From 1e0f8e0aaeaf1bd2ee39c02e922238b641bcf88b Mon Sep 17 00:00:00 2001
From: tjp <tjp@ctrl-c.club>
Date: Mon, 13 Nov 2023 07:25:39 -0700
Subject: refactor contribs to work with a Protocol interface

---
 contrib/fs/handlers.go | 162 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 162 insertions(+)
 create mode 100644 contrib/fs/handlers.go

(limited to 'contrib/fs/handlers.go')

diff --git a/contrib/fs/handlers.go b/contrib/fs/handlers.go
new file mode 100644
index 0000000..75422d9
--- /dev/null
+++ b/contrib/fs/handlers.go
@@ -0,0 +1,162 @@
+package fs
+
+import (
+	"context"
+	"net/url"
+	"os"
+	"path/filepath"
+	"strings"
+	"text/template"
+
+	sr "tildegit.org/tjp/sliderule"
+)
+
+func fileHandler(protocol sr.ServerProtocol, fsroot, urlroot string) sr.Handler {
+	fsroot = strings.TrimRight(fsroot, "/")
+
+	return sr.HandlerFunc(func(ctx context.Context, request *sr.Request) *sr.Response {
+		if !strings.HasPrefix(request.Path, urlroot) {
+			return nil
+		}
+
+		fpath, _ := rebasePath(fsroot, urlroot, request)
+
+		if isPrivate(fpath) {
+			return nil
+		}
+		if isf, err := isFile(fpath); err != nil {
+			return protocol.TemporaryServerError(err)
+		} else if !isf {
+			return nil
+		}
+
+		file, err := os.Open(fpath)
+		if err != nil {
+			return protocol.TemporaryServerError(err)
+		}
+		return protocol.Success(filepath.Base(fpath), file)
+	})
+}
+
+func directoryDefault(
+	protocol sr.ServerProtocol,
+	fsroot string,
+	urlroot string,
+	redirectSlash bool,
+	filenames ...string,
+) sr.Handler {
+	fsroot = strings.TrimRight(fsroot, "/")
+
+	return sr.HandlerFunc(func(ctx context.Context, request *sr.Request) *sr.Response {
+		if !strings.HasPrefix(request.Path, urlroot) {
+			return nil
+		}
+
+		fpath, _ := rebasePath(fsroot, urlroot, request)
+
+		if isPrivate(fpath) {
+			return nil
+		}
+		if isd, err := isDir(fpath); err != nil {
+			return protocol.TemporaryServerError(err)
+		} else if !isd {
+			return nil
+		}
+
+		if redirectSlash && !strings.HasSuffix(request.Path, "/") {
+			return protocol.PermanentRedirect(appendSlash(request.URL))
+		}
+
+		for _, fname := range filenames {
+			fpath := filepath.Join(fpath, fname)
+			if isf, err := isFile(fpath); err != nil {
+				return protocol.TemporaryServerError(err)
+			} else if !isf {
+				continue
+			}
+
+			file, err := os.Open(fpath)
+			if err != nil {
+				return protocol.TemporaryServerError(err)
+			}
+			return protocol.Success(filepath.Base(fpath), file)
+		}
+
+		return nil
+	})
+}
+
+func directoryListing(
+	protocol sr.ServerProtocol,
+	fsroot string,
+	urlroot string,
+	successFilename string,
+	redirectSlash bool,
+	tmpl *template.Template,
+) sr.Handler {
+	fsroot = strings.TrimRight(fsroot, "/")
+
+	return sr.HandlerFunc(func(ctx context.Context, request *sr.Request) *sr.Response {
+		if !strings.HasPrefix(request.Path, urlroot) {
+			return nil
+		}
+
+		dpath, rpath := rebasePath(fsroot, urlroot, request)
+
+		if isPrivate(dpath) {
+			return nil
+		}
+		if isd, err := isDir(dpath); err != nil {
+			return protocol.TemporaryServerError(err)
+		} else if !isd {
+			return nil
+		}
+
+		if redirectSlash && !strings.HasSuffix(request.Path, "/") {
+			return protocol.PermanentRedirect(appendSlash(request.URL))
+		}
+
+		body, err := RenderDirectoryListing(dpath, rpath, tmpl, request.Server)
+		if err != nil {
+			return protocol.TemporaryServerError(err)
+		}
+
+		return protocol.Success(successFilename, body)
+	})
+}
+
+func rebasePath(fsroot, urlroot string, request *sr.Request) (string, string) {
+	p := strings.TrimPrefix(request.Path, urlroot)
+	p = strings.Trim(p, "/")
+	return filepath.Join(fsroot, p), p
+}
+
+func appendSlash(u *url.URL) *url.URL {
+	v := *u
+	v.Path += "/"
+	return &v
+}
+
+func isDir(path string) (bool, error) {
+	info, err := os.Stat(path)
+	if err != nil {
+		if isNotFound(err) {
+			err = nil
+		}
+		return false, err
+	}
+	return info.IsDir() && info.Mode()&4 == 4, nil
+}
+
+func isFile(path string) (bool, error) {
+	info, err := os.Stat(path)
+	if err != nil {
+		if isNotFound(err) {
+			err = nil
+		}
+		return false, err
+	}
+	m := info.Mode()
+
+	return m.IsRegular() && m&4 == 4, nil
+}
-- 
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