checkpoint: managing files

magefiles/files.go

@@ -3,6 +3,7 @@
 package main
 
 import (
+	"errors"
 	"fmt"
 	"io/fs"
 	"os"
@@ -69,5 +70,72 @@ func manageFilesFunc(homeConfigDirectory string) fs.WalkDirFunc {
 }
 
 func ensureSymlink(source, dest string) error {
+	absolutePathErrorMessageFormat := "unable to get the absolute path to %s: %w"
+
+	absoluteSourcePath, err := filepath.Abs(source)
+	if err != nil {
+		return fmt.Errorf(absolutePathErrorMessageFormat, source, err)
+	}
+
+	absoluteDestPath, err := filepath.Abs(dest)
+	if err != nil {
+		return fmt.Errorf(absolutePathErrorMessageFormat, dest, err)
+	}
+
+	destInfo, err := os.Lstat(absoluteDestPath)
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			fmt.Printf("Linking %s to %s\n", absoluteDestPath, absoluteSourcePath)
+
+			if err := os.Symlink(absoluteSourcePath, absoluteDestPath); err != nil {
+				return fmt.Errorf(
+					"unable to symlink %s to %s: %w",
+					absoluteDestPath,
+					absoluteSourcePath,
+					err,
+				)
+			}
+
+			return nil
+		}
+
+		return fmt.Errorf("unable to get the file info for %s: %w", absoluteDestPath, err)
+	}
+
+	if destInfo.Mode().Type() != fs.ModeSymlink {
+		return fmt.Errorf("the path %s exists but it is not a symlink", absoluteDestPath)
+	}
+
+	destLinksTo, err := filepath.EvalSymlinks(absoluteDestPath)
+	if err != nil {
+		return fmt.Errorf("unable to evaluate the symlink %s: %w", absoluteDestPath, err)
+	}
+
+	if destLinksTo == absoluteSourcePath {
+		return nil
+	}
+
+	fmt.Printf(
+		"%s should link back to %s but instead links back to %s\n",
+		absoluteDestPath,
+		absoluteSourcePath,
+		destLinksTo,
+	)
+
+	fmt.Println("Recreating:", absoluteDestPath)
+
+	if err := os.Remove(absoluteDestPath); err != nil {
+		return fmt.Errorf("unable to remove %s: %w", absoluteDestPath, err)
+	}
+
+	if err := os.Symlink(absoluteSourcePath, absoluteDestPath); err != nil {
+		return fmt.Errorf(
+			"unable to symlink %s to %s: %w",
+			absoluteDestPath,
+			absoluteSourcePath,
+			err,
+		)
+	}
+
 	return nil
 }