feat: Provide letter-sound letters to other apps

#118

app/src/main/java/ai/elimu/content_provider/provider/LetterContentProvider.java

@@ -14,18 +14,20 @@
 import ai.elimu.content_provider.room.dao.LetterDao;
 import ai.elimu.content_provider.room.db.RoomDb;
 
-@Deprecated
 public class LetterContentProvider extends ContentProvider {
 
     private static final String AUTHORITY = BuildConfig.APPLICATION_ID + ".provider.letter_provider";
     private static final String TABLE_LETTERS = "letters";
     private static final int CODE_LETTERS = 1;
     private static final int CODE_LETTER_ID = 2;
+
+    private static final int CODE_LETTERS_BY_LETTER_SOUND_ID = 3;
     private static final UriMatcher MATCHER = new UriMatcher(UriMatcher.NO_MATCH);
 
     static {
         MATCHER.addURI(AUTHORITY, TABLE_LETTERS, CODE_LETTERS);
         MATCHER.addURI(AUTHORITY, TABLE_LETTERS + "/#", CODE_LETTER_ID);
+        MATCHER.addURI(AUTHORITY, TABLE_LETTERS + "/by-letter-sound-id/#", CODE_LETTERS_BY_LETTER_SOUND_ID);
     }
 
     @Override
@@ -64,6 +66,23 @@ public Cursor query(Uri uri, String[] projection, String selection, String[] sel
 
             cursor.setNotificationUri(context.getContentResolver(), uri);
 
+            return cursor;
+        } else if (code == CODE_LETTERS_BY_LETTER_SOUND_ID) {
+            // Extract the letter-sound correspondence ID from the URI
+            List<String> pathSegments = uri.getPathSegments();
+            Log.i(getClass().getName(), "pathSegments: " + pathSegments);
+            String letterSoundIdAsString = pathSegments.get(2);
+            Long letterSoundId = Long.valueOf(letterSoundIdAsString);
+            Log.i(getClass().getName(), "letterSoundId: " + letterSoundId);
+
+            final Cursor cursor;
+
+            // Get the Room Cursor
+            cursor = letterDao.loadAllByLetterSound(letterSoundId);
+            Log.i(getClass().getName(), "cursor: " + cursor);
+
+            cursor.setNotificationUri(context.getContentResolver(), uri);
+
             return cursor;
         } else if (code == CODE_LETTER_ID) {
             // Extract the Letter ID from the URI

app/src/main/java/ai/elimu/content_provider/room/dao/LetterDao.java

@@ -30,6 +30,9 @@ public interface LetterDao {
     @Query("SELECT * FROM Letter ORDER BY usageCount DESC")
     Cursor loadAllOrderedByUsageCount_Cursor();
 
+    @Query("SELECT * FROM Letter l WHERE l.id IN (SELECT letters_id FROM LetterSound_Letter WHERE LetterSound_id = :letterSoundId)")
+    Cursor loadAllByLetterSound(Long letterSoundId);
+
     @Update
     void update(Letter letter);
 

utils/src/main/java/ai/elimu/content_provider/utils/ContentProviderUtil.java

@@ -41,6 +41,7 @@ public class ContentProviderUtil {
      * If the student has already mastered one or more letters, those will be returned, plus one
      * additional letter to be mastered next.
      */
+    @Deprecated
     public static List<LetterGson> getAvailableLetterGsons(Context context, String contentProviderApplicationId, String analyticsApplicationId) {
         Log.i(ContentProviderUtil.class.getName(), "getAvailableLetterGsons");
 
@@ -64,8 +65,10 @@ public static List<LetterGson> getAvailableLetterGsons(Context context, String c
     }
 
     /**
-     * This method is only meant to be used for testing purposes during development.
+     * This method is only meant to be used for testing purposes during development. For production, 
+     * use {@link #getAvailableLetterGsons} instead.
      */
+    @Deprecated
     public static List<LetterGson> getAllLetterGsons(Context context, String contentProviderApplicationId) {
         Log.i(ContentProviderUtil.class.getName(), "getAllLetterGsons");
 
@@ -103,7 +106,8 @@ public static List<LetterGson> getAllLetterGsons(Context context, String content
     }
 
     /**
-     * This method is only meant to be used for testing purposes during development.
+     * This method is only meant to be used for testing purposes during development. For production, 
+     * use {@link #getAvailableLetterSoundGsons} instead.
      */
     public static List<LetterSoundGson> getAllLetterSoundGsons(Context context, String contentProviderApplicationId) {
         Log.i(ContentProviderUtil.class.getName(), "getAllLetterSoundGsons");
@@ -127,7 +131,7 @@ public static List<LetterSoundGson> getAllLetterSoundGsons(Context context, Stri
                     cursor.moveToNext();
 
                     // Convert from Room to Gson
-                    LetterSoundGson letterSoundGson = CursorToLetterSoundGsonConverter.getLetterSoundGson(cursor);
+                    LetterSoundGson letterSoundGson = CursorToLetterSoundGsonConverter.getLetterSoundGson(cursor, context, contentProviderApplicationId);
 
                     letterSoundGsons.add(letterSoundGson);
 
@@ -172,7 +176,8 @@ public static List<WordGson> getAvailableWordGsons(Context context, String conte
     }
 
     /**
-     * This method is only meant to be used for testing purposes during development.
+     * This method is only meant to be used for testing purposes during development. For production,
+     * use {@link #getAvailableWordGsons} instead.
      */
     public static List<WordGson> getAllWordGsons(Context context, String contentProviderApplicationId) {
         Log.i(ContentProviderUtil.class.getName(), "getAllWordGsons");

utils/src/main/java/ai/elimu/content_provider/utils/converter/CursorToLetterSoundGsonConverter.java

@@ -1,15 +1,21 @@
 package ai.elimu.content_provider.utils.converter;
 
+import android.content.Context;
 import android.database.Cursor;
+import android.net.Uri;
 import android.util.Log;
+import android.widget.Toast;
 
+import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.List;
 
+import ai.elimu.model.v2.gson.content.LetterGson;
 import ai.elimu.model.v2.gson.content.LetterSoundGson;
 
 public class CursorToLetterSoundGsonConverter {
 
-    public static LetterSoundGson getLetterSoundGson(Cursor cursor) {
+    public static LetterSoundGson getLetterSoundGson(Cursor cursor, Context context, String contentProviderApplicationId) {
         Log.i(CursorToLetterSoundGsonConverter.class.getName(), "getLetterSoundGson");
 
         Log.i(CursorToLetterSoundGsonConverter.class.getName(), "Arrays.toString(cursor.getColumnNames()): " + Arrays.toString(cursor.getColumnNames()));
@@ -26,11 +32,38 @@ public static LetterSoundGson getLetterSoundGson(Cursor cursor) {
         Integer usageCount = cursor.getInt(columnIndexUsageCount);
         Log.i(CursorToLetterSoundGsonConverter.class.getName(), "usageCount: " + usageCount);
 
+        List<LetterGson> letterGsons = null;
+        Uri lettersUri = Uri.parse("content://" + contentProviderApplicationId + ".provider.letter_provider/letters/by-letter-sound-id/" + id);
+        Log.i(CursorToLetterSoundGsonConverter.class.getName(), "lettersUri: " + lettersUri);
+        Cursor lettersCursor = context.getContentResolver().query(lettersUri, null, null, null, null);
+        if (lettersCursor == null) {
+            Log.e(CursorToLetterSoundGsonConverter.class.getName(), "lettersCursor == null");
+            Toast.makeText(context, "lettersCursor == null", Toast.LENGTH_LONG).show();
+        } else {
+            Log.i(CursorToLetterSoundGsonConverter.class.getName(), "lettersCursor.getCount(): " + lettersCursor.getCount());
+
+            letterGsons = new ArrayList<>();
+
+            boolean isLast = false;
+            while (!isLast) {
+                lettersCursor.moveToNext();
+
+                // Convert from Room to Gson
+                LetterGson letterGson = CursorToLetterGsonConverter.getLetterGson(lettersCursor);
+                letterGsons.add(letterGson);
+
+                isLast = lettersCursor.isLast();
+            }
+
+            lettersCursor.close();
+            Log.i(CursorToLetterSoundGsonConverter.class.getName(), "lettersCursor.isClosed(): " + lettersCursor.isClosed());
+        }
+
         LetterSoundGson letterSound = new LetterSoundGson();
         letterSound.setId(id);
         letterSound.setRevisionNumber(revisionNumber);
         letterSound.setUsageCount(usageCount);
-        // TODO: letterSound.setLetters(letters);
+        letterSound.setLetters(letterGsons);
         // TODO: letterSound.setSounds(sounds);
 
         return letterSound;