add the android implementation

packages/firestore/android/src/main/java/io/capawesome/capacitorjs/plugins/firebase/firestore/FirebaseFirestoreHelper.java

@@ -10,6 +10,7 @@
 import io.capawesome.capacitorjs.plugins.firebase.firestore.classes.constraints.QueryLimitConstraint;
 import io.capawesome.capacitorjs.plugins.firebase.firestore.classes.constraints.QueryOrderByConstraint;
 import io.capawesome.capacitorjs.plugins.firebase.firestore.classes.constraints.QueryStartAtConstraint;
+import io.capawesome.capacitorjs.plugins.firebase.firestore.classes.fields.FirestoreField;
 import io.capawesome.capacitorjs.plugins.firebase.firestore.interfaces.QueryNonFilterConstraint;
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -45,7 +46,7 @@ public static JSObject createJSObjectFromMap(@Nullable Map<String, Object> map)
             } else if (value instanceof Map) {
                 value = createJSObjectFromMap((Map<String, Object>) value);
             }
-            object.put(key, value);
+            object.put(key, parseObject(value));
         }
         return object;
     }
@@ -54,7 +55,7 @@ public static Object createObjectFromJSValue(Object value) throws JSONException
         if (value.toString().equals("null")) {
             return null;
         } else if (value instanceof JSONObject) {
-            return createHashMapFromJSONObject((JSONObject) value);
+            return createObjectFromJSONObject((JSONObject) value);
         } else if (value instanceof JSONArray) {
             return createArrayListFromJSONArray((JSONArray) value);
         } else {
@@ -108,7 +109,7 @@ private static ArrayList<Object> createArrayListFromJSONArray(JSONArray array) t
         for (int x = 0; x < array.length(); x++) {
             Object value = array.get(x);
             if (value instanceof JSONObject) {
-                value = createHashMapFromJSONObject((JSONObject) value);
+                value = createObjectFromJSONObject((JSONObject) value);
             } else if (value instanceof JSONArray) {
                 value = createArrayListFromJSONArray((JSONArray) value);
             }
@@ -123,7 +124,7 @@ private static JSArray createJSArrayFromArrayList(ArrayList arrayList) {
             if (value instanceof Map) {
                 value = createJSObjectFromMap((Map<String, Object>) value);
             }
-            array.put(value);
+            array.put(parseObject(value));
         }
         return array;
     }
@@ -134,4 +135,24 @@ public static JSObject createSnapshotMetadataResult(DocumentSnapshot snapshot) {
         obj.put("hasPendingWrites", snapshot.getMetadata().hasPendingWrites());
         return obj;
     }
+
+    private static Object createObjectFromJSONObject(@NonNull JSONObject object) throws JSONException {
+        if (FirestoreField.isFirestoreField(object)) {
+            FirestoreField field = FirestoreField.fromJSONObject(object);
+            return field.getField();
+        }
+
+        return createHashMapFromJSONObject(object);
+    }
+
+    /**
+     * Parse an object to return it's firestore field value. Else return the same object.
+     */
+    private static Object parseObject(@NonNull Object object) {
+        try {
+            return FirestoreField.fromObject(object).getJSObject();
+        } catch (Exception e) {}
+
+        return object;
+    }
 }

packages/firestore/android/src/main/java/io/capawesome/capacitorjs/plugins/firebase/firestore/classes/fields/FieldValue.java

@@ -0,0 +1,33 @@
+package io.capawesome.capacitorjs.plugins.firebase.firestore.classes.fields;
+
+import androidx.annotation.NonNull;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import io.capawesome.capacitorjs.plugins.firebase.firestore.enums.FieldValueMethod;
+
+public class FieldValue {
+
+    @NonNull
+    FieldValueMethod method;
+
+    public FieldValue(@NonNull FieldValueMethod method) {
+        this.method = method;
+    }
+
+    public static FieldValue fromJSONObject(@NonNull JSONObject value) throws JSONException {
+        return new FieldValue(
+            FieldValueMethod.fromString(value.getString("method"))
+        );
+    }
+
+    public Object getField() {
+        switch (method) {
+            case CREATE_SERVER_TIMESTAMP:
+                return com.google.firebase.firestore.FieldValue.serverTimestamp();
+            default:
+                return null;
+        }
+    }
+}

packages/firestore/android/src/main/java/io/capawesome/capacitorjs/plugins/firebase/firestore/classes/fields/FirestoreField.java

@@ -0,0 +1,71 @@
+package io.capawesome.capacitorjs.plugins.firebase.firestore.classes.fields;
+
+import androidx.annotation.NonNull;
+
+import com.getcapacitor.JSObject;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import io.capawesome.capacitorjs.plugins.firebase.firestore.enums.FirestoreFieldType;
+
+public class FirestoreField {
+
+    @NonNull
+    private FirestoreFieldType type;
+
+    @NonNull
+    private JSONObject value;
+
+    private static final String FIRESTORE_FIELD_TYPE = "_capacitorFirestoreFieldType";
+    private static final String FIRESTORE_FIELD_VALUE = "_capacitorFirestoreFieldValue";
+
+    /**
+     * Is a JSONObject a serialized Firestore field
+     * @param firestoreFieldData
+     * @return
+     */
+    public static boolean isFirestoreField(JSONObject firestoreFieldData) {
+        if (!firestoreFieldData.has(FIRESTORE_FIELD_TYPE)) {
+            return false;
+        }
+        return true;
+    }
+
+    public FirestoreField(FirestoreFieldType type, JSONObject value) {
+        this.type = type;
+        this.value = value;
+    }
+
+    public static FirestoreField fromJSONObject(JSONObject data) throws JSONException {
+        FirestoreFieldType type = FirestoreFieldType.fromString((String) data.get(FIRESTORE_FIELD_TYPE));
+        JSONObject value = (JSONObject) data.get(FIRESTORE_FIELD_VALUE);
+        return new FirestoreField(type, value);
+    }
+
+    public static FirestoreField fromObject(Object object) throws IllegalArgumentException {
+        if (object instanceof com.google.firebase.Timestamp) {
+            Timestamp timestamp = Timestamp.fromFirestore((com.google.firebase.Timestamp) object);
+            return new FirestoreField(FirestoreFieldType.TIMESTAMP, timestamp.getValue());
+        }
+        throw new IllegalArgumentException("The provided object is not a firestore field");
+    }
+
+    public Object getField() throws JSONException {
+        switch(type) {
+            case FIELD_VALUE:
+                return FieldValue.fromJSONObject(value).getField();
+            case TIMESTAMP:
+                return Timestamp.fromJSONObject(value).getField();
+            default:
+                return null;
+        }
+    }
+
+    public JSObject getJSObject() throws JSONException {
+        JSObject object = new JSObject();
+        object.put(FIRESTORE_FIELD_TYPE, type.toString());
+        object.put(FIRESTORE_FIELD_VALUE, JSObject.fromJSONObject(value));
+        return object;
+    }
+}

packages/firestore/android/src/main/java/io/capawesome/capacitorjs/plugins/firebase/firestore/classes/fields/Timestamp.java

@@ -0,0 +1,51 @@
+package io.capawesome.capacitorjs.plugins.firebase.firestore.classes.fields;
+
+import androidx.annotation.NonNull;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+public class Timestamp {
+
+    @NonNull
+    long seconds;
+
+    @NonNull
+    int nanoseconds;
+
+    public Timestamp(@NonNull long seconds, @NonNull int nanoseconds) {
+        this.seconds = seconds;
+        this.nanoseconds = nanoseconds;
+    }
+
+    public static Timestamp fromJSONObject(@NonNull JSONObject value) throws JSONException {
+        return new Timestamp(
+            ((Number) value.get("seconds")).longValue(),
+            (int) value.get("nanoseconds")
+        );
+    }
+
+    public static Timestamp fromFirestore(@NonNull com.google.firebase.Timestamp timestamp) {
+        return new Timestamp(
+            timestamp.getSeconds(),
+            timestamp.getNanoseconds()
+        );
+    }
+
+    @NonNull
+    public JSONObject getValue() {
+        JSONObject value = new JSONObject();
+        try {
+            value.put("seconds", seconds);
+            value.put("nanoseconds", nanoseconds);
+        } catch (JSONException e) {}
+        return value;
+    }
+
+    public com.google.firebase.Timestamp getField() throws JSONException {
+        return new com.google.firebase.Timestamp(
+            seconds,
+            nanoseconds
+        );
+    }
+}

packages/firestore/android/src/main/java/io/capawesome/capacitorjs/plugins/firebase/firestore/enums/FieldValueMethod.java

@@ -0,0 +1,26 @@
+package io.capawesome.capacitorjs.plugins.firebase.firestore.enums;
+
+public enum FieldValueMethod {
+    CREATE_SERVER_TIMESTAMP("serverTimestamp");
+
+    private String value;
+
+    private FieldValueMethod(String value) {
+        this.value = value;
+    }
+
+    private String getValue() {
+        return value;
+    }
+
+    @Override
+    public String toString() {
+        return this.getValue();
+    }
+
+    public static FieldValueMethod fromString(String value) {
+        for(FieldValueMethod v : values())
+            if(v.getValue().equalsIgnoreCase(value)) return v;
+        throw new IllegalArgumentException();
+    }
+}

packages/firestore/android/src/main/java/io/capawesome/capacitorjs/plugins/firebase/firestore/enums/FirestoreFieldType.java

@@ -0,0 +1,27 @@
+package io.capawesome.capacitorjs.plugins.firebase.firestore.enums;
+
+public enum FirestoreFieldType {
+    FIELD_VALUE("fieldvalue"),
+    TIMESTAMP("timestamp");
+
+    private String value;
+
+    private FirestoreFieldType(String value) {
+        this.value = value;
+    }
+
+    private String getValue() {
+        return value;
+    }
+
+    @Override
+    public String toString() {
+        return this.getValue();
+    }
+
+    public static FirestoreFieldType fromString(String value) {
+        for(FirestoreFieldType v : values())
+            if(v.getValue().equalsIgnoreCase(value)) return v;
+        throw new IllegalArgumentException();
+    }
+}