base/memory/raw_ptr.h"
#include "base/observer_list.h"
#include "chrome/browser/new_tab_page/one_google_bar/one_google_bar_loader.h"
#include "components/signin/public/identity_manager/identity_manager.h"

class OneGoogleBarService::SigninObserver
    : public signin::IdentityManager::Observer {
 public:
  using SigninStatusChangedCallback = base::RepeatingClosure;

  SigninObserver(signin::IdentityManager* identity_manager,
                 const SigninStatusChangedCallback& callback)
      : identity_manager_(identity_manager), callback_(callback) {
    identity_manager_->AddObserver(this);
  }

  ~SigninObserver() override { identity_manager_->RemoveObserver(this); }

 private:
  // IdentityManager::Observer implementation.
  void OnAccountsInCookieUpdated(
      const signin::AccountsInCookieJarInfo& accounts_in_cookie_jar_info,
      const GoogleServiceAuthError& error) override {
    callback_.Run();
  }

  const raw_ptr<signin::IdentityManager> identity_manager_;
  SigninStatusChangedCallback callback_;
};

OneGoogleBarService::OneGoogleBarService(
    signin::IdentityManager* identity_manager,
    std::unique_ptr<OneGoogleBarLoader> loader)
    : loader_(std::move(loader)),
      signin_observer_(std::make_unique<SigninObserver>(
          identity_manager,
          base::BindRepeating(&OneGoogleBarService::SigninStatusChanged,
                              base::Unretained(this)))) {}

OneGoogleBarService::~OneGoogleBarService() = default;

void OneGoogleBarService::Shutdown() {
  for (auto& observer : observers_) {
    observer.OnOneGoogleBarServiceShuttingDown();
  }

  signin_observer_.reset();
  DCHECK(observers_.empty());
}

void OneGoogleBarService::Refresh() {
  loader_->Load(base::BindOnce(&OneGoogleBarService::OneGoogleBarDataLoaded,
                               base::Unretained(this)));
}

void OneGoogleBarService::AddObserver(OneGoogleBarServiceObserver* observer) {
  observers_.AddObserver(observer);
}

void OneGoogleBarService::RemoveObserver(
    OneGoogleBarServiceObserver* observer) {
  observers_.RemoveObserver(observer);
}

void OneGoogleBarService::SetLanguageCodeForTesting(
    const std::string& language_code) {
  language_code_ = language_code;
}

void OneGoogleBarService::SetAdditionalQueryParams(
    const std::map<std::string, std::string>& params) {
  return loader_->SetAdditionalQueryParams(params);
}

void OneGoogleBarService::SigninStatusChanged() {
  // If we have cached data, clear it and notify observers.
  if (one_google_bar_data_.has_value()) {
    one_google_bar_data_ = std::nullopt;
    NotifyObservers();
  }
}

void OneGoogleBarService::OneGoogleBarDataLoaded(
    OneGoogleBarLoader::Status status,
    const std::optional<OneGoogleBarData>& data) {
  // In case of transient errors, keep our cached data (if any), but still
  // notify observers of the finished load (attempt).
  if (status != OneGoogleBarLoader::Status::TRANSIENT_ERROR) {
    one_google_bar_data_ = data;
    language_code_ = data.has_value() ? data->language_code : std::string();
  }
  NotifyObservers();
}

void OneGoogleBarService::NotifyObservers() {
  for (auto& observer : observers_) {
    observer.OnOneGoogleBarDataUpdated();
  }
}