Add comment sorting with temporary dropdown

lib/comment_tree.dart

@@ -1,5 +1,16 @@
 import 'package:lemmy_api_client/lemmy_api_client.dart';
 
+import 'util/hot_rank.dart';
+
+enum CommentSortType {
+  hot,
+  top,
+  // ignore: constant_identifier_names
+  new_,
+  old,
+  chat,
+}
+
 class CommentTree {
   CommentView comment;
   List<CommentTree> children;
@@ -30,4 +41,63 @@ class CommentTree {
     var result = parents.map(gatherChildren).toList();
     return result;
   }
+
+  void sort(CommentSortType sortType) {
+    switch (sortType) {
+      case CommentSortType.chat:
+        throw Exception('i dont do this kinda stuff kido');
+      case CommentSortType.hot:
+        return _sort((b, a) =>
+            a.comment.computedHotRank.compareTo(b.comment.computedHotRank));
+      case CommentSortType.new_:
+        return _sort(
+            (b, a) => a.comment.published.compareTo(b.comment.published));
+      case CommentSortType.old:
+        return _sort(
+            (b, a) => b.comment.published.compareTo(a.comment.published));
+      case CommentSortType.top:
+        return _sort((b, a) => a.comment.score.compareTo(b.comment.score));
+    }
+  }
+
+  void _sort(int compare(CommentTree a, CommentTree b)) {
+    children.sort(compare);
+    for (var el in children) {
+      el._sort(compare);
+    }
+  }
+
+  static void sortList(CommentSortType sortType, List<CommentTree> comms) {
+    switch (sortType) {
+      case CommentSortType.chat:
+        throw Exception('i dont do this kinda stuff kido');
+      case CommentSortType.hot:
+        comms.sort((b, a) =>
+            a.comment.computedHotRank.compareTo(b.comment.computedHotRank));
+        for (var i = 0; i < comms.length; i++) {
+          comms[i].sort(sortType);
+        }
+        break;
+      case CommentSortType.new_:
+        comms
+            .sort((b, a) => a.comment.published.compareTo(b.comment.published));
+        for (var i = 0; i < comms.length; i++) {
+          comms[i].sort(sortType);
+        }
+        break;
+      case CommentSortType.old:
+        comms
+            .sort((b, a) => b.comment.published.compareTo(a.comment.published));
+        for (var i = 0; i < comms.length; i++) {
+          comms[i].sort(sortType);
+        }
+        break;
+      case CommentSortType.top:
+        comms.sort((b, a) => a.comment.score.compareTo(b.comment.score));
+        for (var i = 0; i < comms.length; i++) {
+          comms[i].sort(sortType);
+        }
+        break;
+    }
+  }
 }

lib/widgets/comment.dart

@@ -1,7 +1,9 @@
 import 'package:cached_network_image/cached_network_image.dart';
 import 'package:flutter/material.dart';
+import 'package:timeago/timeago.dart' as timeago;
 
 import '../comment_tree.dart';
+import '../util/text_color.dart';
 import 'markdown_text.dart';
 
 class Comment extends StatelessWidget {
@@ -22,7 +24,7 @@ class Comment extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    var comment = commentTree.comment;
+    final comment = commentTree.comment;
 
     // decide which username to use
     final username = () {
@@ -91,6 +93,8 @@ class Comment extends StatelessWidget {
                 if (comment.bannedFromCommunity)
                   CommentTag('BANNED FROM COMMUNITY', Colors.red),
                 Spacer(),
+                Text(timeago.format(comment.published, locale: 'en_short')),
+                Text(' · '),
                 Text(comment.score.toString()),
               ]),
               Row(children: [body]),
@@ -137,7 +141,7 @@ class CommentTag extends StatelessWidget {
           padding: EdgeInsets.symmetric(horizontal: 3, vertical: 2),
           child: Text(text,
               style: TextStyle(
-                color: Colors.white,
+                color: textColorBasedOnBackground(bgColor),
                 fontSize: Theme.of(context).textTheme.bodyText1.fontSize - 5,
                 fontWeight: FontWeight.w800,
               )),

lib/widgets/comment_section.dart

@@ -16,7 +16,55 @@ class CommentSection extends HookWidget {
         assert(postCreatorId != null);
 
   @override
-  Widget build(BuildContext context) => Column(children: [
+  Widget build(BuildContext context) {
+    var rawComms = useState(rawComments);
+    var comms = useState(comments);
+    var sorting = useState(CommentSortType.hot);
+
+    return Column(children: [
+      Padding(
+        padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 15),
+        child: Row(
+          children: [
+            Container(
+              padding: const EdgeInsets.symmetric(vertical: 5, horizontal: 10),
+              decoration: BoxDecoration(
+                border: Border.all(color: Colors.black45),
+                borderRadius: BorderRadius.all(Radius.circular(10)),
+              ),
+              child: DropdownButton(
+                // TODO: change it to universal BottomModal
+                underline: Container(),
+                isDense: true,
+                // ignore: avoid_types_on_closure_parameters
+                onChanged: (CommentSortType val) {
+                  if (val != sorting.value && val != CommentSortType.chat) {
+                    CommentTree.sortList(val, comms.value);
+                  } else {
+                    rawComms.value
+                        .sort((a, b) => a.published.compareTo(b.published));
+                  }
+                  sorting.value = val;
+                },
+                value: sorting.value,
+                items: [
+                  DropdownMenuItem(
+                      child: Text('Hot'), value: CommentSortType.hot),
+                  DropdownMenuItem(
+                      child: Text('Top'), value: CommentSortType.top),
+                  DropdownMenuItem(
+                      child: Text('New'), value: CommentSortType.new_),
+                  DropdownMenuItem(
+                      child: Text('Old'), value: CommentSortType.old),
+                  DropdownMenuItem(
+                      child: Text('Chat'), value: CommentSortType.chat),
+                ],
+              ),
+            ),
+            Spacer(),
+          ],
+        ),
+      ),
       // sorting menu goes here
       if (comments.isEmpty)
         Padding(
@@ -25,7 +73,15 @@ class CommentSection extends HookWidget {
             'no comments yet',
             style: TextStyle(fontStyle: FontStyle.italic),
           ),
-          ),
+        )
-        for (var com in comments) Comment(com, postCreatorId: postCreatorId),
+      else if (sorting.value == CommentSortType.chat)
+        for (final com in rawComms.value)
+          Comment(
+            CommentTree(com),
+            postCreatorId: postCreatorId,
+          )
+      else
+        for (var com in comms.value) Comment(com, postCreatorId: postCreatorId),
     ]);
   }
+}