Add feed discovery page

src/state/models/discovery/feeds.ts

@@ -0,0 +1,97 @@
+import {makeAutoObservable} from 'mobx'
+import {AppBskyUnspeccedGetPopularFeedGenerators} from '@atproto/api'
+import {RootStoreModel} from '../root-store'
+import {bundleAsync} from 'lib/async/bundle'
+import {cleanError} from 'lib/strings/errors'
+import {CustomFeedModel} from '../feeds/custom-feed'
+
+export class FeedsDiscoveryModel {
+  // state
+  isLoading = false
+  isRefreshing = false
+  hasLoaded = false
+  error = ''
+
+  // data
+  feeds: CustomFeedModel[] = []
+
+  constructor(public rootStore: RootStoreModel) {
+    makeAutoObservable(
+      this,
+      {
+        rootStore: false,
+      },
+      {autoBind: true},
+    )
+  }
+
+  get hasMore() {
+    return false
+  }
+
+  get hasContent() {
+    return this.feeds.length > 0
+  }
+
+  get hasError() {
+    return this.error !== ''
+  }
+
+  get isEmpty() {
+    return this.hasLoaded && !this.hasContent
+  }
+
+  // public api
+  // =
+
+  refresh = bundleAsync(async () => {
+    this._xLoading()
+    try {
+      const res =
+        await this.rootStore.agent.app.bsky.unspecced.getPopularFeedGenerators(
+          {},
+        )
+      this._replaceAll(res)
+      this._xIdle()
+    } catch (e: any) {
+      this._xIdle(e)
+    }
+  })
+
+  clear() {
+    this.isLoading = false
+    this.isRefreshing = false
+    this.hasLoaded = false
+    this.error = ''
+    this.feeds = []
+  }
+
+  // state transitions
+  // =
+
+  _xLoading() {
+    this.isLoading = true
+    this.isRefreshing = true
+    this.error = ''
+  }
+
+  _xIdle(err?: any) {
+    this.isLoading = false
+    this.isRefreshing = false
+    this.hasLoaded = true
+    this.error = cleanError(err)
+    if (err) {
+      this.rootStore.log.error('Failed to fetch popular feeds', err)
+    }
+  }
+
+  // helper functions
+  // =
+
+  _replaceAll(res: AppBskyUnspeccedGetPopularFeedGenerators.Response) {
+    this.feeds = []
+    for (const f of res.data.feeds) {
+      this.feeds.push(new CustomFeedModel(this.rootStore, f))
+    }
+  }
+}