[mob][photos] Get unique random numbers + write method to get mathcing fileIDs from promptData

mobile/lib/services/magic_cache_service.dart

@@ -1,6 +1,7 @@
 import 'dart:math';
 
 import "package:logging/logging.dart";
+import "package:photos/services/machine_learning/semantic_search/semantic_search_service.dart";
 import "package:shared_preferences/shared_preferences.dart";
 
 const _promptsJson = {
@@ -48,7 +49,8 @@ class MagicCacheService {
   List<Map<String, Object>> getRandomPrompts() {
     final promptsJson = _promptsJson["prompts"];
     final randomPrompts = <Map<String, Object>>[];
-    final randomNumbers = _generateRandomNumbers(promptsJson!.length - 1, 4);
+    final randomNumbers =
+        _generateUniqueRandomNumbers(promptsJson!.length - 1, 4);
     for (int i = 0; i < randomNumbers.length; i++) {
       randomPrompts.add(promptsJson[randomNumbers[i]]);
     }
@@ -56,10 +58,25 @@ class MagicCacheService {
     return randomPrompts;
   }
 
-  List<int> _generateRandomNumbers(int max, int count) {
+  Future<List<int>> getMatchingFileIDsForPromptData(
+    Map<String, Object> promptData,
+  ) {
+    return SemanticSearchService.instance.getMatchingFileIDs(
+      promptData["prompt"] as String,
+      promptData["minimumScore"] as double,
+    );
+  }
+
+  ///Generates from 0 to max unique random numbers
+  List<int> _generateUniqueRandomNumbers(int max, int count) {
     final numbers = <int>[];
-    for (int i = 1; i <= count; i++) {
-      numbers.add(Random().nextInt(max + 1));
+    for (int i = 1; i <= count;) {
+      final randomNumber = Random().nextInt(max + 1);
+      if (numbers.contains(randomNumber)) {
+        continue;
+      }
+      numbers.add(randomNumber);
+      i++;
     }
     return numbers;
   }