tidy source files

separating logging and web serving into modules

web/main.go

@@ -0,0 +1,204 @@
+package web
+
+import (
+	_ "embed"
+	"fmt"
+	"html/template"
+	"io/fs"
+	"mime"
+	"net/http"
+	"os"
+	"path"
+	"path/filepath"
+	"slices"
+	"strings"
+
+	"github.com/gomarkdown/markdown"
+	"github.com/gomarkdown/markdown/html"
+	"github.com/gomarkdown/markdown/parser"
+)
+
+type (
+	AppState struct {
+		Root			string
+		FilesDir		string
+		IgnoredFiles	[]string
+	}
+
+	Directory struct {
+		Name string
+		Root bool
+		Files []*File
+		Readme template.HTML
+		CSS template.CSS
+	}
+
+	File struct {
+		Name string
+		URI string
+		IsDir bool
+		Size string
+		ModifiedDate string
+	}
+)
+
+//go:embed dir.html
+var dirTemplateSrc string
+var dirTemplate = template.Must(template.New("dir").Parse(dirTemplateSrc))
+
+func Handler(app *AppState) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if !strings.HasPrefix(r.URL.Path, app.Root) {
+			http.NotFound(w, r)
+			return
+		}
+		isRoot := r.URL.Path == app.Root
+
+		fpath := path.Join(app.FilesDir, strings.TrimPrefix(r.URL.Path, app.Root))
+		info, err := os.Stat(fpath)
+		if err != nil {
+			http.NotFound(w, r)
+			return
+		}
+
+		// downloading file
+		if !info.IsDir() {
+			if strings.HasSuffix(r.URL.Path, "/") {
+				http.Redirect(w, r, strings.TrimSuffix(r.URL.Path, "/"), http.StatusFound)
+				return
+			}
+
+			file, err := os.Open(fpath)
+			if err != nil {
+				http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+				return
+			}
+
+			defer func() {
+				err := file.Close()
+				if err != nil {
+					fmt.Fprintf(os.Stderr, "failed to close file %s: %v\n", fpath, err)
+				}
+			}()
+
+			mimeType := "application/octet-stream"
+			extPos := strings.LastIndex(info.Name(), ".")
+			if extPos != -1 {
+				if m := mime.TypeByExtension(info.Name()[extPos:]); m != "" {
+					mimeType = m
+				}
+			}
+
+			w.Header().Set("Content-Type", mimeType)
+			w.WriteHeader(http.StatusOK)
+
+			_, err = file.WriteTo(w)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "failed to send file %s: %v\n", fpath, err)
+			}
+			return
+		}
+
+		if !strings.HasSuffix(r.URL.Path, "/") {
+			http.Redirect(w, r, r.URL.Path + "/", http.StatusFound)
+			return
+		}
+
+		// serve index.html if present (case-sensitive)
+		indexPath := filepath.Join(fpath, "index.html")
+		if indexInfo, err := os.Stat(indexPath); err == nil && !indexInfo.IsDir() {
+			http.ServeFile(w, r, indexPath)
+			return
+		}
+
+		// load index.css if present
+		var customCSS template.CSS
+		cssPath := filepath.Join(fpath, "index.css")
+		if cssInfo, err := os.Stat(cssPath); err == nil && !cssInfo.IsDir() {
+			if src, err := os.ReadFile(cssPath); err == nil {
+				customCSS = template.CSS(src)
+			}
+		}
+
+		// embeded readme
+		var readmeHTML template.HTML
+		entries, err := os.ReadDir(fpath)
+		if err == nil {
+			for _, entry := range entries {
+				if strings.EqualFold(entry.Name(), "readme.md") {
+					src, err := os.ReadFile(filepath.Join(fpath, entry.Name()))
+					if err == nil {
+						mdFlags := html.CommonFlags | html.HrefTargetBlank
+						mdRenderer := html.NewRenderer(html.RendererOptions{Flags: mdFlags})
+						mdParser := parser.NewWithExtensions(parser.CommonExtensions | parser.AutoHeadingIDs)
+						md := mdParser.Parse(src)
+						readmeHTML = template.HTML(markdown.Render(md, mdRenderer))
+					}
+					break
+				}
+			}
+		}
+
+		data := Directory{
+			Root: isRoot,
+			Name: r.URL.Path,
+			Files: []*File{},
+			Readme: readmeHTML,
+			CSS: customCSS,
+		}
+
+		fsDir := os.DirFS(fpath)
+		directories, err := fs.ReadDir(fsDir, ".")
+		for _, dir := range directories {
+			name := dir.Name()
+			if slices.Contains(app.IgnoredFiles, name) { continue }
+
+			info, err := dir.Info()
+			if err != nil { continue }
+
+			var uri string
+			if isRoot {
+				uri = app.Root + name
+			} else {
+				uri = r.URL.Path + name
+			}
+
+			sizeStr := "—"
+			if !info.IsDir() {
+				size := info.Size()
+				sizeDenom := "B"
+				if size > 1000 {
+					size /= 1000
+					sizeDenom = "KB"
+				}
+				if size > 1000 {
+					size /= 1000
+					sizeDenom = "MB"
+				}
+				if size > 1000 {
+					size /= 1000
+					sizeDenom = "GB"
+				}
+				sizeStr = fmt.Sprintf("%d%s", size, sizeDenom)
+			}
+
+			dateStr := info.ModTime().Format("02-Jan-2006 15:04")
+
+			data.Files = append(data.Files, &File{
+				Name: name,
+				URI: uri,
+				IsDir: info.IsDir(),
+				Size: sizeStr,
+				ModifiedDate: dateStr,
+			})
+		}
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "failed to open directory: %v\n", err)
+		}
+
+		w.Header().Set("Content-Type", "text/html")
+		w.Header().Set("Server", "indir")
+		w.WriteHeader(http.StatusOK)
+		dirTemplate.Execute(w, data)
+	}
+}