From 51a79a3dce9c992db2336ee78bee3e3dd78880b2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E3=83=9E=E3=83=AA=E3=82=A6=E3=82=B9?=
 <marius@xn--gckvb8fzb.com>
Date: Fri, 28 Jan 2022 23:18:39 -0500
Subject: [PATCH] Implemented sorting by latest reply in thread

---
 database/database.go | 27 ++++++++++++++++++++++-----
 models/article.go    |  4 +++-
 2 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/database/database.go b/database/database.go
index babaeac..4bfdd44 100644
--- a/database/database.go
+++ b/database/database.go
@@ -257,15 +257,32 @@ func (db *Database) ListArticles() ([]*models.Article, []*models.Article, error)
   var articlesRoots []*models.Article
   for i := 0; i < len(articles); i++ {
     if articles[i].InReplyToID != "" {
-      if _, exist := articlesMap[articles[i].InReplyToID]; exist == true {
-        (*articlesMap[articles[i].InReplyToID]).Replies =
-          append((*articlesMap[articles[i].InReplyToID]).Replies, articles[i])
+      inReplyTo := articles[i].InReplyToID
+      if _, exist := articlesMap[inReplyTo]; exist == true {
+
+        (*articlesMap[inReplyTo]).Replies =
+          append((*articlesMap[inReplyTo]).Replies, articles[i])
+        (*articlesMap[inReplyTo]).LatestReply = articles[i].Date
+        continue
       }
-    } else {
-      articlesRoots = append(articlesRoots, articles[i])
     }
+    articlesRoots = append(articlesRoots, articles[i])
   }
 
+  sort.SliceStable(articlesRoots, func(i, j int) bool {
+    iLatest := articlesRoots[i].LatestReply
+    if iLatest <= 0 {
+      iLatest = articlesRoots[i].Date
+    }
+
+    jLatest := articlesRoots[j].LatestReply
+    if jLatest <= 0 {
+      jLatest = articlesRoots[j].Date
+    }
+
+    return iLatest > jLatest
+  })
+
   return articles, articlesRoots, nil
 }
 
diff --git a/models/article.go b/models/article.go
index 8f0a21a..97b45b8 100644
--- a/models/article.go
+++ b/models/article.go
@@ -18,7 +18,9 @@ type Article struct {
   Body         string    `mapstructure:"body" json:"-" validate:"required,min=3,max=524288"`
 
   Replies      []*Article `mapstructure:"-" json:"-" validate:"-"`
-  Read         bool      `mapstructure:"-" json:"read" validate:"-"`
+  LatestReply  int64      `mapstructure:"-" json:"-" validate:"-"`
+
+  Read         bool       `mapstructure:"-" json:"read" validate:"-"`
 }
 
 func NewArticle() (*Article) {