(WIP) Produces valid RSS

Still very much P.O.C quality code, i.e., crappy

rss.go → rss-server.go

@@ -2,7 +2,6 @@ package main
 
 import (
   "context"
-  "fmt"
   "net/http"
   "net/url"
   "os"
@@ -15,6 +14,7 @@ import (
   "github.com/mrusme/superhighway84/config"
   "github.com/mrusme/superhighway84/database"
   "github.com/mrusme/superhighway84/models"
+  "github.com/mrusme/superhighway84/rss"
   "go.uber.org/zap"
 )
 
@@ -41,15 +41,6 @@ func NewLogger(filename string) (*zap.Logger, error) {
   return cfg.Build()
 }
 
-// Apparently there's no `min` for ints in golang
-// https://stackoverflow.com/questions/27516387/what-is-the-correct-way-to-find-the-min-between-two-integers-in-go
-func minInt(x, y int) int {
-    if x < y {
-        return x
-    }
-    return y
-}
-
 func main() {
   ctx, cancel := context.WithCancel(context.Background())
   defer cancel()
@@ -118,18 +109,14 @@ func main() {
 
   createResponse := func(w http.ResponseWriter, articles []*models.Article) {
 
-    fmt.Fprintf(w, "<RSS HEADER>\n")
+    feedOptions := rss.NewFeedOptions()
+    rssFeed := rss.NewFeed(articles, feedOptions)
+    err := rssFeed.Write(w)
 
-    numArticles := minInt(len(articles), 10)
-
-    if numArticles > 0 {
-      for i, article := range articles[0:numArticles] {
-        fmt.Fprintf(w, "[%d] %s\n", i, article.Subject)
-        fmt.Fprintf(w, "   from:%s in:%s\n", article.From, article.Newsgroup)
-      }
+    if err != nil {
+      log.Printf("Failed to write feed in response: %v", err)
     }
 
-    fmt.Fprintf(w, "<RSS FOOTER>\n")
   }
 
   articlesHandler := func(w http.ResponseWriter, r *http.Request) {

rss/rss.go

@@ -0,0 +1,98 @@
+package rss
+
+import (
+  "fmt"
+  "io"
+  "github.com/mrusme/superhighway84/models"
+)
+
+// ☠️  This is Proof of concept code!
+// For example, it's currently composing the feed for each request, which doesn't
+// make sense given how (not) frequently the articles update.
+
+type FeedOptions struct {
+  MaxArticles    int
+}
+
+type Feed struct {
+  Options     FeedOptions
+  Articles    []*models.Article
+}
+
+func NewFeedOptions() (FeedOptions) {
+  return FeedOptions{10}
+}
+
+// Apparently there's no `min` for ints in golang
+// https://stackoverflow.com/questions/27516387/what-is-the-correct-way-to-find-the-min-between-two-integers-in-go
+func minInt(x, y int) int {
+    if x < y {
+        return x
+    }
+    return y
+}
+
+func NewFeed(articles []*models.Article, feedOptions FeedOptions) (Feed) {
+
+  numArticles := minInt(len(articles), feedOptions.MaxArticles)
+  articlesSlice := articles[0:numArticles]
+
+  return Feed{
+    Options: feedOptions,
+    Articles: articlesSlice,
+  }
+}
+
+const header = `
+<rss version="2.0">
+  <channel>
+    <title>%s</title>
+    <link>%s</link>
+    <description>%s</description>
+    <language>%s</language>
+    <pubDate>%s</pubDate>
+    <lastBuildDate>%s</lastBuildDate>
+    <docs>%s</docs>
+    <generator>%s</generator>
+`
+
+const footer = `
+  </channel>
+</rss>
+`
+
+const item = `
+    <item>
+      <title>%s</title>
+      <link>%s</link>
+      <description>%s</description>
+      <pubDate>%s</pubDate>
+      <guid>%s</guid>
+    </item>
+`
+
+func (feed *Feed) Write(w io.Writer) (error) {
+
+  title := "Superhighway84"
+  link := "https://xn--gckvb8fzb.com/superhighway84/"
+  description := "USENET-INSPIRED DECENTRALIZED INTERNET DISCUSSION SYSTEM"
+  language := "en-us"
+  pubDate := "Tue, 10 Jun 2003 04:00:00 GMT"
+  buildDate := "Tue, 10 Jun 2003 09:41:01 GMT"
+  docsLink := "http://blogs.law.harvard.edu/tech/rss"
+  generator := "Superhighway84 RSS Generator"
+  fmt.Fprintf(w, header, title, link, description, language, pubDate, buildDate, docsLink, generator)
+
+  for _, article := range feed.Articles {
+    title := article.Subject
+    link := fmt.Sprintf("superhighway84://%s", article.ID)
+    description := fmt.Sprintf("Posted by %s in %s<br>%d replies<br>%s", article.From, article.Newsgroup, len(article.Replies), article.Body)
+    pubDate := "Tue, 03 Jun 2003 09:39:21 GMT"
+    guid := article.ID
+    fmt.Fprintf(w, item, title, link, description, pubDate, guid)
+  }
+
+  fmt.Fprintf(w, footer)
+
+  return nil
+}