1 files changed, 129 insertions, 0 deletions
diff --git a/internal/build/rss.go b/internal/build/rss.go
new file mode 100644
index 0000000..ad22615
--- /dev/null
+++ b/internal/build/rss.go
@@ -0,0 +1,129 @@
+package build
+
+import (
+	"fmt"
+	"os"
+	"time"
+
+	"github.com/HimanshuSardana/kite/pkg/config"
+	"github.com/HimanshuSardana/kite/pkg/content"
+)
+
+type RSSItem struct {
+	Title   string
+	Link    string
+	Date    string
+	Content string
+}
+
+type RSSFeed struct {
+	Title       string
+	Link        string
+	Description string
+	Items       []RSSItem
+}
+
+func GenerateRSS(outputDir, configPath, siteURL string, posts []content.PostSummary) error {
+	if configPath == "" {
+		configPath = "config.yaml"
+	}
+
+	cfg, err := config.Load(configPath)
+	if err != nil {
+		return fmt.Errorf("loading config: %w", err)
+	}
+
+	feed := RSSFeed{
+		Title:       cfg.SiteTitle,
+		Link:        siteURL,
+		Description: cfg.AuthorBio,
+		Items:       make([]RSSItem, 0, len(posts)),
+	}
+
+	for _, post := range posts {
+		dateStr := post.Date
+		var pubDate time.Time
+
+		if t, err := time.Parse("2006-01-02", post.Date); err == nil {
+			pubDate = t
+			dateStr = pubDate.Format(time.RFC1123)
+		} else if t, err := time.Parse("Jan 2006", post.Date); err == nil {
+			pubDate = t
+			dateStr = pubDate.Format(time.RFC1123)
+		}
+
+		feed.Items = append(feed.Items, RSSItem{
+			Title:   post.Title,
+			Link:    fmt.Sprintf("%s/%s/", siteURL, post.Slug),
+			Date:    dateStr,
+			Content: fmt.Sprintf("Read more at %s/%s/", siteURL, post.Slug),
+		})
+	}
+
+	rssContent := renderRSS(feed)
+
+	feedPath := "feed.xml"
+	if outputDir != "" && outputDir != "." {
+		feedPath = outputDir + "/feed.xml"
+	}
+
+	if err := os.WriteFile(feedPath, []byte(rssContent), 0644); err != nil {
+		return fmt.Errorf("writing feed: %w", err)
+	}
+
+	fmt.Println("Feed written to", feedPath)
+	return nil
+}
+
+func renderRSS(feed RSSFeed) string {
+	updated := time.Now().Format(time.RFC1123)
+
+	s := `<?xml version="1.0" encoding="UTF-8"?>
+<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">
+  <channel>
+    <title>` + escapeXML(feed.Title) + `</title>
+    <link>` + escapeXML(feed.Link) + `</link>
+    <description>` + escapeXML(feed.Description) + `</description>
+    <language>en-us</language>
+    <lastBuildDate>` + updated + `</lastBuildDate>
+    <atom:link href="` + escapeXML(feed.Link) + `/feed.xml" rel="self" type="application/rss+xml"/>
+`
+
+	for _, item := range feed.Items {
+		s += `    <item>
+      <title>` + escapeXML(item.Title) + `</title>
+      <link>` + escapeXML(item.Link) + `</link>
+      <guid>` + escapeXML(item.Link) + `</guid>
+      <pubDate>` + item.Date + `</pubDate>
+      <description>` + escapeXML(item.Content) + `</description>
+    </item>
+`
+	}
+
+	s += `  </channel>
+</rss>`
+
+	return s
+}
+
+func escapeXML(s string) string {
+	s = replaceAll(s, "&", "&amp;")
+	s = replaceAll(s, "<", "&lt;")
+	s = replaceAll(s, ">", "&gt;")
+	s = replaceAll(s, "\"", "&quot;")
+	s = replaceAll(s, "'", "&apos;")
+	return s
+}
+
+func replaceAll(s, old, new string) string {
+	result := ""
+	for i := 0; i < len(s); i++ {
+		if i+len(old) <= len(s) && s[i:i+len(old)] == old {
+			result += new
+			i += len(old) - 1
+		} else {
+			result += string(s[i])
+		}
+	}
+	return result
+}