From 21b7e666bbed73083485aab27b510079337f13b8 Mon Sep 17 00:00:00 2001
From: Arnas Udovic <zordsdavini@gmail.com>
Date: Sat, 11 Jan 2025 23:30:59 +0200
Subject: [PATCH] added Apps config to pre format file

---
 README.md | 17 ++++++++++-
 tree.go   | 91 ++++++++++++++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 99 insertions(+), 9 deletions(-)

diff --git a/README.md b/README.md
index 7bb0fad..286898b 100644
--- a/README.md
+++ b/README.md
@@ -64,8 +64,23 @@ Hear goes content. It can be written in html, markdown or whatever what can be p
 
 There are two main commands: `PopulateTree` to prepare source (format, add metadata and add Id) and separate images and other data files and `BuildTree` to get object of tree.
 
-Also both commands use `Config` object that can be prepared by `NewConfig` command. With it can be configurable readable formats, attachment directory, custom meta and excludes (not movable files by regexp).
+Also both commands use `Config` object that can be prepared by `NewConfig` command. With it can be configurable readable formats, attachment directory, custom meta, excludes (not movable files by regexp) and list of functions to apply before file formatting (read bellow).
 
 `Tree` object has methods: `FileById` to get `File` by Id, `Slice` to get sub-tree of given path and `Filter` to filter tree by filter.
 Filter contains array of meta key and searching value. `tag` key is searched as equal and other meta values of keys can contain part. If `-` is before key - filter is filter out.
 
+By full file path and config meta there is possibility to get file params: `Id`, `Meta` and `Tags`:
+
+```
+GetFileParams(fullPath string, meta []string) (string, []string, map[string]string, error)
+```
+
+### Functions to apply before file formatting
+
+There is possibility to add custom functions to apply before file formatting. That is passed with custom function what returns string.
+
+```
+func(dir string, content string, info os.FileInfo) (string, error)
+```
+
+`dir` is path to directory of file, `content` is file content and `info` is file info.
diff --git a/tree.go b/tree.go
index c877069..c4269ed 100644
--- a/tree.go
+++ b/tree.go
@@ -24,8 +24,11 @@ type Config struct {
 	AttachmentDirName string
 	CustomMeta        map[string]func() string
 	Excludes          []string
+	Apps              map[string]appCallback
 }
 
+type appCallback func(dir string, content string, info os.FileInfo) (string, error)
+
 type File struct {
 	Id       string
 	Name     string
@@ -164,6 +167,13 @@ func PopulateTree(sourcePath string, meta []string, config Config) error {
 	var err error
 	var attachmentRegistry map[string]string
 
+	for _, app := range config.Apps {
+		err = applyApp(app, sourcePath, config)
+		if err != nil {
+			return err
+		}
+	}
+
 	attachmentRegistry, err = moveAttachments(sourcePath, config)
 	if err != nil {
 		return err
@@ -250,6 +260,57 @@ func moveAttachments(dir string, config Config) (map[string]string, error) {
 	return attachmentRegistry, err
 }
 
+func applyApp(app appCallback, dir string, config Config) error {
+	err := filepath.Walk(dir, func(fullPath string, info os.FileInfo, e error) error {
+		if e != nil {
+			return e
+		}
+
+		if info.Mode().IsRegular() && slices.Contains(config.ReadableFormats, path.Ext(fullPath)) {
+			osf, err := os.Open(fullPath)
+			if err != nil {
+				return err
+			}
+
+			// remove all empty lines and separate split line
+			content := ""
+			format := true
+			scanner := bufio.NewScanner(osf)
+			scanner.Split(bufio.ScanLines)
+			for scanner.Scan() {
+				line := scanner.Text()
+				if line == "---" {
+					format = false
+				}
+
+				if format {
+					line = strings.Trim(line, " ")
+					if line != "" {
+						content = content + "\n" + line
+					}
+				} else {
+					content = content + "\n" + line
+				}
+			}
+
+			content, err = app(dir, content, info)
+			if err != nil {
+				return err
+			}
+
+			data := []byte(content)
+
+			err = os.WriteFile(fullPath, data, 0644)
+			if err != nil {
+				return err
+			}
+		}
+		return nil
+	})
+
+	return err
+}
+
 func fixFormat(dir string, attachmentRegistry map[string]string, config Config) error {
 	err := filepath.Walk(dir, func(fullPath string, info os.FileInfo, e error) error {
 		if e != nil {
@@ -516,13 +577,30 @@ func readFile(file fs.DirEntry, fullPath string, category []string, meta []strin
 		Name:     file.Name(),
 		FullPath: fullPath,
 		Category: category,
-		Meta:     map[string]string{},
 	}
 
+	id, tags, fileMeta, err := GetFileParams(fullPath, meta)
+	if err != nil {
+		return f, err
+	}
+
+	f.Id = id
+	f.Tags = tags
+	f.Meta = fileMeta
+
+	return f, nil
+}
+
+func GetFileParams(fullPath string, meta []string) (string, []string, map[string]string, error) {
+	fileMeta := map[string]string{}
+	tags := []string{}
+	id := ""
+
 	osf, err := os.Open(fullPath)
 	if err != nil {
-		return File{}, err
+		return id, tags, fileMeta, err
 	}
+
 	scanner := bufio.NewScanner(osf)
 	scanner.Split(bufio.ScanLines)
 	for scanner.Scan() {
@@ -534,27 +612,24 @@ func readFile(file fs.DirEntry, fullPath string, category []string, meta []strin
 		if strings.HasPrefix(line, "* tags:") {
 			line = strings.TrimPrefix(line, "* tags:")
 			t := strings.Split(line, ",")
-			tags := []string{}
 			for _, tag := range t {
 				tags = append(tags, strings.Trim(tag, " "))
 			}
-
-			f.Tags = tags
 		}
 		if strings.HasPrefix(line, "* id:") {
 			line = strings.TrimPrefix(line, "* id:")
-			f.Id = strings.Trim(line, " ")
+			id = strings.Trim(line, " ")
 		}
 		for _, option := range meta {
 			if strings.HasPrefix(line, "* "+option) {
 				line = strings.TrimPrefix(line, "* "+option+":")
-				f.Meta[option] = strings.Trim(line, " ")
+				fileMeta[option] = strings.Trim(line, " ")
 			}
 		}
 	}
 	_ = osf.Close()
 
-	return f, nil
+	return id, tags, fileMeta, nil
 }
 
 func ReadFileContent(file File) (string, error) {