Added the update_item function

src/calendar/cached_calendar.rs

@@ -36,19 +36,41 @@ impl CachedCalendar {
         self.mock_behaviour = mock_behaviour;
     }
 
-    /// Add an item
-    async fn regular_add_item(&mut self, item: Item) -> Result<SyncStatus, Box<dyn Error>> {
-        // TODO: here (and in the remote version, display an errror in case we overwrite something?)
+
+    #[cfg(feature = "local_calendar_mocks_remote_calendars")]
+    async fn add_item_maybe_mocked(&mut self, item: Item) -> Result<SyncStatus, Box<dyn Error>> {
+        self.mock_behaviour.as_ref().map_or(Ok(()), |b| b.lock().unwrap().can_add_item())?;
+
+        if self.mock_behaviour.is_some() {
+            self.add_or_update_item_force_synced(item).await
+        } else {
+            self.regular_add_or_update_item(item).await
+        }
+    }
+
+    #[cfg(feature = "local_calendar_mocks_remote_calendars")]
+    async fn update_item_maybe_mocked(&mut self, item: Item) -> Result<SyncStatus, Box<dyn Error>> {
+        self.mock_behaviour.as_ref().map_or(Ok(()), |b| b.lock().unwrap().can_update_item())?;
+
+        if self.mock_behaviour.is_some() {
+            self.add_or_update_item_force_synced(item).await
+        } else {
+            self.regular_add_or_update_item(item).await
+        }
+    }
+
+    /// Add or update an item
+    async fn regular_add_or_update_item(&mut self, item: Item) -> Result<SyncStatus, Box<dyn Error>> {
         let ss_clone = item.sync_status().clone();
-        log::debug!("Adding an item with {:?}", ss_clone);
+        log::debug!("Adding or updating an item with {:?}", ss_clone);
         self.items.insert(item.id().clone(), item);
         Ok(ss_clone)
     }
 
-    /// Add an item, but force a "synced" SyncStatus. This is the typical behaviour on a remote calendar
+    /// Add or update an item, but force a "synced" SyncStatus. This is the normal behaviour that would happen on a server
     #[cfg(feature = "local_calendar_mocks_remote_calendars")]
-    async fn add_item_force_synced(&mut self, mut item: Item) -> Result<SyncStatus, Box<dyn Error>> {
-        log::debug!("Adding an item, but forces a synced SyncStatus");
+    async fn add_or_update_item_force_synced(&mut self, mut item: Item) -> Result<SyncStatus, Box<dyn Error>> {
+        log::debug!("Adding or updating an item, but forces a synced SyncStatus");
         match item.sync_status() {
             SyncStatus::Synced(_) => (),
             _ => item.set_sync_status(SyncStatus::random_synced()),
@@ -108,20 +130,26 @@ impl BaseCalendar for CachedCalendar {
         self.supported_components
     }
 
-    #[cfg(not(feature = "local_calendar_mocks_remote_calendars"))]
     async fn add_item(&mut self, item: Item) -> Result<SyncStatus, Box<dyn Error>> {
-        self.regular_add_item(item).await
+        if self.items.contains_key(item.id()) {
+            return Err(format!("Item {:?} cannot be added, it exists already", item.id()).into());
     }
-    #[cfg(feature = "local_calendar_mocks_remote_calendars")]
-    async fn add_item(&mut self, item: Item) -> Result<SyncStatus, Box<dyn Error>> {
+        #[cfg(not(feature = "local_calendar_mocks_remote_calendars"))]
+        return self.regular_add_or_update_item(item).await;
+
         #[cfg(feature = "local_calendar_mocks_remote_calendars")]
-        self.mock_behaviour.as_ref().map_or(Ok(()), |b| b.lock().unwrap().can_add_item())?;
+        return self.add_item_maybe_mocked(item).await;
+    }
 
-        if self.mock_behaviour.is_some() {
-            self.add_item_force_synced(item).await
-        } else {
-            self.regular_add_item(item).await
+    async fn update_item(&mut self, item: Item) -> Result<SyncStatus, Box<dyn Error>> {
+        if self.items.contains_key(item.id()) == false {
+            return Err(format!("Item {:?} cannot be updated, it does not already exist", item.id()).into());
         }
+        #[cfg(not(feature = "local_calendar_mocks_remote_calendars"))]
+        return self.regular_add_or_update_item(item).await;
+
+        #[cfg(feature = "local_calendar_mocks_remote_calendars")]
+        return self.update_item_maybe_mocked(item).await;
     }
 }
 

src/calendar/remote_calendar.rs

@@ -48,7 +48,6 @@ impl BaseCalendar for RemoteCalendar {
         self.supported_components
     }
 
-    /// Add an item into this calendar
     async fn add_item(&mut self, item: Item) -> Result<SyncStatus, Box<dyn Error>> {
         let ical_text = crate::ical::build_from(&item)?;
 
@@ -72,6 +71,36 @@ impl BaseCalendar for RemoteCalendar {
             }
         }
     }
+
+    async fn update_item(&mut self, item: Item) -> Result<SyncStatus, Box<dyn Error>> {
+        let old_etag = match item.sync_status() {
+            SyncStatus::NotSynced => return Err("Cannot update an item that has not been synced already".into()),
+            SyncStatus::Synced(_) => return Err("Cannot update an item that has not changed".into()),
+            SyncStatus::LocallyModified(etag) => etag,
+            SyncStatus::LocallyDeleted(etag) => etag,
+        };
+        let ical_text = crate::ical::build_from(&item)?;
+
+        let request = reqwest::Client::new()
+            .put(item.id().as_url().clone())
+            .header("If-Match", old_etag.as_str())
+            .header(CONTENT_TYPE, "text/calendar")
+            .header(CONTENT_LENGTH, ical_text.len())
+            .basic_auth(self.resource.username(), Some(self.resource.password()))
+            .body(ical_text)
+            .send()
+            .await?;
+
+        let reply_hdrs = request.headers();
+        match reply_hdrs.get("ETag") {
+            None => Err(format!("No ETag in these response headers: {:?} (request was {:?})", reply_hdrs, item.id()).into()),
+            Some(etag) => {
+                let vtag_str = etag.to_str()?;
+                let vtag = VersionTag::from(String::from(vtag_str));
+                Ok(SyncStatus::Synced(vtag))
+            }
+        }
+    }
 }
 
 #[async_trait]

src/item.rs

@@ -190,6 +190,11 @@ impl From<String> for VersionTag {
 }
 
 impl VersionTag {
+    /// Get the inner version tag (usually a WebDAV `ctag` or `etag`)
+    pub fn as_str(&self) -> &str {
+        &self.tag
+    }
+
     /// Generate a random VesionTag
     #[cfg(feature = "local_calendar_mocks_remote_calendars")]
     pub fn random() -> Self {

src/mock_behaviour.rs

@@ -17,6 +17,7 @@ pub struct MockBehaviour {
 
     // From the BaseCalendar trait
     pub add_item_behaviour: (u32, u32),
+    pub update_item_behaviour: (u32, u32),
 
     // From the DavCalendar trait
     pub get_item_version_tags_behaviour: (u32, u32),
@@ -37,6 +38,7 @@ impl MockBehaviour {
             //get_calendar_behaviour: (0, n_fails),
             create_calendar_behaviour: (0, n_fails),
             add_item_behaviour: (0, n_fails),
+            update_item_behaviour: (0, n_fails),
             get_item_version_tags_behaviour: (0, n_fails),
             get_item_by_id_behaviour: (0, n_fails),
             delete_item_behaviour: (0, n_fails),
@@ -73,6 +75,10 @@ impl MockBehaviour {
         if self.is_suspended { return Ok(()) }
         decrement(&mut self.add_item_behaviour, "add_item")
     }
+    pub fn can_update_item(&mut self) -> Result<(), Box<dyn Error>> {
+        if self.is_suspended { return Ok(()) }
+        decrement(&mut self.update_item_behaviour, "update_item")
+    }
     pub fn can_get_item_version_tags(&mut self) -> Result<(), Box<dyn Error>> {
         if self.is_suspended { return Ok(()) }
         decrement(&mut self.get_item_version_tags_behaviour, "get_item_version_tags")

src/traits.rs

@@ -42,6 +42,10 @@ pub trait BaseCalendar {
     /// For remote calendars, the sync status is updated by the server
     async fn add_item(&mut self, item: Item) -> Result<SyncStatus, Box<dyn Error>>;
 
+    /// Update an item that already exists in this calendar and returns its new `SyncStatus`
+    /// This replaces a given item at a given URL
+    async fn update_item(&mut self, item: Item) -> Result<SyncStatus, Box<dyn Error>>;
+
     /// Returns whether this calDAV calendar supports to-do items
     fn supports_todo(&self) -> bool {
         self.supported_components().contains(crate::calendar::SupportedComponents::TODO)