Initial MVP: Go + templ Tolino-optimized ebook library scaffold

internal/library/library.go

@@ -0,0 +1,78 @@
+package library
+
+import (
+	"crypto/sha1"
+	"encoding/hex"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+)
+
+type Service struct {
+	booksDir string
+}
+
+func New(booksDir string) *Service {
+	return &Service{booksDir: booksDir}
+}
+
+func (s *Service) BooksDir() string { return s.booksDir }
+
+func (s *Service) ListBooks() ([]Book, error) {
+	entries, err := os.ReadDir(s.booksDir)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return []Book{}, nil
+		}
+		return nil, err
+	}
+
+	books := make([]Book, 0, len(entries))
+	for _, e := range entries {
+		if e.IsDir() {
+			continue
+		}
+
+		ext := strings.ToLower(filepath.Ext(e.Name()))
+		if ext != ".epub" && ext != ".pdf" {
+			continue
+		}
+
+		fullPath := filepath.Join(s.booksDir, e.Name())
+		id := stableID(e.Name())
+		title := strings.TrimSuffix(e.Name(), filepath.Ext(e.Name()))
+
+		books = append(books, Book{
+			ID:       id,
+			Title:    title,
+			Filename: e.Name(),
+			Path:     fullPath,
+			Format:   strings.TrimPrefix(ext, "."),
+		})
+	}
+
+	sort.Slice(books, func(i, j int) bool {
+		return strings.ToLower(books[i].Title) < strings.ToLower(books[j].Title)
+	})
+
+	return books, nil
+}
+
+func (s *Service) FindBook(id string) (*Book, error) {
+	books, err := s.ListBooks()
+	if err != nil {
+		return nil, err
+	}
+	for i := range books {
+		if books[i].ID == id {
+			return &books[i], nil
+		}
+	}
+	return nil, nil
+}
+
+func stableID(input string) string {
+	h := sha1.Sum([]byte(strings.ToLower(input)))
+	return hex.EncodeToString(h[:8])
+}

internal/library/model.go

@@ -0,0 +1,9 @@
+package library
+
+type Book struct {
+	ID       string
+	Title    string
+	Filename string
+	Path     string
+	Format   string
+}