src/com/android/tv/search/TvProviderSearch.java - platform/packages/apps/TV - Git at Google

 /*
  * Copyright (C) 2015 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.tv.search;

 import android.content.ContentResolver;
 import android.content.Context;
 import android.content.Intent;
 import android.database.Cursor;
 import android.media.tv.TvContentRating;
 import android.media.tv.TvContract;
 import android.media.tv.TvContract.Channels;
 import android.media.tv.TvContract.Programs;
 import android.media.tv.TvContract.WatchedPrograms;
 import android.media.tv.TvInputInfo;
 import android.media.tv.TvInputManager;
 import android.net.Uri;
 import android.os.SystemClock;
 import android.support.annotation.WorkerThread;
 import android.text.TextUtils;
 import android.util.Log;

 import com.android.tv.common.TvContentRatingCache;
 import com.android.tv.search.LocalSearchProvider.SearchResult;
 import com.android.tv.util.PermissionUtils;
 import com.android.tv.util.Utils;

 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;

 /**
  * An implementation of {@link SearchInterface} to search query from TvProvider directly.
  */
 public class TvProviderSearch implements SearchInterface {
     private static final String TAG = "TvProviderSearch";
     private static final boolean DEBUG = false;

     private static final int NO_LIMIT = 0;

     private final Context mContext;
     private final ContentResolver mContentResolver;
     private final TvInputManager mTvInputManager;
     private final TvContentRatingCache mTvContentRatingCache = TvContentRatingCache.getInstance();

     TvProviderSearch(Context context) {
         mContext = context;
         mContentResolver = context.getContentResolver();
         mTvInputManager = (TvInputManager) context.getSystemService(Context.TV_INPUT_SERVICE);
     }

     /**
      * Search channels, inputs, or programs from TvProvider.
      * This assumes that parental control settings will not be change while searching.
      *
      * @param action One of {@link #ACTION_TYPE_SWITCH_CHANNEL}, {@link #ACTION_TYPE_SWITCH_INPUT},
      *               or {@link #ACTION_TYPE_AMBIGUOUS},
      */
     @Override
     @WorkerThread
     public List<SearchResult> search(String query, int limit, int action) {
         List<SearchResult> results = new ArrayList<>();
         if (!PermissionUtils.hasAccessAllEpg(mContext)) {
             // TODO: support this feature for non-system LC app. b/23939816
             return results;
         }
         Set<Long> channelsFound = new HashSet<>();
         if (action == ACTION_TYPE_SWITCH_CHANNEL) {
             results.addAll(searchChannels(query, channelsFound, limit));
         } else if (action == ACTION_TYPE_SWITCH_INPUT) {
             results.addAll(searchInputs(query, limit));
         } else {
             // Search channels first.
             results.addAll(searchChannels(query, channelsFound, limit));
             if (results.size() >= limit) {
                 return results;
             }

             // In case the user wanted to perform the action "switch to XXX", which is indicated by
             // setting the limit to 1, search inputs.
             if (limit == 1) {
                 results.addAll(searchInputs(query, limit));
                 if (!results.isEmpty()) {
                     return results;
                 }
             }

             // Lastly, search programs.
             limit -= results.size();
             results.addAll(searchPrograms(query, null, new String[] {
                     Programs.COLUMN_TITLE, Programs.COLUMN_SHORT_DESCRIPTION },
                     channelsFound, limit));
         }
         return results;
     }

     private void appendSelectionString(StringBuilder sb, String[] columnForExactMatching,
             String[] columnForPartialMatching) {
         boolean firstColumn = true;
         if (columnForExactMatching != null) {
             for (String column : columnForExactMatching) {
                 if (!firstColumn) {
                     sb.append(" OR ");
                 } else {
                     firstColumn = false;
                 }
                 sb.append(column).append("=?");
             }
         }
         if (columnForPartialMatching != null) {
             for (String column : columnForPartialMatching) {
                 if (!firstColumn) {
                     sb.append(" OR ");
                 } else {
                     firstColumn = false;
                 }
                 sb.append(column).append(" LIKE ?");
             }
         }
     }

     private void insertSelectionArgumentStrings(String[] selectionArgs, int pos,
             String query, String[] columnForExactMatching, String[] columnForPartialMatching) {
         if (columnForExactMatching != null) {
             int until = pos + columnForExactMatching.length;
             for (; pos < until; ++pos) {
                 selectionArgs[pos] = query;
             }
         }
         String selectionArg = "%" + query + "%";
         if (columnForPartialMatching != null) {
             int until = pos + columnForPartialMatching.length;
             for (; pos < until; ++pos) {
                 selectionArgs[pos] = selectionArg;
             }
         }
     }

     @WorkerThread
     private List<SearchResult> searchChannels(String query, Set<Long> channels, int limit) {
         if (DEBUG) Log.d(TAG, "Searching channels: '" + query + "'");
         long time = SystemClock.elapsedRealtime();
         List<SearchResult> results = new ArrayList<>();
         if (TextUtils.isDigitsOnly(query)) {
             results.addAll(searchChannels(query, new String[] { Channels.COLUMN_DISPLAY_NUMBER },
                     null, channels, NO_LIMIT));
             if (results.size() > 1) {
                 Collections.sort(results, new ChannelComparatorWithSameDisplayNumber());
             }
         }
         if (results.size() < limit) {
             results.addAll(searchChannels(query, null,
                     new String[] { Channels.COLUMN_DISPLAY_NAME, Channels.COLUMN_DESCRIPTION },
                     channels, limit - results.size()));
         }
         if (results.size() > limit) {
             results = results.subList(0, limit);
         }
         for (SearchResult result : results) {
             fillProgramInfo(result);
         }
         if (DEBUG) {
             Log.d(TAG, "Found " + results.size() + " channels. Elapsed time for searching" +
                     " channels: " + (SystemClock.elapsedRealtime() - time) + "(msec)");
         }
         return results;
     }

     @WorkerThread
     private List<SearchResult> searchChannels(String query, String[] columnForExactMatching,
             String[] columnForPartialMatching, Set<Long> channelsFound, int limit) {
         String[] projection = {
                 Channels._ID,
                 Channels.COLUMN_DISPLAY_NUMBER,
                 Channels.COLUMN_DISPLAY_NAME,
                 Channels.COLUMN_DESCRIPTION
         };

         StringBuilder sb = new StringBuilder();
         sb.append(Channels.COLUMN_BROWSABLE).append("=1 AND ")
                 .append(Channels.COLUMN_SEARCHABLE).append("=1");
         if (mTvInputManager.isParentalControlsEnabled()) {
             sb.append(" AND ").append(Channels.COLUMN_LOCKED).append("=0");
         }
         sb.append(" AND (");
         appendSelectionString(sb, columnForExactMatching, columnForPartialMatching);
         sb.append(")");
         String selection = sb.toString();

         int len = (columnForExactMatching == null ? 0 : columnForExactMatching.length) +
                 (columnForPartialMatching == null ? 0 : columnForPartialMatching.length);
         String[] selectionArgs = new String[len];
         insertSelectionArgumentStrings(selectionArgs, 0, query, columnForExactMatching,
                 columnForPartialMatching);

         List<SearchResult> searchResults = new ArrayList<>();

         try (Cursor c = mContentResolver.query(Channels.CONTENT_URI, projection, selection,
                 selectionArgs, null)) {
             if (c != null) {
                 int count = 0;
                 while (c.moveToNext()) {
                     long id = c.getLong(0);
                     // Filter out the channel which has been already searched.
                     if (channelsFound.contains(id)) {
                         continue;
                     }
                     channelsFound.add(id);

                     SearchResult result = new SearchResult();
                     result.channelId = id;
                     result.channelNumber = c.getString(1);
                     result.title = c.getString(2);
                     result.description = c.getString(3);
                     result.imageUri = TvContract.buildChannelLogoUri(result.channelId).toString();
                     result.intentAction = Intent.ACTION_VIEW;
                     result.intentData = buildIntentData(result.channelId);
                     result.contentType = Programs.CONTENT_ITEM_TYPE;
                     result.isLive = true;
                     result.progressPercentage = LocalSearchProvider.PROGRESS_PERCENTAGE_HIDE;

                     searchResults.add(result);

                     if (limit != NO_LIMIT && ++count >= limit) {
                         break;
                     }
                 }
             }
         }
         return searchResults;
     }

     /**
      * Replaces the channel information - title, description, channel logo - with the current
      * program information of the channel if the current program information exists and it is not
      * blocked.
      */
     @WorkerThread
     private void fillProgramInfo(SearchResult result) {
         long now = System.currentTimeMillis();
         Uri uri = TvContract.buildProgramsUriForChannel(result.channelId, now, now);
         String[] projection = new String[] {
                 Programs.COLUMN_TITLE,
                 Programs.COLUMN_POSTER_ART_URI,
                 Programs.COLUMN_CONTENT_RATING,
                 Programs.COLUMN_VIDEO_WIDTH,
                 Programs.COLUMN_VIDEO_HEIGHT,
                 Programs.COLUMN_START_TIME_UTC_MILLIS,
                 Programs.COLUMN_END_TIME_UTC_MILLIS
         };

         try (Cursor c = mContentResolver.query(uri, projection, null, null, null)) {
             if (c != null && c.moveToNext() && !isRatingBlocked(c.getString(2))) {
                 String channelName = result.title;
                 long startUtcMillis = c.getLong(5);
                 long endUtcMillis = c.getLong(6);
                 result.title = c.getString(0);
                 result.description = buildProgramDescription(result.channelNumber, channelName,
                         startUtcMillis, endUtcMillis);
                 String imageUri = c.getString(1);
                 if (imageUri != null) {
                     result.imageUri = imageUri;
                 }
                 result.videoWidth = c.getInt(3);
                 result.videoHeight = c.getInt(4);
                 result.duration = endUtcMillis - startUtcMillis;
                 result.progressPercentage = getProgressPercentage(startUtcMillis, endUtcMillis);
             }
         }
     }

     private String buildProgramDescription(String channelNumber, String channelName,
             long programStartUtcMillis, long programEndUtcMillis) {
         return Utils.getDurationString(mContext, programStartUtcMillis, programEndUtcMillis, false)
                 + System.lineSeparator() + channelNumber + " " + channelName;
     }

     private int getProgressPercentage(long startUtcMillis, long endUtcMillis) {
         long current = System.currentTimeMillis();
         if (startUtcMillis > current || endUtcMillis <= current) {
             return LocalSearchProvider.PROGRESS_PERCENTAGE_HIDE;
         }
         return (int)(100 * (current - startUtcMillis) / (endUtcMillis - startUtcMillis));
     }

     @WorkerThread
     private List<SearchResult> searchPrograms(String query, String[] columnForExactMatching,
             String[] columnForPartialMatching, Set<Long> channelsFound, int limit) {
         if (DEBUG) Log.d(TAG, "Searching programs: '" + query + "'");
         long time = SystemClock.elapsedRealtime();
         String[] projection = {
                 Programs.COLUMN_CHANNEL_ID,
                 Programs.COLUMN_TITLE,
                 Programs.COLUMN_POSTER_ART_URI,
                 Programs.COLUMN_CONTENT_RATING,
                 Programs.COLUMN_VIDEO_WIDTH,
                 Programs.COLUMN_VIDEO_HEIGHT,
                 Programs.COLUMN_START_TIME_UTC_MILLIS,
                 Programs.COLUMN_END_TIME_UTC_MILLIS
         };

         StringBuilder sb = new StringBuilder();
         // Search among the programs which are now being on the air.
         sb.append(Programs.COLUMN_START_TIME_UTC_MILLIS).append("<=? AND ");
         sb.append(Programs.COLUMN_END_TIME_UTC_MILLIS).append(">=? AND (");
         appendSelectionString(sb, columnForExactMatching, columnForPartialMatching);
         sb.append(")");
         String selection = sb.toString();

         int len = (columnForExactMatching == null ? 0 : columnForExactMatching.length) +
                 (columnForPartialMatching == null ? 0 : columnForPartialMatching.length);
         String[] selectionArgs = new String[len + 2];
         selectionArgs[0] = selectionArgs[1] = String.valueOf(System.currentTimeMillis());
         insertSelectionArgumentStrings(selectionArgs, 2, query, columnForExactMatching,
                 columnForPartialMatching);

         List<SearchResult> searchResults = new ArrayList<>();

         try (Cursor c = mContentResolver.query(Programs.CONTENT_URI, projection, selection,
                 selectionArgs, null)) {
             if (c != null) {
                 int count = 0;
                 while (c.moveToNext()) {
                     long id = c.getLong(0);
                     // Filter out the program whose channel is already searched.
                     if (channelsFound.contains(id)) {
                         continue;
                     }
                     channelsFound.add(id);

                     // Don't know whether the channel is searchable or not.
                     String[] channelProjection = {
                             Channels._ID,
                             Channels.COLUMN_DISPLAY_NUMBER,
                             Channels.COLUMN_DISPLAY_NAME
                     };
                     sb = new StringBuilder();
                     sb.append(Channels._ID).append("=? AND ")
                             .append(Channels.COLUMN_BROWSABLE).append("=1 AND ")
                             .append(Channels.COLUMN_SEARCHABLE).append("=1");
                     if (mTvInputManager.isParentalControlsEnabled()) {
                         sb.append(" AND ").append(Channels.COLUMN_LOCKED).append("=0");
                     }
                     String selectionChannel = sb.toString();
                     try (Cursor cChannel = mContentResolver.query(Channels.CONTENT_URI,
                             channelProjection, selectionChannel,
                             new String[] { String.valueOf(id) }, null)) {
                         if (cChannel != null && cChannel.moveToNext()
                                 && !isRatingBlocked(c.getString(3))) {
                             long startUtcMillis = c.getLong(6);
                             long endUtcMillis = c.getLong(7);
                             SearchResult result = new SearchResult();
                             result.channelId = c.getLong(0);
                             result.title = c.getString(1);
                             result.description = buildProgramDescription(cChannel.getString(1),
                                     cChannel.getString(2), startUtcMillis, endUtcMillis);
                             result.imageUri = c.getString(2);
                             result.intentAction = Intent.ACTION_VIEW;
                             result.intentData = buildIntentData(id);
                             result.contentType = Programs.CONTENT_ITEM_TYPE;
                             result.isLive = true;
                             result.videoWidth = c.getInt(4);
                             result.videoHeight = c.getInt(5);
                             result.duration = endUtcMillis - startUtcMillis;
                             result.progressPercentage = getProgressPercentage(startUtcMillis,
                                     endUtcMillis);
                             searchResults.add(result);

                             if (limit != NO_LIMIT && ++count >= limit) {
                                 break;
                             }
                         }
                     }
                 }
             }
         }
         if (DEBUG) {
             Log.d(TAG, "Found " + searchResults.size() + " programs. Elapsed time for searching" +
                     " programs: " + (SystemClock.elapsedRealtime() - time) + "(msec)");
         }
         return searchResults;
     }

     private String buildIntentData(long channelId) {
         return TvContract.buildChannelUri(channelId).toString();
     }

     private boolean isRatingBlocked(String ratings) {
         if (TextUtils.isEmpty(ratings) || !mTvInputManager.isParentalControlsEnabled()) {
             return false;
         }
         TvContentRating[] ratingArray = mTvContentRatingCache.getRatings(ratings);
         if (ratingArray != null) {
             for (TvContentRating r : ratingArray) {
                 if (mTvInputManager.isRatingBlocked(r)) {
                     return true;
                 }
             }
         }
         return false;
     }

     private List<SearchResult> searchInputs(String query, int limit) {
         if (DEBUG) Log.d(TAG, "Searching inputs: '" + query + "'");
         long time = SystemClock.elapsedRealtime();

         query = canonicalizeLabel(query);
         List<TvInputInfo> inputList = mTvInputManager.getTvInputList();
         List<SearchResult> results = new ArrayList<>();

         // Find exact matches first.
         for (TvInputInfo input : inputList) {
             if (input.getType() == TvInputInfo.TYPE_TUNER) {
                 continue;
             }
             String label = canonicalizeLabel(input.loadLabel(mContext));
             String customLabel = canonicalizeLabel(input.loadCustomLabel(mContext));
             if (TextUtils.equals(query, label) || TextUtils.equals(query, customLabel)) {
                 results.add(buildSearchResultForInput(input.getId()));
                 if (results.size() >= limit) {
                     if (DEBUG) {
                         Log.d(TAG, "Found " + results.size() + " inputs. Elapsed time for" +
                                 " searching inputs: " + (SystemClock.elapsedRealtime() - time) +
                                 "(msec)");
                     }
                     return results;
                 }
             }
         }

         // Then look for partial matches.
         for (TvInputInfo input : inputList) {
             if (input.getType() == TvInputInfo.TYPE_TUNER) {
                 continue;
             }
             String label = canonicalizeLabel(input.loadLabel(mContext));
             String customLabel = canonicalizeLabel(input.loadCustomLabel(mContext));
             if ((label != null && label.contains(query)) ||
                     (customLabel != null && customLabel.contains(query))) {
                 results.add(buildSearchResultForInput(input.getId()));
                 if (results.size() >= limit) {
                     if (DEBUG) {
                         Log.d(TAG, "Found " + results.size() + " inputs. Elapsed time for" +
                                 " searching inputs: " + (SystemClock.elapsedRealtime() - time) +
                                 "(msec)");
                     }
                     return results;
                 }
             }
         }
         if (DEBUG) {
             Log.d(TAG, "Found " + results.size() + " inputs. Elapsed time for searching" +
                     " inputs: " + (SystemClock.elapsedRealtime() - time) + "(msec)");
         }
         return results;
     }

     private String canonicalizeLabel(CharSequence cs) {
         Locale locale = mContext.getResources().getConfiguration().locale;
         return cs != null ? cs.toString().replaceAll("[ -]", "").toLowerCase(locale) : null;
     }

     private SearchResult buildSearchResultForInput(String inputId) {
         SearchResult result = new SearchResult();
         result.intentAction = Intent.ACTION_VIEW;
         result.intentData = TvContract.buildChannelUriForPassthroughInput(inputId).toString();
         return result;
     }

     @WorkerThread
     private class ChannelComparatorWithSameDisplayNumber implements Comparator<SearchResult> {
         private final Map<Long, Long> mMaxWatchStartTimeMap = new HashMap<>();

         @Override
         public int compare(SearchResult lhs, SearchResult rhs) {
             // Show recently watched channel first
             Long lhsMaxWatchStartTime = mMaxWatchStartTimeMap.get(lhs.channelId);
             if (lhsMaxWatchStartTime == null) {
                 lhsMaxWatchStartTime = getMaxWatchStartTime(lhs.channelId);
                 mMaxWatchStartTimeMap.put(lhs.channelId, lhsMaxWatchStartTime);
             }
             Long rhsMaxWatchStartTime = mMaxWatchStartTimeMap.get(rhs.channelId);
             if (rhsMaxWatchStartTime == null) {
                 rhsMaxWatchStartTime = getMaxWatchStartTime(rhs.channelId);
                 mMaxWatchStartTimeMap.put(rhs.channelId, rhsMaxWatchStartTime);
             }
             if (!Objects.equals(lhsMaxWatchStartTime, rhsMaxWatchStartTime)) {
                 return Long.compare(rhsMaxWatchStartTime, lhsMaxWatchStartTime);
             }
             // Show recently added channel first if there's no watch history.
             return Long.compare(rhs.channelId, lhs.channelId);
         }

         private long getMaxWatchStartTime(long channelId) {
             Uri uri = WatchedPrograms.CONTENT_URI;
             String[] projections = new String[] {
                     "MAX(" + WatchedPrograms.COLUMN_START_TIME_UTC_MILLIS
                     + ") AS max_watch_start_time"
             };
             String selection = WatchedPrograms.COLUMN_CHANNEL_ID + "=?";
             String[] selectionArgs = new String[] { Long.toString(channelId) };
             try (Cursor c = mContentResolver.query(uri, projections, selection, selectionArgs,
                     null)) {
                 if (c != null && c.moveToNext()) {
                     return c.getLong(0);
                 }
             }
             return -1;
         }
     }
 }
	/*
	* Copyright (C) 2015 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.tv.search;

	import android.content.ContentResolver;
	import android.content.Context;
	import android.content.Intent;
	import android.database.Cursor;
	import android.media.tv.TvContentRating;
	import android.media.tv.TvContract;
	import android.media.tv.TvContract.Channels;
	import android.media.tv.TvContract.Programs;
	import android.media.tv.TvContract.WatchedPrograms;
	import android.media.tv.TvInputInfo;
	import android.media.tv.TvInputManager;
	import android.net.Uri;
	import android.os.SystemClock;
	import android.support.annotation.WorkerThread;
	import android.text.TextUtils;
	import android.util.Log;

	import com.android.tv.common.TvContentRatingCache;
	import com.android.tv.search.LocalSearchProvider.SearchResult;
	import com.android.tv.util.PermissionUtils;
	import com.android.tv.util.Utils;

	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.Comparator;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.List;
	import java.util.Locale;
	import java.util.Map;
	import java.util.Objects;
	import java.util.Set;

	/**
	* An implementation of {@link SearchInterface} to search query from TvProvider directly.
	*/
	public class TvProviderSearch implements SearchInterface {
	private static final String TAG = "TvProviderSearch";
	private static final boolean DEBUG = false;

	private static final int NO_LIMIT = 0;

	private final Context mContext;
	private final ContentResolver mContentResolver;
	private final TvInputManager mTvInputManager;
	private final TvContentRatingCache mTvContentRatingCache = TvContentRatingCache.getInstance();

	TvProviderSearch(Context context) {
	mContext = context;
	mContentResolver = context.getContentResolver();
	mTvInputManager = (TvInputManager) context.getSystemService(Context.TV_INPUT_SERVICE);
	}

	/**
	* Search channels, inputs, or programs from TvProvider.
	* This assumes that parental control settings will not be change while searching.
	*
	* @param action One of {@link #ACTION_TYPE_SWITCH_CHANNEL}, {@link #ACTION_TYPE_SWITCH_INPUT},
	* or {@link #ACTION_TYPE_AMBIGUOUS},
	*/
	@Override
	@WorkerThread
	public List<SearchResult> search(String query, int limit, int action) {
	List<SearchResult> results = new ArrayList<>();
	if (!PermissionUtils.hasAccessAllEpg(mContext)) {
	// TODO: support this feature for non-system LC app. b/23939816
	return results;
	}
	Set<Long> channelsFound = new HashSet<>();
	if (action == ACTION_TYPE_SWITCH_CHANNEL) {
	results.addAll(searchChannels(query, channelsFound, limit));
	} else if (action == ACTION_TYPE_SWITCH_INPUT) {
	results.addAll(searchInputs(query, limit));
	} else {
	// Search channels first.
	results.addAll(searchChannels(query, channelsFound, limit));
	if (results.size() >= limit) {
	return results;
	}

	// In case the user wanted to perform the action "switch to XXX", which is indicated by
	// setting the limit to 1, search inputs.
	if (limit == 1) {
	results.addAll(searchInputs(query, limit));
	if (!results.isEmpty()) {
	return results;
	}
	}

	// Lastly, search programs.
	limit -= results.size();
	results.addAll(searchPrograms(query, null, new String[] {
	Programs.COLUMN_TITLE, Programs.COLUMN_SHORT_DESCRIPTION },
	channelsFound, limit));
	}
	return results;
	}

	private void appendSelectionString(StringBuilder sb, String[] columnForExactMatching,
	String[] columnForPartialMatching) {
	boolean firstColumn = true;
	if (columnForExactMatching != null) {
	for (String column : columnForExactMatching) {
	if (!firstColumn) {
	sb.append(" OR ");
	} else {
	firstColumn = false;
	}
	sb.append(column).append("=?");
	}
	}
	if (columnForPartialMatching != null) {
	for (String column : columnForPartialMatching) {
	if (!firstColumn) {
	sb.append(" OR ");
	} else {
	firstColumn = false;
	}
	sb.append(column).append(" LIKE ?");
	}
	}
	}

	private void insertSelectionArgumentStrings(String[] selectionArgs, int pos,
	String query, String[] columnForExactMatching, String[] columnForPartialMatching) {
	if (columnForExactMatching != null) {
	int until = pos + columnForExactMatching.length;
	for (; pos < until; ++pos) {
	selectionArgs[pos] = query;
	}
	}
	String selectionArg = "%" + query + "%";
	if (columnForPartialMatching != null) {
	int until = pos + columnForPartialMatching.length;
	for (; pos < until; ++pos) {
	selectionArgs[pos] = selectionArg;
	}
	}
	}

	@WorkerThread
	private List<SearchResult> searchChannels(String query, Set<Long> channels, int limit) {
	if (DEBUG) Log.d(TAG, "Searching channels: '" + query + "'");
	long time = SystemClock.elapsedRealtime();
	List<SearchResult> results = new ArrayList<>();
	if (TextUtils.isDigitsOnly(query)) {
	results.addAll(searchChannels(query, new String[] { Channels.COLUMN_DISPLAY_NUMBER },
	null, channels, NO_LIMIT));
	if (results.size() > 1) {
	Collections.sort(results, new ChannelComparatorWithSameDisplayNumber());
	}
	}
	if (results.size() < limit) {
	results.addAll(searchChannels(query, null,
	new String[] { Channels.COLUMN_DISPLAY_NAME, Channels.COLUMN_DESCRIPTION },
	channels, limit - results.size()));
	}
	if (results.size() > limit) {
	results = results.subList(0, limit);
	}
	for (SearchResult result : results) {
	fillProgramInfo(result);
	}
	if (DEBUG) {
	Log.d(TAG, "Found " + results.size() + " channels. Elapsed time for searching" +
	" channels: " + (SystemClock.elapsedRealtime() - time) + "(msec)");
	}
	return results;
	}

	@WorkerThread
	private List<SearchResult> searchChannels(String query, String[] columnForExactMatching,
	String[] columnForPartialMatching, Set<Long> channelsFound, int limit) {
	String[] projection = {
	Channels._ID,
	Channels.COLUMN_DISPLAY_NUMBER,
	Channels.COLUMN_DISPLAY_NAME,
	Channels.COLUMN_DESCRIPTION
	};

	StringBuilder sb = new StringBuilder();
	sb.append(Channels.COLUMN_BROWSABLE).append("=1 AND ")
	.append(Channels.COLUMN_SEARCHABLE).append("=1");
	if (mTvInputManager.isParentalControlsEnabled()) {
	sb.append(" AND ").append(Channels.COLUMN_LOCKED).append("=0");
	}
	sb.append(" AND (");
	appendSelectionString(sb, columnForExactMatching, columnForPartialMatching);
	sb.append(")");
	String selection = sb.toString();

	int len = (columnForExactMatching == null ? 0 : columnForExactMatching.length) +
	(columnForPartialMatching == null ? 0 : columnForPartialMatching.length);
	String[] selectionArgs = new String[len];
	insertSelectionArgumentStrings(selectionArgs, 0, query, columnForExactMatching,
	columnForPartialMatching);

	List<SearchResult> searchResults = new ArrayList<>();

	try (Cursor c = mContentResolver.query(Channels.CONTENT_URI, projection, selection,
	selectionArgs, null)) {
	if (c != null) {
	int count = 0;
	while (c.moveToNext()) {
	long id = c.getLong(0);
	// Filter out the channel which has been already searched.
	if (channelsFound.contains(id)) {
	continue;
	}
	channelsFound.add(id);

	SearchResult result = new SearchResult();
	result.channelId = id;
	result.channelNumber = c.getString(1);
	result.title = c.getString(2);
	result.description = c.getString(3);
	result.imageUri = TvContract.buildChannelLogoUri(result.channelId).toString();
	result.intentAction = Intent.ACTION_VIEW;
	result.intentData = buildIntentData(result.channelId);
	result.contentType = Programs.CONTENT_ITEM_TYPE;
	result.isLive = true;
	result.progressPercentage = LocalSearchProvider.PROGRESS_PERCENTAGE_HIDE;

	searchResults.add(result);

	if (limit != NO_LIMIT && ++count >= limit) {
	break;
	}
	}
	}
	}
	return searchResults;
	}

	/**
	* Replaces the channel information - title, description, channel logo - with the current
	* program information of the channel if the current program information exists and it is not
	* blocked.
	*/
	@WorkerThread
	private void fillProgramInfo(SearchResult result) {
	long now = System.currentTimeMillis();
	Uri uri = TvContract.buildProgramsUriForChannel(result.channelId, now, now);
	String[] projection = new String[] {
	Programs.COLUMN_TITLE,
	Programs.COLUMN_POSTER_ART_URI,
	Programs.COLUMN_CONTENT_RATING,
	Programs.COLUMN_VIDEO_WIDTH,
	Programs.COLUMN_VIDEO_HEIGHT,
	Programs.COLUMN_START_TIME_UTC_MILLIS,
	Programs.COLUMN_END_TIME_UTC_MILLIS
	};

	try (Cursor c = mContentResolver.query(uri, projection, null, null, null)) {
	if (c != null && c.moveToNext() && !isRatingBlocked(c.getString(2))) {
	String channelName = result.title;
	long startUtcMillis = c.getLong(5);
	long endUtcMillis = c.getLong(6);
	result.title = c.getString(0);
	result.description = buildProgramDescription(result.channelNumber, channelName,
	startUtcMillis, endUtcMillis);
	String imageUri = c.getString(1);
	if (imageUri != null) {
	result.imageUri = imageUri;
	}
	result.videoWidth = c.getInt(3);
	result.videoHeight = c.getInt(4);
	result.duration = endUtcMillis - startUtcMillis;
	result.progressPercentage = getProgressPercentage(startUtcMillis, endUtcMillis);
	}
	}
	}

	private String buildProgramDescription(String channelNumber, String channelName,
	long programStartUtcMillis, long programEndUtcMillis) {
	return Utils.getDurationString(mContext, programStartUtcMillis, programEndUtcMillis, false)
	+ System.lineSeparator() + channelNumber + " " + channelName;
	}

	private int getProgressPercentage(long startUtcMillis, long endUtcMillis) {
	long current = System.currentTimeMillis();
	if (startUtcMillis > current \|\| endUtcMillis <= current) {
	return LocalSearchProvider.PROGRESS_PERCENTAGE_HIDE;
	}
	return (int)(100 * (current - startUtcMillis) / (endUtcMillis - startUtcMillis));
	}

	@WorkerThread
	private List<SearchResult> searchPrograms(String query, String[] columnForExactMatching,
	String[] columnForPartialMatching, Set<Long> channelsFound, int limit) {
	if (DEBUG) Log.d(TAG, "Searching programs: '" + query + "'");
	long time = SystemClock.elapsedRealtime();
	String[] projection = {
	Programs.COLUMN_CHANNEL_ID,
	Programs.COLUMN_TITLE,
	Programs.COLUMN_POSTER_ART_URI,
	Programs.COLUMN_CONTENT_RATING,
	Programs.COLUMN_VIDEO_WIDTH,
	Programs.COLUMN_VIDEO_HEIGHT,
	Programs.COLUMN_START_TIME_UTC_MILLIS,
	Programs.COLUMN_END_TIME_UTC_MILLIS
	};

	StringBuilder sb = new StringBuilder();
	// Search among the programs which are now being on the air.
	sb.append(Programs.COLUMN_START_TIME_UTC_MILLIS).append("<=? AND ");
	sb.append(Programs.COLUMN_END_TIME_UTC_MILLIS).append(">=? AND (");
	appendSelectionString(sb, columnForExactMatching, columnForPartialMatching);
	sb.append(")");
	String selection = sb.toString();

	int len = (columnForExactMatching == null ? 0 : columnForExactMatching.length) +
	(columnForPartialMatching == null ? 0 : columnForPartialMatching.length);
	String[] selectionArgs = new String[len + 2];
	selectionArgs[0] = selectionArgs[1] = String.valueOf(System.currentTimeMillis());
	insertSelectionArgumentStrings(selectionArgs, 2, query, columnForExactMatching,
	columnForPartialMatching);

	List<SearchResult> searchResults = new ArrayList<>();

	try (Cursor c = mContentResolver.query(Programs.CONTENT_URI, projection, selection,
	selectionArgs, null)) {
	if (c != null) {
	int count = 0;
	while (c.moveToNext()) {
	long id = c.getLong(0);
	// Filter out the program whose channel is already searched.
	if (channelsFound.contains(id)) {
	continue;
	}
	channelsFound.add(id);

	// Don't know whether the channel is searchable or not.
	String[] channelProjection = {
	Channels._ID,
	Channels.COLUMN_DISPLAY_NUMBER,
	Channels.COLUMN_DISPLAY_NAME
	};
	sb = new StringBuilder();
	sb.append(Channels._ID).append("=? AND ")
	.append(Channels.COLUMN_BROWSABLE).append("=1 AND ")
	.append(Channels.COLUMN_SEARCHABLE).append("=1");
	if (mTvInputManager.isParentalControlsEnabled()) {
	sb.append(" AND ").append(Channels.COLUMN_LOCKED).append("=0");
	}
	String selectionChannel = sb.toString();
	try (Cursor cChannel = mContentResolver.query(Channels.CONTENT_URI,
	channelProjection, selectionChannel,
	new String[] { String.valueOf(id) }, null)) {
	if (cChannel != null && cChannel.moveToNext()
	&& !isRatingBlocked(c.getString(3))) {
	long startUtcMillis = c.getLong(6);
	long endUtcMillis = c.getLong(7);
	SearchResult result = new SearchResult();
	result.channelId = c.getLong(0);
	result.title = c.getString(1);
	result.description = buildProgramDescription(cChannel.getString(1),
	cChannel.getString(2), startUtcMillis, endUtcMillis);
	result.imageUri = c.getString(2);
	result.intentAction = Intent.ACTION_VIEW;
	result.intentData = buildIntentData(id);
	result.contentType = Programs.CONTENT_ITEM_TYPE;
	result.isLive = true;
	result.videoWidth = c.getInt(4);
	result.videoHeight = c.getInt(5);
	result.duration = endUtcMillis - startUtcMillis;
	result.progressPercentage = getProgressPercentage(startUtcMillis,
	endUtcMillis);
	searchResults.add(result);

	if (limit != NO_LIMIT && ++count >= limit) {
	break;
	}
	}
	}
	}
	}
	}
	if (DEBUG) {
	Log.d(TAG, "Found " + searchResults.size() + " programs. Elapsed time for searching" +
	" programs: " + (SystemClock.elapsedRealtime() - time) + "(msec)");
	}
	return searchResults;
	}

	private String buildIntentData(long channelId) {
	return TvContract.buildChannelUri(channelId).toString();
	}

	private boolean isRatingBlocked(String ratings) {
	if (TextUtils.isEmpty(ratings) \|\| !mTvInputManager.isParentalControlsEnabled()) {
	return false;
	}
	TvContentRating[] ratingArray = mTvContentRatingCache.getRatings(ratings);
	if (ratingArray != null) {
	for (TvContentRating r : ratingArray) {
	if (mTvInputManager.isRatingBlocked(r)) {
	return true;
	}
	}
	}
	return false;
	}

	private List<SearchResult> searchInputs(String query, int limit) {
	if (DEBUG) Log.d(TAG, "Searching inputs: '" + query + "'");
	long time = SystemClock.elapsedRealtime();

	query = canonicalizeLabel(query);
	List<TvInputInfo> inputList = mTvInputManager.getTvInputList();
	List<SearchResult> results = new ArrayList<>();

	// Find exact matches first.
	for (TvInputInfo input : inputList) {
	if (input.getType() == TvInputInfo.TYPE_TUNER) {
	continue;
	}
	String label = canonicalizeLabel(input.loadLabel(mContext));
	String customLabel = canonicalizeLabel(input.loadCustomLabel(mContext));
	if (TextUtils.equals(query, label) \|\| TextUtils.equals(query, customLabel)) {
	results.add(buildSearchResultForInput(input.getId()));
	if (results.size() >= limit) {
	if (DEBUG) {
	Log.d(TAG, "Found " + results.size() + " inputs. Elapsed time for" +
	" searching inputs: " + (SystemClock.elapsedRealtime() - time) +
	"(msec)");
	}
	return results;
	}
	}
	}

	// Then look for partial matches.
	for (TvInputInfo input : inputList) {
	if (input.getType() == TvInputInfo.TYPE_TUNER) {
	continue;
	}
	String label = canonicalizeLabel(input.loadLabel(mContext));
	String customLabel = canonicalizeLabel(input.loadCustomLabel(mContext));
	if ((label != null && label.contains(query)) \|\|
	(customLabel != null && customLabel.contains(query))) {
	results.add(buildSearchResultForInput(input.getId()));
	if (results.size() >= limit) {
	if (DEBUG) {
	Log.d(TAG, "Found " + results.size() + " inputs. Elapsed time for" +
	" searching inputs: " + (SystemClock.elapsedRealtime() - time) +
	"(msec)");
	}
	return results;
	}
	}
	}
	if (DEBUG) {
	Log.d(TAG, "Found " + results.size() + " inputs. Elapsed time for searching" +
	" inputs: " + (SystemClock.elapsedRealtime() - time) + "(msec)");
	}
	return results;
	}

	private String canonicalizeLabel(CharSequence cs) {
	Locale locale = mContext.getResources().getConfiguration().locale;
	return cs != null ? cs.toString().replaceAll("[ -]", "").toLowerCase(locale) : null;
	}

	private SearchResult buildSearchResultForInput(String inputId) {
	SearchResult result = new SearchResult();
	result.intentAction = Intent.ACTION_VIEW;
	result.intentData = TvContract.buildChannelUriForPassthroughInput(inputId).toString();
	return result;
	}

	@WorkerThread
	private class ChannelComparatorWithSameDisplayNumber implements Comparator<SearchResult> {
	private final Map<Long, Long> mMaxWatchStartTimeMap = new HashMap<>();

	@Override
	public int compare(SearchResult lhs, SearchResult rhs) {
	// Show recently watched channel first
	Long lhsMaxWatchStartTime = mMaxWatchStartTimeMap.get(lhs.channelId);
	if (lhsMaxWatchStartTime == null) {
	lhsMaxWatchStartTime = getMaxWatchStartTime(lhs.channelId);
	mMaxWatchStartTimeMap.put(lhs.channelId, lhsMaxWatchStartTime);
	}
	Long rhsMaxWatchStartTime = mMaxWatchStartTimeMap.get(rhs.channelId);
	if (rhsMaxWatchStartTime == null) {
	rhsMaxWatchStartTime = getMaxWatchStartTime(rhs.channelId);
	mMaxWatchStartTimeMap.put(rhs.channelId, rhsMaxWatchStartTime);
	}
	if (!Objects.equals(lhsMaxWatchStartTime, rhsMaxWatchStartTime)) {
	return Long.compare(rhsMaxWatchStartTime, lhsMaxWatchStartTime);
	}
	// Show recently added channel first if there's no watch history.
	return Long.compare(rhs.channelId, lhs.channelId);
	}

	private long getMaxWatchStartTime(long channelId) {
	Uri uri = WatchedPrograms.CONTENT_URI;
	String[] projections = new String[] {
	"MAX(" + WatchedPrograms.COLUMN_START_TIME_UTC_MILLIS
	+ ") AS max_watch_start_time"
	};
	String selection = WatchedPrograms.COLUMN_CHANNEL_ID + "=?";
	String[] selectionArgs = new String[] { Long.toString(channelId) };
	try (Cursor c = mContentResolver.query(uri, projections, selection, selectionArgs,
	null)) {
	if (c != null && c.moveToNext()) {
	return c.getLong(0);
	}
	}
	return -1;
	}
	}
	}