Add custom deserializer for EmojiCategory and Emoji class, to fix parsing error

app/src/main/java/awais/instagrabber/customviews/emoji/Emoji.java

@@ -2,7 +2,6 @@ package awais.instagrabber.customviews.emoji;
 
 import androidx.annotation.NonNull;
 
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Objects;
 
@@ -12,10 +11,12 @@ public class Emoji {
     private final List<Emoji> variants;
     private GoogleCompatEmojiDrawable drawable;
 
-    public Emoji(final String unicode, final String name) {
+    public Emoji(final String unicode,
+                 final String name,
+                 final List<Emoji> variants) {
         this.unicode = unicode;
         this.name = name;
-        this.variants = new LinkedList<>();
+        this.variants = variants;
     }
 
     public String getUnicode() {

app/src/main/java/awais/instagrabber/customviews/emoji/EmojiCategory.java

@@ -1,8 +1,8 @@
 package awais.instagrabber.customviews.emoji;
 
 import androidx.annotation.DrawableRes;
+import androidx.annotation.NonNull;
 
-import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Objects;
 
@@ -10,16 +10,13 @@ import awais.instagrabber.R;
 
 public class EmojiCategory {
     private final EmojiCategoryType type;
-    private final Map<String, Emoji> emojis = new LinkedHashMap<>();
+    private final Map<String, Emoji> emojis;
     @DrawableRes
     private int drawableRes;
 
-    public EmojiCategory(final EmojiCategoryType type) {
+    public EmojiCategory(final EmojiCategoryType type, final Map<String, Emoji> emojis) {
         this.type = type;
-    }
-
-    public EmojiCategory() {
-        this.type = null;
+        this.emojis = emojis;
     }
 
     public EmojiCategoryType getType() {
@@ -78,8 +75,12 @@ public class EmojiCategory {
         return Objects.hash(type);
     }
 
+    @NonNull
     @Override
     public String toString() {
-        return "EmojiCategory {TYPE=" + type + ", EMOJIS=" + emojis + "}";
+        return "EmojiCategory{" +
+                "type=" + type +
+                ", emojis=" + emojis +
+                '}';
     }
 }

app/src/main/java/awais/instagrabber/utils/emoji/EmojiCategoryDeserializer.java

@@ -0,0 +1,52 @@
+package awais.instagrabber.utils.emoji;
+
+import android.util.Log;
+
+import com.google.gson.JsonDeserializationContext;
+import com.google.gson.JsonDeserializer;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParseException;
+
+import java.lang.reflect.Type;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import awais.instagrabber.customviews.emoji.Emoji;
+import awais.instagrabber.customviews.emoji.EmojiCategory;
+import awais.instagrabber.customviews.emoji.EmojiCategoryType;
+
+public class EmojiCategoryDeserializer implements JsonDeserializer<EmojiCategory> {
+    private static final String TAG = EmojiCategoryDeserializer.class.getSimpleName();
+
+    @Override
+    public EmojiCategory deserialize(final JsonElement json,
+                                     final Type typeOfT,
+                                     final JsonDeserializationContext context) throws JsonParseException {
+        final JsonObject jsonObject = json.getAsJsonObject();
+        final JsonElement typeElement = jsonObject.get("type");
+        final JsonObject emojisObject = jsonObject.getAsJsonObject("emojis");
+        if (typeElement == null || emojisObject == null) {
+            throw new JsonParseException("Invalid json for EmojiCategory");
+        }
+        final String typeString = typeElement.getAsString();
+        EmojiCategoryType type;
+        try {
+            type = EmojiCategoryType.valueOf(typeString);
+        } catch (IllegalArgumentException e) {
+            Log.e(TAG, "deserialize: ", e);
+            type = EmojiCategoryType.OTHERS;
+        }
+        final Map<String, Emoji> emojis = new LinkedHashMap<>();
+        for (final Map.Entry<String, JsonElement> emojiObjectEntry : emojisObject.entrySet()) {
+            final String unicode = emojiObjectEntry.getKey();
+            final JsonElement value = emojiObjectEntry.getValue();
+            if (unicode == null || value == null) {
+                throw new JsonParseException("Invalid json for EmojiCategory");
+            }
+            final Emoji emoji = context.deserialize(value, Emoji.class);
+            emojis.put(unicode, emoji);
+        }
+        return new EmojiCategory(type, emojis);
+    }
+}

app/src/main/java/awais/instagrabber/utils/emoji/EmojiDeserializer.java

@@ -0,0 +1,44 @@
+package awais.instagrabber.utils.emoji;
+
+import com.google.gson.JsonArray;
+import com.google.gson.JsonDeserializationContext;
+import com.google.gson.JsonDeserializer;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParseException;
+
+import java.lang.reflect.Type;
+import java.util.LinkedList;
+import java.util.List;
+
+import awais.instagrabber.customviews.emoji.Emoji;
+
+public class EmojiDeserializer implements JsonDeserializer<Emoji> {
+    @Override
+    public Emoji deserialize(final JsonElement json,
+                             final Type typeOfT,
+                             final JsonDeserializationContext context) throws JsonParseException {
+        final JsonObject jsonObject = json.getAsJsonObject();
+        final JsonElement unicodeElement = jsonObject.get("unicode");
+        final JsonElement nameElement = jsonObject.get("name");
+        if (unicodeElement == null || nameElement == null) {
+            throw new JsonParseException("Invalid json for Emoji class");
+        }
+        final JsonElement variantsElement = jsonObject.get("variants");
+        final List<Emoji> variants = new LinkedList<>();
+        if (variantsElement != null) {
+            final JsonArray variantsArray = variantsElement.getAsJsonArray();
+            for (final JsonElement variantElement : variantsArray) {
+                final Emoji variant = context.deserialize(variantElement, Emoji.class);
+                if (variant != null) {
+                    variants.add(variant);
+                }
+            }
+        }
+        return new Emoji(
+                unicodeElement.getAsString(),
+                nameElement.getAsString(),
+                variants
+        );
+    }
+}

app/src/main/java/awais/instagrabber/utils/emoji/EmojiParser.java

@@ -3,10 +3,11 @@ package awais.instagrabber.utils.emoji;
 import android.util.Log;
 
 import com.google.common.collect.ImmutableList;
+import com.google.gson.FieldNamingPolicy;
 import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
 import com.google.gson.reflect.TypeToken;
 
-import java.io.IOException;
 import java.io.InputStream;
 import java.lang.reflect.Type;
 import java.util.Collection;
@@ -52,7 +53,12 @@ public final class EmojiParser {
         }
         try (final InputStream in = classLoader.getResourceAsStream(file)) {
             final String json = NetworkUtils.readFromInputStream(in);
-            final Gson gson = new Gson();
+            final Gson gson = new GsonBuilder()
+                    .setFieldNamingPolicy(FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES)
+                    .registerTypeAdapter(EmojiCategory.class, new EmojiCategoryDeserializer())
+                    .registerTypeAdapter(Emoji.class, new EmojiDeserializer())
+                    .setLenient()
+                    .create();
             final Type type = new TypeToken<Map<EmojiCategoryType, EmojiCategory>>() {}.getType();
             categoryMap = gson.fromJson(json, type);
             // Log.d(TAG, "EmojiParser: " + categoryMap);