Add custom feeds selector, rework search, simplify onboarding (#325)

* Get home screen's swipable pager working with the drawer

* Add tab bar to pager

* Implement popular & following views on home screen

* Visual tune-up

* Move the feed selector to the footer

* Fix to 'new posts' poll

* Add the view header as a feed item

* Use the native driver on the tabbar indicator to improve perf

* Reduce home polling to the currently active page; also reuse some code

* Add soft reset on tap selected in tab bar

* Remove explicit 'onboarding' flow

* Choose good stuff based on service

* Add foaf-based follow discovery

* Fall back to who to follow

* Fix backgrounds

* Switch to the off-spec goodstuff route

* 1.8

* Fix for dev & staging

* Swap the tab bar items and rename suggested to what's hot

* Go to whats-hot by default if you have no follows

* Implement pager and tabbar for desktop web

* Pin deps to make expo happy

* Add language filtering to goodstuff

src/lib/api/feed-manip.ts

@@ -1,5 +1,7 @@
 import {AppBskyFeedFeedViewPost} from '@atproto/api'
+import lande from 'lande'
 type FeedViewPost = AppBskyFeedFeedViewPost.Main
+import {hasProp} from '@atproto/lexicon'
 
 export type FeedTunerFn = (
   tuner: FeedTuner,
@@ -140,7 +142,8 @@ export class FeedTuner {
       for (const item of slice.items) {
         this.seenUris.add(item.post.uri)
       }
-      slice.logSelf()
+      // DEBUG uncomment to get a quick view of the data
+      // slice.logSelf()
     }
 
     return slices
@@ -177,6 +180,33 @@ export class FeedTuner {
       }
     }
   }
+
+  static englishOnly(tuner: FeedTuner, slices: FeedViewPostsSlice[]) {
+    // TEMP
+    // remove slices with no english in them
+    // we very soon need to get the local user's language and filter
+    // according to their preferences, but for the moment
+    // we're just rolling with english
+    // -prf
+    for (let i = slices.length - 1; i >= 0; i--) {
+      let hasEnglish = false
+      for (const item of slices[i].items) {
+        if (
+          hasProp(item.post.record, 'text') &&
+          typeof item.post.record.text === 'string'
+        ) {
+          const res = lande(item.post.record.text)
+          if (res[0][0] === 'eng') {
+            hasEnglish = true
+            break
+          }
+        }
+      }
+      if (!hasEnglish) {
+        slices.splice(i, 1)
+      }
+    }
+  }
 }
 
 function getSelfReplyUri(item: FeedViewPost): string | undefined {