Add ebook metadata, author and cover display

go.mod

@@ -2,4 +2,7 @@ module github.com/arnef/ebooks
 
 go 1.25.0
 
-require github.com/a-h/templ v0.3.1020
+require (
+	github.com/a-h/templ v0.3.1020
+	github.com/bmaupin/go-epub v0.0.0-20210915022040-e113c1c5e4a3
+)

internal/library/library.go

@@ -1,9 +1,15 @@
 package library
 
 import (
+	"archive/zip"
+	"bytes"
 	"crypto/sha1"
 	"encoding/hex"
+	"encoding/xml"
+	"fmt"
+	"io"
 	"os"
+	"path"
 	"path/filepath"
 	"sort"
 	"strings"
@@ -41,14 +47,32 @@ func (s *Service) ListBooks() ([]Book, error) {
 
 		fullPath := filepath.Join(s.booksDir, e.Name())
 		id := stableID(e.Name())
-		title := strings.TrimSuffix(e.Name(), filepath.Ext(e.Name()))
+		fallbackTitle := strings.TrimSuffix(e.Name(), filepath.Ext(e.Name()))
+		author := "Unbekannt"
+		hasCover := false
+		title := fallbackTitle
+
+		if ext == ".epub" {
+			meta, err := readEPUBMetadata(fullPath)
+			if err == nil {
+				if strings.TrimSpace(meta.Title) != "" {
+					title = strings.TrimSpace(meta.Title)
+				}
+				if strings.TrimSpace(meta.Author) != "" {
+					author = strings.TrimSpace(meta.Author)
+				}
+				hasCover = meta.HasCover
+			}
+		}
 
 		books = append(books, Book{
 			ID:       id,
 			Title:    title,
+			Author:   author,
 			Filename: e.Name(),
 			Path:     fullPath,
 			Format:   strings.TrimPrefix(ext, "."),
+			HasCover: hasCover,
 		})
 	}
 
@@ -72,7 +96,219 @@ func (s *Service) FindBook(id string) (*Book, error) {
 	return nil, nil
 }
 
+func (s *Service) CoverBytes(id string) ([]byte, string, error) {
+	book, err := s.FindBook(id)
+	if err != nil {
+		return nil, "", err
+	}
+	if book == nil {
+		return nil, "", nil
+	}
+	if book.Format != "epub" {
+		return nil, "", nil
+	}
+	return readEPUBCover(book.Path)
+}
+
 func stableID(input string) string {
 	h := sha1.Sum([]byte(strings.ToLower(input)))
 	return hex.EncodeToString(h[:8])
 }
+
+type epubMetadata struct {
+	Title    string
+	Author   string
+	HasCover bool
+}
+
+type containerXML struct {
+	Rootfiles []struct {
+		FullPath string `xml:"full-path,attr"`
+	} `xml:"rootfiles>rootfile"`
+}
+
+type packageXML struct {
+	Metadata struct {
+		Titles []string `xml:"title"`
+		Creators []string `xml:"creator"`
+		Metas []struct {
+			Name    string `xml:"name,attr"`
+			Content string `xml:"content,attr"`
+		} `xml:"meta"`
+	} `xml:"metadata"`
+	Manifest struct {
+		Items []struct {
+			ID        string `xml:"id,attr"`
+			Href      string `xml:"href,attr"`
+			MediaType string `xml:"media-type,attr"`
+			Properties string `xml:"properties,attr"`
+		} `xml:"item"`
+	} `xml:"manifest"`
+}
+
+func readEPUBMetadata(filePath string) (epubMetadata, error) {
+	r, rootPath, pkg, err := openEPUBPackage(filePath)
+	if err != nil {
+		return epubMetadata{}, err
+	}
+	defer r.Close()
+
+	meta := epubMetadata{}
+	if len(pkg.Metadata.Titles) > 0 {
+		meta.Title = strings.TrimSpace(pkg.Metadata.Titles[0])
+	}
+	if len(pkg.Metadata.Creators) > 0 {
+		meta.Author = strings.TrimSpace(pkg.Metadata.Creators[0])
+	}
+
+	coverPath := findEPUBCoverPath(rootPath, pkg)
+	meta.HasCover = coverPath != ""
+	return meta, nil
+}
+
+func readEPUBCover(filePath string) ([]byte, string, error) {
+	r, rootPath, pkg, err := openEPUBPackage(filePath)
+	if err != nil {
+		return nil, "", err
+	}
+	defer r.Close()
+
+	coverPath := findEPUBCoverPath(rootPath, pkg)
+	if coverPath == "" {
+		return nil, "", nil
+	}
+
+	for _, f := range r.File {
+		if path.Clean(f.Name) != coverPath {
+			continue
+		}
+		rc, err := f.Open()
+		if err != nil {
+			return nil, "", err
+		}
+		defer rc.Close()
+		data, err := io.ReadAll(rc)
+		if err != nil {
+			return nil, "", err
+		}
+		return data, detectContentType(data, f.Name), nil
+	}
+
+	return nil, "", nil
+}
+
+func openEPUBPackage(filePath string) (*zip.ReadCloser, string, packageXML, error) {
+	r, err := zip.OpenReader(filePath)
+	if err != nil {
+		return nil, "", packageXML{}, err
+	}
+
+	containerData, err := readZipFile(r.File, "META-INF/container.xml")
+	if err != nil {
+		r.Close()
+		return nil, "", packageXML{}, err
+	}
+
+	var container containerXML
+	if err := xml.Unmarshal(containerData, &container); err != nil {
+		r.Close()
+		return nil, "", packageXML{}, err
+	}
+	if len(container.Rootfiles) == 0 || strings.TrimSpace(container.Rootfiles[0].FullPath) == "" {
+		r.Close()
+		return nil, "", packageXML{}, fmt.Errorf("missing rootfile in epub container")
+	}
+
+	packagePath := path.Clean(container.Rootfiles[0].FullPath)
+	packageData, err := readZipFile(r.File, packagePath)
+	if err != nil {
+		r.Close()
+		return nil, "", packageXML{}, err
+	}
+
+	var pkg packageXML
+	if err := xml.Unmarshal(packageData, &pkg); err != nil {
+		r.Close()
+		return nil, "", packageXML{}, err
+	}
+
+	return r, path.Dir(packagePath), pkg, nil
+}
+
+func findEPUBCoverPath(rootPath string, pkg packageXML) string {
+	coverID := ""
+	for _, meta := range pkg.Metadata.Metas {
+		if strings.EqualFold(strings.TrimSpace(meta.Name), "cover") {
+			coverID = strings.TrimSpace(meta.Content)
+			break
+		}
+	}
+
+	for _, item := range pkg.Manifest.Items {
+		if strings.Contains(item.Properties, "cover-image") {
+			return cleanEPUBPath(rootPath, item.Href)
+		}
+		if coverID != "" && item.ID == coverID {
+			return cleanEPUBPath(rootPath, item.Href)
+		}
+	}
+
+	for _, item := range pkg.Manifest.Items {
+		if strings.HasPrefix(item.MediaType, "image/") && strings.Contains(strings.ToLower(item.Href), "cover") {
+			return cleanEPUBPath(rootPath, item.Href)
+		}
+	}
+
+	return ""
+}
+
+func cleanEPUBPath(rootPath, href string) string {
+	joined := path.Clean(path.Join(rootPath, href))
+	if strings.HasPrefix(joined, "../") {
+		return ""
+	}
+	return joined
+}
+
+func readZipFile(files []*zip.File, name string) ([]byte, error) {
+	cleanName := path.Clean(name)
+	for _, f := range files {
+		if path.Clean(f.Name) != cleanName {
+			continue
+		}
+		rc, err := f.Open()
+		if err != nil {
+			return nil, err
+		}
+		defer rc.Close()
+		return io.ReadAll(rc)
+	}
+	return nil, os.ErrNotExist
+}
+
+func detectContentType(data []byte, filename string) string {
+	if len(data) > 0 {
+		return httpDetectContentType(data)
+	}
+	ext := strings.ToLower(path.Ext(filename))
+	switch ext {
+	case ".jpg", ".jpeg":
+		return "image/jpeg"
+	case ".png":
+		return "image/png"
+	case ".gif":
+		return "image/gif"
+	case ".webp":
+		return "image/webp"
+	default:
+		return "application/octet-stream"
+	}
+}
+
+func httpDetectContentType(data []byte) string {
+	return strings.TrimSpace(strings.SplitN(fmt.Sprintf("%s", bytes.TrimSpace([]byte(httpContentType(data)))), ";", 2)[0])
+}
+
+func httpContentType(data []byte) string {
+	return io.NopCloser(bytes.NewReader(data)).(interface{ Read([]byte) (int, error) }) // unreachable shim
+}

internal/library/model.go

@@ -3,7 +3,9 @@ package library
 type Book struct {
 	ID       string
 	Title    string
+	Author   string
 	Filename string
 	Path     string
 	Format   string
+	HasCover bool
 }

internal/web/handlers.go

@@ -24,6 +24,7 @@ func (h *Handler) RegisterRoutes(mux *http.ServeMux) {
 	mux.HandleFunc("GET /", h.listBooks)
 	mux.HandleFunc("GET /book/{id}", h.bookDetails)
 	mux.HandleFunc("GET /download/{id}", h.downloadBook)
+	mux.HandleFunc("GET /cover/{id}", h.bookCover)
 	mux.Handle("GET /static/", http.StripPrefix("/static/", http.FileServer(http.Dir("static"))))
 }
 
@@ -84,6 +85,31 @@ func (h *Handler) downloadBook(w http.ResponseWriter, r *http.Request) {
 	http.ServeFile(w, r, cleanPath)
 }
 
+func (h *Handler) bookCover(w http.ResponseWriter, r *http.Request) {
+	id := r.PathValue("id")
+	if id == "" {
+		http.NotFound(w, r)
+		return
+	}
+
+	data, contentType, err := h.lib.CoverBytes(id)
+	if err != nil {
+		http.Error(w, "failed to load cover", http.StatusInternalServerError)
+		return
+	}
+	if len(data) == 0 {
+		http.NotFound(w, r)
+		return
+	}
+	if contentType == "" {
+		contentType = "application/octet-stream"
+	}
+
+	w.Header().Set("Content-Type", contentType)
+	w.Header().Set("Cache-Control", "public, max-age=3600")
+	_, _ = w.Write(data)
+}
+
 func render(w http.ResponseWriter, ctx context.Context, c templ.Component) {
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
 	if err := c.Render(ctx, w); err != nil && !errors.Is(err, context.Canceled) {

static/styles.css

@@ -1,20 +1,32 @@
 :root {
   color-scheme: light;
+  --bg: #f6f4ee;
+  --surface: #ffffff;
+  --surface-muted: #f0ece2;
+  --text: #1d1b16;
+  --muted: #6b6458;
+  --border: #d6cebf;
+  --shadow: 0 2px 10px rgba(0, 0, 0, 0.06);
 }
 
 html, body {
   margin: 0;
   padding: 0;
-  background: #fff;
+  background: var(--bg);
-  color: #000;
+  color: var(--text);
   font-family: Arial, sans-serif;
   font-size: 18px;
   line-height: 1.45;
 }
 
+img {
+  max-width: 100%;
+}
+
 .header {
-  border-bottom: 2px solid #000;
+  border-bottom: 1px solid var(--border);
-  padding: 0.75rem 1rem;
+  background: var(--surface);
+  padding: 0.9rem 1rem;
 }
 
 .header h1 {
@@ -29,51 +41,174 @@ html, body {
 
 .container {
   padding: 1rem;
-  max-width: 42rem;
+  max-width: 56rem;
+  margin: 0 auto;
 }
 
 h2 {
   margin-top: 0;
-  font-size: 1.25rem;
+  font-size: 1.4rem;
+}
+
+.page-head {
+  margin-bottom: 1rem;
+}
+
+.page-subtitle {
+  margin: 0.35rem 0 0;
+  color: var(--muted);
+  font-size: 0.95rem;
 }
 
 .book-list {
   list-style: none;
   margin: 0;
   padding: 0;
+  display: grid;
+  gap: 0.85rem;
 }
 
 .book-item {
-  border: 1px solid #000;
+  margin: 0;
-  margin-bottom: 0.6rem;
-  padding: 0.6rem;
 }
 
-.book-link {
+.book-card {
-  display: inline-block;
+  display: grid;
-  min-height: 44px;
+  grid-template-columns: 5.5rem 1fr;
-  color: #000;
+  gap: 0.9rem;
+  align-items: start;
+  border: 1px solid var(--border);
+  border-radius: 14px;
+  background: var(--surface);
+  padding: 0.8rem;
+  color: inherit;
   text-decoration: none;
+  box-shadow: var(--shadow);
+}
+
+.book-card-cover,
+.book-detail-cover {
+  display: flex;
+  align-items: flex-start;
+  justify-content: center;
+}
+
+.book-cover,
+.book-cover-placeholder {
+  width: 100%;
+  max-width: 5.5rem;
+  aspect-ratio: 2 / 3;
+  border-radius: 10px;
+  border: 1px solid var(--border);
+  background: var(--surface-muted);
+  object-fit: cover;
+  overflow: hidden;
+}
+
+.book-cover-placeholder {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  color: var(--muted);
+  font-size: 0.85rem;
   font-weight: bold;
+  letter-spacing: 0.08em;
+}
+
+.book-cover-detail,
+.book-cover-placeholder-detail {
+  max-width: 12rem;
+}
+
+.book-card-body {
+  min-width: 0;
+}
+
+.book-title {
+  display: block;
+  font-size: 1.05rem;
+}
+
+.book-author,
+.book-author-detail {
+  display: block;
+  color: var(--muted);
+}
+
+.book-author {
+  margin-top: 0.2rem;
+  font-size: 0.95rem;
+}
+
+.book-author-detail {
+  margin: -0.35rem 0 1rem;
 }
 
 .format {
-  display: block;
+  display: inline-block;
-  margin-top: 0.2rem;
+  margin-top: 0.6rem;
-  font-size: 0.95rem;
+  padding: 0.15rem 0.5rem;
+  border: 1px solid var(--border);
+  border-radius: 999px;
+  font-size: 0.85rem;
+  text-transform: uppercase;
+  background: var(--surface-muted);
+}
+
+.book-detail {
+  display: grid;
+  gap: 1.25rem;
+}
+
+.book-detail-body {
+  min-width: 0;
+}
+
+.book-meta {
+  margin: 0 0 1.25rem;
+}
+
+.book-meta div {
+  margin-bottom: 0.8rem;
+}
+
+.book-meta dt {
+  font-weight: bold;
+}
+
+.book-meta dd {
+  margin: 0.2rem 0 0;
+  color: var(--muted);
+  word-break: break-word;
+}
+
+.back-link {
+  color: var(--muted);
+  text-decoration: none;
 }
 
 .btn {
   display: inline-block;
   min-height: 44px;
   padding: 0.7rem 1rem;
-  border: 2px solid #000;
+  border: 1px solid var(--text);
+  border-radius: 999px;
   text-decoration: none;
-  color: #000;
+  color: #fff;
+  background: var(--text);
   font-weight: bold;
 }
 
 code {
-  border: 1px solid #000;
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  background: var(--surface);
   padding: 0.1rem 0.3rem;
 }
+
+@media (min-width: 700px) {
+  .book-detail {
+    grid-template-columns: 12rem 1fr;
+    align-items: start;
+  }
+}

views/pages.templ

@@ -22,17 +22,38 @@ templ Layout(title string) {
 </html>
 }
 
+templ BookCover(book library.Book, detail bool) {
+  if book.HasCover {
+    <img class={ coverClass(detail) } src={ "/cover/" + book.ID } alt={ "Cover von " + book.Title } loading="lazy" />
+  } else {
+    <div class={ placeholderClass(detail) } aria-hidden="true">
+      <span>{ strings.ToUpper(book.Format) }</span>
+    </div>
+  }
+}
+
 templ IndexPage(books []library.Book) {
   @Layout("Bibliothek") {
+    <section class="page-head">
       <h2>Meine Bücher</h2>
+      <p class="page-subtitle">Titel, Autor und Cover auf einen Blick.</p>
+    </section>
     if len(books) == 0 {
       <p>Keine eBooks gefunden. Lege EPUB- oder PDF-Dateien im Ordner <code>books/</code> ab.</p>
     } else {
       <ul class="book-list">
         for _, b := range books {
           <li class="book-item">
-            <a class="book-link" href={ "/book/" + b.ID }>{ b.Title }</a>
+            <a class="book-card" href={ "/book/" + b.ID }>
+              <div class="book-card-cover">
+                @BookCover(b, false)
+              </div>
+              <div class="book-card-body">
+                <strong class="book-title">{ b.Title }</strong>
+                <span class="book-author">{ b.Author }</span>
                 <span class="format">{ b.Format }</span>
+              </div>
+            </a>
           </li>
         }
       </ul>
@@ -42,12 +63,40 @@ templ IndexPage(books []library.Book) {
 
 templ BookPage(book library.Book) {
   @Layout(book.Title) {
-    <article>
+    <article class="book-detail">
+      <div class="book-detail-cover">
+        @BookCover(book, true)
+      </div>
+      <div class="book-detail-body">
+        <p><a class="back-link" href="/">← Zurück zur Liste</a></p>
         <h2>{ book.Title }</h2>
-      <p><strong>Datei:</strong> { book.Filename }</p>
+        <p class="book-author-detail">{ book.Author }</p>
-      <p><strong>Format:</strong> { book.Format }</p>
+        <dl class="book-meta">
+          <div>
+            <dt>Datei</dt>
+            <dd>{ book.Filename }</dd>
+          </div>
+          <div>
+            <dt>Format</dt>
+            <dd>{ book.Format }</dd>
+          </div>
+        </dl>
         <p><a class="btn" href={ "/download/" + book.ID }>Auf Tolino herunterladen</a></p>
-      <p><a href="/">← Zurück zur Liste</a></p>
+      </div>
     </article>
   }
 }
+
+func coverClass(detail bool) string {
+  if detail {
+    return "book-cover book-cover-detail"
+  }
+  return "book-cover"
+}
+
+func placeholderClass(detail bool) string {
+  if detail {
+    return "book-cover-placeholder book-cover-placeholder-detail"
+  }
+  return "book-cover-placeholder"
+}