reduce size of Pair class

lib/models/isar/exchange_cache/pair.dart

@@ -1,10 +1,19 @@
 import 'package:isar/isar.dart';
-import 'package:stackwallet/utilities/logger.dart';
 
 part 'pair.g.dart';
 
+// embedded enum // no not modify
+enum SupportedRateType { fixed, estimated, both }
+
 @collection
 class Pair {
+  Pair({
+    required this.exchangeName,
+    required this.from,
+    required this.to,
+    required this.rateType,
+  });
+
   Id? id;
 
   @Index()
@@ -15,54 +24,19 @@ class Pair {
     CompositeIndex("to"),
   ])
   final String from;
-  final String fromNetwork;
 
   final String to;
-  final String toNetwork;
 
-  final bool fixedRate;
-  final bool floatingRate;
-
-  Pair({
-    required this.exchangeName,
-    required this.from,
-    required this.fromNetwork,
-    required this.to,
-    required this.toNetwork,
-    required this.fixedRate,
-    required this.floatingRate,
-  });
-
-  factory Pair.fromMap(
-    Map<String, dynamic> map, {
-    required String exchangeName,
-  }) {
-    try {
-      return Pair(
-        exchangeName: exchangeName,
-        from: map["from"] as String,
-        fromNetwork: map["fromNetwork"] as String,
-        to: map["to"] as String,
-        toNetwork: map["toNetwork"] as String,
-        fixedRate: map["fixedRate"] as bool,
-        floatingRate: map["floatingRate"] as bool,
-      )..id = map["id"] as int?;
-    } catch (e, s) {
-      Logging.instance.log("Pair.fromMap(): $e\n$s", level: LogLevel.Error);
-      rethrow;
-    }
-  }
+  @enumerated
+  final SupportedRateType rateType;
 
   Map<String, dynamic> toMap() {
     return {
       "id": id,
       "exchangeName": exchangeName,
       "from": from,
-      "fromNetwork": fromNetwork,
       "to": to,
-      "toNetwork": toNetwork,
-      "fixedRate": fixedRate,
-      "floatingRate": floatingRate,
+      "rateType": rateType,
     };
   }
 
@@ -71,22 +45,15 @@ class Pair {
       other is Pair &&
       exchangeName == other.exchangeName &&
       from == other.from &&
-      fromNetwork == other.fromNetwork &&
       to == other.to &&
-      toNetwork == other.toNetwork &&
-      fixedRate == other.fixedRate &&
-      floatingRate == other.floatingRate;
+      rateType == other.rateType;
 
   @override
   int get hashCode => Object.hash(
-        id,
         exchangeName,
         from,
-        fromNetwork,
         to,
-        toNetwork,
-        fixedRate,
-        floatingRate,
+        rateType,
       );
 
   @override

lib/services/exchange/change_now/change_now_api.dart

@@ -843,10 +843,7 @@ class ChangeNowAPI {
               exchangeName: ChangeNowExchange.exchangeName,
               from: stringPair[0],
               to: stringPair[1],
-              fromNetwork: "",
-              toNetwork: "",
-              fixedRate: false,
-              floatingRate: true,
+              rateType: SupportedRateType.estimated,
             ),
           );
         } catch (_) {

lib/services/exchange/change_now/change_now_exchange.dart

@@ -104,11 +104,8 @@ class ChangeNowExchange extends Exchange {
           Pair(
             exchangeName: ChangeNowExchange.exchangeName,
             from: market.from,
-            fromNetwork: "",
             to: market.to,
-            toNetwork: "",
-            fixedRate: true,
-            floatingRate: false,
+            rateType: SupportedRateType.fixed,
           ),
         );
       }

lib/services/exchange/majestic_bank/majestic_bank_exchange.dart

@@ -139,11 +139,8 @@ class MajesticBankExchange extends Exchange {
       final pair = Pair(
         exchangeName: MajesticBankExchange.exchangeName,
         from: rate.fromCurrency,
-        fromNetwork: "",
         to: rate.toCurrency,
-        toNetwork: "",
-        fixedRate: true,
-        floatingRate: true,
+        rateType: SupportedRateType.both,
       );
       pairs.add(pair);
     }

lib/services/exchange/simpleswap/simpleswap_api.dart

@@ -274,11 +274,8 @@ class SimpleSwapAPI {
               Pair(
                 exchangeName: SimpleSwapExchange.exchangeName,
                 from: from,
-                fromNetwork: "",
                 to: to as String,
-                toNetwork: "",
-                fixedRate: args.item2,
-                floatingRate: !args.item2,
+                rateType: SupportedRateType.estimated,
               ),
             );
           }