Time Zone data loader

- Use CountryZonesFinder to provide time zone id and region-to-timezone
  mapping, where the underlying data is updatable through an unbundled time zone
  data app in some devices.

Bug: 73952488
Bug: 72144448
Test: m RunSettingsRoboTests
Change-Id: I2e01e167c48987ebb98d4881a1a528d16dd82944
diff --git a/src/com/android/settings/datetime/timezone/TimeZoneInfo.java b/src/com/android/settings/datetime/timezone/TimeZoneInfo.java
index 96a2067..8cb1d4e 100644
--- a/src/com/android/settings/datetime/timezone/TimeZoneInfo.java
+++ b/src/com/android/settings/datetime/timezone/TimeZoneInfo.java
@@ -15,9 +15,16 @@
  */
 package com.android.settings.datetime.timezone;
 
+import android.icu.text.TimeZoneFormat;
+import android.icu.text.TimeZoneNames;
 import android.icu.util.TimeZone;
 import android.text.TextUtils;
 
+import com.android.settingslib.datetime.ZoneGetter;
+
+import java.util.Date;
+import java.util.Locale;
+
 /**
  * Data object containing information for displaying a time zone for the user to select.
  */
@@ -131,6 +138,51 @@
             }
             return new TimeZoneInfo(this);
         }
-
     }
+
+    public static class Formatter {
+        private final Locale mLocale;
+        private final Date mNow;
+        private final TimeZoneFormat mTimeZoneFormat;
+
+        public Formatter(Locale locale, Date now) {
+            mLocale = locale;
+            mNow = now;
+            mTimeZoneFormat = TimeZoneFormat.getInstance(locale);
+        }
+
+        /**
+         * @param timeZoneId Olson time zone id
+         * @return TimeZoneInfo containing time zone names, exemplar locations and GMT offset
+         */
+        public TimeZoneInfo format(String timeZoneId) {
+            TimeZone timeZone = TimeZone.getFrozenTimeZone(timeZoneId);
+            return format(timeZone);
+        }
+
+        /**
+         * @param timeZone Olson time zone object
+         * @return TimeZoneInfo containing time zone names, exemplar locations and GMT offset
+         */
+        public TimeZoneInfo format(TimeZone timeZone) {
+            final String id = timeZone.getID();
+            final TimeZoneNames timeZoneNames = mTimeZoneFormat.getTimeZoneNames();
+            final java.util.TimeZone javaTimeZone = android.icu.impl.TimeZoneAdapter.wrap(timeZone);
+            final CharSequence gmtOffset = ZoneGetter.getGmtOffsetText(mTimeZoneFormat, mLocale,
+                javaTimeZone, mNow);
+            return new TimeZoneInfo.Builder(timeZone)
+                    .setGenericName(timeZoneNames.getDisplayName(id,
+                            TimeZoneNames.NameType.LONG_GENERIC, mNow.getTime()))
+                    .setStandardName(timeZoneNames.getDisplayName(id,
+                            TimeZoneNames.NameType.LONG_STANDARD, mNow.getTime()))
+                    .setDaylightName(timeZoneNames.getDisplayName(id,
+                            TimeZoneNames.NameType.LONG_DAYLIGHT, mNow.getTime()))
+                    .setExemplarLocation(timeZoneNames.getExemplarLocationName(id))
+                    .setGmtOffset(gmtOffset)
+                    // TODO: move Item id to TimeZoneInfoAdapter
+                    .setItemId(0)
+                    .build();
+        }
+    }
+
 }
diff --git a/src/com/android/settings/datetime/timezone/model/FilteredCountryTimeZones.java b/src/com/android/settings/datetime/timezone/model/FilteredCountryTimeZones.java
new file mode 100644
index 0000000..d1b6ed9
--- /dev/null
+++ b/src/com/android/settings/datetime/timezone/model/FilteredCountryTimeZones.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2018 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.settings.datetime.timezone.model;
+
+import libcore.util.CountryTimeZones;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.stream.Collectors;
+
+/**
+ * Wrap {@class CountryTimeZones} to filter time zone that are shown in the picker.
+ */
+public class FilteredCountryTimeZones {
+
+    private final CountryTimeZones mCountryTimeZones;
+    private final List<String> mTimeZoneIds;
+
+    public FilteredCountryTimeZones(CountryTimeZones countryTimeZones) {
+        mCountryTimeZones = countryTimeZones;
+        List<String> timeZoneIds = countryTimeZones.getTimeZoneMappings().stream()
+                .filter(timeZoneMapping -> timeZoneMapping.showInPicker)
+                .map(timeZoneMapping -> timeZoneMapping.timeZoneId)
+                .collect(Collectors.toList());
+        mTimeZoneIds = Collections.unmodifiableList(timeZoneIds);
+    }
+
+    public List<String> getTimeZoneIds() {
+        return mTimeZoneIds;
+    }
+
+    public CountryTimeZones getCountryTimeZones() {
+        return mCountryTimeZones;
+    }
+
+    public String getRegionId() {
+        return TimeZoneData.normalizeRegionId(mCountryTimeZones.getCountryIso());
+    }
+}
diff --git a/src/com/android/settings/datetime/timezone/model/TimeZoneData.java b/src/com/android/settings/datetime/timezone/model/TimeZoneData.java
new file mode 100644
index 0000000..a863bfc
--- /dev/null
+++ b/src/com/android/settings/datetime/timezone/model/TimeZoneData.java
@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2018 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.settings.datetime.timezone.model;
+
+import android.support.annotation.VisibleForTesting;
+
+import libcore.util.CountryTimeZones;
+import libcore.util.CountryZonesFinder;
+import libcore.util.TimeZoneFinder;
+
+import java.lang.ref.WeakReference;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Locale;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+/**
+ * Wrapper of CountryZonesFinder to normalize the country code and only show the regions that are
+ * has time zone shown in the time zone picker.
+ * The constructor reads the data from underlying file, and this means it should not be called
+ * from the UI thread.
+ */
+public class TimeZoneData {
+
+    private static WeakReference<TimeZoneData> sCache = null;
+
+    private final CountryZonesFinder mCountryZonesFinder;
+    private final Set<String> mRegionIds;
+
+    public static synchronized TimeZoneData getInstance() {
+        TimeZoneData data = sCache == null ? null : sCache.get();
+        if (data != null) {
+            return data;
+        }
+        data = new TimeZoneData();
+        sCache = new WeakReference<>(data);
+        return data;
+    }
+
+    public TimeZoneData() {
+        this(TimeZoneFinder.getInstance().getCountryZonesFinder());
+    }
+
+    @VisibleForTesting
+    TimeZoneData(CountryZonesFinder countryZonesFinder) {
+        mCountryZonesFinder = countryZonesFinder;
+        mRegionIds = getNormalizedRegionIds(mCountryZonesFinder.lookupAllCountryIsoCodes());
+    }
+
+    public Set<String> getRegionIds() {
+        return mRegionIds;
+    }
+
+    public Set<String> lookupCountryCodesForZoneId(String tzId) {
+        if (tzId == null) {
+            return Collections.emptySet();
+        }
+        return mCountryZonesFinder.lookupCountryTimeZonesForZoneId(tzId).stream()
+                .filter(countryTimeZones ->
+                    countryTimeZones.getTimeZoneMappings().stream()
+                            .anyMatch(mapping ->
+                                    mapping.timeZoneId.equals(tzId) && mapping.showInPicker))
+                .map(countryTimeZones -> normalizeRegionId(countryTimeZones.getCountryIso()))
+                .collect(Collectors.toSet());
+    }
+
+    public FilteredCountryTimeZones lookupCountryTimeZones(String regionId) {
+        CountryTimeZones finder = regionId == null ? null
+                : mCountryZonesFinder.lookupCountryTimeZones(regionId);
+       return finder == null ? null : new FilteredCountryTimeZones(finder);
+    }
+
+    private static Set<String> getNormalizedRegionIds(List<String> regionIds) {
+        final Set<String> result = new HashSet<>(regionIds.size());
+        for (String regionId : regionIds) {
+            result.add(normalizeRegionId(regionId));
+        }
+        return Collections.unmodifiableSet(result);
+    }
+
+    // Uppercase ASCII is normalized for the purpose of using ICU API
+    public static String normalizeRegionId(String regionId) {
+        return regionId == null ? null : regionId.toUpperCase(Locale.US);
+    }
+}
diff --git a/src/com/android/settings/datetime/timezone/model/TimeZoneDataLoader.java b/src/com/android/settings/datetime/timezone/model/TimeZoneDataLoader.java
new file mode 100644
index 0000000..89908d8
--- /dev/null
+++ b/src/com/android/settings/datetime/timezone/model/TimeZoneDataLoader.java
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2018 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.settings.datetime.timezone.model;
+
+import android.app.LoaderManager;
+import android.content.Context;
+import android.content.Loader;
+import android.os.Bundle;
+
+import com.android.settingslib.utils.AsyncLoader;
+
+public class TimeZoneDataLoader extends AsyncLoader<TimeZoneData> {
+
+    public TimeZoneDataLoader(Context context) {
+        super(context);
+    }
+
+    @Override
+    public TimeZoneData loadInBackground() {
+        // Heavy operation due to reading the underlying file
+        return new TimeZoneData();
+    }
+
+    @Override
+    protected void onDiscardResult(TimeZoneData result) {
+        // This class doesn't hold resource of the result.
+    }
+
+    public interface OnDataReadyCallback {
+        void onTimeZoneDataReady(TimeZoneData data);
+    }
+
+    public static class LoaderCreator implements LoaderManager.LoaderCallbacks<TimeZoneData> {
+
+        private final Context mContext;
+        private final OnDataReadyCallback mCallback;
+
+        public LoaderCreator(Context context, OnDataReadyCallback callback) {
+            mContext = context;
+            mCallback = callback;
+        }
+
+        @Override
+        public Loader onCreateLoader(int id, Bundle args) {
+            return new TimeZoneDataLoader(mContext);
+        }
+
+        @Override
+        public void onLoadFinished(Loader<TimeZoneData> loader, TimeZoneData data) {
+            if (mCallback != null) {
+                mCallback.onTimeZoneDataReady(data);
+            }
+        }
+
+        @Override
+        public void onLoaderReset(Loader<TimeZoneData> loader) {
+            //It's okay to keep the time zone data when loader is reset
+        }
+    }
+}
diff --git a/tests/robotests/src/com/android/settings/datetime/timezone/TimeZoneInfoTest.java b/tests/robotests/src/com/android/settings/datetime/timezone/TimeZoneInfoTest.java
new file mode 100644
index 0000000..6042dd3
--- /dev/null
+++ b/tests/robotests/src/com/android/settings/datetime/timezone/TimeZoneInfoTest.java
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2018 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.settings.datetime.timezone;
+
+
+import com.android.settings.TestConfig;
+import com.android.settings.datetime.timezone.TimeZoneInfo.Formatter;
+import com.android.settings.testutils.SettingsRobolectricTestRunner;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.annotation.Config;
+
+import java.util.Date;
+import java.util.Locale;
+
+import static com.google.common.truth.Truth.assertThat;
+
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class TimeZoneInfoTest {
+
+    @Test
+    public void testFormat() {
+        Date now = new Date(0L); // 00:00 1/1/1970
+        Formatter formatter = new Formatter(Locale.US, now);
+
+        TimeZoneInfo timeZoneInfo = formatter.format("America/Los_Angeles");
+        assertThat(timeZoneInfo.getId()).isEqualTo("America/Los_Angeles");
+        assertThat(timeZoneInfo.getExemplarLocation()).isEqualTo("Los Angeles");
+        assertThat(timeZoneInfo.getGmtOffset().toString()).isEqualTo("GMT-08:00");
+        assertThat(timeZoneInfo.getGenericName()).isEqualTo("Pacific Time");
+        assertThat(timeZoneInfo.getStandardName()).isEqualTo("Pacific Standard Time");
+        assertThat(timeZoneInfo.getDaylightName()).isEqualTo("Pacific Daylight Time");
+    }
+}
diff --git a/tests/robotests/src/com/android/settings/datetime/timezone/model/TimeZoneDataTest.java b/tests/robotests/src/com/android/settings/datetime/timezone/model/TimeZoneDataTest.java
new file mode 100644
index 0000000..2748604
--- /dev/null
+++ b/tests/robotests/src/com/android/settings/datetime/timezone/model/TimeZoneDataTest.java
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2018 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.settings.datetime.timezone.model;
+
+import com.android.settings.TestConfig;
+import com.android.settings.testutils.SettingsRobolectricTestRunner;
+
+import libcore.util.CountryTimeZones;
+import libcore.util.CountryZonesFinder;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.annotation.Config;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Set;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.junit.Assert.assertSame;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class TimeZoneDataTest {
+
+    private CountryZonesFinder mCountryZonesFinder;
+
+    @Before
+    public void setUp() throws Exception {
+        mCountryZonesFinder = mock(CountryZonesFinder.class);
+        when(mCountryZonesFinder.lookupAllCountryIsoCodes()).thenReturn(new ArrayList<>());
+    }
+
+    @Test
+    public void testRegionsWithTimeZone() {
+        TimeZoneData timeZoneData = new TimeZoneData(mCountryZonesFinder);
+        CountryTimeZones countryTimeZones = mock(CountryTimeZones.class);
+        when(countryTimeZones.getTimeZoneMappings()).thenReturn(Collections.emptyList());
+        when(mCountryZonesFinder.lookupCountryTimeZones("US")).thenReturn(countryTimeZones);
+        assertThat(timeZoneData.lookupCountryTimeZones("US").getCountryTimeZones())
+                .isSameAs(countryTimeZones);
+    }
+
+    @Test
+    public void testGetRegionIds() {
+        when(mCountryZonesFinder.lookupAllCountryIsoCodes()).thenReturn(Arrays.asList());
+        TimeZoneData timeZoneData = new TimeZoneData(mCountryZonesFinder);
+        assertThat(timeZoneData.getRegionIds()).isEmpty();
+
+        when(mCountryZonesFinder.lookupAllCountryIsoCodes()).thenReturn(Arrays.asList("us", "GB"));
+        timeZoneData = new TimeZoneData(mCountryZonesFinder);
+        assertThat(timeZoneData.getRegionIds()).containsExactly("US", "GB");
+    }
+
+    @Test
+    public void testLookupCountryCodesForZoneId() {
+        TimeZoneData timeZoneData = new TimeZoneData(mCountryZonesFinder);
+        assertThat(timeZoneData.lookupCountryCodesForZoneId(null)).isEmpty();
+        CountryTimeZones US = mock(CountryTimeZones.class);
+        when(US.getCountryIso()).thenReturn("us");
+        when(US.getTimeZoneMappings()).thenReturn(Arrays.asList(
+           new CountryTimeZones.TimeZoneMapping("Unknown/Secret_City", true),
+           new CountryTimeZones.TimeZoneMapping("Unknown/Secret_City2", false)
+        ));
+        CountryTimeZones GB = mock(CountryTimeZones.class);
+        when(GB.getCountryIso()).thenReturn("gb");
+        when(GB.getTimeZoneMappings()).thenReturn(Arrays.asList(
+           new CountryTimeZones.TimeZoneMapping("Unknown/Secret_City", true)
+        ));
+        when(mCountryZonesFinder.lookupCountryTimeZonesForZoneId("Unknown/Secret_City"))
+                .thenReturn(Arrays.asList(US, GB));
+        assertThat(timeZoneData.lookupCountryCodesForZoneId("Unknown/Secret_City"))
+                .containsExactly("US", "GB");
+        assertThat(timeZoneData.lookupCountryCodesForZoneId("Unknown/Secret_City2")).isEmpty();
+    }
+}
diff --git a/tests/robotests/src/libcore/util/CountryTimeZones.java b/tests/robotests/src/libcore/util/CountryTimeZones.java
new file mode 100644
index 0000000..2087848
--- /dev/null
+++ b/tests/robotests/src/libcore/util/CountryTimeZones.java
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2018 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 libcore.util;
+
+import java.util.List;
+
+/**
+ * Empty implementation of CountryTimeZones for Robolectric test.
+ */
+public class CountryTimeZones {
+    public CountryTimeZones() {
+    }
+
+    public final static class TimeZoneMapping {
+        public final String timeZoneId;
+        public final boolean showInPicker;
+
+        public TimeZoneMapping(String timeZoneId, boolean showInPicker) {
+            this.timeZoneId = timeZoneId;
+            this.showInPicker = showInPicker;
+        }
+    }
+
+    public List<TimeZoneMapping> getTimeZoneMappings() {
+        return null;
+    }
+
+    public String getCountryIso() {
+        return null;
+    }
+}
diff --git a/tests/robotests/src/libcore/util/CountryZonesFinder.java b/tests/robotests/src/libcore/util/CountryZonesFinder.java
new file mode 100644
index 0000000..51149ec
--- /dev/null
+++ b/tests/robotests/src/libcore/util/CountryZonesFinder.java
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2018 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 libcore.util;
+
+import java.util.List;
+
+/**
+ * Empty implementation of CountryZonesFinder for Robolectric test.
+ */
+public class CountryZonesFinder {
+    public CountryZonesFinder(List<CountryTimeZones> countryTimeZonesList) {}
+
+    public List<String> lookupAllCountryIsoCodes() {
+        return null;
+    }
+
+    public List<CountryTimeZones> lookupCountryTimeZonesForZoneId(String zoneId) {
+        return null;
+    }
+
+    public CountryTimeZones lookupCountryTimeZones(String countryIso) {
+        return null;
+    }
+}