Import source: handler/fs/path

Import the existing local project snapshot. This commit organizes existing files; it does not represent newly developed functionality.

handler/fs/path.go

@@ -0,0 +1,94 @@
+package fs
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"io/fs"
+	"os"
+	"path"
+	"path/filepath"
+)
+
+var (
+	// ErrNoCurrentDir returned on creating the content file before the current
+	// directory was created.
+	ErrNoCurrentDir = errors.New("current dir was not created")
+
+	// ErrInvalidDest returned when provided save path is not a valid directory.
+	ErrInvalidDest = errors.New("invalid destination path")
+)
+
+type PathResolver struct {
+	// Dest contains a base directory for all folders that will be created.
+	// It should be a valid absolute or relative path and must already exist.
+	Dest string
+
+	absDest     string
+	currentDest string
+}
+
+// NewPathResolver returns new *PathResolver along with resolving provided dest
+// value. If an incorrect dest value is provided an error will be returned.
+func NewPathResolver(dest string) (*PathResolver, error) {
+	absDest, err := filepath.Abs(dest)
+	if err != nil {
+		return nil, ErrInvalidDest
+	}
+
+	stat, err := os.Stat(absDest)
+	if err != nil || !stat.IsDir() {
+		return nil, ErrInvalidDest
+	}
+
+	return &PathResolver{
+		Dest:    dest,
+		absDest: absDest,
+	}, nil
+}
+
+// CreateFolder creates a new dir with the provided name within PathResolver.Dest dir.
+// Created dir will be marked as current dir. If dir already exists the creation
+// step will be skipped.
+func (p *PathResolver) CreateFolder(name string) error {
+	err := os.Chdir(p.absDest)
+	if err != nil {
+		return fmt.Errorf("cannot resolve path for folder %s: %w", name, err)
+	}
+
+	p.currentDest = path.Join(p.absDest, name)
+
+	err = os.Mkdir(name, fs.ModePerm)
+	if err != nil {
+		if os.IsExist(err) {
+			return nil
+		}
+		return fmt.Errorf("cannot create folder %s: %w", p.currentDest, err)
+	}
+
+	return nil
+}
+
+// CreateFile creates a new file with the corresponding name and returns its
+// io.WriteCloser. If FSResolver.currentDest wasn't created before, then an error
+// will be returned.
+func (p *PathResolver) CreateFile(name string) (io.WriteCloser, error) {
+	if p.currentDest == "" {
+		return nil, ErrNoCurrentDir
+	}
+
+	filePath := path.Join(p.currentDest, name)
+
+	f, err := os.Create(filePath)
+	if err != nil {
+		return nil, fmt.Errorf("cannot create file %s: %w", filePath, err)
+	}
+
+	return f, nil
+}
+
+// Remove removes file or dir by its name. If the provided path wasn't found the
+// deletion step will be skipped.
+func (p *PathResolver) Remove(name string) {
+	_ = os.Remove(name)
+}