[Gekidou] Sort unfiltered find channels by mention / unread (#6340)

* Sort unfiltered find channels by mention / unread

* Prevent Double tap to access find channels

app/helpers/database/index.ts

@@ -5,6 +5,24 @@ import {General} from '@constants';
 
 import type Model from '@nozbe/watermelondb/Model';
 import type ChannelModel from '@typings/database/models/servers/channel';
+import type MyChannelModel from '@typings/database/models/servers/my_channel';
+
+type NotifyProps = {
+    [key: string]: Partial<ChannelNotifyProps>;
+}
+
+/**
+ * Filtering / Sorting:
+ *
+ * Unreads, Mentions, and Muted Mentions Only
+ * Mentions on top, then unreads, then muted channels with mentions.
+ */
+
+ type FilterAndSortMyChannelsArgs = [
+    MyChannelModel[],
+    Record<string, ChannelModel>,
+    NotifyProps,
+]
 
 export const extractRecordsForTable = <T>(records: Model[], tableName: string): T[] => {
     // @ts-expect-error constructor.table not exposed in type definition
@@ -32,3 +50,44 @@ export function extractChannelDisplayName(raw: Pick<Channel, 'type' | 'display_n
 
     return displayName;
 }
+
+export const makeChannelsMap = (channels: ChannelModel[]) => {
+    return channels.reduce<Record<string, ChannelModel>>((result, c) => {
+        result[c.id] = c;
+        return result;
+    }, {});
+};
+
+export const filterAndSortMyChannels = ([myChannels, channels, notifyProps]: FilterAndSortMyChannelsArgs): ChannelModel[] => {
+    const mentions: ChannelModel[] = [];
+    const unreads: ChannelModel[] = [];
+    const mutedMentions: ChannelModel[] = [];
+
+    const isMuted = (id: string) => {
+        return notifyProps[id]?.mark_unread === 'mention';
+    };
+
+    for (const myChannel of myChannels) {
+        const id = myChannel.id;
+
+        // is it a mention?
+        if (!isMuted(id) && myChannel.mentionsCount > 0 && channels[id]) {
+            mentions.push(channels[id]);
+            continue;
+        }
+
+        // is it unread?
+        if (!isMuted(myChannel.id) && myChannel.isUnread && channels[id]) {
+            unreads.push(channels[id]);
+            continue;
+        }
+
+        // is it a muted mention?
+        if (isMuted(myChannel.id) && myChannel.mentionsCount > 0 && channels[id]) {
+            mutedMentions.push(channels[id]);
+            continue;
+        }
+    }
+
+    return [...mentions, ...unreads, ...mutedMentions];
+};