Items include a last modified (DTSTAMP) date

Cargo.lock

@@ -73,6 +73,20 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "chrono"
+version = "0.4.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "670ad68c9088c2a963aaa298cb369688cf3f9465ce5e2d4ca10e6e0098a1ce73"
+dependencies = [
+ "libc",
+ "num-integer",
+ "num-traits",
+ "serde",
+ "time",
+ "winapi",
+]
+
 [[package]]
 name = "core-foundation"
 version = "0.9.1"
@@ -437,6 +451,7 @@ version = "0.1.0"
 dependencies = [
  "async-trait",
  "bitflags",
+ "chrono",
  "env_logger",
  "ical",
  "ics",
@@ -478,6 +493,25 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "num-integer"
+version = "0.1.44"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d2cc698a63b549a70bc047073d2949cce27cd1c7b0a4a862d08a8031bc2801db"
+dependencies = [
+ "autocfg",
+ "num-traits",
+]
+
+[[package]]
+name = "num-traits"
+version = "0.2.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a64b1ec5cda2586e284722486d802acf1f7dbdc623e2bfc57e65ca1cd099290"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "num_cpus"
 version = "1.13.0"
@@ -886,6 +920,16 @@ dependencies = [
  "once_cell",
 ]
 
+[[package]]
+name = "time"
+version = "0.1.43"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ca8a50ef2360fbd1eeb0ecd46795a87a19024eb4b53c5dc916ca1fd95fe62438"
+dependencies = [
+ "libc",
+ "winapi",
+]
+
 [[package]]
 name = "tinyvec"
 version = "1.1.1"

Cargo.toml

@@ -25,3 +25,4 @@ uuid = { version = "0.8", features = ["v4"] }
 sanitize-filename = "0.3"
 ical = "0.7"
 ics = "0.5"
+chrono = { version = "0.4", features = ["serde"] }

src/event.rs

@@ -1,6 +1,7 @@
 //! Calendar events
 
 use serde::{Deserialize, Serialize};
+use chrono::{DateTime, Utc};
 
 use crate::item::ItemId;
 use crate::item::SyncStatus;
@@ -31,6 +32,10 @@ impl Event {
         &self.name
     }
 
+    pub fn last_modified(&self) -> &DateTime<Utc> {
+        unimplemented!()
+    }
+
     pub fn sync_status(&self) -> &SyncStatus {
         &self.sync_status
     }

src/ical/builder.rs

@@ -2,7 +2,8 @@
 
 use std::error::Error;
 
-use ics::properties::{Comment, Status, Summary};
+use chrono::{DateTime, Utc};
+use ics::properties::{LastModified, Status, Summary};
 use ics::{ICalendar, ToDo};
 
 use crate::item::Item;
@@ -14,9 +15,14 @@ fn ical_product_id() -> String {
 
 /// Create an iCal item from a `crate::item::Item`
 pub fn build_from(item: &Item) -> Result<String, Box<dyn Error>> {
-    let mut todo = ToDo::new(item.uid(), "20181021T190000");
+    let s_last_modified = format_date_time(item.last_modified());
-    todo.push(Summary::new("Take pictures of squirrels (with ÜTF-8 chars)"));
+
-    todo.push(Comment::new("That's really something I'd like to do one day"));
+    let mut todo = ToDo::new(
+        item.uid(),
+        s_last_modified.clone(),
+    );
+    todo.push(LastModified::new(s_last_modified));
+    todo.push(Summary::new(item.name()));
 
     match item {
         Item::Task(t) => {
@@ -34,6 +40,9 @@ pub fn build_from(item: &Item) -> Result<String, Box<dyn Error>> {
     Ok(calendar.to_string())
 }
 
+fn format_date_time(dt: &DateTime<Utc>) -> String {
+    dt.format("%Y%m%dT%H%M%S").to_string()
+}
 
 
 #[cfg(test)]
@@ -44,20 +53,21 @@ mod tests {
     #[test]
     fn test_ical_from_task() {
         let cal_id = "http://my.calend.ar/id".parse().unwrap();
+        let now = format_date_time(&Utc::now());
+
         let task = Item::Task(Task::new(
-            String::from("This is a task"), true, &cal_id
+            String::from("This is a task with ÜTF-8 characters"), true, &cal_id
         ));
         let expected_ical = format!("BEGIN:VCALENDAR\r\n\
             VERSION:2.0\r\n\
             PRODID:-//{}//{}//EN\r\n\
             BEGIN:VTODO\r\n\
             UID:{}\r\n\
-            DTSTAMP:20181021T190000\r\n\
+            DTSTAMP:{}\r\n\
-            SUMMARY:Take pictures of squirrels (with ÜTF-8 chars)\r\n\
+            SUMMARY:This is a task with ÜTF-8 characters\r\n\
-            COMMENT:That's really something I'd like to do one day\r\n\
             STATUS:COMPLETED\r\n\
             END:VTODO\r\n\
-            END:VCALENDAR\r\n", ORG_NAME, PRODUCT_NAME, task.uid());
+            END:VCALENDAR\r\n", ORG_NAME, PRODUCT_NAME, task.uid(), now);
 
         let ical = build_from(&task);
         assert_eq!(ical.unwrap(), expected_ical);

src/ical/parser.rs

@@ -3,6 +3,7 @@
 use std::error::Error;
 
 use ical::parser::ical::component::{IcalCalendar, IcalEvent, IcalTodo};
+use chrono::{DateTime, TimeZone, Utc};
 
 use crate::Item;
 use crate::item::SyncStatus;
@@ -31,6 +32,7 @@ pub fn parse(content: &str, item_id: ItemId, sync_status: SyncStatus) -> Result<
             let mut name = None;
             let mut uid = None;
             let mut completed = false;
+            let mut last_modified = None;
             for prop in &todo.properties {
                 if prop.name == "SUMMARY" {
                     name = prop.value.clone();
@@ -48,6 +50,19 @@ pub fn parse(content: &str, item_id: ItemId, sync_status: SyncStatus) -> Result<
                 if prop.name == "UID" {
                     uid = prop.value.clone();
                 }
+                if prop.name == "DTSTAMP" {
+                    // this property specifies the date and time that the information associated with
+                    // the calendar component was last revised in the calendar store.
+                    last_modified = prop.value.as_ref()
+                        .and_then(|s| {
+                            parse_date_time(s)
+                            .map_err(|err| {
+                                log::warn!("Invalid DTSTAMP: {}", s);
+                                err
+                            })
+                            .ok()
+                        })
+                }
             }
             let name = match name {
                 Some(name) => name,
@@ -57,8 +72,12 @@ pub fn parse(content: &str, item_id: ItemId, sync_status: SyncStatus) -> Result<
                 Some(uid) => uid,
                 None => return Err(format!("Missing UID for item {}", item_id).into()),
             };
+            let last_modified = match last_modified {
+                Some(dt) => dt,
+                None => return Err(format!("Missing DTSTAMP for item {}, but this is required by RFC5545", item_id).into()),
+            };
 
-            Item::Task(Task::new_with_parameters(name, completed, uid, item_id, sync_status))
+            Item::Task(Task::new_with_parameters(name, completed, uid, item_id, sync_status, last_modified))
         },
     };
 
@@ -71,6 +90,12 @@ pub fn parse(content: &str, item_id: ItemId, sync_status: SyncStatus) -> Result<
     Ok(item)
 }
 
+fn parse_date_time(dt: &str) -> Result<DateTime<Utc>, chrono::format::ParseError> {
+    Utc.datetime_from_str(dt, "%Y%m%dT%H%M%S")
+}
+
+
+
 enum CurrentType<'a> {
     Event(&'a IcalEvent),
     Todo(&'a IcalTodo),
@@ -171,6 +196,7 @@ END:VCALENDAR
         assert_eq!(task.uid(), "0633de27-8c32-42be-bcb8-63bc879c6185@some-domain.com");
         assert_eq!(task.completed(), false);
         assert_eq!(task.sync_status(), &sync_status);
+        assert_eq!(task.last_modified(), &Utc.ymd(2021, 03, 21).and_hms(0, 16, 0));
     }
 
     #[test]

src/item.rs

@@ -5,6 +5,7 @@ use std::str::FromStr;
 
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
 use url::Url;
+use chrono::{DateTime, Utc};
 
 use crate::resource::Resource;
 use crate::calendar::CalendarId;
@@ -39,6 +40,13 @@ impl Item {
         }
     }
 
+    pub fn last_modified(&self) -> &DateTime<Utc> {
+        match self {
+            Item::Event(e) => e.last_modified(),
+            Item::Task(t) => t.last_modified(),
+        }
+    }
+
     pub fn sync_status(&self) -> &SyncStatus {
         match self {
             Item::Event(e) => e.sync_status(),

src/task.rs

@@ -1,5 +1,6 @@
 use serde::{Deserialize, Serialize};
 use uuid::Uuid;
+use chrono::{DateTime, Utc};
 
 use crate::item::ItemId;
 use crate::item::SyncStatus;
@@ -17,6 +18,8 @@ pub struct Task {
 
     /// The sync status of this item
     sync_status: SyncStatus,
+    /// The last time this item was modified
+    last_modified: DateTime<Utc>,
 
     /// The display name of the task
     name: String,
@@ -31,17 +34,19 @@ impl Task {
         let new_item_id = ItemId::random(parent_calendar_id);
         let new_sync_status = SyncStatus::NotSynced;
         let new_uid = Uuid::new_v4().to_hyphenated().to_string();
-        Self::new_with_parameters(name, completed, new_uid, new_item_id, new_sync_status)
+        let new_last_modified = Utc::now();
+        Self::new_with_parameters(name, completed, new_uid, new_item_id, new_sync_status, new_last_modified)
     }
 
     /// Create a new Task instance, that may be synced already
-    pub fn new_with_parameters(name: String, completed: bool, uid: String, id: ItemId, sync_status: SyncStatus) -> Self {
+    pub fn new_with_parameters(name: String, completed: bool, uid: String, id: ItemId, sync_status: SyncStatus, last_modified: DateTime<Utc>) -> Self {
         Self {
             id,
             uid,
             name,
             sync_status,
             completed,
+            last_modified,
         }
     }
 
@@ -50,6 +55,7 @@ impl Task {
     pub fn name(&self) -> &str      { &self.name        }
     pub fn completed(&self) -> bool { self.completed    }
     pub fn sync_status(&self) -> &SyncStatus     { &self.sync_status  }
+    pub fn last_modified(&self) -> &DateTime<Utc> { &self.last_modified }
 
     pub fn has_same_observable_content_as(&self, other: &Task) -> bool {
            self.id == other.id
@@ -77,10 +83,16 @@ impl Task {
         }
     }
 
+    fn update_last_modified(&mut self) {
+        self.last_modified = Utc::now();
+    }
+
+
     /// Rename a task.
     /// This updates its "last modified" field
     pub fn set_name(&mut self, new_name: String) {
         self.update_sync_status();
+        self.update_last_modified();
         self.name = new_name;
     }
     #[cfg(feature = "local_calendar_mocks_remote_calendars")]
@@ -93,6 +105,7 @@ impl Task {
     /// Set the completion status
     pub fn set_completed(&mut self, new_value: bool) {
         self.update_sync_status();
+        self.update_last_modified();
         self.completed = new_value;
     }
     #[cfg(feature = "local_calendar_mocks_remote_calendars")]