From dd4de698cf993407797f535cffc266cad39483ea Mon Sep 17 00:00:00 2001
From: Tobias Weingartner <weingart@tepid.org>
Date: Sun, 17 Apr 2016 10:58:51 -0700
Subject: [PATCH] Better search for config. Handle LastModifiedHeader better.
 Handle HEAD/GET.

---
 middleware/markdown/markdown.go | 147 ++++++++++++++++++++------------
 1 file changed, 92 insertions(+), 55 deletions(-)

diff --git a/middleware/markdown/markdown.go b/middleware/markdown/markdown.go
index 5d6da36f..00e0f72d 100644
--- a/middleware/markdown/markdown.go
+++ b/middleware/markdown/markdown.go
@@ -8,6 +8,7 @@ import (
 	"os"
 	"path"
 	"text/template"
+	"time"
 
 	"github.com/mholt/caddy/middleware"
 	"github.com/russross/blackfriday"
@@ -65,75 +66,111 @@ type Config struct {
 
 // ServeHTTP implements the http.Handler interface.
 func (md Markdown) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error) {
-	for _, cfg := range md.Configs {
-		if !middleware.Path(r.URL.Path).Matches(cfg.PathScope) {
-			continue
+	var cfg *Config
+	for _, c := range md.Configs {
+		if middleware.Path(r.URL.Path).Matches(c.PathScope) { // not negated
+			cfg = c
+			break // or goto
+		}
+	}
+	if cfg == nil {
+		return md.Next.ServeHTTP(w, r) // exit early
+	}
+
+	// We only deal with HEAD/GET
+	switch r.Method {
+	case http.MethodGet, http.MethodHead:
+	default:
+		return http.StatusMethodNotAllowed, nil
+	}
+
+	var dirents []os.FileInfo
+	var lastModTime time.Time
+	fpath := r.URL.Path
+	if idx, ok := middleware.IndexFile(md.FileSys, fpath, md.IndexFiles); ok {
+		// We're serving a directory index file, which may be a markdown
+		// file with a template.  Let's grab a list of files this directory
+		// URL points to, and pass that in to any possible template invocations,
+		// so that templates can customize the look and feel of a directory.
+		fdp, err := md.FileSys.Open(fpath)
+		if err != nil {
+			if os.IsPermission(err) {
+				return http.StatusForbidden, err
+			}
+			return http.StatusInternalServerError, err
 		}
 
-		var dirents []os.FileInfo
-		fpath := r.URL.Path
-		if idx, ok := middleware.IndexFile(md.FileSys, fpath, md.IndexFiles); ok {
-			// We're serving a directory index file, which may be a markdown
-			// file with a template.  Let's grab a list of files this directory
-			// URL points to, and pass that in to any possible template invocations,
-			// so that templates can customize the look and feel of a directory.
-
-			fdp, err := md.FileSys.Open(fpath)
-			if err != nil {
-				return http.StatusInternalServerError, err
-			}
-			dirents, err = fdp.Readdir(-1)
-			if err != nil {
-				return http.StatusInternalServerError, err
-			}
-
-			// Set path to found index file
-			fpath = idx
+		// Grab a possible set of directory entries.  Note, we do not check
+		// for errors here (unreadable directory, for example).  It may
+		// still be useful to have a directory template file, without the
+		// directory contents being present.
+		dirents, _ = fdp.Readdir(-1)
+		for _, d := range dirents {
+			lastModTime = latest(lastModTime, d.ModTime())
 		}
 
-		// If supported extension, process it
-		if _, ok := cfg.Extensions[path.Ext(fpath)]; ok {
-			f, err := md.FileSys.Open(fpath)
-			if err != nil {
-				if os.IsPermission(err) {
-					return http.StatusForbidden, err
-				}
-				return http.StatusNotFound, nil
-			}
+		// Set path to found index file
+		fpath = idx
+	}
 
-			fs, err := f.Stat()
-			if err != nil {
-				return http.StatusNotFound, nil
+	// If supported extension, process it
+	if _, ok := cfg.Extensions[path.Ext(fpath)]; ok {
+		f, err := md.FileSys.Open(fpath)
+		if err != nil {
+			if os.IsPermission(err) {
+				return http.StatusForbidden, err
 			}
+			return http.StatusNotFound, nil
+		}
 
-			body, err := ioutil.ReadAll(f)
-			if err != nil {
-				return http.StatusInternalServerError, err
-			}
+		fs, err := f.Stat()
+		if err != nil {
+			return http.StatusNotFound, nil
+		}
+		lastModTime = latest(lastModTime, fs.ModTime())
 
-			ctx := middleware.Context{
-				Root: md.FileSys,
-				Req:  r,
-				URL:  r.URL,
-			}
-			html, err := cfg.Markdown(fpath, body, dirents, ctx)
-			if err != nil {
-				return http.StatusInternalServerError, err
-			}
+		body, err := ioutil.ReadAll(f)
+		if err != nil {
+			return http.StatusInternalServerError, err
+		}
 
-			// TODO(weingart): move template execution here, something like:
-			//
-			// html, err = md.execTemplate(cfg, html, ctx)
-			// if err != nil {
-			// 	return http.StatusInternalServerError, err
-			// }
+		ctx := middleware.Context{
+			Root: md.FileSys,
+			Req:  r,
+			URL:  r.URL,
+		}
+		html, err := cfg.Markdown(fpath, body, dirents, ctx)
+		if err != nil {
+			return http.StatusInternalServerError, err
+		}
 
-			middleware.SetLastModifiedHeader(w, fs.ModTime())
+		// TODO(weingart): move template execution here, something like:
+		//
+		// html, err = md.execTemplate(cfg, html, ctx)
+		// if err != nil {
+		// 	return http.StatusInternalServerError, err
+		// }
+
+		middleware.SetLastModifiedHeader(w, lastModTime)
+		if r.Method == "GET" {
 			w.Write(html)
-			return http.StatusOK, nil
 		}
+		return http.StatusOK, nil
 	}
 
 	// Didn't qualify to serve as markdown; pass-thru
 	return md.Next.ServeHTTP(w, r)
 }
+
+// latest returns the latest time.Time
+func latest(t ...time.Time) time.Time {
+	var last time.Time
+
+	for _, tt := range t {
+		if tt.After(last) {
+			last = tt
+		}
+	}
+
+	return last
+}