/*
 * Copyright (C) 2017 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.dialer.calllog.ui;

import android.database.Cursor;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.annotation.VisibleForTesting;
import android.support.v4.app.Fragment;
import android.support.v4.app.LoaderManager.LoaderCallbacks;
import android.support.v4.content.Loader;
import android.support.v4.content.LocalBroadcastManager;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.android.dialer.calllog.CallLogComponent;
import com.android.dialer.calllog.RefreshAnnotatedCallLogReceiver;
import com.android.dialer.common.LogUtil;
import com.android.dialer.common.concurrent.DefaultFutureCallback;
import com.android.dialer.common.concurrent.ThreadUtil;
import com.android.dialer.metrics.Metrics;
import com.android.dialer.metrics.MetricsComponent;
import com.android.dialer.metrics.jank.RecyclerViewJankLogger;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.MoreExecutors;
import java.util.concurrent.TimeUnit;

/** The "new" call log fragment implementation, which is built on top of the annotated call log. */
public final class NewCallLogFragment extends Fragment implements LoaderCallbacks<Cursor> {

  @VisibleForTesting
  static final long MARK_ALL_CALLS_READ_WAIT_MILLIS = TimeUnit.SECONDS.toMillis(3);

  private RefreshAnnotatedCallLogReceiver refreshAnnotatedCallLogReceiver;
  private RecyclerView recyclerView;

  private boolean shouldMarkCallsRead = false;
  private final Runnable setShouldMarkCallsReadTrue = () -> shouldMarkCallsRead = true;

  public NewCallLogFragment() {
    LogUtil.enterBlock("NewCallLogFragment.NewCallLogFragment");
  }

  @Override
  public void onActivityCreated(@Nullable Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);

    LogUtil.enterBlock("NewCallLogFragment.onActivityCreated");

    refreshAnnotatedCallLogReceiver = new RefreshAnnotatedCallLogReceiver(getContext());
  }

  @Override
  public void onStart() {
    super.onStart();

    LogUtil.enterBlock("NewCallLogFragment.onStart");
  }

  @Override
  public void onResume() {
    super.onResume();

    boolean isHidden = isHidden();
    LogUtil.i("NewCallLogFragment.onResume", "isHidden = %s", isHidden);

    // As a fragment's onResume() is tied to the containing Activity's onResume(), being resumed is
    // not equivalent to becoming visible.
    // For example, when an activity with a hidden fragment is resumed, the fragment's onResume()
    // will be called but it is not visible.
    if (!isHidden) {
      onFragmentShown();
    }
  }

  @Override
  public void onPause() {
    super.onPause();
    LogUtil.enterBlock("NewCallLogFragment.onPause");

    onFragmentHidden();
  }

  @Override
  public void onHiddenChanged(boolean hidden) {
    super.onHiddenChanged(hidden);
    LogUtil.i("NewCallLogFragment.onHiddenChanged", "hidden = %s", hidden);

    if (hidden) {
      onFragmentHidden();
    } else {
      onFragmentShown();
    }
  }

  /**
   * To be called when the fragment becomes visible.
   *
   * <p>Note that for a fragment, being resumed is not equivalent to becoming visible.
   *
   * <p>For example, when an activity with a hidden fragment is resumed, the fragment's onResume()
   * will be called but it is not visible.
   */
  private void onFragmentShown() {
    registerRefreshAnnotatedCallLogReceiver();

    CallLogComponent.get(getContext())
        .getRefreshAnnotatedCallLogNotifier()
        .notify(/* checkDirty = */ true);

    // There are some types of data that we show in the call log that are not represented in the
    // AnnotatedCallLog. For example, CP2 information for invalid numbers can sometimes only be
    // fetched at display time. Because of this, we need to clear the adapter's cache and update it
    // whenever the user arrives at the call log (rather than relying on changes to the CursorLoader
    // alone).
    if (recyclerView.getAdapter() != null) {
      ((NewCallLogAdapter) recyclerView.getAdapter()).clearCache();
      recyclerView.getAdapter().notifyDataSetChanged();
    }

    // We shouldn't mark the calls as read immediately when the 3 second timer expires because we
    // don't want to disrupt the UI; instead we set a bit indicating to mark them read when the user
    // leaves the fragment (in onPause).
    shouldMarkCallsRead = false;
    ThreadUtil.getUiThreadHandler()
        .postDelayed(setShouldMarkCallsReadTrue, MARK_ALL_CALLS_READ_WAIT_MILLIS);
  }

  /**
   * To be called when the fragment becomes hidden.
   *
   * <p>This can happen in the following two cases:
   *
   * <ul>
   *   <li>hide the fragment but keep the parent activity visible (e.g., calling {@link
   *       android.support.v4.app.FragmentTransaction#hide(Fragment)} in an activity, or
   *   <li>the parent activity is paused.
   * </ul>
   */
  private void onFragmentHidden() {
    // This is pending work that we don't actually need to follow through with.
    ThreadUtil.getUiThreadHandler().removeCallbacks(setShouldMarkCallsReadTrue);

    unregisterRefreshAnnotatedCallLogReceiver();

    if (shouldMarkCallsRead) {
      Futures.addCallback(
          CallLogComponent.get(getContext()).getClearMissedCalls().clearAll(),
          new DefaultFutureCallback<>(),
          MoreExecutors.directExecutor());
    }
  }

  @Override
  public View onCreateView(
      LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    LogUtil.enterBlock("NewCallLogFragment.onCreateView");

    View view = inflater.inflate(R.layout.new_call_log_fragment, container, false);
    recyclerView = view.findViewById(R.id.new_call_log_recycler_view);
    recyclerView.addOnScrollListener(
        new RecyclerViewJankLogger(
            MetricsComponent.get(getContext()).metrics(), Metrics.NEW_CALL_LOG_JANK_EVENT_NAME));

    getLoaderManager().restartLoader(0, null, this);

    return view;
  }

  private void registerRefreshAnnotatedCallLogReceiver() {
    LogUtil.enterBlock("NewCallLogFragment.registerRefreshAnnotatedCallLogReceiver");

    LocalBroadcastManager.getInstance(getContext())
        .registerReceiver(
            refreshAnnotatedCallLogReceiver, RefreshAnnotatedCallLogReceiver.getIntentFilter());
  }

  private void unregisterRefreshAnnotatedCallLogReceiver() {
    LogUtil.enterBlock("NewCallLogFragment.unregisterRefreshAnnotatedCallLogReceiver");

    // Cancel pending work as we don't need it any more.
    CallLogComponent.get(getContext()).getRefreshAnnotatedCallLogNotifier().cancel();

    LocalBroadcastManager.getInstance(getContext())
        .unregisterReceiver(refreshAnnotatedCallLogReceiver);
  }

  @Override
  public Loader<Cursor> onCreateLoader(int id, Bundle args) {
    LogUtil.enterBlock("NewCallLogFragment.onCreateLoader");
    return new CoalescedAnnotatedCallLogCursorLoader(getContext());
  }

  @Override
  public void onLoadFinished(Loader<Cursor> loader, Cursor newCursor) {
    LogUtil.enterBlock("NewCallLogFragment.onLoadFinished");

    if (newCursor == null) {
      // This might be possible when the annotated call log hasn't been created but we're trying
      // to show the call log.
      LogUtil.w("NewCallLogFragment.onLoadFinished", "null cursor");
      return;
    }

    // TODO(zachh): Handle empty cursor by showing empty view.
    if (recyclerView.getAdapter() == null) {
      recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
      recyclerView.setAdapter(
          new NewCallLogAdapter(getContext(), newCursor, System::currentTimeMillis));
    } else {
      ((NewCallLogAdapter) recyclerView.getAdapter()).updateCursor(newCursor);
    }
  }

  @Override
  public void onLoaderReset(Loader<Cursor> loader) {
    LogUtil.enterBlock("NewCallLogFragment.onLoaderReset");
    recyclerView.setAdapter(null);
  }
}