/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * 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
 */

package com.android.incallui.answer.impl.hint;

import android.content.Context;
import android.content.SharedPreferences;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.support.annotation.NonNull;
import android.support.annotation.VisibleForTesting;
import com.android.dialer.common.Assert;
import com.android.dialer.common.LogUtil;
import com.android.dialer.configprovider.ConfigProviderComponent;
import com.android.dialer.storage.StorageComponent;
import com.android.incallui.util.AccessibilityUtil;

/**
 * Selects a AnswerHint to show. If there's no suitable hints {@link EmptyAnswerHint} will be used,
 * which does nothing.
 */
public class AnswerHintFactory {

  @VisibleForTesting(otherwise = VisibleForTesting.PRIVATE)
  static final String CONFIG_ANSWER_HINT_ANSWERED_THRESHOLD_KEY = "answer_hint_answered_threshold";

  @VisibleForTesting(otherwise = VisibleForTesting.PRIVATE)
  static final String CONFIG_ANSWER_HINT_WHITELISTED_DEVICES_KEY =
      "answer_hint_whitelisted_devices";
  // Most popular devices released before NDR1 is whitelisted. Their user are likely to have seen
  // the legacy UI.
  private static final String DEFAULT_WHITELISTED_DEVICES_CSV =
      "/hammerhead//bullhead//angler//shamu//gm4g//gm4g_s//AQ4501//gce_x86_phone//gm4gtkc_s/"
          + "/Sparkle_V//Mi-498//AQ4502//imobileiq2//A65//H940//m8_google//m0xx//A10//ctih220/"
          + "/Mi438S//bacon/";

  @VisibleForTesting
  static final String ANSWERED_COUNT_PREFERENCE_KEY = "answer_hint_answered_count";

  private final PawImageLoader pawImageLoader;

  public AnswerHintFactory(@NonNull PawImageLoader pawImageLoader) {
    this.pawImageLoader = Assert.isNotNull(pawImageLoader);
  }

  @NonNull
  public AnswerHint create(Context context, long puckUpDuration, long puckUpDelay) {
    if (shouldShowAnswerHint(context, Build.PRODUCT)) {
      return new DotAnswerHint(context, puckUpDuration, puckUpDelay);
    }

    // Display the event answer hint if the payload is available.
    Drawable eventPayload = pawImageLoader.loadPayload(context);
    if (eventPayload != null) {
      return new PawAnswerHint(context, eventPayload, puckUpDuration, puckUpDelay);
    }

    return new EmptyAnswerHint();
  }

  public static void increaseAnsweredCount(Context context) {
    SharedPreferences sharedPreferences = StorageComponent.get(context).unencryptedSharedPrefs();
    int answeredCount = sharedPreferences.getInt(ANSWERED_COUNT_PREFERENCE_KEY, 0);
    sharedPreferences.edit().putInt(ANSWERED_COUNT_PREFERENCE_KEY, answeredCount + 1).apply();
  }

  @VisibleForTesting
  static boolean shouldShowAnswerHint(Context context, String device) {
    if (AccessibilityUtil.isTouchExplorationEnabled(context)) {
      return false;
    }
    // Devices that has the legacy dialer installed are whitelisted as they are likely to go through
    // a UX change during updates.
    if (!isDeviceWhitelisted(context, device)) {
      return false;
    }

    // If the user has gone through the process a few times we can assume they have learnt the
    // method.
    int answeredCount =
        StorageComponent.get(context)
            .unencryptedSharedPrefs()
            .getInt(ANSWERED_COUNT_PREFERENCE_KEY, 0);
    long threshold =
        ConfigProviderComponent.get(context)
            .getConfigProvider()
            .getLong(CONFIG_ANSWER_HINT_ANSWERED_THRESHOLD_KEY, 3);
    LogUtil.i(
        "AnswerHintFactory.shouldShowAnswerHint",
        "answerCount: %d, threshold: %d",
        answeredCount,
        threshold);
    return answeredCount < threshold;
  }

  /**
   * @param device should be the value of{@link Build#PRODUCT}.
   * @param configProvider should provide a list of devices quoted with '/' concatenated to a
   *     string.
   */
  private static boolean isDeviceWhitelisted(Context context, String device) {
    return ConfigProviderComponent.get(context)
        .getConfigProvider()
        .getString(CONFIG_ANSWER_HINT_WHITELISTED_DEVICES_KEY, DEFAULT_WHITELISTED_DEVICES_CSV)
        .contains("/" + device + "/");
  }
}