1 files changed, 75 insertions, 0 deletions
diff --git a/src/main/java/com/keuin/kbackupfabric/util/BackupNameSuggestionProvider.java b/src/main/java/com/keuin/kbackupfabric/util/BackupNameSuggestionProvider.java
new file mode 100644
index 0000000..08e12b2
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/util/BackupNameSuggestionProvider.java
@@ -0,0 +1,75 @@
+package com.keuin.kbackupfabric.util;
+
+import com.mojang.brigadier.suggestion.SuggestionProvider;
+import com.mojang.brigadier.suggestion.Suggestions;
+import com.mojang.brigadier.suggestion.SuggestionsBuilder;
+import net.minecraft.server.command.ServerCommandSource;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Locale;
+import java.util.concurrent.CompletableFuture;
+
+public class BackupNameSuggestionProvider {
+    private static final List<String> candidateCacheList = new ArrayList<>();
+    private static final Object syncSetDirectory = new Object();
+    private static final Object syncUpdate = new Object();
+    private static final long CACHE_TTL = 10000;
+    private static String backupSaveDirectory;
+    private static long cacheUpdateTime = 0;
+
+    public static void setBackupSaveDirectory(String backupSaveDirectory) {
+        synchronized (syncSetDirectory) {
+            BackupNameSuggestionProvider.backupSaveDirectory = backupSaveDirectory;
+        }
+        // Immediately perform a update
+        updateCandidateList();
+    }
+
+    public static void updateCandidateList() {
+        synchronized (syncUpdate) {
+            try {
+                File file = new File(backupSaveDirectory);
+                candidateCacheList.clear();
+                File[] files = file.listFiles();
+                if (files == null)
+                    return;
+                for (File f : files)
+                    candidateCacheList.add(BackupFilesystemUtil.getBackupName(f.getName()));
+                cacheUpdateTime = System.currentTimeMillis();
+            } catch (NullPointerException ignored) {
+            }
+        }
+    }
+
+//    private static void updateCandidateList(Collection<String> stringCollection) {
+//        candidateList.clear();
+//        candidateList.addAll(stringCollection);
+//    }
+
+    public static SuggestionProvider<ServerCommandSource> getSuggestionProvider() {
+        return (context, builder) -> getCompletableFuture(builder);
+    }
+
+    private static CompletableFuture<Suggestions> getCompletableFuture(SuggestionsBuilder builder) {
+        if (isCacheExpired())
+            updateCandidateList();
+        String remaining = builder.getRemaining().toLowerCase(Locale.ROOT);
+
+        if (candidateCacheList.isEmpty()) { // If the list is empty then return no suggestions
+            return Suggestions.empty(); // No suggestions
+        }
+
+        for (String string : candidateCacheList) { // Iterate through the supplied list
+            if (string.toLowerCase(Locale.ROOT).startsWith(remaining)) {
+                builder.suggest(string); // Add every single entry to suggestions list.
+            }
+        }
+        return builder.buildFuture(); // Create the CompletableFuture containing all the suggestions
+    }
+
+    private static boolean isCacheExpired() {
+        return System.currentTimeMillis() - cacheUpdateTime > CACHE_TTL;
+    }
+}