1 /*
2  * Copyright 2019 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package android.app.timezonedetector;
18 
19 import android.annotation.IntDef;
20 import android.annotation.NonNull;
21 import android.annotation.Nullable;
22 import android.os.Parcel;
23 import android.os.Parcelable;
24 import android.os.ShellCommand;
25 import android.text.TextUtils;
26 
27 import java.io.PrintWriter;
28 import java.lang.annotation.Retention;
29 import java.lang.annotation.RetentionPolicy;
30 import java.util.ArrayList;
31 import java.util.Collections;
32 import java.util.List;
33 import java.util.Objects;
34 
35 /**
36  * A time zone suggestion from an identified telephony source, e.g. from MCC and NITZ information
37  * associated with a specific radio.
38  *
39  * <p>{@code slotIndex} identifies the suggestion source. This enables detection logic to identify
40  * suggestions from the same source when there are several in use.
41  *
42  * <p>{@code zoneId}. When not {@code null}, {@code zoneId} contains the suggested time zone ID,
43  * e.g. "America/Los_Angeles". Suggestion metadata like {@code matchType} and {@code quality} can be
44  * used to judge quality / certainty of the suggestion. {@code zoneId} can be {@code null} to
45  * indicate that the telephony source has entered an "un-opinionated" state and any previous
46  * suggestion from the same source is being withdrawn.
47  *
48  * <p>{@code matchType} must be set to {@link #MATCH_TYPE_NA} when {@code zoneId} is {@code null},
49  * and one of the other {@code MATCH_TYPE_} values when it is not {@code null}.
50  *
51  * <p>{@code quality} must be set to {@link #QUALITY_NA} when {@code zoneId} is {@code null},
52  * and one of the other {@code QUALITY_} values when it is not {@code null}.
53  *
54  * <p>{@code debugInfo} contains debugging metadata associated with the suggestion. This is used to
55  * record why the suggestion exists, e.g. what triggered it to be made and what heuristic was used
56  * to determine the time zone or its absence. This information exists only to aid in debugging and
57  * therefore is used by {@link #toString()}, but it is not for use in detection logic and is not
58  * considered in {@link #hashCode()} or {@link #equals(Object)}.
59  *
60  * @hide
61  */
62 public final class TelephonyTimeZoneSuggestion implements Parcelable {
63 
64     /** @hide */
65     @NonNull
66     public static final Creator<TelephonyTimeZoneSuggestion> CREATOR =
67             new Creator<TelephonyTimeZoneSuggestion>() {
68                 public TelephonyTimeZoneSuggestion createFromParcel(Parcel in) {
69                     return TelephonyTimeZoneSuggestion.createFromParcel(in);
70                 }
71 
72                 public TelephonyTimeZoneSuggestion[] newArray(int size) {
73                     return new TelephonyTimeZoneSuggestion[size];
74                 }
75             };
76 
77     /**
78      * Creates an empty time zone suggestion, i.e. one that will cancel previous suggestions with
79      * the same {@code slotIndex}.
80      */
81     @NonNull
createEmptySuggestion( int slotIndex, @NonNull String debugInfo)82     public static TelephonyTimeZoneSuggestion createEmptySuggestion(
83             int slotIndex, @NonNull String debugInfo) {
84         return new Builder(slotIndex).addDebugInfo(debugInfo).build();
85     }
86 
87     /** @hide */
88     @IntDef({ MATCH_TYPE_NA, MATCH_TYPE_NETWORK_COUNTRY_ONLY, MATCH_TYPE_NETWORK_COUNTRY_AND_OFFSET,
89             MATCH_TYPE_EMULATOR_ZONE_ID, MATCH_TYPE_TEST_NETWORK_OFFSET_ONLY })
90     @Retention(RetentionPolicy.SOURCE)
91     public @interface MatchType {}
92 
93     /** Used when match type is not applicable. */
94     public static final int MATCH_TYPE_NA = 0;
95 
96     /**
97      * Only the network country is known.
98      */
99     public static final int MATCH_TYPE_NETWORK_COUNTRY_ONLY = 2;
100 
101     /**
102      * Both the network county and offset were known.
103      */
104     public static final int MATCH_TYPE_NETWORK_COUNTRY_AND_OFFSET = 3;
105 
106     /**
107      * The device is running in an emulator and an NITZ signal was simulated containing an
108      * Android extension with an explicit Olson ID.
109      */
110     public static final int MATCH_TYPE_EMULATOR_ZONE_ID = 4;
111 
112     /**
113      * The phone is most likely running in a test network not associated with a country (this is
114      * distinct from the country just not being known yet).
115      * Historically, Android has just picked an arbitrary time zone with the correct offset when
116      * on a test network.
117      */
118     public static final int MATCH_TYPE_TEST_NETWORK_OFFSET_ONLY = 5;
119 
120     /** @hide */
121     @IntDef({ QUALITY_NA, QUALITY_SINGLE_ZONE, QUALITY_MULTIPLE_ZONES_WITH_SAME_OFFSET,
122             QUALITY_MULTIPLE_ZONES_WITH_DIFFERENT_OFFSETS })
123     @Retention(RetentionPolicy.SOURCE)
124     public @interface Quality {}
125 
126     /** Used when quality is not applicable. */
127     public static final int QUALITY_NA = 0;
128 
129     /** There is only one answer */
130     public static final int QUALITY_SINGLE_ZONE = 1;
131 
132     /**
133      * There are multiple answers, but they all shared the same offset / DST state at the time
134      * the suggestion was created. i.e. it might be the wrong zone but the user won't notice
135      * immediately if it is wrong.
136      */
137     public static final int QUALITY_MULTIPLE_ZONES_WITH_SAME_OFFSET = 2;
138 
139     /**
140      * There are multiple answers with different offsets. The one given is just one possible.
141      */
142     public static final int QUALITY_MULTIPLE_ZONES_WITH_DIFFERENT_OFFSETS = 3;
143 
144     private final int mSlotIndex;
145     @Nullable private final String mZoneId;
146     @MatchType private final int mMatchType;
147     @Quality private final int mQuality;
148     @Nullable private List<String> mDebugInfo;
149 
TelephonyTimeZoneSuggestion(Builder builder)150     private TelephonyTimeZoneSuggestion(Builder builder) {
151         mSlotIndex = builder.mSlotIndex;
152         mZoneId = builder.mZoneId;
153         mMatchType = builder.mMatchType;
154         mQuality = builder.mQuality;
155         mDebugInfo = builder.mDebugInfo != null ? new ArrayList<>(builder.mDebugInfo) : null;
156     }
157 
158     @SuppressWarnings("unchecked")
createFromParcel(Parcel in)159     private static TelephonyTimeZoneSuggestion createFromParcel(Parcel in) {
160         // Use the Builder so we get validation during build().
161         int slotIndex = in.readInt();
162         TelephonyTimeZoneSuggestion suggestion = new Builder(slotIndex)
163                 .setZoneId(in.readString())
164                 .setMatchType(in.readInt())
165                 .setQuality(in.readInt())
166                 .build();
167         List<String> debugInfo =
168                 in.readArrayList(TelephonyTimeZoneSuggestion.class.getClassLoader(), java.lang.String.class);
169         if (debugInfo != null) {
170             suggestion.addDebugInfo(debugInfo);
171         }
172         return suggestion;
173     }
174 
175     @Override
writeToParcel(@onNull Parcel dest, int flags)176     public void writeToParcel(@NonNull Parcel dest, int flags) {
177         dest.writeInt(mSlotIndex);
178         dest.writeString(mZoneId);
179         dest.writeInt(mMatchType);
180         dest.writeInt(mQuality);
181         dest.writeList(mDebugInfo);
182     }
183 
184     @Override
describeContents()185     public int describeContents() {
186         return 0;
187     }
188 
189     /**
190      * Returns an identifier for the source of this suggestion.
191      *
192      * <p>See {@link TelephonyTimeZoneSuggestion} for more information about {@code slotIndex}.
193      */
getSlotIndex()194     public int getSlotIndex() {
195         return mSlotIndex;
196     }
197 
198     /**
199      * Returns the suggested time zone Olson ID, e.g. "America/Los_Angeles". {@code null} means that
200      * the caller is no longer sure what the current time zone is.
201      *
202      * <p>See {@link TelephonyTimeZoneSuggestion} for more information about {@code zoneId}.
203      */
204     @Nullable
getZoneId()205     public String getZoneId() {
206         return mZoneId;
207     }
208 
209     /**
210      * Returns information about how the suggestion was determined which could be used to rank
211      * suggestions when several are available from different sources.
212      *
213      * <p>See {@link TelephonyTimeZoneSuggestion} for more information about {@code matchType}.
214      */
215     @MatchType
getMatchType()216     public int getMatchType() {
217         return mMatchType;
218     }
219 
220     /**
221      * Returns information about the likelihood of the suggested zone being correct.
222      *
223      * <p>See {@link TelephonyTimeZoneSuggestion} for more information about {@code quality}.
224      */
225     @Quality
getQuality()226     public int getQuality() {
227         return mQuality;
228     }
229 
230     /**
231      * Returns debug metadata for the suggestion.
232      *
233      * <p>See {@link TelephonyTimeZoneSuggestion} for more information about {@code debugInfo}.
234      */
235     @NonNull
getDebugInfo()236     public List<String> getDebugInfo() {
237         return mDebugInfo == null
238                 ? Collections.emptyList() : Collections.unmodifiableList(mDebugInfo);
239     }
240 
241     /**
242      * Associates information with the instance that can be useful for debugging / logging.
243      *
244      * <p>See {@link TelephonyTimeZoneSuggestion} for more information about {@code debugInfo}.
245      */
addDebugInfo(@onNull String debugInfo)246     public void addDebugInfo(@NonNull String debugInfo) {
247         if (mDebugInfo == null) {
248             mDebugInfo = new ArrayList<>();
249         }
250         mDebugInfo.add(debugInfo);
251     }
252 
253     /**
254      * Associates information with the instance that can be useful for debugging / logging.
255      *
256      * <p>See {@link TelephonyTimeZoneSuggestion} for more information about {@code debugInfo}.
257      */
addDebugInfo(@onNull List<String> debugInfo)258     public void addDebugInfo(@NonNull List<String> debugInfo) {
259         if (mDebugInfo == null) {
260             mDebugInfo = new ArrayList<>(debugInfo.size());
261         }
262         mDebugInfo.addAll(debugInfo);
263     }
264 
265     @Override
equals(@ullable Object o)266     public boolean equals(@Nullable Object o) {
267         if (this == o) {
268             return true;
269         }
270         if (o == null || getClass() != o.getClass()) {
271             return false;
272         }
273         TelephonyTimeZoneSuggestion that = (TelephonyTimeZoneSuggestion) o;
274         return mSlotIndex == that.mSlotIndex
275                 && mMatchType == that.mMatchType
276                 && mQuality == that.mQuality
277                 && Objects.equals(mZoneId, that.mZoneId);
278     }
279 
280     @Override
hashCode()281     public int hashCode() {
282         return Objects.hash(mSlotIndex, mZoneId, mMatchType, mQuality);
283     }
284 
285     @Override
toString()286     public String toString() {
287         return "TelephonyTimeZoneSuggestion{"
288                 + "mSlotIndex=" + mSlotIndex
289                 + ", mZoneId='" + mZoneId + '\''
290                 + ", mMatchType=" + mMatchType
291                 + ", mQuality=" + mQuality
292                 + ", mDebugInfo=" + mDebugInfo
293                 + '}';
294     }
295 
296     /**
297      * Builds {@link TelephonyTimeZoneSuggestion} instances.
298      *
299      * @hide
300      */
301     public static final class Builder {
302         private final int mSlotIndex;
303         @Nullable private String mZoneId;
304         @MatchType private int mMatchType;
305         @Quality private int mQuality;
306         @Nullable private List<String> mDebugInfo;
307 
308         /**
309          * Creates a builder with the specified {@code slotIndex}.
310          *
311          * <p>See {@link TelephonyTimeZoneSuggestion} for more information about {@code slotIndex}.
312          */
Builder(int slotIndex)313         public Builder(int slotIndex) {
314             mSlotIndex = slotIndex;
315         }
316 
317         /**
318          * Returns the builder for call chaining.
319          *
320          * <p>See {@link TelephonyTimeZoneSuggestion} for more information about {@code zoneId}.
321          */
322         @NonNull
setZoneId(@ullable String zoneId)323         public Builder setZoneId(@Nullable String zoneId) {
324             mZoneId = zoneId;
325             return this;
326         }
327 
328         /**
329          * Returns the builder for call chaining.
330          *
331          * <p>See {@link TelephonyTimeZoneSuggestion} for more information about {@code matchType}.
332          */
333         @NonNull
setMatchType(@atchType int matchType)334         public Builder setMatchType(@MatchType int matchType) {
335             mMatchType = matchType;
336             return this;
337         }
338 
339         /**
340          * Returns the builder for call chaining.
341          *
342          * <p>See {@link TelephonyTimeZoneSuggestion} for more information about {@code quality}.
343          */
344         @NonNull
setQuality(@uality int quality)345         public Builder setQuality(@Quality int quality) {
346             mQuality = quality;
347             return this;
348         }
349 
350         /**
351          * Returns the builder for call chaining.
352          *
353          * <p>See {@link TelephonyTimeZoneSuggestion} for more information about {@code debugInfo}.
354          */
355         @NonNull
addDebugInfo(@onNull String debugInfo)356         public Builder addDebugInfo(@NonNull String debugInfo) {
357             if (mDebugInfo == null) {
358                 mDebugInfo = new ArrayList<>();
359             }
360             mDebugInfo.add(debugInfo);
361             return this;
362         }
363 
364         /**
365          * Performs basic structural validation of this instance. e.g. Are all the fields populated
366          * that must be? Are the enum ints set to valid values?
367          */
validate()368         void validate() {
369             int quality = mQuality;
370             int matchType = mMatchType;
371             if (mZoneId == null) {
372                 if (quality != QUALITY_NA || matchType != MATCH_TYPE_NA) {
373                     throw new RuntimeException("Invalid quality or match type for null zone ID."
374                             + " quality=" + quality + ", matchType=" + matchType);
375                 }
376             } else {
377                 boolean qualityValid = (quality == QUALITY_SINGLE_ZONE
378                         || quality == QUALITY_MULTIPLE_ZONES_WITH_SAME_OFFSET
379                         || quality == QUALITY_MULTIPLE_ZONES_WITH_DIFFERENT_OFFSETS);
380                 boolean matchTypeValid = (matchType == MATCH_TYPE_NETWORK_COUNTRY_ONLY
381                         || matchType == MATCH_TYPE_NETWORK_COUNTRY_AND_OFFSET
382                         || matchType == MATCH_TYPE_EMULATOR_ZONE_ID
383                         || matchType == MATCH_TYPE_TEST_NETWORK_OFFSET_ONLY);
384                 if (!qualityValid || !matchTypeValid) {
385                     throw new RuntimeException("Invalid quality or match type with zone ID."
386                             + " quality=" + quality + ", matchType=" + matchType);
387                 }
388             }
389         }
390 
391         /** Returns the {@link TelephonyTimeZoneSuggestion}. */
392         @NonNull
build()393         public TelephonyTimeZoneSuggestion build() {
394             validate();
395             return new TelephonyTimeZoneSuggestion(this);
396         }
397     }
398 
399     /** @hide */
parseCommandLineArg(@onNull ShellCommand cmd)400     public static TelephonyTimeZoneSuggestion parseCommandLineArg(@NonNull ShellCommand cmd)
401             throws IllegalArgumentException {
402         Integer slotIndex = null;
403         String zoneId = null;
404         Integer quality = null;
405         Integer matchType = null;
406         String opt;
407         while ((opt = cmd.getNextArg()) != null) {
408             switch (opt) {
409                 case "--slot_index": {
410                     slotIndex = Integer.parseInt(cmd.getNextArgRequired());
411                     break;
412                 }
413                 case "--zone_id": {
414                     zoneId = cmd.getNextArgRequired();
415                     break;
416                 }
417                 case "--quality": {
418                     quality = parseQualityCommandLineArg(cmd.getNextArgRequired());
419                     break;
420                 }
421                 case "--match_type": {
422                     matchType = parseMatchTypeCommandLineArg(cmd.getNextArgRequired());
423                     break;
424                 }
425                 default: {
426                     throw new IllegalArgumentException("Unknown option: " + opt);
427                 }
428             }
429         }
430 
431         if (slotIndex == null) {
432             throw new IllegalArgumentException("No slotIndex specified.");
433         }
434 
435         Builder builder = new Builder(slotIndex);
436         if (!(TextUtils.isEmpty(zoneId) || "_".equals(zoneId))) {
437             builder.setZoneId(zoneId);
438         }
439         if (quality != null) {
440             builder.setQuality(quality);
441         }
442         if (matchType != null) {
443             builder.setMatchType(matchType);
444         }
445         builder.addDebugInfo("Command line injection");
446         return builder.build();
447     }
448 
parseQualityCommandLineArg(@onNull String arg)449     private static int parseQualityCommandLineArg(@NonNull String arg) {
450         switch (arg) {
451             case "single":
452                 return QUALITY_SINGLE_ZONE;
453             case "multiple_same":
454                 return QUALITY_MULTIPLE_ZONES_WITH_SAME_OFFSET;
455             case "multiple_different":
456                 return QUALITY_MULTIPLE_ZONES_WITH_DIFFERENT_OFFSETS;
457             default:
458                 throw new IllegalArgumentException("Unrecognized quality: " + arg);
459         }
460     }
461 
parseMatchTypeCommandLineArg(@onNull String arg)462     private static int parseMatchTypeCommandLineArg(@NonNull String arg) {
463         switch (arg) {
464             case "emulator":
465                 return MATCH_TYPE_EMULATOR_ZONE_ID;
466             case "country_with_offset":
467                 return MATCH_TYPE_NETWORK_COUNTRY_AND_OFFSET;
468             case "country":
469                 return MATCH_TYPE_NETWORK_COUNTRY_ONLY;
470             case "test_network":
471                 return MATCH_TYPE_TEST_NETWORK_OFFSET_ONLY;
472             default:
473                 throw new IllegalArgumentException("Unrecognized match_type: " + arg);
474         }
475     }
476 
477     /** @hide */
printCommandLineOpts(@onNull PrintWriter pw)478     public static void printCommandLineOpts(@NonNull PrintWriter pw) {
479         pw.println("Telephony suggestion options:");
480         pw.println("  --slot_index <number>");
481         pw.println("  To withdraw a previous suggestion:");
482         pw.println("    [--zone_id \"_\"]");
483         pw.println("  To make a new suggestion:");
484         pw.println("    --zone_id <Olson ID>");
485         pw.println("    --quality <single|multiple_same|multiple_different>");
486         pw.println("    --match_type <emulator|country_with_offset|country|test_network>");
487         pw.println();
488         pw.println("See " + TelephonyTimeZoneSuggestion.class.getName() + " for more information");
489     }
490 }
491