2 files changed, 65 insertions, 0 deletions
diff --git a/src/main/java/com/keuin/kbackupfabric/autobackup/AutoBackupScheduler.java b/src/main/java/com/keuin/kbackupfabric/autobackup/AutoBackupScheduler.java
new file mode 100644
index 0000000..c35a35d
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/autobackup/AutoBackupScheduler.java
@@ -0,0 +1,50 @@
+package com.keuin.kbackupfabric.autobackup;
+
+import java.util.Optional;
+import java.util.Timer;
+import java.util.TimerTask;
+import java.util.logging.Logger;
+
+public class AutoBackupScheduler {
+
+    private Timer timer = null;
+    private final Logger logger = Logger.getLogger(AutoBackupScheduler.class.getName());
+    private boolean skipIfNoPlayerLoggedIn;
+    private final PlayerActivityTracker playerActivityTracker;
+
+    public AutoBackupScheduler(int intervalSeconds, boolean skipIfNoPlayerLoggedIn, PlayerActivityTracker playerActivityTracker) {
+        this.skipIfNoPlayerLoggedIn = skipIfNoPlayerLoggedIn;
+        this.playerActivityTracker = playerActivityTracker;
+        if (intervalSeconds > 0)
+            setInterval(intervalSeconds);
+    }
+
+    public synchronized void setInterval(int intervalSeconds) {
+        Optional.ofNullable(timer).ifPresent(Timer::cancel);
+        Timer newTimer = new Timer("AutoBackupTimer");
+        newTimer.schedule(new TimerTask() {
+            @Override
+            public void run() {
+                toggleBackup();
+            }
+        }, 0L, intervalSeconds * 1000L);
+        timer = newTimer;
+    }
+
+    public void setSkipIfNoPlayerLoggedIn(boolean skipIfNoPlayerLoggedIn) {
+        this.skipIfNoPlayerLoggedIn = skipIfNoPlayerLoggedIn;
+    }
+
+    public synchronized void stop() {
+        timer.cancel();
+        timer = null;
+    }
+
+    private void toggleBackup() {
+        if (playerActivityTracker.getCheckpoint() || !skipIfNoPlayerLoggedIn) {
+            logger.info("Interval backup event is triggered.");
+            // TODO: perform a backup
+        }
+    }
+
+}
diff --git a/src/main/java/com/keuin/kbackupfabric/autobackup/PlayerActivityTracker.java b/src/main/java/com/keuin/kbackupfabric/autobackup/PlayerActivityTracker.java
new file mode 100644
index 0000000..ef2b85e
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/autobackup/PlayerActivityTracker.java
@@ -0,0 +1,15 @@
+package com.keuin.kbackupfabric.autobackup;
+
+public interface PlayerActivityTracker {
+    /**
+     * Update the checkpoint, return accumulated result.
+     *
+     * @return if there is at least one player logged in since last checkpoint.
+     */
+    boolean getCheckpoint();
+
+    /**
+     * Mark dirty. In the next checkpoint, the backup will be performed.
+     */
+    void setCheckpoint();
+}