Flub/watch mvbox only (#3028)

* Make set_config() look a bit nicer

* Add OnlyFetchMvbox option

* Add test for the config

* Add option to only watch mvbox

This is supposed to support having a server-side rule which moves
emails to the mvbox already.  The new option makes sure the mvbox is
wathched and also makes sure no messages are feched from folders other
than the mvbox and the spam folder if enabled.  It does not interact
with the other settings.

* Fixup ignore conditions

* Cleanup some bits

* Watch the mvbox when `WatchMvboxOnly` is set

* Rename back to only_fetch_mvbox (flub said it's OK for him)

* typo

* clippy, more typos

Co-authored-by: Hocuri <hocuri@gmx.de>

src/config.rs

@@ -74,6 +74,13 @@ pub enum Config {
     #[strum(props(default = "0"))]
     SentboxMove, // If `MvboxMove` is true, this config is ignored. Currently only used in tests.
 
+    /// Watch for new messages in the "Mvbox" (aka DeltaChat folder) only.
+    ///
+    /// This will not entirely disable other folders, e.g. the spam folder will also still
+    /// be watched for new messages.
+    #[strum(props(default = "0"))]
+    OnlyFetchMvbox,
+
     #[strum(props(default = "0"))] // also change ShowEmails.default() on changes
     ShowEmails,
 
@@ -225,6 +232,11 @@ impl Context {
         Ok(self.get_config_int(key).await? != 0)
     }
 
+    pub(crate) async fn should_watch_mvbox(&self) -> Result<bool> {
+        Ok(self.get_config_bool(Config::MvboxMove).await?
+            || self.get_config_bool(Config::OnlyFetchMvbox).await?)
+    }
+
     /// Gets configured "delete_server_after" value.
     ///
     /// `None` means never delete the message, `Some(0)` means delete
@@ -281,31 +293,25 @@ impl Context {
                     }
                 }
                 self.emit_event(EventType::SelfavatarChanged);
-                Ok(())
             }
             Config::DeleteDeviceAfter => {
-                let ret = self
-                    .sql
-                    .set_raw_config(key, value)
-                    .await
-                    .map_err(Into::into);
+                let ret = self.sql.set_raw_config(key, value).await;
                 // Force chatlist reload to delete old messages immediately.
                 self.emit_event(EventType::MsgsChanged {
                     msg_id: MsgId::new(0),
                     chat_id: ChatId::new(0),
                 });
-                ret
+                ret?
             }
             Config::Displayname => {
                 let value = value.map(improve_single_line_input);
                 self.sql.set_raw_config(key, value.as_deref()).await?;
-                Ok(())
             }
             _ => {
                 self.sql.set_raw_config(key, value).await?;
-                Ok(())
             }
         }
+        Ok(())
     }
 
     pub async fn set_config_bool(&self, key: Config, value: bool) -> Result<()> {

src/configure.rs

@@ -443,7 +443,7 @@ async fn configure(ctx: &Context, param: &mut LoginParam) -> Result<()> {
 
     progress!(ctx, 900);
 
-    let create_mvbox = ctx.get_config_bool(Config::MvboxMove).await?;
+    let create_mvbox = ctx.should_watch_mvbox().await?;
 
     imap.configure_folders(ctx, create_mvbox).await?;
 

src/context.rs

@@ -358,6 +358,7 @@ impl Context {
         let sentbox_watch = self.get_config_int(Config::SentboxWatch).await?;
         let mvbox_move = self.get_config_int(Config::MvboxMove).await?;
         let sentbox_move = self.get_config_int(Config::SentboxMove).await?;
+        let only_fetch_mvbox = self.get_config_int(Config::OnlyFetchMvbox).await?;
         let folders_configured = self
             .sql
             .get_raw_config_int("folders_configured")
@@ -422,6 +423,7 @@ impl Context {
         res.insert("sentbox_watch", sentbox_watch.to_string());
         res.insert("mvbox_move", mvbox_move.to_string());
         res.insert("sentbox_move", sentbox_move.to_string());
+        res.insert("only_fetch_mvbox", only_fetch_mvbox.to_string());
         res.insert("folders_configured", folders_configured.to_string());
         res.insert("configured_sentbox_folder", configured_sentbox_folder);
         res.insert("configured_mvbox_folder", configured_mvbox_folder);

src/imap.rs

@@ -664,6 +664,11 @@ impl Imap {
         folder: &str,
         fetch_existing_msgs: bool,
     ) -> Result<bool> {
+        if should_ignore_folder(context, folder).await? {
+            info!(context, "Not fetching from {}", folder);
+            return Ok(false);
+        }
+
         let new_emails = self.select_with_uidvalidity(context, folder).await?;
 
         if !new_emails && !fetch_existing_msgs {
@@ -1636,7 +1641,11 @@ async fn spam_target_folder(
         }
     }
 
-    if needs_move_to_mvbox(context, headers).await? {
+    if needs_move_to_mvbox(context, headers).await?
+        // We don't want to move the message to the inbox or sentbox where we wouldn't
+        // fetch it again:
+        || context.get_config_bool(Config::OnlyFetchMvbox).await?
+    {
         Ok(Some(Config::ConfiguredMvboxFolder))
     } else if needs_move_to_sentbox(context, folder, headers).await? {
         Ok(Some(Config::ConfiguredSentboxFolder))
@@ -2118,6 +2127,21 @@ pub async fn get_config_last_seen_uid(context: &Context, folder: &str) -> Result
     }
 }
 
+/// Whether to ignore fetching messages from a folder.
+///
+/// This caters for the [`Config::OnlyFetchMvbox`] setting which means mails from folders
+/// not explicitly watched should not be fetched.
+async fn should_ignore_folder(context: &Context, folder: &str) -> Result<bool> {
+    if !context.get_config_bool(Config::OnlyFetchMvbox).await? {
+        return Ok(false);
+    }
+    if context.is_sentbox(folder).await? {
+        // Still respect the SentboxWatch setting.
+        return Ok(!context.get_config_bool(Config::SentboxWatch).await?);
+    }
+    Ok(!(context.is_mvbox(folder).await? || context.is_spam_folder(folder).await?))
+}
+
 /// Builds a list of sequence/uid sets. The returned sets have each no more than around 1000
 /// characters because according to <https://tools.ietf.org/html/rfc2683#section-3.2.1.5>
 /// command lines should not be much more than 1000 chars (servers should allow at least 8000 chars)

src/imap/idle.rs

@@ -157,7 +157,6 @@ impl Imap {
                     // in anything.  If so, we behave as if IDLE had data but
                     // will have already fetched the messages so perform_*_fetch
                     // will not find any new.
-
                     match self.fetch_new_messages(context, &watch_folder, false).await {
                         Ok(res) => {
                             info!(context, "fetch_new_messages returned {:?}", res);

src/imap/scan_folders.rs

@@ -103,20 +103,22 @@ impl Imap {
     }
 }
 
+pub(crate) async fn get_watched_folder_configs(context: &Context) -> Result<Vec<Config>> {
+    let mut res = vec![Config::ConfiguredInboxFolder];
+    if context.get_config_bool(Config::SentboxWatch).await? {
+        res.push(Config::ConfiguredSentboxFolder);
+    }
+    if context.should_watch_mvbox().await? {
+        res.push(Config::ConfiguredMvboxFolder);
+    }
+    Ok(res)
+}
+
 pub(crate) async fn get_watched_folders(context: &Context) -> Result<Vec<String>> {
     let mut res = Vec::new();
-    if let Some(inbox_folder) = context.get_config(Config::ConfiguredInboxFolder).await? {
-        res.push(inbox_folder);
-    }
-    let folder_watched_configured = &[
-        (Config::SentboxWatch, Config::ConfiguredSentboxFolder),
-        (Config::MvboxMove, Config::ConfiguredMvboxFolder),
-    ];
-    for (watched, configured) in folder_watched_configured {
-        if context.get_config_bool(*watched).await? {
-            if let Some(folder) = context.get_config(*configured).await? {
-                res.push(folder);
-            }
+    for folder_config in get_watched_folder_configs(context).await? {
+        if let Some(folder) = context.get_config(folder_config).await? {
+            res.push(folder);
         }
     }
     Ok(res)

src/scheduler.rs

@@ -378,7 +378,7 @@ impl Scheduler {
             }))
         };
 
-        if ctx.get_config_bool(Config::MvboxMove).await? {
+        if ctx.should_watch_mvbox().await? {
             let ctx = ctx.clone();
             mvbox_handle = Some(task::spawn(async move {
                 simple_imap_loop(

src/scheduler/connectivity.rs

@@ -5,6 +5,7 @@ use async_std::sync::{Mutex, RwLockReadGuard};
 
 use crate::dc_tools::time;
 use crate::events::EventType;
+use crate::imap::scan_folders::get_watched_folder_configs;
 use crate::quota::{
     QUOTA_ERROR_THRESHOLD_PERCENTAGE, QUOTA_MAX_AGE_SECONDS, QUOTA_WARN_THRESHOLD_PERCENTAGE,
 };
@@ -362,17 +363,14 @@ impl Context {
                 [
                     (
                         Config::ConfiguredInboxFolder,
-                        None,
                         inbox.state.connectivity.clone(),
                     ),
                     (
                         Config::ConfiguredMvboxFolder,
-                        Some(Config::MvboxMove),
                         mvbox.state.connectivity.clone(),
                     ),
                     (
                         Config::ConfiguredSentboxFolder,
-                        Some(Config::SentboxWatch),
                         sentbox.state.connectivity.clone(),
                     ),
                 ],
@@ -391,20 +389,12 @@ impl Context {
         //                               - "Sent": Connected
         // =============================================================================================
 
+        let watched_folders = get_watched_folder_configs(self).await?;
         ret += &format!("<h3>{}</h3><ul>", stock_str::incoming_messages(self).await);
-        for (folder, watch, state) in &folders_states {
-            let w = if let Some(watch_config) = *watch {
-                self.get_config(watch_config)
-                    .await
-                    .ok_or_log(self)
-                    .flatten()
-                    == Some("1".to_string())
-            } else {
-                true
-            };
-
+        for (folder, state) in &folders_states {
             let mut folder_added = false;
-            if w {
+
+            if watched_folders.contains(folder) {
                 let f = self.get_config(*folder).await.ok_or_log(self).flatten();
 
                 if let Some(foldername) = f {