rewrite code a bit

Signed-off-by: Naman Sood <mail@nsood.in>

server/server.go

@@ -0,0 +1,201 @@
+package server
+
+import (
+	"bytes"
+	"log"
+	"net/http"
+	"prose/common"
+	"prose/errorcatcher"
+	"prose/postmap"
+	"prose/stylemap"
+	"prose/tplmap"
+	"prose/watcher"
+	"strings"
+
+	"github.com/aymerick/raymond"
+)
+
+type server struct {
+	staticHandler http.Handler
+
+	templates watcher.AutoMap[string, *raymond.Template]
+	posts     watcher.OrderedAutoMap[string, *postmap.Post]
+	styles    watcher.AutoMap[string, string]
+	homeImage []byte
+}
+
+func New() error {
+	s := &server{
+		staticHandler: http.FileServer(http.Dir("static/")),
+	}
+
+	var imgBuffer bytes.Buffer
+	err := common.CreateImage(common.BlogTitle, common.BlogSummary, common.BlogURL, &imgBuffer)
+	if err != nil {
+		return err
+	}
+	s.homeImage = imgBuffer.Bytes()
+
+	s.posts, err = postmap.New()
+	if err != nil {
+		return err
+	}
+
+	s.templates, err = tplmap.New()
+	if err != nil {
+		return err
+	}
+
+	s.styles, err = stylemap.New()
+	if err != nil {
+		return err
+	}
+
+	handlers := map[string]http.HandlerFunc{
+		"GET /{$}":              s.serveGetHome,
+		"GET /banner.png":       s.serveGetImage(s.homeImage),
+		"GET /rss.xml":          s.serveGetRSS,
+		"GET /{slug}":           s.serveGetPost,
+		"GET /img/banner/{img}": s.serveGetPostImage,
+		"GET /css/{filename}":   s.serveGetStylesheet,
+		"GET /":                 s.staticHandler.ServeHTTP,
+	}
+
+	for pattern, handler := range handlers {
+		http.Handle(pattern, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w = errorcatcher.New(w, r, s.templates)
+			handler(w, r)
+		}))
+	}
+
+	return nil
+}
+
+func (s *server) errorInRequest(res http.ResponseWriter, req *http.Request, err error) {
+	res.WriteHeader(http.StatusInternalServerError)
+	log.Printf("ERR %s: %s", req.URL.Path, err)
+}
+
+func (s *server) createWebPage(title, subtitle, contents, banner string) (string, error) {
+	ctx := map[string]interface{}{
+		"title":    title,
+		"subtitle": subtitle,
+		"contents": contents,
+		"banner":   banner,
+	}
+	tpl, _ := s.templates.Get("page.html")
+	return tpl.Exec(ctx)
+}
+
+func (s *server) serveGetPost(w http.ResponseWriter, r *http.Request) {
+	p, ok := s.posts.Get(r.PathValue("slug"))
+	if !ok {
+		w.WriteHeader(http.StatusNotFound)
+		return
+	}
+	w.Header().Add("content-type", "text/html; charset=utf-8")
+	tpl, _ := s.templates.Get("fullpost.html")
+	contents, err := p.Render(tpl)
+	if err != nil {
+		s.errorInRequest(w, r, err)
+		return
+	}
+	page, err := s.createWebPage(p.Metadata.Title, p.Metadata.Summary, contents, "/img/banner/"+p.Slug+".png")
+	if err != nil {
+		s.errorInRequest(w, r, err)
+		return
+	}
+	w.Write([]byte(page))
+}
+
+func (s *server) serveGetHome(w http.ResponseWriter, r *http.Request) {
+	w.Header().Add("content-type", "text/html; charset=utf-8")
+
+	var posts string
+
+	summaryTpl, _ := s.templates.Get("summary.html")
+	for _, p := range s.posts.All() {
+		summary, err := p.Render(summaryTpl)
+		if err != nil {
+			log.Printf("could not render post summary for %s", p.Slug)
+		}
+		posts = posts + summary
+	}
+
+	page, err := s.createWebPage("Home", common.BlogSummary, posts, "/banner.png")
+
+	if err != nil {
+		s.errorInRequest(w, r, err)
+		return
+	}
+
+	w.Write([]byte(page))
+}
+
+func (s *server) serveGetPostImage(w http.ResponseWriter, r *http.Request) {
+	slug, ok := strings.CutSuffix(r.PathValue("img"), ".png")
+	if !ok {
+		w.WriteHeader(http.StatusNotFound)
+		return
+	}
+	post, ok := s.posts.Get(slug)
+	if !ok {
+		w.WriteHeader(http.StatusNotFound)
+		return
+	}
+	s.serveGetImage(post.Image)(w, r)
+}
+
+func (s *server) serveGetImage(img []byte) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Add("content-type", "image/png")
+		w.Write(img)
+	}
+}
+
+func (s *server) serveGetRSS(w http.ResponseWriter, r *http.Request) {
+	w.Header().Add("content-type", "text/xml; charset=utf-8")
+
+	var posts, pubDate string
+
+	rssItemTpl, _ := s.templates.Get("rss-item.xml")
+	for _, p := range s.posts.All() {
+		if pubDate != "" {
+			pubDate = common.RSSDatetime(p.Metadata.Time)
+		}
+		summary, err := p.Render(rssItemTpl)
+		if err != nil {
+			log.Printf("could not render post summary for %s", p.Slug)
+		}
+		posts = posts + summary
+	}
+	if pubDate == "" {
+		pubDate = common.RSSDatetime(0)
+	}
+
+	rssPageTpl, _ := s.templates.Get("rss-channel.xml")
+	page, err := rssPageTpl.Exec(map[string]string{
+		"title":       common.BlogTitle,
+		"description": common.BlogSummary,
+		"link":        common.BlogURL,
+		"pubDate":     pubDate,
+		"items":       posts,
+	})
+
+	if err != nil {
+		s.errorInRequest(w, r, err)
+		return
+	}
+
+	w.Write([]byte(page))
+}
+
+func (s *server) serveGetStylesheet(w http.ResponseWriter, r *http.Request) {
+	contents, ok := s.styles.Get(r.PathValue("filename"))
+	if !ok {
+		w.WriteHeader(http.StatusNotFound)
+		return
+	}
+	w.Header().Add("content-type", "text/css")
+	w.Write([]byte(contents))
+}