wip: render feeds

2 files changed, 337 insertions, 0 deletions

diff --git a/cmd/build/atom.go b/cmd/build/atom.go
new file mode 100644
index 0000000..9116278
--- /dev/null
+++ b/cmd/build/atom.go
@@ -0,0 +1,43 @@
+package main
+
+import (
+	"encoding/xml"
+	"time"
+
+	. "alanpearce.eu/website/internal/config"
+)
+
+func makeTagURI(config Config, specific string) string {
+	return "tag:" + config.OriginalDomain + "," + config.DomainStartDate + ":" + specific
+}
+
+type Link struct {
+	XMLName xml.Name `xml:"link"`
+	Rel     string   `xml:"rel,attr"`
+	Type    string   `xml:"type,attr"`
+	Href    string   `xml:"href,attr"`
+}
+
+func makeLink(url string) Link {
+	return Link{
+		Rel:  "alternate",
+		Type: "text/html",
+		Href: url,
+	}
+}
+
+type FeedContent struct {
+	Content string `xml:",innerxml"`
+	Type    string `xml:"type,attr"`
+}
+
+type FeedEntry struct {
+	XMLName xml.Name    `xml:"entry"`
+	Title   string      `xml:"title"`
+	Link    Link        `xml:"link"`
+	Id      string      `xml:"id"`
+	Updated time.Time   `xml:"updated"`
+	Summary string      `xml:"summary,omitempty"`
+	Author  string      `xml:"author>name"`
+	Content FeedContent `xml:"content"`
+}
diff --git a/cmd/build/main.go b/cmd/build/main.go
new file mode 100644
index 0000000..48c9739
--- /dev/null
+++ b/cmd/build/main.go
@@ -0,0 +1,294 @@
+package main
+
+import (
+	"bytes"
+	"encoding/xml"
+	"fmt"
+	"log"
+	"os"
+	"path"
+	"path/filepath"
+	"slices"
+	"strings"
+	"time"
+
+	. "alanpearce.eu/website/internal/config"
+
+	"github.com/PuerkitoBio/goquery"
+	"github.com/adrg/frontmatter"
+	"github.com/antchfx/xmlquery"
+	mapset "github.com/deckarep/golang-set/v2"
+	"github.com/yuin/goldmark"
+	"github.com/yuin/goldmark/extension"
+)
+
+type PostMatter struct {
+	Date        time.Time `toml:"date"`
+	Description string    `toml:"description"`
+	Title       string    `toml:"title"`
+	Taxonomies  struct {
+		Tags []string `toml:"tags"`
+	} `toml:"taxonomies"`
+}
+
+type Post struct {
+	Input    string
+	Output   string
+	Basename string
+	URL      string
+	Content  string
+	PostMatter
+}
+
+type Tags mapset.Set[string]
+
+func check(err error) {
+	if err != nil {
+		log.Panic(err)
+	}
+}
+
+func getPost(filename string) (PostMatter, []byte) {
+	matter := PostMatter{}
+	content, err := os.Open(filename)
+	check(err)
+	rest, err := frontmatter.Parse(content, &matter)
+	check(err)
+
+	return matter, rest
+}
+
+func readPosts(root string, inputDir string, outputDir string) ([]Post, Tags) {
+	tags := mapset.NewSet[string]()
+	posts := []Post{}
+	subdir := filepath.Join(root, inputDir)
+	files, err := os.ReadDir(subdir)
+	outputReplacer := strings.NewReplacer(root, outputDir, ".md", "/index.html")
+	urlReplacer := strings.NewReplacer(root, "", ".md", "/")
+	check(err)
+	md := goldmark.New(
+		goldmark.WithExtensions(
+			extension.GFM,
+			extension.Footnote,
+			extension.Typographer,
+		),
+	)
+	for _, f := range files {
+		pathFromRoot := filepath.Join(subdir, f.Name())
+		check(err)
+		if !f.IsDir() && path.Ext(pathFromRoot) == ".md" {
+			output := outputReplacer.Replace(pathFromRoot)
+			url := urlReplacer.Replace(pathFromRoot)
+			matter, content := getPost(pathFromRoot)
+
+			for _, tag := range matter.Taxonomies.Tags {
+				tags.Add(strings.ToLower(tag))
+			}
+
+			var buf bytes.Buffer
+			err := md.Convert(content, &buf)
+			check(err)
+			post := Post{
+				Input:      pathFromRoot,
+				Output:     output,
+				Basename:   filepath.Base(url),
+				URL:        url,
+				PostMatter: matter,
+				Content:    buf.String(),
+			}
+
+			posts = append(posts, post)
+		}
+	}
+	slices.SortFunc(posts, func(a, b Post) int {
+		return b.Date.Compare(a.Date)
+	})
+	return posts, tags
+}
+
+func layout(html string, config Config, pageTitle string) *goquery.Document {
+	css, err := os.ReadFile("templates/style.css")
+	check(err)
+	doc, err := goquery.NewDocumentFromReader(strings.NewReader(html))
+	check(err)
+	doc.Find("html").SetAttr("lang", config.DefaultLanguage)
+	doc.Find("head > link[rel=alternate]").Add(".title").SetAttr("title", config.Title)
+	doc.Find("title").Add(".p-name").SetText(pageTitle)
+	doc.Find("head > style").SetText(string(css))
+	nav := doc.Find("nav")
+	navLink := doc.Find("nav a")
+	nav.Empty()
+	for _, link := range config.Menus["main"] {
+		nav.AppendSelection(navLink.Clone().SetAttr("href", link.URL).SetText(link.Name))
+	}
+	return doc
+}
+
+func renderPost(post Post, config Config) string {
+	tbytes, err := os.ReadFile("templates/post.html")
+	check(err)
+	doc := layout(string(tbytes), config, post.PostMatter.Title)
+	doc.Find(".title").AddClass("h-card p-author").SetAttr("rel", "author")
+	datetime, err := post.PostMatter.Date.MarshalText()
+	check(err)
+	doc.Find(".h-entry .dt-published").SetAttr("datetime", string(datetime)).SetText(
+		post.PostMatter.Date.Format("2006-01-02"),
+	)
+	doc.Find(".h-entry .e-content").SetHtml(post.Content)
+	categories := doc.Find(".h-entry .p-categories")
+	cat := categories.Find(".p-category").ParentsUntilSelection(categories)
+	cat.Remove()
+	for _, tag := range post.Taxonomies.Tags {
+		categories.AppendSelection(cat.Clone().Find(".p-category").SetAttr("href", fmt.Sprintf("/tags/%s/", tag)).SetText("#" + tag)).Parent()
+	}
+	html, err := doc.Html()
+	check(err)
+	return html
+}
+
+func renderTags(tags Tags, config Config) string {
+	tbytes, err := os.ReadFile("templates/tags.html")
+	check(err)
+
+	doc := layout(string(tbytes), config, config.Title)
+	tagList := doc.Find(".tags")
+	tpl := doc.Find(".h-feed")
+	tpl.Remove()
+	for _, tag := range mapset.Sorted(tags) {
+		tagList.AppendSelection(
+			tpl.Clone().SetAttr("href", fmt.Sprintf("/tags/%s/", tag)).SetText("#" + tag),
+		)
+	}
+	html, err := doc.Html()
+	check(err)
+	return html
+}
+
+func renderListPage(tag string, config Config, posts []Post) string {
+	tbytes, err := os.ReadFile("templates/list.html")
+	check(err)
+	var title string
+	if len(tag) > 0 {
+		title = tag
+	} else {
+		title = config.Title
+	}
+	doc := layout(string(tbytes), config, title)
+	feed := doc.Find(".h-feed")
+	tpl := feed.Find(".h-entry")
+	tpl.Remove()
+
+	doc.Find(".title").AddClass("h-card p-author").SetAttr("rel", "author")
+	if tag == "" {
+		doc.Find(".filter").Remove()
+	} else {
+		doc.Find(".filter").Find("h3").SetText("#" + tag)
+	}
+
+	for _, post := range posts {
+		entry := tpl.Clone()
+		datetime, err := post.PostMatter.Date.MarshalText()
+		check(err)
+
+		entry.Find(".p-name").SetText(post.Title).SetAttr("href", post.URL)
+		entry.Find(".dt-published").SetAttr("datetime", string(datetime)).SetText(post.PostMatter.Date.Format("2006-01-02"))
+		feed.AppendSelection(entry)
+	}
+
+	html, err := doc.Html()
+	check(err)
+	return html
+}
+
+func renderFeed(title string, config Config, posts []Post, specific string) string {
+	reader, err := os.Open("templates/feed.xml")
+	check(err)
+	doc, err := xmlquery.Parse(reader)
+	feed := doc.SelectElement("feed")
+	feed.SelectElement("title").FirstChild.Data = title
+	feed.SelectElement("link").SetAttr("href", config.BaseURL)
+	feed.SelectElement("id").FirstChild.Data = makeTagURI(config, specific)
+	datetime, err := posts[0].Date.MarshalText()
+	feed.SelectElement("updated").FirstChild.Data = string(datetime)
+	tpl := feed.SelectElement("entry")
+	xmlquery.RemoveFromTree(tpl)
+
+	for _, post := range posts {
+		text, err := xml.MarshalIndent(&FeedEntry{
+			Title:   post.Title,
+			Link:    makeLink(post.URL),
+			Id:      makeTagURI(config, post.Basename),
+			Updated: post.Date,
+			Summary: post.Description,
+			Author:  config.Title,
+			Content: FeedContent{
+				Content: post.Content,
+				Type:    "html",
+			},
+		}, "  ", "    ")
+		check(err)
+		entry, err := xmlquery.ParseWithOptions(strings.NewReader(string(text)), xmlquery.ParserOptions{
+			Decoder: &xmlquery.DecoderOptions{
+				Strict:    false,
+				AutoClose: xml.HTMLAutoClose,
+				Entity:    xml.HTMLEntity,
+			},
+		})
+		check(err)
+		xmlquery.AddChild(feed, entry.SelectElement("entry"))
+	}
+
+	return doc.OutputXML(true)
+}
+
+func main() {
+	err, config := GetConfig()
+	check(err)
+	err = os.MkdirAll("public/post", 0755)
+	check(err)
+	log.Print("Generating site...")
+	posts, tags := readPosts("content", "post", "public")
+	for _, post := range posts {
+		err := os.MkdirAll(path.Join("public", "post", post.Basename), 0755)
+		check(err)
+		// output := renderPost(post, config)
+		// err = os.WriteFile(post.Output, []byte(output), 0755)
+		// check(err)
+	}
+	err = os.MkdirAll("public/tags", 0755)
+	check(err)
+	// fmt.Printf("%+v\n", renderTags(tags, config))
+	// err = os.WriteFile("public/tags/index.html", []byte(renderTags(tags, config)), 0755)
+	// check(err)
+	for _, tag := range tags.ToSlice() {
+		matchingPosts := []Post{}
+		for _, post := range posts {
+			if slices.Contains(post.Taxonomies.Tags, tag) {
+				matchingPosts = append(matchingPosts, post)
+			}
+		}
+		err := os.MkdirAll(path.Join("public", "tags", tag), 0755)
+		check(err)
+		// tagPage := renderListPage(tag, config, matchingPosts)
+		// fmt.Printf("%+v\n", tagPage)
+		// err = os.WriteFile(path.Join("public", "tags", tag, "index.html"), []byte(tagPage), 0755)
+		// check(err)
+
+		// TODO: tag atom
+		// fmt.Printf("%+v\n", renderFeed(fmt.Sprintf("%s - %s", config.Title, tag), config, matchingPosts, tag))
+
+		// fmt.Printf("%+v\n", renderListPage("", config, posts))
+
+		// TODO: atom
+		// fmt.Printf("%+v\n", renderFeed(config.Title, config, posts, "feed"))
+
+		// TODO: renderFeedStyles
+
+		// TODO: renderHomepage
+
+		// TODO: render404Page
+	}
+
+	fmt.Printf("%+v\n", tags)
+	fmt.Println()
+}