Restructure go project (#2356)

* Move main to cmd
* Move api to internal
* Move logger and manager to internal
* Move shell hiding code to separate package
* Decouple job from desktop and utils
* Decouple session from config
* Move static into internal
* Decouple config from dlna
* Move desktop to internal
* Move dlna to internal
* Decouple remaining packages from config
* Move config into internal
* Move jsonschema and paths to models
* Make ffmpeg functions private
* Move file utility methods into fsutil package
* Move symwalk into fsutil
* Move single-use util functions into client package
* Move slice functions to separate packages
* Add env var to suppress windowsgui arg
* Move hash functions into separate package
* Move identify to internal
* Move autotag to internal
* Touch UI when generating backend

pkg/fsutil/dir.go

@@ -0,0 +1,101 @@
+package fsutil
+
+import (
+	"fmt"
+	"io/fs"
+	"os"
+	"os/user"
+	"path/filepath"
+	"strings"
+)
+
+// DirExists returns true if the given path exists and is a directory
+func DirExists(path string) (bool, error) {
+	fileInfo, err := os.Stat(path)
+	if err != nil {
+		return false, fs.ErrNotExist
+	}
+	if !fileInfo.IsDir() {
+		return false, fmt.Errorf("path is not a directory <%s>", path)
+	}
+	return true, nil
+}
+
+// IsPathInDir returns true if pathToCheck is within dir.
+func IsPathInDir(dir, pathToCheck string) bool {
+	rel, err := filepath.Rel(dir, pathToCheck)
+
+	if err == nil {
+		if !strings.HasPrefix(rel, "..") {
+			return true
+		}
+	}
+
+	return false
+}
+
+// GetHomeDirectory returns the path of the user's home directory.  ~ on Unix and C:\Users\UserName on Windows
+func GetHomeDirectory() string {
+	currentUser, err := user.Current()
+	if err != nil {
+		panic(err)
+	}
+	return currentUser.HomeDir
+}
+
+// EnsureDir will create a directory at the given path if it doesn't already exist
+func EnsureDir(path string) error {
+	exists, err := DirExists(path)
+	if !exists {
+		err = os.Mkdir(path, 0755)
+		return err
+	}
+	return err
+}
+
+// EnsureDirAll will create a directory at the given path along with any necessary parents if they don't already exist
+func EnsureDirAll(path string) error {
+	return os.MkdirAll(path, 0755)
+}
+
+// RemoveDir removes the given dir (if it exists) along with all of its contents
+func RemoveDir(path string) error {
+	return os.RemoveAll(path)
+}
+
+// EmptyDir will recursively remove the contents of a directory at the given path
+func EmptyDir(path string) error {
+	d, err := os.Open(path)
+	if err != nil {
+		return err
+	}
+	defer d.Close()
+
+	names, err := d.Readdirnames(-1)
+	if err != nil {
+		return err
+	}
+
+	for _, name := range names {
+		err = os.RemoveAll(filepath.Join(path, name))
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// GetIntraDir returns a string that can be added to filepath.Join to implement directory depth, "" on error
+// eg given a pattern of 0af63ce3c99162e9df23a997f62621c5 and a depth of 2 length of 3
+// returns 0af/63c or 0af\63c ( dependin on os)  that can be later used like this  filepath.Join(directory, intradir, basename)
+func GetIntraDir(pattern string, depth, length int) string {
+	if depth < 1 || length < 1 || (depth*length > len(pattern)) {
+		return ""
+	}
+	intraDir := pattern[0:length] // depth 1 , get length number of characters from pattern
+	for i := 1; i < depth; i++ {  // for every extra depth: move to the right of the pattern length positions, get length number of chars
+		intraDir = filepath.Join(intraDir, pattern[length*i:length*(i+1)]) //  adding each time to intradir the extra characters with a filepath join
+	}
+	return intraDir
+}