1 files changed, 203 insertions, 0 deletions
diff --git a/hugofs/files/classifier.go b/hugofs/files/classifier.go
new file mode 100644
index 000000000..5e26bbac0
--- /dev/null
+++ b/hugofs/files/classifier.go
@@ -0,0 +1,203 @@
+// Copyright 2019 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package files
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"unicode"
+
+	"github.com/spf13/afero"
+)
+
+var (
+	// This should be the only list of valid extensions for content files.
+	contentFileExtensions = []string{
+		"html", "htm",
+		"mdown", "markdown", "md",
+		"asciidoc", "adoc", "ad",
+		"rest", "rst",
+		"mmark",
+		"org",
+		"pandoc", "pdc"}
+
+	contentFileExtensionsSet map[string]bool
+
+	htmlFileExtensions = []string{
+		"html", "htm"}
+
+	htmlFileExtensionsSet map[string]bool
+)
+
+func init() {
+	contentFileExtensionsSet = make(map[string]bool)
+	for _, ext := range contentFileExtensions {
+		contentFileExtensionsSet[ext] = true
+	}
+	htmlFileExtensionsSet = make(map[string]bool)
+	for _, ext := range htmlFileExtensions {
+		htmlFileExtensionsSet[ext] = true
+	}
+}
+
+func IsContentFile(filename string) bool {
+	return contentFileExtensionsSet[strings.TrimPrefix(filepath.Ext(filename), ".")]
+}
+
+func IsHTMLFile(filename string) bool {
+	return htmlFileExtensionsSet[strings.TrimPrefix(filepath.Ext(filename), ".")]
+}
+
+func IsContentExt(ext string) bool {
+	return contentFileExtensionsSet[ext]
+}
+
+type ContentClass string
+
+const (
+	ContentClassLeaf    ContentClass = "leaf"
+	ContentClassBranch  ContentClass = "branch"
+	ContentClassFile    ContentClass = "zfile" // Sort below
+	ContentClassContent ContentClass = "zcontent"
+)
+
+func (c ContentClass) IsBundle() bool {
+	return c == ContentClassLeaf || c == ContentClassBranch
+}
+
+func ClassifyContentFile(filename string, open func() (afero.File, error)) ContentClass {
+	if !IsContentFile(filename) {
+		return ContentClassFile
+	}
+
+	if IsHTMLFile(filename) {
+		// We need to look inside the file. If the first non-whitespace
+		// character is a "<", then we treat it as a regular file.
+		// Eearlier we created pages for these files, but that had all sorts
+		// of troubles, and isn't what it says in the documentation.
+		// See https://github.com/gohugoio/hugo/issues/7030
+		if open == nil {
+			panic(fmt.Sprintf("no file opener provided for %q", filename))
+		}
+
+		f, err := open()
+		if err != nil {
+			return ContentClassFile
+		}
+		ishtml := isHTMLContent(f)
+		f.Close()
+		if ishtml {
+			return ContentClassFile
+		}
+
+	}
+
+	if strings.HasPrefix(filename, "_index.") {
+		return ContentClassBranch
+	}
+
+	if strings.HasPrefix(filename, "index.") {
+		return ContentClassLeaf
+	}
+
+	return ContentClassContent
+}
+
+var htmlComment = []rune{'<', '!', '-', '-'}
+
+func isHTMLContent(r io.Reader) bool {
+	br := bufio.NewReader(r)
+	i := 0
+	for {
+		c, _, err := br.ReadRune()
+		if err != nil {
+			break
+		}
+
+		if i > 0 {
+			if i >= len(htmlComment) {
+				return false
+			}
+
+			if c != htmlComment[i] {
+				return true
+			}
+
+			i++
+			continue
+		}
+
+		if !unicode.IsSpace(c) {
+			if i == 0 && c != '<' {
+				return false
+			}
+			i++
+		}
+	}
+	return true
+}
+
+const (
+	ComponentFolderArchetypes = "archetypes"
+	ComponentFolderStatic     = "static"
+	ComponentFolderLayouts    = "layouts"
+	ComponentFolderContent    = "content"
+	ComponentFolderData       = "data"
+	ComponentFolderAssets     = "assets"
+	ComponentFolderI18n       = "i18n"
+
+	FolderResources = "resources"
+)
+
+var (
+	ComponentFolders = []string{
+		ComponentFolderArchetypes,
+		ComponentFolderStatic,
+		ComponentFolderLayouts,
+		ComponentFolderContent,
+		ComponentFolderData,
+		ComponentFolderAssets,
+		ComponentFolderI18n,
+	}
+
+	componentFoldersSet = make(map[string]bool)
+)
+
+func init() {
+	sort.Strings(ComponentFolders)
+	for _, f := range ComponentFolders {
+		componentFoldersSet[f] = true
+	}
+}
+
+// ResolveComponentFolder returns "content" from "content/blog/foo.md" etc.
+func ResolveComponentFolder(filename string) string {
+	filename = strings.TrimPrefix(filename, string(os.PathSeparator))
+	for _, cf := range ComponentFolders {
+		if strings.HasPrefix(filename, cf) {
+			return cf
+		}
+	}
+
+	return ""
+}
+
+func IsComponentFolder(name string) bool {
+	return componentFoldersSet[name]
+}