Added on-demand configuration for stream vs download

2 files changed, 78 insertions, 1 deletions

diff --git a/core/src/main/java/de/danoeh/antennapod/core/preferences/UsageStatistics.java b/core/src/main/java/de/danoeh/antennapod/core/preferences/UsageStatistics.java
new file mode 100644
index 000000000..a5b00b08c
--- /dev/null
+++ b/core/src/main/java/de/danoeh/antennapod/core/preferences/UsageStatistics.java
@@ -0,0 +1,73 @@
+package de.danoeh.antennapod.core.preferences;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import androidx.annotation.NonNull;
+
+import java.util.Calendar;
+
+/**
+ * Collects statistics about the app usage. The statistics are used to allow on-demand configuration:
+ * "Looks like you stream a lot. Do you want to toggle the 'Prefer streaming' setting?".
+ * The data is only stored locally on the device. It is NOT used for analytics/tracking.
+ * A private instance of this class must first be instantiated via
+ * init() or otherwise every public method will throw an Exception
+ * when called.
+ */
+public class UsageStatistics {
+    private UsageStatistics() {
+
+    }
+
+    private static final String PREF_DB_NAME = "UsageStatistics";
+    private static final float MOVING_AVERAGE_WEIGHT = 0.8f;
+    private static final float MOVING_AVERAGE_BIAS_THRESHOLD = 0.1f;
+    private static final long ASK_AGAIN_LATER_DELAY = 1000 * 3600 * 24 * 10; // 10 days
+    private static final String SUFFIX_HIDDEN_UNTIL = "_hiddenUntil";
+    private static SharedPreferences prefs;
+
+    public static final StatsAction ACTION_STREAM = new StatsAction("downloadVsStream", 0);
+    public static final StatsAction ACTION_DOWNLOAD = new StatsAction("downloadVsStream", 1);
+
+    /**
+     * Sets up the UsageStatistics class.
+     *
+     * @throws IllegalArgumentException if context is null
+     */
+    public static void init(@NonNull Context context) {
+        prefs = context.getSharedPreferences(PREF_DB_NAME, Context.MODE_PRIVATE);
+    }
+
+    public static void logAction(StatsAction action) {
+        int numExecutions = prefs.getInt(action.type + action.value, 0);
+        float movingAverage = prefs.getFloat(action.type, 0.5f);
+        prefs.edit()
+                .putInt(action.type + action.value, numExecutions + 1)
+                .putFloat(action.type, MOVING_AVERAGE_WEIGHT * movingAverage
+                        + (1 - MOVING_AVERAGE_WEIGHT) * action.value)
+                .apply();
+    }
+
+    public static boolean hasSignificantBiasTo(StatsAction action) {
+        final float movingAverage = prefs.getFloat(action.type, 0.5f);
+        final long askAfter = prefs.getLong(action.type + SUFFIX_HIDDEN_UNTIL, 0);
+        return Math.abs(action.value - movingAverage) < MOVING_AVERAGE_BIAS_THRESHOLD
+                && Calendar.getInstance().getTimeInMillis() > askAfter;
+    }
+
+    public static void askAgainLater(StatsAction action) {
+        prefs.edit().putLong(action.type + SUFFIX_HIDDEN_UNTIL,
+                Calendar.getInstance().getTimeInMillis() + ASK_AGAIN_LATER_DELAY)
+                .apply();
+    }
+
+    public static final class StatsAction {
+        public final String type;
+        public final int value;
+
+        public StatsAction(String type, int value) {
+            this.type = type;
+            this.value = value;
+        }
+    }
+}
diff --git a/core/src/main/java/de/danoeh/antennapod/core/preferences/UserPreferences.java b/core/src/main/java/de/danoeh/antennapod/core/preferences/UserPreferences.java
index cb5a405c0..14900ac20 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/preferences/UserPreferences.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/preferences/UserPreferences.java
@@ -996,10 +996,14 @@ public class UserPreferences {
         return prefs.getBoolean(PREF_TIME_RESPECTS_SPEED, false);
     }
 
-    public static boolean streamOverDownload() {
+    public static boolean isStreamOverDownload() {
         return prefs.getBoolean(PREF_STREAM_OVER_DOWNLOAD, false);
     }
 
+    public static void setStreamOverDownload(boolean stream) {
+        prefs.edit().putBoolean(PREF_STREAM_OVER_DOWNLOAD, stream).apply();
+    }
+
     /**
      * Returns if the queue is in keep sorted mode.
      *