From f811a9c8f46d3161457947cd3b534c577e187224 Mon Sep 17 00:00:00 2001
From: Jordan Petridis <jordanpetridis@protonmail.com>
Date: Wed, 18 Apr 2018 08:20:26 +0300
Subject: [PATCH] Feed: Split index_channel_items method.

---
 hammond-data/src/feed.rs | 92 ++++++++++++++++++++++++----------------
 1 file changed, 56 insertions(+), 36 deletions(-)

diff --git a/hammond-data/src/feed.rs b/hammond-data/src/feed.rs
index 078c79e..249076a 100644
--- a/hammond-data/src/feed.rs
+++ b/hammond-data/src/feed.rs
@@ -42,45 +42,19 @@ impl Feed {
 
     fn index_channel_items(self, pd: Podcast) -> Box<Future<Item = (), Error = DataError> + Send> {
         let stream = stream::iter_ok::<_, DataError>(self.channel.items_owned());
-        let insert = stream
-            .filter_map(move |item| {
-                glue(&item, pd.id())
-                    .map_err(|err| error!("Failed to parse an episode: {}", err))
-                    .ok()
-             })
-            .filter_map(|state| match state {
-                IndexState::NotChanged => None,
-                // Update individual rows, and filter them
-                IndexState::Update((ref ep, rowid)) => {
-                    ep.update(rowid)
-                        .map_err(|err| error!("{}", err))
-                        .map_err(|_| error!("Failed to index episode: {:?}.", ep.title()))
-                        .ok();
 
-                    None
-                },
-                IndexState::Index(s) => Some(s),
-            })
-            // only Index is left, collect them for batch index
-            .collect();
-
-        let idx = insert.map(|vec| {
-            if !vec.is_empty() {
-                info!("Indexing {} episodes.", vec.len());
-                if let Err(err) = dbqueries::index_new_episodes(vec.as_slice()) {
-                    error!("Failed batch indexng, Fallign back to individual indexing.");
-                    error!("{}", err);
-
-                    vec.iter().for_each(|ep| {
-                        if let Err(err) = ep.index() {
-                            error!("Failed to index episode: {:?}.", ep.title());
-                            error!("{}", err);
-                        };
-                    })
-                }
-            }
+        // Parse the episodes
+        let episodes = stream.filter_map(move |item| {
+            glue(&item, pd.id())
+                .map_err(|err| error!("Failed to parse an episode: {}", err))
+                .ok()
         });
 
+        // Filter errors, Index updatable episodes, return insertables.
+        let insertables = filter_episodes(episodes);
+        // Batch index insertable episodes.
+        let idx = insertables.and_then(|eps| ok(batch_insert_episodes(eps)));
+
         Box::new(idx)
     }
 }
@@ -110,6 +84,52 @@ fn determine_ep_state(
     }
 }
 
+fn filter_episodes<'a, S>(
+    stream: S,
+) -> Box<Future<Item = Vec<NewEpisode>, Error = DataError> + Send + 'a>
+where
+    S: Stream<Item = IndexState<NewEpisode>, Error = DataError> + Send + 'a,
+{
+    let list = stream.filter_map(|state| match state {
+        IndexState::NotChanged => None,
+        // Update individual rows, and filter them
+        IndexState::Update((ref ep, rowid)) => {
+            ep.update(rowid)
+                .map_err(|err| error!("{}", err))
+                .map_err(|_| error!("Failed to index episode: {:?}.", ep.title()))
+                .ok();
+
+            None
+        },
+        IndexState::Index(s) => Some(s),
+    })
+    // only Index is left, collect them for batch index
+    .collect();
+
+    Box::new(list)
+}
+
+fn batch_insert_episodes(episodes: Vec<NewEpisode>) {
+    if episodes.is_empty() {
+        return;
+    };
+
+    info!("Indexing {} episodes.", episodes.len());
+    dbqueries::index_new_episodes(episodes.as_slice())
+        .map_err(|err| {
+            error!("Failed batch indexng: {}", err);
+            info!("Fallign back to individual indexing.");
+        })
+        .unwrap_or_else(|_| {
+            episodes.iter().for_each(|ep| {
+                ep.index()
+                    .map_err(|err| error!("Error: {}.", err))
+                    .map_err(|_| error!("Failed to index episode: {:?}.", ep.title()))
+                    .ok();
+            });
+        })
+}
+
 #[cfg(test)]
 mod tests {
     use rss::Channel;