feat(feed): feed widget support

src/background/feed.js

@@ -0,0 +1,60 @@
+module.exports = class Feed {
+    constructor({sphinx})
+    {
+        this.feed = []
+        this.sphinx = sphinx
+    }
+
+    async save() {
+		console.log('saving feed')
+		await this.sphinx.query('delete from feed where id > 0')
+		let id = 0
+		return Promise.all(
+			this.feed.map(
+				async record => await this.sphinx.query('insert into feed(id, data) values(?, ?)', [++id, JSON.stringify(record)])
+			)
+		)
+    }
+    
+    async load() {
+        this.feed = await this.sphinx.query('select * from feed limit 1000')
+	    if(this.feed && this.feed.length > 0)
+            this.feed = this.feed.map(f => JSON.parse(f.data))
+        else
+            this.feed = []
+            
+        this._order()
+    }
+
+    clear()
+    {
+        this.feed = []
+    }
+
+    add(data) {
+        if(typeof data == 'object')
+        {
+            data.feedDate = Math.floor(Date.now() / 1000)
+        }
+
+        this.feed.push(data)
+        this._order()
+    }
+
+    _order() {
+        this.feed.sort((a, b) => this._compare(b) - this._compare(a))
+    }
+
+    _compare(x)
+    {
+        const rating = 0
+        const comments = 0
+        const time = Math.floor(Date.now() / 1000) - x.feedDate
+
+        const maxTime = 600000
+        if(time > maxTime)
+            time = maxTime
+        const relativeTime = (maxTime - time) / maxTime
+        return relativeTime * relativeTime + rating * 1.5 * relativeTime + comments * 4 * relativeTime
+    }
+}