1 files changed, 47 insertions, 1 deletions
diff --git a/crates/vcs_data/src/data/local/latest_info.rs b/crates/vcs_data/src/data/local/latest_info.rs
index e8fa641..e4f45b1 100644
--- a/crates/vcs_data/src/data/local/latest_info.rs
+++ b/crates/vcs_data/src/data/local/latest_info.rs
@@ -1,5 +1,8 @@
+use std::time::{SystemTime, UNIX_EPOCH};
+
 use cfg_file::ConfigFile;
-use serde::{Deserialize, Serialize};
+use serde::{Deserialize, Deserializer, Serialize, Serializer};
+use tokio::time::Instant;
 
 use crate::{
     constants::CLIENT_FILE_LATEST_INFO,
@@ -23,6 +26,13 @@ pub struct LatestInfo {
     /// Reference sheet data, indicating what files I can get from the reference sheet
     pub ref_sheet_content: SheetData,
 
+    /// Update instant
+    #[serde(
+        serialize_with = "serialize_instant",
+        deserialize_with = "deserialize_instant"
+    )]
+    pub update_instant: Option<Instant>,
+
     // Members
     /// All member information of the vault, allowing me to contact them more conveniently
     pub vault_members: Vec<Member>,
@@ -33,3 +43,39 @@ pub struct SheetInfo {
     pub sheet_name: SheetName,
     pub holder_name: Option<MemberId>,
 }
+
+fn serialize_instant<S>(instant: &Option<Instant>, serializer: S) -> Result<S::Ok, S::Error>
+where
+    S: Serializer,
+{
+    let system_now = SystemTime::now();
+    let instant_now = Instant::now();
+    let duration_since_epoch = instant
+        .as_ref()
+        .and_then(|i| i.checked_duration_since(instant_now))
+        .map(|d| system_now.checked_add(d))
+        .unwrap_or(Some(system_now))
+        .and_then(|t| t.duration_since(UNIX_EPOCH).ok())
+        .unwrap_or_else(|| SystemTime::now().duration_since(UNIX_EPOCH).unwrap());
+
+    serializer.serialize_u64(duration_since_epoch.as_millis() as u64)
+}
+
+fn deserialize_instant<'de, D>(deserializer: D) -> Result<Option<Instant>, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    let millis = u64::deserialize(deserializer)?;
+    let duration_since_epoch = std::time::Duration::from_millis(millis);
+    let system_time = UNIX_EPOCH + duration_since_epoch;
+    let now_system = SystemTime::now();
+    let now_instant = Instant::now();
+
+    if let Ok(elapsed) = system_time.elapsed() {
+        Ok(Some(now_instant - elapsed))
+    } else if let Ok(duration_until) = system_time.duration_since(now_system) {
+        Ok(Some(now_instant + duration_until))
+    } else {
+        Ok(Some(now_instant))
+    }
+}