From 97bd2a6b1b22d537569368bb17eae6a99d99a39c Mon Sep 17 00:00:00 2001
From: Henning Vogt <henning@vogt.family>
Date: Sat, 10 Jun 2023 20:18:51 +0200
Subject: [PATCH] Add sitemap.xml

---
 generator.go      | 48 ++++++++++++++++++++++++++++++++++++++++++++++-
 go.mod            |  2 +-
 page.go           | 15 +++++++++++++++
 sitemap/url.go    | 11 +++++++++++
 sitemap/urlset.go |  9 +++++++++
 5 files changed, 83 insertions(+), 2 deletions(-)
 create mode 100644 sitemap/url.go
 create mode 100644 sitemap/urlset.go

diff --git a/generator.go b/generator.go
index 2a98a93..ce4ae39 100644
--- a/generator.go
+++ b/generator.go
@@ -1,11 +1,14 @@
 package main
 
 import (
+	"encoding/xml"
 	"html/template"
 	"os"
 	"path/filepath"
 
 	cp "github.com/otiai10/copy"
+
+	"github.com/bytehunger/snack/sitemap"
 )
 
 const outputDir = "build"
@@ -56,7 +59,9 @@ func (g *Generator) Generate() error {
 		}
 	}
 
-	return nil
+	err = g.GenerateSitemap(site)
+
+	return err
 }
 
 func (g *Generator) GeneratePage(data *RenderData) error {
@@ -140,3 +145,44 @@ func (g *Generator) GeneratePage(data *RenderData) error {
 
 	return nil
 }
+
+func (g *Generator) GenerateSitemap(site Site) error {
+	urls := []sitemap.URL{}
+
+	for _, page := range site.Pages {
+
+		// Do not include noindex pages.
+		if page.NoIndex {
+			continue
+		}
+
+		// Append all pages to the URLSet.
+		urls = append(urls, sitemap.URL{
+			Loc: page.URL(site.Host),
+		})
+	}
+
+	urlset := sitemap.URLSet{
+		URLs:  urls,
+		XMLNS: "http://www.sitemaps.org/schemas/sitemap/0.9",
+	}
+
+	sitemap, err := xml.MarshalIndent(urlset, "", " ")
+
+	if err != nil {
+		return err
+	}
+
+	path := filepath.Join(outputDir, "sitemap.xml")
+	file, err := os.Create(path)
+
+	if err != nil {
+		return err
+	}
+
+	defer file.Close()
+
+	_, err = file.Write(sitemap)
+
+	return err
+}
diff --git a/go.mod b/go.mod
index 32e230c..3fe56e7 100644
--- a/go.mod
+++ b/go.mod
@@ -1,4 +1,4 @@
-module github.com/webhunger-ch/snack
+module github.com/bytehunger/snack
 
 go 1.18
 
diff --git a/page.go b/page.go
index d7ee90b..3ce738e 100644
--- a/page.go
+++ b/page.go
@@ -1,5 +1,7 @@
 package main
 
+import "net/url"
+
 type Page struct {
 	Title       string    `yaml:"title"`
 	Path        string    `yaml:"path"`
@@ -7,3 +9,16 @@ type Page struct {
 	Sections    []Section `yaml:"sections"`
 	NoIndex     bool      `yaml:"noIndex" json:"noIndex"`
 }
+
+// Assemble the complete URL for the page with given domain.
+func (p *Page) URL(host string) string {
+	url, err := url.Parse(host)
+
+	if err != nil {
+		panic(err)
+	}
+
+	url.Path = p.Path
+
+	return url.String()
+}
diff --git a/sitemap/url.go b/sitemap/url.go
new file mode 100644
index 0000000..1dc95da
--- /dev/null
+++ b/sitemap/url.go
@@ -0,0 +1,11 @@
+package sitemap
+
+import "encoding/xml"
+
+type URL struct {
+	XMLName    xml.Name `xml:"url"`
+	Loc        string   `xml:"loc"`
+	ChangeFreq string   `xml:"changefreq,omitempty"`
+	LastMod    string   `xml:"lastmod,omitempty"`
+	Priority   string   `xml:"priority,omitempty"`
+}
diff --git a/sitemap/urlset.go b/sitemap/urlset.go
new file mode 100644
index 0000000..745c959
--- /dev/null
+++ b/sitemap/urlset.go
@@ -0,0 +1,9 @@
+package sitemap
+
+import "encoding/xml"
+
+type URLSet struct {
+	XMLName xml.Name `xml:"urlset"`
+	XMLNS   string   `xml:"xmlns,attr"`
+	URLs    []URL    `xml:"url"`
+}