Move SuggestionRanker to SettingsIntelligence.

Bug: 65065268
Test: robotests
Change-Id: I68ed88a7c88af8bea67e3d3f6b142313bccc6f39
diff --git a/src/com/android/settings/intelligence/suggestions/ranking/EventStore.java b/src/com/android/settings/intelligence/suggestions/ranking/EventStore.java
new file mode 100644
index 0000000..4772fae
--- /dev/null
+++ b/src/com/android/settings/intelligence/suggestions/ranking/EventStore.java
@@ -0,0 +1,104 @@
+/*
+ * 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.settings.intelligence.suggestions.ranking;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.util.Log;
+
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * Copied from packages/apps/Settings/src/.../dashboard/suggestions/EventStore
+ */
+public class EventStore {
+    public static final String TAG = "SuggestionEventStore";
+
+    public static final String EVENT_SHOWN = "shown";
+    public static final String EVENT_DISMISSED = "dismissed";
+    public static final String EVENT_CLICKED = "clicked";
+    public static final String METRIC_LAST_EVENT_TIME = "last_event_time";
+    public static final String METRIC_COUNT = "count";
+
+    private static final Set<String> EVENTS = new HashSet<String>(
+            Arrays.asList(new String[]{EVENT_SHOWN, EVENT_DISMISSED, EVENT_CLICKED}));
+    private static final Set<String> METRICS = new HashSet<String>(
+            Arrays.asList(new String[]{METRIC_LAST_EVENT_TIME, METRIC_COUNT}));
+
+    private final SharedPreferences mSharedPrefs;
+
+    public EventStore(Context context) {
+        mSharedPrefs = context.getSharedPreferences(TAG, Context.MODE_PRIVATE);
+    }
+
+    /**
+     * Writes individual log events.
+     *
+     * @param pkgName:   Package for which this event is reported.
+     * @param eventType: Type of event (one of {@link #EVENTS}).
+     */
+    public void writeEvent(String pkgName, String eventType) {
+        if (!EVENTS.contains(eventType)) {
+            Log.w(TAG, "Reported event type " + eventType + " is not a valid type!");
+            return;
+        }
+        final String lastTimePrefKey = getPrefKey(pkgName, eventType, METRIC_LAST_EVENT_TIME);
+        final String countPrefKey = getPrefKey(pkgName, eventType, METRIC_COUNT);
+        writePref(lastTimePrefKey, System.currentTimeMillis());
+        writePref(countPrefKey, readPref(countPrefKey, (long) 0) + 1);
+    }
+
+    /**
+     * Reads metric of the the reported events (e.g., counts).
+     *
+     * @param pkgName:    Package for which this metric is queried.
+     * @param eventType:  Type of event (one of {@link #EVENTS}).
+     * @param metricType: Type of the queried metric (one of {@link #METRICS}).
+     * @return the corresponding metric.
+     */
+    public long readMetric(String pkgName, String eventType, String metricType) {
+        if (!EVENTS.contains(eventType)) {
+            Log.w(TAG, "Reported event type " + eventType + " is not a valid event!");
+            return 0;
+        } else if (!METRICS.contains(metricType)) {
+            Log.w(TAG, "Required stat type + " + metricType + " is not a valid stat!");
+            return 0;
+        }
+        return readPref(getPrefKey(pkgName, eventType, metricType), (long) 0);
+    }
+
+    private void writePref(String prefKey, long value) {
+        mSharedPrefs.edit().putLong(prefKey, value).commit();
+    }
+
+    private long readPref(String prefKey, Long defaultValue) {
+        return mSharedPrefs.getLong(prefKey, defaultValue);
+    }
+
+    private String getPrefKey(String pkgName, String eventType, String statType) {
+        return new StringBuilder()
+                .append("setting_suggestion_")
+                .append(pkgName)
+                .append("_")
+                .append(eventType)
+                .append("_")
+                .append(statType)
+                .toString();
+    }
+}
\ No newline at end of file
diff --git a/src/com/android/settings/intelligence/suggestions/ranking/SuggestionFeaturizer.java b/src/com/android/settings/intelligence/suggestions/ranking/SuggestionFeaturizer.java
new file mode 100644
index 0000000..9844268
--- /dev/null
+++ b/src/com/android/settings/intelligence/suggestions/ranking/SuggestionFeaturizer.java
@@ -0,0 +1,114 @@
+/*
+ * 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.settings.intelligence.suggestions.ranking;
+
+import android.service.settings.suggestions.Suggestion;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Creates a set of interaction features (i.e., metrics) to represent each setting suggestion. These
+ * features currently include normalized time from previous events (shown, dismissed and clicked)
+ * for any particular suggestion and also counts of these events. These features are used as signals
+ * to find the best ranking for suggestion items.
+ * <p/>
+ * Copied from packages/apps/Settings/src/.../dashboard/suggestions/SuggestionFeaturizer
+ */
+public class SuggestionFeaturizer {
+    // Key of the features used for ranking.
+    public static final String FEATURE_IS_SHOWN = "is_shown";
+    public static final String FEATURE_IS_DISMISSED = "is_dismissed";
+    public static final String FEATURE_IS_CLICKED = "is_clicked";
+    public static final String FEATURE_TIME_FROM_LAST_SHOWN = "time_from_last_shown";
+    public static final String FEATURE_TIME_FROM_LAST_DISMISSED = "time_from_last_dismissed";
+    public static final String FEATURE_TIME_FROM_LAST_CLICKED = "time_from_last_clicked";
+    public static final String FEATURE_SHOWN_COUNT = "shown_count";
+    public static final String FEATURE_DISMISSED_COUNT = "dismissed_count";
+    public static final String FEATURE_CLICKED_COUNT = "clicked_count";
+
+    // The following numbers are estimated from histograms.
+    public static final double TIME_NORMALIZATION_FACTOR = 2e10;
+    public static final double COUNT_NORMALIZATION_FACTOR = 500;
+
+    private final EventStore mEventStore;
+
+    /**
+     * Constructor
+     *
+     * @param eventStore An instance of {@code EventStore} which maintains the recorded suggestion
+     *                   events.
+     */
+    public SuggestionFeaturizer(EventStore eventStore) {
+        mEventStore = eventStore;
+    }
+
+    /**
+     * Extracts the features for each package name.
+     *
+     * @return A Map containing the features, keyed by the package names. Each map value contains
+     * another map with key-value pairs of the features.
+     */
+    public Map<String, Map<String, Double>> featurize(List<Suggestion> suggestions) {
+        Map<String, Map<String, Double>> features = new HashMap<>();
+        Long curTimeMs = System.currentTimeMillis();
+        List<String> pkgNames = new ArrayList<>(suggestions.size());
+        for (Suggestion suggestion : suggestions) {
+            pkgNames.add(suggestion.getId());
+        }
+        for (String pkgName : pkgNames) {
+            Map<String, Double> featureMap = new HashMap<>();
+            features.put(pkgName, featureMap);
+            Long lastShownTime = mEventStore
+                    .readMetric(pkgName, EventStore.EVENT_SHOWN, EventStore.METRIC_LAST_EVENT_TIME);
+            Long lastDismissedTime = mEventStore.readMetric(pkgName, EventStore.EVENT_DISMISSED,
+                    EventStore.METRIC_LAST_EVENT_TIME);
+            Long lastClickedTime = mEventStore.readMetric(pkgName, EventStore.EVENT_CLICKED,
+                    EventStore.METRIC_LAST_EVENT_TIME);
+            featureMap.put(FEATURE_IS_SHOWN, booleanToDouble(lastShownTime > 0));
+            featureMap.put(FEATURE_IS_DISMISSED, booleanToDouble(lastDismissedTime > 0));
+            featureMap.put(FEATURE_IS_CLICKED, booleanToDouble(lastClickedTime > 0));
+            featureMap.put(FEATURE_TIME_FROM_LAST_SHOWN,
+                    normalizedTimeDiff(curTimeMs, lastShownTime));
+            featureMap.put(FEATURE_TIME_FROM_LAST_DISMISSED,
+                    normalizedTimeDiff(curTimeMs, lastDismissedTime));
+            featureMap.put(FEATURE_TIME_FROM_LAST_CLICKED,
+                    normalizedTimeDiff(curTimeMs, lastClickedTime));
+            featureMap.put(FEATURE_SHOWN_COUNT, normalizedCount(mEventStore
+                    .readMetric(pkgName, EventStore.EVENT_SHOWN, EventStore.METRIC_COUNT)));
+            featureMap.put(FEATURE_DISMISSED_COUNT, normalizedCount(mEventStore
+                    .readMetric(pkgName, EventStore.EVENT_DISMISSED, EventStore.METRIC_COUNT)));
+            featureMap.put(FEATURE_CLICKED_COUNT, normalizedCount(mEventStore
+                    .readMetric(pkgName, EventStore.EVENT_CLICKED, EventStore.METRIC_COUNT)));
+        }
+        return features;
+    }
+
+    private static double booleanToDouble(boolean bool) {
+        return bool ? 1 : 0;
+    }
+
+    private static double normalizedTimeDiff(long curTimeMs, long preTimeMs) {
+        return Math.min(1, (curTimeMs - preTimeMs) / TIME_NORMALIZATION_FACTOR);
+    }
+
+    private static double normalizedCount(long count) {
+        return Math.min(1, count / COUNT_NORMALIZATION_FACTOR);
+    }
+}
\ No newline at end of file
diff --git a/src/com/android/settings/intelligence/suggestions/ranking/SuggestionRanker.java b/src/com/android/settings/intelligence/suggestions/ranking/SuggestionRanker.java
new file mode 100644
index 0000000..887f922
--- /dev/null
+++ b/src/com/android/settings/intelligence/suggestions/ranking/SuggestionRanker.java
@@ -0,0 +1,95 @@
+/*
+ * 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.settings.intelligence.suggestions.ranking;
+
+import android.content.Context;
+import android.service.settings.suggestions.Suggestion;
+import android.support.annotation.VisibleForTesting;
+
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Copied from packages/apps/Settings/src/.../dashboard/suggestions/SuggestionRanker
+ */
+public class SuggestionRanker {
+    private static final String TAG = "SuggestionRanker";
+
+    // The following coefficients form a linear model, which mixes the features to obtain a
+    // relevance metric for ranking the suggestion items. This model is learned with off-line data
+    // by training a binary classifier to detect the clicked items. The higher the obtained
+    // relevance metric, the higher chance of getting clicked.
+    private static final Map<String, Double> WEIGHTS = new HashMap<String, Double>() {{
+        put(SuggestionFeaturizer.FEATURE_IS_SHOWN, 5.05140842519);
+        put(SuggestionFeaturizer.FEATURE_IS_DISMISSED, 2.29641455171);
+        put(SuggestionFeaturizer.FEATURE_IS_CLICKED, -2.98812233623);
+        put(SuggestionFeaturizer.FEATURE_TIME_FROM_LAST_SHOWN, 5.02807250202);
+        put(SuggestionFeaturizer.FEATURE_TIME_FROM_LAST_DISMISSED, 2.49589700842);
+        put(SuggestionFeaturizer.FEATURE_TIME_FROM_LAST_CLICKED, -4.3377039948);
+        put(SuggestionFeaturizer.FEATURE_SHOWN_COUNT, -2.35993512546);
+    }};
+
+    private static SuggestionRanker sInstance;
+
+    private final SuggestionFeaturizer mSuggestionFeaturizer;
+    private final Map<Suggestion, Double> relevanceMetrics;
+
+    Comparator<Suggestion> suggestionComparator = new Comparator<Suggestion>() {
+        @Override
+        public int compare(Suggestion suggestion1, Suggestion suggestion2) {
+            return relevanceMetrics.get(suggestion1) < relevanceMetrics.get(suggestion2) ? 1 : -1;
+        }
+    };
+
+    @VisibleForTesting
+    SuggestionRanker(SuggestionFeaturizer suggestionFeaturizer) {
+        mSuggestionFeaturizer = suggestionFeaturizer;
+        relevanceMetrics = new HashMap<>();
+    }
+
+    public static SuggestionRanker getInstance(Context context) {
+        if (sInstance == null) {
+            sInstance = new SuggestionRanker(
+                    new SuggestionFeaturizer(new EventStore(context.getApplicationContext())));
+        }
+        return sInstance;
+    }
+
+    public void rankSuggestions(List<Suggestion> suggestions) {
+        relevanceMetrics.clear();
+        Map<String, Map<String, Double>> features = mSuggestionFeaturizer.featurize(suggestions);
+        for (Suggestion suggestion : suggestions) {
+            relevanceMetrics.put(suggestion, getRelevanceMetric(features.get(suggestion.getId())));
+        }
+        Collections.sort(suggestions, suggestionComparator);
+    }
+
+    @VisibleForTesting
+    double getRelevanceMetric(Map<String, Double> features) {
+        double sum = 0;
+        if (features == null) {
+            return sum;
+        }
+        for (String feature : WEIGHTS.keySet()) {
+            sum += WEIGHTS.get(feature) * features.get(feature);
+        }
+        return sum;
+    }
+}
\ No newline at end of file
diff --git a/tests/robotests/Android.mk b/tests/robotests/Android.mk
index 37a52a7..cb106ca 100644
--- a/tests/robotests/Android.mk
+++ b/tests/robotests/Android.mk
@@ -8,6 +8,7 @@
 
 # Include the testing libraries (JUnit4 + Robolectric libs).
 LOCAL_STATIC_JAVA_LIBRARIES := \
+    mockito-robolectric-prebuilt \
     truth-prebuilt
 
 LOCAL_JAVA_LIBRARIES := \
diff --git a/tests/robotests/src/android/service/settings/suggestions/Suggestion.java b/tests/robotests/src/android/service/settings/suggestions/Suggestion.java
new file mode 100644
index 0000000..2bb6192
--- /dev/null
+++ b/tests/robotests/src/android/service/settings/suggestions/Suggestion.java
@@ -0,0 +1,119 @@
+/*
+ * 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 android.service.settings.suggestions;
+
+import android.app.PendingIntent;
+import android.os.Parcel;
+import android.text.TextUtils;
+
+public class Suggestion {
+    private final String mId;
+    private final CharSequence mTitle;
+    private final CharSequence mSummary;
+    private final PendingIntent mPendingIntent;
+
+    /**
+     * Gets the id for the suggestion object.
+     */
+    public String getId() {
+        return mId;
+    }
+
+    /**
+     * Title of the suggestion that is shown to the user.
+     */
+    public CharSequence getTitle() {
+        return mTitle;
+    }
+
+    /**
+     * Optional summary describing what this suggestion controls.
+     */
+    public CharSequence getSummary() {
+        return mSummary;
+    }
+
+    /**
+     * The Intent to launch when the suggestion is activated.
+     */
+    public PendingIntent getPendingIntent() {
+        return mPendingIntent;
+    }
+
+    private Suggestion(Builder builder) {
+        mTitle = builder.mTitle;
+        mSummary = builder.mSummary;
+        mPendingIntent = builder.mPendingIntent;
+        mId = builder.mId;
+    }
+
+    private Suggestion(Parcel in) {
+        mId = in.readString();
+        mTitle = in.readCharSequence();
+        mSummary = in.readCharSequence();
+        mPendingIntent = in.readParcelable(PendingIntent.class.getClassLoader());
+    }
+
+    /**
+     * Builder class for {@link Suggestion}.
+     */
+    public static class Builder {
+        private final String mId;
+        private CharSequence mTitle;
+        private CharSequence mSummary;
+        private PendingIntent mPendingIntent;
+
+        public Builder(String id) {
+            if (TextUtils.isEmpty(id)) {
+                throw new IllegalArgumentException("Suggestion id cannot be empty");
+            }
+            mId = id;
+        }
+
+        /**
+         * Sets suggestion title
+         */
+
+        public Builder setTitle(CharSequence title) {
+            mTitle = title;
+            return this;
+        }
+
+        /**
+         * Sets suggestion summary
+         */
+        public Builder setSummary(CharSequence summary) {
+            mSummary = summary;
+            return this;
+        }
+
+        /**
+         * Sets suggestion intent
+         */
+        public Builder setPendingIntent(PendingIntent pendingIntent) {
+            mPendingIntent = pendingIntent;
+            return this;
+        }
+
+        /**
+         * Builds an immutable {@link Suggestion} object.
+         */
+        public Suggestion build() {
+            return new Suggestion(this /* builder */);
+        }
+    }
+}
diff --git a/tests/robotests/src/com/android/settings/intelligence/suggestions/ranking/EventStoreTest.java b/tests/robotests/src/com/android/settings/intelligence/suggestions/ranking/EventStoreTest.java
new file mode 100644
index 0000000..c99b972
--- /dev/null
+++ b/tests/robotests/src/com/android/settings/intelligence/suggestions/ranking/EventStoreTest.java
@@ -0,0 +1,68 @@
+/*
+ * 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.settings.intelligence.suggestions.ranking;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.android.settings.intelligence.SettingsIntelligenceRobolectricTestRunner;
+import com.android.settings.intelligence.TestConfig;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RuntimeEnvironment;
+import org.robolectric.annotation.Config;
+
+@RunWith(SettingsIntelligenceRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class EventStoreTest {
+    private EventStore mEventStore;
+
+    @Before
+    public void setUp() {
+        mEventStore = new EventStore(RuntimeEnvironment.application);
+    }
+
+    @Test
+    public void testWriteRead() {
+        mEventStore.writeEvent("pkg", EventStore.EVENT_SHOWN);
+        long timeMs = System.currentTimeMillis();
+        assertThat(mEventStore.readMetric("pkg", EventStore.EVENT_SHOWN, EventStore.METRIC_COUNT))
+                .isEqualTo(1);
+        assertThat(Math.abs(timeMs - mEventStore.readMetric("pkg", EventStore.EVENT_SHOWN,
+                EventStore.METRIC_LAST_EVENT_TIME)) < 10000)
+                .isTrue();
+    }
+
+    @Test
+    public void testWriteRead_shouldHaveLatestValues() {
+        mEventStore.writeEvent("pkg", EventStore.EVENT_DISMISSED);
+        mEventStore.writeEvent("pkg", EventStore.EVENT_DISMISSED);
+        assertThat(
+                mEventStore.readMetric("pkg", EventStore.EVENT_DISMISSED, EventStore.METRIC_COUNT))
+                .isEqualTo(2);
+    }
+
+    @Test
+    public void testWriteRead_shouldReturnDefaultIfNotAvailable() {
+        assertThat(mEventStore.readMetric("pkg", EventStore.EVENT_SHOWN, EventStore.METRIC_COUNT))
+                .isEqualTo(0);
+        assertThat(mEventStore.readMetric("pkg", EventStore.EVENT_SHOWN,
+                EventStore.METRIC_LAST_EVENT_TIME))
+                .isEqualTo(0);
+    }
+}
diff --git a/tests/robotests/src/com/android/settings/intelligence/suggestions/ranking/SuggestionFeaturizerTest.java b/tests/robotests/src/com/android/settings/intelligence/suggestions/ranking/SuggestionFeaturizerTest.java
new file mode 100644
index 0000000..c82428c
--- /dev/null
+++ b/tests/robotests/src/com/android/settings/intelligence/suggestions/ranking/SuggestionFeaturizerTest.java
@@ -0,0 +1,120 @@
+/*
+ * 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.settings.intelligence.suggestions.ranking;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import android.service.settings.suggestions.Suggestion;
+
+import com.android.settings.intelligence.SettingsIntelligenceRobolectricTestRunner;
+import com.android.settings.intelligence.TestConfig;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RuntimeEnvironment;
+import org.robolectric.annotation.Config;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+
+@RunWith(SettingsIntelligenceRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class SuggestionFeaturizerTest {
+
+    private EventStore mEventStore;
+    private SuggestionFeaturizer mSuggestionFeaturizer;
+
+    @Before
+    public void setUp() {
+        mEventStore = new EventStore(RuntimeEnvironment.application);
+        mSuggestionFeaturizer = new SuggestionFeaturizer(mEventStore);
+    }
+
+    @Test
+    public void testFeaturize_singlePackage() {
+        mEventStore.writeEvent("pkg", EventStore.EVENT_DISMISSED);
+        mEventStore.writeEvent("pkg", EventStore.EVENT_SHOWN);
+        mEventStore.writeEvent("pkg", EventStore.EVENT_SHOWN);
+        final Map<String, Double> features = mSuggestionFeaturizer
+                .featurize(Arrays.asList(new Suggestion.Builder("pkg").build()))
+                .get("pkg");
+        assertThat(features.get(SuggestionFeaturizer.FEATURE_IS_SHOWN)).isEqualTo(1.0);
+        assertThat(features.get(SuggestionFeaturizer.FEATURE_IS_DISMISSED)).isEqualTo(1.0);
+        assertThat(features.get(SuggestionFeaturizer.FEATURE_IS_CLICKED)).isEqualTo(0.0);
+
+        assertThat(features.get(SuggestionFeaturizer.FEATURE_TIME_FROM_LAST_SHOWN)).isLessThan
+                (1.0);
+        assertThat(features.get(SuggestionFeaturizer.FEATURE_TIME_FROM_LAST_DISMISSED))
+                .isLessThan(1.0);
+        assertThat(features.get(SuggestionFeaturizer.FEATURE_TIME_FROM_LAST_CLICKED))
+                .isEqualTo(1.0);
+        assertThat(features.get(SuggestionFeaturizer.FEATURE_SHOWN_COUNT))
+                .isEqualTo(2.0 / SuggestionFeaturizer.COUNT_NORMALIZATION_FACTOR);
+        assertThat(features.get(SuggestionFeaturizer.FEATURE_DISMISSED_COUNT))
+                .isEqualTo(1.0 / SuggestionFeaturizer.COUNT_NORMALIZATION_FACTOR);
+        assertThat(features.get(SuggestionFeaturizer.FEATURE_CLICKED_COUNT)).isEqualTo(0.0);
+    }
+
+    @Test
+    public void testFeaturize_multiplePackages() {
+        mEventStore.writeEvent("pkg1", EventStore.EVENT_DISMISSED);
+        mEventStore.writeEvent("pkg2", EventStore.EVENT_SHOWN);
+        mEventStore.writeEvent("pkg1", EventStore.EVENT_SHOWN);
+        final List<Suggestion> suggestions = new ArrayList<Suggestion>() {
+            {
+                add(new Suggestion.Builder("pkg1").build());
+                add(new Suggestion.Builder("pkg2").build());
+            }
+        };
+        final Map<String, Map<String, Double>> features = mSuggestionFeaturizer
+                .featurize(suggestions);
+        final Map<String, Double> features1 = features.get("pkg1");
+        final Map<String, Double> features2 = features.get("pkg2");
+
+        assertThat(features1.get(SuggestionFeaturizer.FEATURE_IS_SHOWN)).isEqualTo(1.0);
+        assertThat(features1.get(SuggestionFeaturizer.FEATURE_IS_DISMISSED)).isEqualTo(1.0);
+        assertThat(features1.get(SuggestionFeaturizer.FEATURE_IS_CLICKED)).isEqualTo(0.0);
+        assertThat(features1.get(SuggestionFeaturizer.FEATURE_TIME_FROM_LAST_SHOWN))
+                .isLessThan(1.0);
+        assertThat(features1.get(SuggestionFeaturizer.FEATURE_TIME_FROM_LAST_DISMISSED))
+                .isLessThan(1.0);
+        assertThat(features1.get(SuggestionFeaturizer.FEATURE_TIME_FROM_LAST_CLICKED))
+                .isEqualTo(1.0);
+        assertThat(features1.get(SuggestionFeaturizer.FEATURE_SHOWN_COUNT))
+                .isEqualTo(1.0 / SuggestionFeaturizer.COUNT_NORMALIZATION_FACTOR);
+        assertThat(features1.get(SuggestionFeaturizer.FEATURE_DISMISSED_COUNT))
+                .isEqualTo(1.0 / SuggestionFeaturizer.COUNT_NORMALIZATION_FACTOR);
+        assertThat(features1.get(SuggestionFeaturizer.FEATURE_CLICKED_COUNT)).isEqualTo(0.0);
+
+        assertThat(features2.get(SuggestionFeaturizer.FEATURE_IS_SHOWN)).isEqualTo(1.0);
+        assertThat(features2.get(SuggestionFeaturizer.FEATURE_IS_DISMISSED)).isEqualTo(0.0);
+        assertThat(features2.get(SuggestionFeaturizer.FEATURE_IS_CLICKED)).isEqualTo(0.0);
+        assertThat(features2.get(SuggestionFeaturizer.FEATURE_TIME_FROM_LAST_SHOWN))
+                .isLessThan(1.0);
+        assertThat(features2.get(SuggestionFeaturizer.FEATURE_TIME_FROM_LAST_DISMISSED))
+                .isEqualTo(1.0);
+        assertThat(features2.get(SuggestionFeaturizer.FEATURE_TIME_FROM_LAST_CLICKED))
+                .isEqualTo(1.0);
+        assertThat(features2.get(SuggestionFeaturizer.FEATURE_SHOWN_COUNT))
+                .isEqualTo(1.0 / SuggestionFeaturizer.COUNT_NORMALIZATION_FACTOR);
+        assertThat(features2.get(SuggestionFeaturizer.FEATURE_DISMISSED_COUNT)).isEqualTo(0.0);
+        assertThat(features2.get(SuggestionFeaturizer.FEATURE_CLICKED_COUNT)).isEqualTo(0.0);
+    }
+}
diff --git a/tests/robotests/src/com/android/settings/intelligence/suggestions/ranking/SuggestionRankerTest.java b/tests/robotests/src/com/android/settings/intelligence/suggestions/ranking/SuggestionRankerTest.java
new file mode 100644
index 0000000..7866ea3
--- /dev/null
+++ b/tests/robotests/src/com/android/settings/intelligence/suggestions/ranking/SuggestionRankerTest.java
@@ -0,0 +1,73 @@
+package com.android.settings.intelligence.suggestions.ranking;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.Matchers.same;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.when;
+
+import android.service.settings.suggestions.Suggestion;
+
+import com.android.settings.intelligence.SettingsIntelligenceRobolectricTestRunner;
+import com.android.settings.intelligence.TestConfig;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.annotation.Config;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+@RunWith(SettingsIntelligenceRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class SuggestionRankerTest {
+
+    @Mock
+    private SuggestionRanker mSuggestionRanker;
+    @Mock
+    private SuggestionFeaturizer mSuggestionFeaturizer;
+
+    private Map<String, Map<String, Double>> mFeatures;
+    private List<Suggestion> mSuggestions;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mFeatures = new HashMap<>();
+        mFeatures.put("pkg1", new HashMap<>());
+        mFeatures.put("pkg2", new HashMap<>());
+        mFeatures.put("pkg3", new HashMap<>());
+        mSuggestions = new ArrayList<Suggestion>() {
+            {
+                add(new Suggestion.Builder("pkg1").build());
+                add(new Suggestion.Builder("pkg2").build());
+                add(new Suggestion.Builder("pkg3").build());
+            }
+        };
+        mSuggestionFeaturizer = mock(SuggestionFeaturizer.class);
+        mSuggestionRanker = new SuggestionRanker(mSuggestionFeaturizer);
+        when(mSuggestionFeaturizer.featurize(mSuggestions)).thenReturn(mFeatures);
+        mSuggestionRanker = spy(mSuggestionRanker);
+        when(mSuggestionRanker.getRelevanceMetric(same(mFeatures.get("pkg1")))).thenReturn(0.9);
+        when(mSuggestionRanker.getRelevanceMetric(same(mFeatures.get("pkg2")))).thenReturn(0.1);
+        when(mSuggestionRanker.getRelevanceMetric(same(mFeatures.get("pkg3")))).thenReturn(0.5);
+    }
+
+    @Test
+    public void testRank() {
+        List<Suggestion> expectedOrderdList = new ArrayList<Suggestion>() {
+            {
+                add(mSuggestions.get(0)); // relevance = 0.9
+                add(mSuggestions.get(2)); // relevance = 0.5
+                add(mSuggestions.get(1)); // relevance = 0.1
+            }
+        };
+        mSuggestionRanker.rankSuggestions(mSuggestions);
+        assertThat(mSuggestions).isEqualTo(expectedOrderdList);
+    }
+}
\ No newline at end of file