Add track file command

Author: iamd3vil

cmd/shelf/actions.go

@@ -46,7 +46,89 @@ func CreateShelf(cliCtx *cli.Context) error {
 		return err
 	}
 
-	fmt.Printf("[*] Created a shelf named: %s", shelfName)
+	// Create a shelf db
+	_, err = NewDB(shelfPath, shelfName)
+	if err != nil {
+		return err
+	}
+
+	fmt.Printf("[*] Created a shelf named: %s\n", shelfName)
+
+	return nil
+}
+
+// TrackFile tracks the given file.
+// The file is moved to the shelf and a symlink is created in its place.
+// It stores the filename and symlink path in the shelf's db.
+func TrackFile(cliCtx *cli.Context) error {
+	// Get Home Directory path
+	home, err := GetHomeDirectory()
+	if err != nil {
+		return err
+	}
+
+	shelfName := cliCtx.Args().Get(0)
+	if shelfName == "" {
+		return errors.New("Shelf name has to be given")
+	}
+
+	filePath := cliCtx.Args().Get(1)
+	if filePath == "" {
+		return errors.New("File path to track can't be blank")
+	}
+
+	// Check if the given shelf exists
+	_, err = os.Stat(path.Join(home, shelfName))
+	if err != nil {
+		if os.IsNotExist(err) {
+			return fmt.Errorf("Shelf named: %s doesn't exist", shelfName)
+		}
+		return err
+	}
+
+	// Check if the file exists and is not a symlink
+	stat, err := os.Lstat(filePath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return fmt.Errorf("%s doesn't exist", filePath)
+		}
+		return err
+	}
+	if stat.Mode()&os.ModeSymlink == os.ModeSymlink {
+		return fmt.Errorf("%s shouldn't be a symlink", filePath)
+	}
+
+	// Move file to the shelf
+	err = os.Rename(filePath, path.Join(home, shelfName, path.Base(filePath)))
+	if err != nil {
+		return err
+	}
+
+	// Create symlink
+	err = os.Symlink(path.Join(home, shelfName, path.Base(filePath)), filePath)
+	if err != nil {
+		// Since we can't create a symlink, we should put back the file which is moved
+		err = os.Rename(path.Join(home, shelfName, path.Base(filePath)), filePath)
+		if err != nil {
+			return err
+		}
+		return err
+	}
+
+	// Put it in the db
+	db, dbPath, err := GetDB(path.Join(home, shelfName))
+	if err != nil {
+		return err
+	}
+	db.AddLink(path.Base(filePath), filePath)
+	f, err := os.Create(dbPath)
+	if err != nil {
+		return err
+	}
+	err = db.Marshal(f)
+	if err != nil {
+		return err
+	}
 
 	return nil
 }

cmd/shelf/db.go

@@ -0,0 +1,72 @@
+package main
+
+import (
+	"encoding/json"
+	"io"
+	"os"
+	"path"
+)
+
+// DB is the db for shelf to store where each symlink is supposed to go.
+// This is a JSON File generally stored in
+type DB struct {
+	Name  string            `json:"name"`
+	Links map[string]string `json:"links"`
+}
+
+// Marshal marshals DB into JSON
+func (db *DB) Marshal(w io.Writer) error {
+	encoder := json.NewEncoder(w)
+	encoder.SetIndent("", "    ")
+	err := encoder.Encode(&db)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// AddLink adds the file and link paths to the DB
+func (db *DB) AddLink(filePath, linkPath string) {
+	db.Links[filePath] = linkPath
+}
+
+// NewDB creates a shelf DB
+func NewDB(shelfPath string, shelfName string) (*DB, error) {
+	db := DB{
+		Name:  shelfName,
+		Links: make(map[string]string),
+	}
+
+	p := path.Join(shelfPath, "shelf.json")
+
+	f, err := os.Create(p)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	err = db.Marshal(f)
+	if err != nil {
+		return nil, err
+	}
+
+	return &db, nil
+}
+
+// GetDB returns the DB in the given shelf
+func GetDB(shelfPath string) (*DB, string, error) {
+	dbPath := path.Join(shelfPath, "shelf.json")
+	f, err := os.Open(dbPath)
+	if err != nil {
+		return nil, "", err
+	}
+	defer f.Close()
+
+	db := &DB{}
+	err = json.NewDecoder(f).Decode(db)
+	if err != nil {
+		return nil, "", err
+	}
+
+	return db, dbPath, nil
+}

cmd/shelf/main.go

@@ -15,6 +15,14 @@ func main() {
 				Usage:   "complete a task on the list",
 				Action:  CreateShelf,
 			},
+			{
+				Name:        "track",
+				Aliases:     []string{"t"},
+				Usage:       "track a file",
+				ArgsUsage:   "[shelfname] [filepath]",
+				Action:      TrackFile,
+				Description: "Tracks given file. The file is moved from the path and a symlink is created in it's place.",
+			},
 		},
 		Name:        "shelf",
 		Description: "A Good Symlinks Manager",