1 files changed, 570 insertions, 0 deletions
diff --git a/cmd/build/build.go b/cmd/build/build.go
new file mode 100644
index 0000000..ecc40a8
--- /dev/null
+++ b/cmd/build/build.go
@@ -0,0 +1,570 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"encoding/xml"
+	"fmt"
+	"io"
+	"io/fs"
+	"log"
+	"log/slog"
+	"net/url"
+	"os"
+	"os/exec"
+	"path"
+	"path/filepath"
+	"slices"
+	"strings"
+	"time"
+
+	. "website/internal/config"
+
+	"github.com/BurntSushi/toml"
+	"github.com/PuerkitoBio/goquery"
+	"github.com/adrg/frontmatter"
+	"github.com/antchfx/xmlquery"
+	"github.com/antchfx/xpath"
+	mapset "github.com/deckarep/golang-set/v2"
+	"github.com/pkg/errors"
+	"github.com/yuin/goldmark"
+	"github.com/yuin/goldmark/extension"
+	"github.com/yuin/goldmark/renderer/html"
+)
+
+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 getPost(filename string) (*PostMatter, *[]byte, error) {
+	matter := PostMatter{}
+	content, err := os.Open(filename)
+	defer content.Close()
+	if err != nil {
+		return nil, nil, errors.WithMessagef(err, "could not open post %s", filename)
+	}
+	rest, err := frontmatter.MustParse(content, &matter)
+	if err != nil {
+		return nil, nil, errors.WithMessagef(err, "could not parse front matter of post %s", filename)
+	}
+
+	return &matter, &rest, nil
+}
+
+func readPosts(root string, inputDir string, outputDir string) ([]Post, Tags, error) {
+	tags := mapset.NewSet[string]()
+	posts := []Post{}
+	subdir := filepath.Join(root, inputDir)
+	files, err := os.ReadDir(subdir)
+	if err != nil {
+		return nil, nil, errors.WithMessagef(err, "could not read post directory %s", subdir)
+	}
+	outputReplacer := strings.NewReplacer(root, outputDir, ".md", "/index.html")
+	urlReplacer := strings.NewReplacer(root, "", ".md", "/")
+	markdown := goldmark.New(
+		goldmark.WithRendererOptions(
+			html.WithUnsafe(),
+		),
+		goldmark.WithExtensions(
+			extension.GFM,
+			extension.Footnote,
+			extension.Typographer,
+		),
+	)
+	for _, f := range files {
+		pathFromRoot := filepath.Join(subdir, f.Name())
+		if !f.IsDir() && path.Ext(pathFromRoot) == ".md" {
+			output := outputReplacer.Replace(pathFromRoot)
+			url := urlReplacer.Replace(pathFromRoot)
+			slog.Debug("reading post", "post", pathFromRoot)
+			matter, content, err := getPost(pathFromRoot)
+			if err != nil {
+				return nil, nil, err
+			}
+
+			for _, tag := range matter.Taxonomies.Tags {
+				tags.Add(strings.ToLower(tag))
+			}
+
+			var buf bytes.Buffer
+			slog.Debug("rendering markdown in post", "post", pathFromRoot)
+			if err := markdown.Convert(*content, &buf); err != nil {
+				return nil, nil, errors.WithMessage(err, "could not convert markdown content")
+			}
+			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, nil
+}
+
+type purgeCSSOutput struct {
+	CSS  string `json:"css"`
+	File string
+}
+
+var purgedCSS map[string]string
+
+func purgeCSS(htmlFilename string, cssFilename string) (string, error) {
+	if purgedCSS == nil {
+		purgedCSS = make(map[string]string)
+	} else if purgedCSS[htmlFilename] == "" {
+		slog.Debug("running purgecss", "html", htmlFilename, "css", cssFilename)
+		bytes, err := exec.Command("bun", "./node_modules/.bin/purgecss", "--css", cssFilename, "--content", htmlFilename).Output()
+		if err != nil {
+			return "", errors.WithMessage(err, "failed running `purgecss` command")
+		}
+		var out []purgeCSSOutput
+		err = json.Unmarshal(bytes, &out)
+		if err != nil {
+			return "", errors.WithMessage(err, "failed decoding `purgecss` output")
+		}
+		purgedCSS[htmlFilename] = out[0].CSS
+	}
+	return purgedCSS[htmlFilename], nil
+}
+
+func layout(filename string, config Config, pageTitle string) (*goquery.Document, error) {
+	html, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	defer html.Close()
+	css, err := purgeCSS(filename, "templates/style.css")
+	if err != nil {
+		bytes, err := os.ReadFile("templates/style.css")
+		if err != nil {
+			return nil, err
+		}
+		css = string(bytes)
+	}
+	doc, err := goquery.NewDocumentFromReader(html)
+	if err != nil {
+		return nil, err
+	}
+	doc.Find("html").SetAttr("lang", config.DefaultLanguage)
+	doc.Find("head > link[rel=alternate]").SetAttr("title", config.Title)
+	doc.Find(".title").SetText(config.Title)
+	doc.Find("title").Add(".p-name").SetText(pageTitle)
+	doc.Find("head > style").SetHtml("\n" + 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, nil
+}
+
+func renderHTML(doc *goquery.Document) io.Reader {
+	r, w := io.Pipe()
+	go func() {
+		goquery.Render(w, doc.Children())
+		defer w.Close()
+	}()
+	return r
+}
+
+func renderPost(post Post, config Config) (r io.Reader, err error) {
+	doc, err := layout("templates/post.html", config, post.PostMatter.Title)
+	if err != nil {
+		return nil, err
+	}
+	doc.Find(".title").AddClass("p-author h-card").SetAttr("rel", "author")
+	doc.Find(".h-entry .dt-published").
+		SetAttr("datetime", post.PostMatter.Date.UTC().Format(time.RFC3339)).
+		SetText(
+			post.PostMatter.Date.Format("2006-01-02"),
+		)
+	doc.Find(".h-entry .e-content").SetHtml(post.Content)
+	categories := doc.Find(".h-entry .p-categories")
+	tpl := categories.Find(".p-category").ParentsUntilSelection(categories)
+	tpl.Remove()
+	for _, tag := range post.Taxonomies.Tags {
+		cat := tpl.Clone()
+		cat.Find(".p-category").SetAttr("href", fmt.Sprintf("/tags/%s/", tag)).SetText("#" + tag)
+		categories.AppendSelection(cat)
+	}
+
+	return renderHTML(doc), nil
+}
+
+func renderTags(tags Tags, config Config) (io.Reader, error) {
+	doc, err := layout("templates/tags.html", config, config.Title)
+	if err != nil {
+		return nil, err
+	}
+	tagList := doc.Find(".tags")
+	tpl := doc.Find(".h-feed")
+	tpl.Remove()
+	for _, tag := range mapset.Sorted(tags) {
+		li := tpl.Clone()
+		li.Find("a").SetAttr("href", fmt.Sprintf("/tags/%s/", tag)).SetText("#" + tag)
+		tagList.AppendSelection(li)
+	}
+	return renderHTML(doc), nil
+}
+
+func renderListPage(tag string, config Config, posts []Post) (io.Reader, error) {
+	var title string
+	if len(tag) > 0 {
+		title = tag
+	} else {
+		title = config.Title
+	}
+	doc, err := layout("templates/list.html", config, title)
+	if err != nil {
+		return nil, err
+	}
+	feed := doc.Find(".h-feed")
+	tpl := feed.Find(".h-entry")
+	tpl.Remove()
+
+	doc.Find(".title").AddClass("p-author h-card").SetAttr("rel", "author")
+	if tag == "" {
+		doc.Find(".filter").Remove()
+	} else {
+		doc.Find(".filter").Find("h3").SetText("#" + tag)
+	}
+
+	for _, post := range posts {
+		entry := tpl.Clone()
+		entry.Find(".p-name").SetText(post.Title).SetAttr("href", post.URL)
+		entry.Find(".dt-published").
+			SetAttr("datetime", post.PostMatter.Date.UTC().Format(time.RFC3339)).
+			SetText(post.PostMatter.Date.Format("2006-01-02"))
+		feed.AppendSelection(entry)
+	}
+
+	return renderHTML(doc), nil
+}
+
+func renderHomepage(config Config, posts []Post) (io.Reader, error) {
+	_, index, err := getPost("content/_index.md")
+	if err != nil {
+		return nil, err
+	}
+	doc, err := layout("templates/homepage.html", config, config.Title)
+	if err != nil {
+		return nil, err
+	}
+	doc.Find("body").AddClass("h-card")
+	doc.Find(".title").AddClass("p-name u-url")
+	var buf bytes.Buffer
+
+	md := goldmark.New(goldmark.WithRendererOptions(html.WithUnsafe()))
+	if err := md.Convert(*index, &buf); err != nil {
+		return nil, err
+	}
+	doc.Find("#content").SetHtml(buf.String())
+
+	feed := doc.Find(".h-feed")
+	tpl := feed.Find(".h-entry")
+	tpl.Remove()
+
+	for _, post := range posts[0:3] {
+		entry := tpl.Clone()
+		entry.Find(".p-name").SetText(post.Title)
+		entry.Find(".u-url").SetAttr("href", post.URL)
+		entry.
+			Find(".dt-published").
+			SetAttr("datetime", post.PostMatter.Date.UTC().Format(time.RFC3339)).
+			SetText(post.PostMatter.Date.Format("2006-01-02"))
+
+		feed.AppendSelection(entry)
+	}
+	doc.Find(".u-email").
+		SetAttr("href", fmt.Sprintf("mailto:%s", config.Email)).
+		SetText(config.Email)
+
+	elsewhere := doc.Find(".elsewhere")
+	linkRelMe := elsewhere.Find(".u-url[rel=me]").ParentsUntil("ul")
+	linkRelMe.Remove()
+
+	for _, link := range config.Menus["me"] {
+		el := linkRelMe.Clone()
+		el.Find("a").SetAttr("href", link.URL).SetText(link.Name)
+		elsewhere.AppendSelection(el)
+	}
+
+	return renderHTML(doc), nil
+}
+
+func render404(config Config) (io.Reader, error) {
+	doc, err := layout("templates/404.html", config, "404 Not Found")
+	if err != nil {
+		return nil, err
+	}
+	return renderHTML(doc), nil
+}
+
+func renderFeed(title string, config Config, posts []Post, specific string) (io.Reader, error) {
+	reader, err := os.Open("templates/feed.xml")
+	if err != nil {
+		return nil, err
+	}
+	defer reader.Close()
+	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.UTC().MarshalText()
+	feed.SelectElement("updated").FirstChild.Data = string(datetime)
+	tpl := feed.SelectElement("entry")
+	xmlquery.RemoveFromTree(tpl)
+
+	for _, post := range posts {
+		fullURL, err := url.JoinPath(config.BaseURL, post.URL)
+		if err != nil {
+			return nil, err
+		}
+		text, err := xml.MarshalIndent(&FeedEntry{
+			Title:   post.Title,
+			Link:    MakeLink(fullURL),
+			Id:      MakeTagURI(config, post.Basename),
+			Updated: post.Date.UTC(),
+			Summary: post.Description,
+			Author:  config.Title,
+			Content: FeedContent{
+				Content: post.Content,
+				Type:    "html",
+			},
+		}, "  ", "    ")
+		if err != nil {
+			return nil, err
+		}
+		entry, err := xmlquery.ParseWithOptions(strings.NewReader(string(text)), xmlquery.ParserOptions{
+			Decoder: &xmlquery.DecoderOptions{
+				Strict:    false,
+				AutoClose: xml.HTMLAutoClose,
+				Entity:    xml.HTMLEntity,
+			},
+		})
+		if err != nil {
+			return nil, err
+		}
+		xmlquery.AddChild(feed, entry.SelectElement("entry"))
+	}
+
+	return strings.NewReader(doc.OutputXML(true)), nil
+}
+
+func renderFeedStyles() (io.Reader, error) {
+	reader, err := os.Open("templates/feed-styles.xsl")
+	if err != nil {
+		return nil, err
+	}
+	defer reader.Close()
+	nsMap := map[string]string{
+		"xsl":   "http://www.w3.org/1999/XSL/Transform",
+		"atom":  "http://www.w3.org/2005/Atom",
+		"xhtml": "http://www.w3.org/1999/xhtml",
+	}
+	doc, err := xmlquery.Parse(reader)
+	expr, err := xpath.CompileWithNS("//xhtml:style", nsMap)
+	if err != nil {
+		return nil, err
+	}
+	style := xmlquery.QuerySelector(doc, expr)
+	css, err := os.ReadFile("templates/style.css")
+	if err != nil {
+		return nil, err
+	}
+	xmlquery.AddChild(style, &xmlquery.Node{
+		Type: xmlquery.TextNode,
+		Data: string(css),
+	})
+	return strings.NewReader(doc.OutputXML(true)), nil
+}
+
+func mkdirp(dirs ...string) error {
+	return os.MkdirAll(path.Join(dirs...), 0755)
+}
+
+func outputToFile(output io.Reader, filename ...string) error {
+	file, err := os.OpenFile(path.Join(filename...), os.O_WRONLY|os.O_CREATE, 00644)
+	if err != nil {
+		return errors.WithMessage(err, "could not open output file")
+	}
+	defer file.Close()
+
+	if _, err := file.ReadFrom(output); err != nil {
+		return errors.WithMessage(err, "could not write output file")
+	}
+	return nil
+}
+
+func build() error {
+	config, err := GetConfig()
+	if err != nil {
+		return err
+	}
+	outDir := "new"
+	if err := mkdirp(outDir, "post"); err != nil {
+		return errors.WithMessage(err, "could not create post output directory")
+	}
+	slog.Debug("reading posts")
+	posts, tags, err := readPosts("content", "post", outDir)
+	if err != nil {
+		return err
+	}
+
+	for _, post := range posts {
+		if err := mkdirp(outDir, "post", post.Basename); err != nil {
+			return errors.WithMessage(err, "could not create directory for post")
+		}
+		slog.Debug("rendering post", "post", post.Basename)
+		output, err := renderPost(post, *config)
+		if err != nil {
+			return errors.WithMessagef(err, "could not render post %s", post.Input)
+		}
+		if err := outputToFile(output, post.Output); err != nil {
+			return err
+		}
+	}
+
+	if err := mkdirp(outDir, "tags"); err != nil {
+		return errors.WithMessage(err, "could not create directory for tags")
+	}
+	slog.Debug("rendering tags list")
+	output, err := renderTags(tags, *config)
+	if err != nil {
+		return errors.WithMessage(err, "could not render tags")
+	}
+	if err := outputToFile(output, outDir, "tags", "index.html"); err != nil {
+		return err
+	}
+
+	for _, tag := range tags.ToSlice() {
+		matchingPosts := []Post{}
+		for _, post := range posts {
+			if slices.Contains(post.Taxonomies.Tags, tag) {
+				matchingPosts = append(matchingPosts, post)
+			}
+		}
+		if err := mkdirp(outDir, "tags", tag); err != nil {
+			return errors.WithMessage(err, "could not create directory")
+		}
+		slog.Debug("rendering tags page", "tag", tag)
+		output, err := renderListPage(tag, *config, matchingPosts)
+		if err != nil {
+			return errors.WithMessage(err, "could not render tag page")
+		}
+		if err := outputToFile(output, outDir, "tags", tag, "index.html"); err != nil {
+			return err
+		}
+
+		slog.Debug("rendering tags feed", "tag", tag)
+		output, err = renderFeed(fmt.Sprintf("%s - %s", config.Title, tag), *config, matchingPosts, tag)
+		if err != nil {
+			return errors.WithMessage(err, "could not render tag feed page")
+		}
+		if err := outputToFile(output, outDir, "tags", tag, "atom.xml"); err != nil {
+			return err
+		}
+	}
+
+	slog.Debug("rendering list page")
+	listPage, err := renderListPage("", *config, posts)
+	if err != nil {
+		return errors.WithMessage(err, "could not render list page")
+	}
+	if err := outputToFile(listPage, outDir, "post", "index.html"); err != nil {
+		return err
+	}
+
+	slog.Debug("rendering feed")
+	feed, err := renderFeed(config.Title, *config, posts, "feed")
+	if err != nil {
+		return errors.WithMessage(err, "could not render feed")
+	}
+	if err := outputToFile(feed, outDir, "atom.xml"); err != nil {
+		return err
+	}
+
+	slog.Debug("rendering feed styles")
+	feedStyles, err := renderFeedStyles()
+	if err != nil {
+		return errors.WithMessage(err, "could not render feed styles")
+	}
+	if err := outputToFile(feedStyles, outDir, "feed-styles.xsl"); err != nil {
+		return err
+	}
+
+	slog.Debug("rendering homepage")
+	homePage, err := renderHomepage(*config, posts)
+	if err != nil {
+		return errors.WithMessage(err, "could not render homepage")
+	}
+	if err := outputToFile(homePage, outDir, "index.html"); err != nil {
+		return err
+	}
+
+	slog.Debug("rendering 404 page")
+	notFound, err := render404(*config)
+	if err != nil {
+		return errors.WithMessage(err, "could not render 404 page")
+	}
+	if err := outputToFile(notFound, outDir, "404.html"); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func main() {
+	if os.Getenv("DEBUG") != "" {
+		slog.SetLogLoggerLevel(slog.LevelDebug)
+	}
+	slog.Debug("starting build process")
+	_, err := os.Getwd()
+	if err != nil {
+		log.Panic(errors.Errorf("working directory does not exist: %v", err))
+	}
+
+	if err := build(); err != nil {
+		switch cause := errors.Cause(err).(type) {
+		case *fs.PathError:
+			slog.Info("pathError")
+			slog.Error(fmt.Sprintf("%s", err))
+		case toml.ParseError:
+			slog.Info("parseError")
+			slog.Error(fmt.Sprintf("%s", err))
+		default:
+			slog.Info("other")
+			slog.Error(fmt.Sprintf("cause:%+v", errors.Cause(cause)))
+			slog.Error(fmt.Sprintf("%+v", cause))
+		}
+		os.Exit(1)
+	}
+
+	slog.Debug("done")
+}