From 77bf2b9dd3f1aefdda31c4f366ba376ca19a9b00 Mon Sep 17 00:00:00 2001
From: Noah Petherbridge <root@kirsle.net>
Date: Mon, 19 Aug 2019 17:46:44 -0700
Subject: [PATCH] Fix up RSS/Atom feeds

---
 src/controllers/posts/feeds.go | 45 ++++++++++++++++++++++++++++------
 src/middleware/age-gate.go     |  6 +++--
 2 files changed, 41 insertions(+), 10 deletions(-)

diff --git a/src/controllers/posts/feeds.go b/src/controllers/posts/feeds.go
index de9ed2e..5ef5030 100644
--- a/src/controllers/posts/feeds.go
+++ b/src/controllers/posts/feeds.go
@@ -1,15 +1,26 @@
 package postctl
 
 import (
+	"fmt"
 	"net/http"
+	"regexp"
 	"strings"
 	"time"
 
 	"github.com/gorilla/feeds"
-	"github.com/kirsle/blog/src/responses"
 	"github.com/kirsle/blog/models/posts"
 	"github.com/kirsle/blog/models/settings"
 	"github.com/kirsle/blog/models/users"
+	"github.com/kirsle/blog/src/markdown"
+	"github.com/kirsle/blog/src/responses"
+	"github.com/kirsle/blog/src/types"
+)
+
+// Feed configuration. TODO make configurable.
+var (
+	FeedPostsPerPage = 20
+
+	reRelativeLink = regexp.MustCompile(` (src|href|poster)=(['"])/([^'"]+)['"]`)
 )
 
 func feedHandler(w http.ResponseWriter, r *http.Request) {
@@ -34,19 +45,37 @@ func feedHandler(w http.ResponseWriter, r *http.Request) {
 	feed.Items = []*feeds.Item{}
 	for i, p := range RecentPosts(r, "", "") {
 		post, _ := posts.Load(p.ID)
-		var suffix string
-		if strings.Contains(post.Body, "<snip>") {
-			post.Body = strings.Split(post.Body, "<snip>")[0]
-			suffix = "..."
+
+		// Render the post to HTML.
+		var rendered string
+		if post.ContentType == string(types.MARKDOWN) {
+			rendered = markdown.RenderTrustedMarkdown(post.Body)
+		} else {
+			rendered = post.Body
+		}
+
+		// Make relative links absolute.
+		matches := reRelativeLink.FindAllStringSubmatch(rendered, -1)
+		for _, match := range matches {
+			var (
+				attr   = match[1]
+				quote  = match[2]
+				uri    = match[3]
+				absURI = config.Site.URL + "/" + uri
+				new    = fmt.Sprintf(" %s%s%s%s",
+					attr, quote, absURI, quote,
+				)
+			)
+			rendered = strings.Replace(rendered, match[0], new, 1)
 		}
 
 		feed.Items = append(feed.Items, &feeds.Item{
 			Title:       p.Title,
 			Link:        &feeds.Link{Href: config.Site.URL + p.Fragment},
-			Description: post.Body + suffix,
+			Description: rendered,
 			Created:     p.Created,
 		})
-		if i == 9 { // 10 -1
+		if i == FeedPostsPerPage-1 {
 			break
 		}
 	}
@@ -58,7 +87,7 @@ func feedHandler(w http.ResponseWriter, r *http.Request) {
 		w.Write([]byte(atom))
 	} else {
 		rss, _ := feed.ToRss()
-		w.Header().Set("Content-Type", "application/rss+xml")
+		w.Header().Set("Content-Type", "application/rss+xml; encoding=utf-8")
 		w.Write([]byte(rss))
 	}
 }
diff --git a/src/middleware/age-gate.go b/src/middleware/age-gate.go
index 1a404c0..4806e24 100644
--- a/src/middleware/age-gate.go
+++ b/src/middleware/age-gate.go
@@ -11,6 +11,8 @@ import (
 )
 
 var ageGateSuffixes = []string{
+	"/blog.rss", // Allow public access to RSS and Atom feeds.
+	"/blog.atom",
 	".js",
 	".css",
 	".txt",
@@ -39,8 +41,8 @@ func AgeGate(verifyHandler func(http.ResponseWriter, *http.Request)) negroni.Han
 		}
 
 		// Allow static files and things through.
-		for _, prefix := range ageGateSuffixes {
-			if strings.HasSuffix(path, prefix) {
+		for _, suffix := range ageGateSuffixes {
+			if strings.HasSuffix(path, suffix) {
 				next(w, r)
 				return
 			}