Add new constructor to create BatteryHistEntry from interpolation

https://matthew-brett.github.io/teaching/linear_interpolation.html

Bug: 184807417
Test: make SettingsRoboTests
Change-Id: I6dbdb3db8243e40bc54bde3aab7157fda2719de9
diff --git a/src/com/android/settings/fuelgauge/BatteryHistEntry.java b/src/com/android/settings/fuelgauge/BatteryHistEntry.java
index 211d4b6..6130fff 100644
--- a/src/com/android/settings/fuelgauge/BatteryHistEntry.java
+++ b/src/com/android/settings/fuelgauge/BatteryHistEntry.java
@@ -114,6 +114,35 @@
         mBatteryHealth = getInteger(cursor, KEY_BATTERY_HEALTH);
     }
 
+    private BatteryHistEntry(
+          BatteryHistEntry fromEntry,
+          long bootTimestamp,
+          long timestamp,
+          double totalPower,
+          double consumePower,
+          long foregroundUsageTimeInMs,
+          long backgroundUsageTimeInMs,
+          int batteryLevel) {
+        mUid = fromEntry.mUid;
+        mUserId = fromEntry.mUserId;
+        mAppLabel = fromEntry.mAppLabel;
+        mPackageName = fromEntry.mPackageName;
+        mIsHidden = fromEntry.mIsHidden;
+        mBootTimestamp = bootTimestamp;
+        mTimestamp = timestamp;
+        mZoneId = fromEntry.mZoneId;
+        mTotalPower = totalPower;
+        mConsumePower = consumePower;
+        mPercentOfTotal = fromEntry.mPercentOfTotal;
+        mForegroundUsageTimeInMs = foregroundUsageTimeInMs;
+        mBackgroundUsageTimeInMs = backgroundUsageTimeInMs;
+        mDrainType = fromEntry.mDrainType;
+        mConsumerType = fromEntry.mConsumerType;
+        mBatteryLevel = batteryLevel;
+        mBatteryStatus = fromEntry.mBatteryStatus;
+        mBatteryHealth = fromEntry.mBatteryHealth;
+    }
+
     /** Whether this {@link BatteryHistEntry} is valid or not? */
     public boolean isValidEntry() {
         return mIsValidEntry;
@@ -257,4 +286,50 @@
         mIsValidEntry = false;
         return false;
     }
+
+    /** Creates new {@link BatteryHistEntry} from interpolation. */
+    public static BatteryHistEntry interpolate(
+            long slotTimestamp,
+            long upperTimestamp,
+            double ratio,
+            BatteryHistEntry lowerHistEntry,
+            BatteryHistEntry upperHistEntry) {
+        final double totalPower = interpolate(
+            lowerHistEntry == null ? 0 : lowerHistEntry.mTotalPower,
+            upperHistEntry.mTotalPower,
+            ratio);
+        final double consumePower = interpolate(
+            lowerHistEntry == null ? 0 : lowerHistEntry.mConsumePower,
+            upperHistEntry.mConsumePower,
+            ratio);
+        final double foregroundUsageTimeInMs = interpolate(
+            lowerHistEntry == null ? 0 : lowerHistEntry.mForegroundUsageTimeInMs,
+            upperHistEntry.mForegroundUsageTimeInMs,
+            ratio);
+        final double backgroundUsageTimeInMs = interpolate(
+            lowerHistEntry == null ? 0 : lowerHistEntry.mBackgroundUsageTimeInMs,
+            upperHistEntry.mBackgroundUsageTimeInMs,
+            ratio);
+        final double batteryLevel =
+            lowerHistEntry == null
+                ? upperHistEntry.mBatteryLevel
+                : interpolate(
+                    lowerHistEntry.mBatteryLevel,
+                    upperHistEntry.mBatteryLevel,
+                    ratio);
+        return new BatteryHistEntry(
+            upperHistEntry,
+            /*bootTimestamp=*/ upperHistEntry.mBootTimestamp
+                - (upperTimestamp - slotTimestamp),
+            /*timestamp=*/ slotTimestamp,
+            totalPower,
+            consumePower,
+            Math.round(foregroundUsageTimeInMs),
+            Math.round(backgroundUsageTimeInMs),
+            (int) Math.round(batteryLevel));
+    }
+
+    private static double interpolate(double v1, double v2, double ratio) {
+        return v1 + ratio * (v2 - v1);
+    }
 }
diff --git a/tests/robotests/src/com/android/settings/fuelgauge/BatteryHistEntryTest.java b/tests/robotests/src/com/android/settings/fuelgauge/BatteryHistEntryTest.java
index b127cca..ca3109c 100644
--- a/tests/robotests/src/com/android/settings/fuelgauge/BatteryHistEntryTest.java
+++ b/tests/robotests/src/com/android/settings/fuelgauge/BatteryHistEntryTest.java
@@ -87,50 +87,15 @@
 
     @Test
     public void testConstructor_cursor_returnsExpectedResult() {
-        final MatrixCursor cursor = new MatrixCursor(
-            new String[] {
-                BatteryHistEntry.KEY_UID,
-                BatteryHistEntry.KEY_USER_ID,
-                BatteryHistEntry.KEY_APP_LABEL,
-                BatteryHistEntry.KEY_PACKAGE_NAME,
-                BatteryHistEntry.KEY_IS_HIDDEN,
-                BatteryHistEntry.KEY_BOOT_TIMESTAMP,
-                BatteryHistEntry.KEY_TIMESTAMP,
-                BatteryHistEntry.KEY_ZONE_ID,
-                BatteryHistEntry.KEY_TOTAL_POWER,
-                BatteryHistEntry.KEY_CONSUME_POWER,
-                BatteryHistEntry.KEY_PERCENT_OF_TOTAL,
-                BatteryHistEntry.KEY_FOREGROUND_USAGE_TIME,
-                BatteryHistEntry.KEY_BACKGROUND_USAGE_TIME,
-                BatteryHistEntry.KEY_DRAIN_TYPE,
-                BatteryHistEntry.KEY_CONSUMER_TYPE,
-                BatteryHistEntry.KEY_BATTERY_LEVEL,
-                BatteryHistEntry.KEY_BATTERY_STATUS,
-                BatteryHistEntry.KEY_BATTERY_HEALTH});
-        cursor.addRow(
-            new Object[] {
-                Long.valueOf(1001),
-                Long.valueOf(UserHandle.getUserId(1001)),
-                "Settings",
-                "com.google.android.settings.battery",
-                Integer.valueOf(1),
-                Long.valueOf(101l),
-                Long.valueOf(10001L),
-                TimeZone.getDefault().getID(),
-                Double.valueOf(5.1),
-                Double.valueOf(1.1),
-                Double.valueOf(0.3),
-                Long.valueOf(1234L),
-                Long.valueOf(5689L),
-                Integer.valueOf(3),
-                Integer.valueOf(ConvertUtils.CONSUMER_TYPE_SYSTEM_BATTERY),
-                Integer.valueOf(12),
-                Integer.valueOf(BatteryManager.BATTERY_STATUS_FULL),
-                Integer.valueOf(BatteryManager.BATTERY_HEALTH_COLD)});
-        cursor.moveToFirst();
-
         assertBatteryHistEntry(
-            new BatteryHistEntry(cursor),
+            createBatteryHistEntry(
+                /*bootTimestamp=*/ 101L,
+                /*timestamp=*/ 10001L,
+                /*totalPower=*/ 5.1,
+                /*consumePower=*/ 1.1,
+                /*foregroundUsageTimeInMs=*/ 1234L,
+                /*backgroundUsageTimeInMs=*/ 5689L,
+                /*batteryLevel=*/ 12),
             /*drainType=*/ 3,
             /*percentOfTotal=*/ 0.3);
     }
@@ -195,6 +160,82 @@
             .isFalse();
     }
 
+    @Test
+    public void testInterpolate_returnExpectedResult() {
+        final long slotTimestamp = 200L;
+        final long upperTimestamp = 300L;
+        final long lowerTimestamp = 100L;
+        final double ratio = 0.5;
+        final BatteryHistEntry lowerHistEntry = createBatteryHistEntry(
+            /*bootTimestamp=*/ 1000L,
+            lowerTimestamp,
+            /*totalPower=*/ 50,
+            /*consumePower=*/ 10,
+            /*foregroundUsageTimeInMs=*/ 100,
+            /*backgroundUsageTimeInMs=*/ 200,
+            /*batteryLevel=*/ 90);
+        final BatteryHistEntry upperHistEntry = createBatteryHistEntry(
+            /*bootTimestamp=*/ 1200L,
+            upperTimestamp,
+            /*totalPower=*/ 80,
+            /*consumePower=*/ 20,
+            /*foregroundUsageTimeInMs=*/ 200,
+            /*backgroundUsageTimeInMs=*/ 300,
+            /*batteryLevel=*/ 80);
+
+        final BatteryHistEntry newEntry =
+            BatteryHistEntry.interpolate(
+                slotTimestamp,
+                upperTimestamp,
+                ratio,
+                lowerHistEntry,
+                upperHistEntry);
+
+        assertBatteryHistEntry(
+            newEntry, 3, upperHistEntry.mPercentOfTotal,
+            /*bootTimestamp=*/ 1200 - 100,
+            /*timestamp=*/ slotTimestamp,
+            /*totalPower=*/ 50 + 0.5 * (80 - 50),
+            /*consumePower=*/ 10 + 0.5 * (20 - 10),
+            /*foregroundUsageTimeInMs=*/ Math.round(100 + 0.5 * (200 - 100)),
+            /*backgroundUsageTimeInMs=*/ Math.round(200 + 0.5 * (300 - 200)),
+            /*batteryLevel=*/ (int) Math.round(90 + 0.5 * (80 - 90)));
+    }
+
+    @Test
+    public void testInterpolate_withoutLowerEntryData_returnExpectedResult() {
+        final long slotTimestamp = 200L;
+        final long upperTimestamp = 300L;
+        final long lowerTimestamp = 100L;
+        final double ratio = 0.5;
+        final BatteryHistEntry upperHistEntry = createBatteryHistEntry(
+            /*bootTimestamp=*/ 1200L,
+            upperTimestamp,
+            /*totalPower=*/ 80,
+            /*consumePower=*/ 20,
+            /*foregroundUsageTimeInMs=*/ 200,
+            /*backgroundUsageTimeInMs=*/ 300,
+            /*batteryLevel=*/ 80);
+
+        final BatteryHistEntry newEntry =
+            BatteryHistEntry.interpolate(
+                slotTimestamp,
+                upperTimestamp,
+                ratio,
+                /*lowerHistEntry=*/ null,
+                upperHistEntry);
+
+        assertBatteryHistEntry(
+            newEntry, 3, upperHistEntry.mPercentOfTotal,
+            /*bootTimestamp=*/ 1200 - 100,
+            /*timestamp=*/ slotTimestamp,
+            /*totalPower=*/ 0.5 * 80,
+            /*consumePower=*/ 0.5 * 20,
+            /*foregroundUsageTimeInMs=*/ Math.round(0.5 * 200),
+            /*backgroundUsageTimeInMs=*/ Math.round(0.5 * 300),
+            /*batteryLevel=*/ upperHistEntry.mBatteryLevel);
+    }
+
     private static BatteryHistEntry createEntry(int consumerType) {
         return new BatteryHistEntry(getContentValuesWithType(consumerType));
     }
@@ -207,7 +248,29 @@
     }
 
     private void assertBatteryHistEntry(
-        BatteryHistEntry entry, int drainType, double percentOfTotal) {
+            BatteryHistEntry entry, int drainType, double percentOfTotal) {
+        assertBatteryHistEntry(
+            entry, drainType, percentOfTotal,
+            /*bootTimestamp=*/ 101L,
+            /*timestamp=*/ 10001L,
+            /*totalPower=*/ 5.1,
+            /*consumePower=*/ 1.1,
+            /*foregroundUsageTimeInMs=*/ 1234L,
+            /*backgroundUsageTimeInMs=*/ 5689L,
+            /*batteryLevel=*/ 12);
+    }
+
+    private void assertBatteryHistEntry(
+            BatteryHistEntry entry,
+            int drainType,
+            double percentOfTotal,
+            long bootTimestamp,
+            long timestamp,
+            double totalPower,
+            double consumePower,
+            long foregroundUsageTimeInMs,
+            long backgroundUsageTimeInMs,
+            int batteryLevel) {
         assertThat(entry.isValidEntry()).isTrue();
         assertThat(entry.mUid).isEqualTo(1001);
         assertThat(entry.mUserId).isEqualTo(UserHandle.getUserId(1001));
@@ -215,21 +278,73 @@
         assertThat(entry.mPackageName)
             .isEqualTo("com.google.android.settings.battery");
         assertThat(entry.mIsHidden).isTrue();
-        assertThat(entry.mBootTimestamp).isEqualTo(101L);
-        assertThat(entry.mTimestamp).isEqualTo(10001L);
+        assertThat(entry.mBootTimestamp).isEqualTo(bootTimestamp);
+        assertThat(entry.mTimestamp).isEqualTo(timestamp);
         assertThat(entry.mZoneId).isEqualTo(TimeZone.getDefault().getID());
-        assertThat(entry.mTotalPower).isEqualTo(5.1);
-        assertThat(entry.mConsumePower).isEqualTo(1.1);
+        assertThat(entry.mTotalPower).isEqualTo(totalPower);
+        assertThat(entry.mConsumePower).isEqualTo(consumePower);
         assertThat(entry.mPercentOfTotal).isEqualTo(percentOfTotal);
-        assertThat(entry.mForegroundUsageTimeInMs).isEqualTo(1234L);
-        assertThat(entry.mBackgroundUsageTimeInMs).isEqualTo(5689L);
+        assertThat(entry.mForegroundUsageTimeInMs).isEqualTo(foregroundUsageTimeInMs);
+        assertThat(entry.mBackgroundUsageTimeInMs).isEqualTo(backgroundUsageTimeInMs);
         assertThat(entry.mDrainType).isEqualTo(drainType);
         assertThat(entry.mConsumerType)
             .isEqualTo(ConvertUtils.CONSUMER_TYPE_SYSTEM_BATTERY);
-        assertThat(entry.mBatteryLevel).isEqualTo(12);
+        assertThat(entry.mBatteryLevel).isEqualTo(batteryLevel);
         assertThat(entry.mBatteryStatus)
             .isEqualTo(BatteryManager.BATTERY_STATUS_FULL);
         assertThat(entry.mBatteryHealth)
             .isEqualTo(BatteryManager.BATTERY_HEALTH_COLD);
     }
+
+    private BatteryHistEntry createBatteryHistEntry(
+            long bootTimestamp,
+            long timestamp,
+            double totalPower,
+            double consumePower,
+            long foregroundUsageTimeInMs,
+            long backgroundUsageTimeInMs,
+            int batteryLevel) {
+        final MatrixCursor cursor = new MatrixCursor(
+            new String[] {
+                BatteryHistEntry.KEY_UID,
+                BatteryHistEntry.KEY_USER_ID,
+                BatteryHistEntry.KEY_APP_LABEL,
+                BatteryHistEntry.KEY_PACKAGE_NAME,
+                BatteryHistEntry.KEY_IS_HIDDEN,
+                BatteryHistEntry.KEY_BOOT_TIMESTAMP,
+                BatteryHistEntry.KEY_TIMESTAMP,
+                BatteryHistEntry.KEY_ZONE_ID,
+                BatteryHistEntry.KEY_TOTAL_POWER,
+                BatteryHistEntry.KEY_CONSUME_POWER,
+                BatteryHistEntry.KEY_PERCENT_OF_TOTAL,
+                BatteryHistEntry.KEY_FOREGROUND_USAGE_TIME,
+                BatteryHistEntry.KEY_BACKGROUND_USAGE_TIME,
+                BatteryHistEntry.KEY_DRAIN_TYPE,
+                BatteryHistEntry.KEY_CONSUMER_TYPE,
+                BatteryHistEntry.KEY_BATTERY_LEVEL,
+                BatteryHistEntry.KEY_BATTERY_STATUS,
+                BatteryHistEntry.KEY_BATTERY_HEALTH});
+        cursor.addRow(
+            new Object[] {
+                Long.valueOf(1001),
+                Long.valueOf(UserHandle.getUserId(1001)),
+                "Settings",
+                "com.google.android.settings.battery",
+                Integer.valueOf(1),
+                Long.valueOf(bootTimestamp),
+                Long.valueOf(timestamp),
+                TimeZone.getDefault().getID(),
+                Double.valueOf(totalPower),
+                Double.valueOf(consumePower),
+                Double.valueOf(0.3),
+                Long.valueOf(foregroundUsageTimeInMs),
+                Long.valueOf(backgroundUsageTimeInMs),
+                Integer.valueOf(3),
+                Integer.valueOf(ConvertUtils.CONSUMER_TYPE_SYSTEM_BATTERY),
+                Integer.valueOf(batteryLevel),
+                Integer.valueOf(BatteryManager.BATTERY_STATUS_FULL),
+                Integer.valueOf(BatteryManager.BATTERY_HEALTH_COLD)});
+        cursor.moveToFirst();
+        return new BatteryHistEntry(cursor);
+    }
 }