Add insert command

cmd/insert.go

@@ -0,0 +1,90 @@
+package cmd
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/spf13/cobra"
+
+	"github.com/rogeecn/renamer/internal/insert"
+	"github.com/rogeecn/renamer/internal/listing"
+)
+
+func newInsertCommand() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "insert <position> <text>",
+		Short: "Insert text into filenames at specified positions",
+		Long: `Insert a Unicode string into each candidate filename at a specific position.
+Supported positions: "^" (start), "$" (before extension), positive indexes (1-based),
+negative indexes counting back from the end.`,
+		Args: cobra.MinimumNArgs(2),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			scope, err := listing.ScopeFromCmd(cmd)
+			if err != nil {
+				return err
+			}
+
+			req := insert.NewRequest(scope)
+
+			dryRun, err := getBool(cmd, "dry-run")
+			if err != nil {
+				return err
+			}
+			autoApply, err := getBool(cmd, "yes")
+			if err != nil {
+				return err
+			}
+			if dryRun && autoApply {
+				return errors.New("--dry-run cannot be combined with --yes; remove one of them")
+			}
+			req.SetExecutionMode(dryRun, autoApply)
+
+			positionToken := args[0]
+			insertText := strings.Join(args[1:], " ")
+			req.SetPositionAndText(positionToken, insertText)
+
+			summary, planned, err := insert.Preview(cmd.Context(), req, cmd.OutOrStdout())
+			if err != nil {
+				return err
+			}
+
+			if summary.HasConflicts() {
+				return errors.New("conflicts detected; resolve them before applying")
+			}
+
+			if dryRun || !autoApply {
+				if !autoApply {
+					fmt.Fprintln(cmd.OutOrStdout(), "Preview complete. Re-run with --yes to apply.")
+				}
+				return nil
+			}
+
+			if len(planned) == 0 {
+				if summary.TotalCandidates == 0 {
+					fmt.Fprintln(cmd.OutOrStdout(), "No candidates found.")
+				} else {
+					fmt.Fprintln(cmd.OutOrStdout(), "Nothing to apply; files already reflect requested insert.")
+				}
+				return nil
+			}
+
+			entry, err := insert.Apply(cmd.Context(), req, planned, summary)
+			if err != nil {
+				return err
+			}
+
+			fmt.Fprintf(cmd.OutOrStdout(), "Applied %d insert updates. Ledger updated.\n", len(entry.Operations))
+			return nil
+		},
+	}
+
+	cmd.Example = `  renamer insert ^ "[2025] " --dry-run
+  renamer insert -1 _FINAL --yes --path ./reports`
+
+	return cmd
+}
+
+func init() {
+	rootCmd.AddCommand(newInsertCommand())
+}

cmd/root.go

@@ -48,6 +48,7 @@ func NewRootCommand() *cobra.Command {
 	cmd.AddCommand(NewReplaceCommand())
 	cmd.AddCommand(NewRemoveCommand())
 	cmd.AddCommand(NewExtensionCommand())
+	cmd.AddCommand(newInsertCommand())
 	cmd.AddCommand(newUndoCommand())
 
 	return cmd

cmd/undo.go

@@ -29,12 +29,25 @@ func newUndoCommand() *cobra.Command {
 			out := cmd.OutOrStdout()
 			fmt.Fprintf(out, "Undo applied: %d operations reversed\n", len(entry.Operations))
 
-			if entry.Command == "extension" && entry.Metadata != nil {
-				if target, ok := entry.Metadata["targetExtension"].(string); ok && target != "" {
-					fmt.Fprintf(out, "Restored extensions to %s\n", target)
-				}
-				if sources, ok := entry.Metadata["sourceExtensions"].([]string); ok && len(sources) > 0 {
-					fmt.Fprintf(out, "Previous sources: %s\n", strings.Join(sources, ", "))
+			if entry.Metadata != nil {
+				switch entry.Command {
+				case "extension":
+					if target, ok := entry.Metadata["targetExtension"].(string); ok && target != "" {
+						fmt.Fprintf(out, "Restored extensions to %s\n", target)
+					}
+					if sources, ok := entry.Metadata["sourceExtensions"].([]string); ok && len(sources) > 0 {
+						fmt.Fprintf(out, "Previous sources: %s\n", strings.Join(sources, ", "))
+					}
+				case "insert":
+					insertText, _ := entry.Metadata["insertText"].(string)
+					positionToken, _ := entry.Metadata["positionToken"].(string)
+					if insertText != "" {
+						if positionToken != "" {
+							fmt.Fprintf(out, "Inserted text %q removed from position %s\n", insertText, positionToken)
+						} else {
+							fmt.Fprintf(out, "Inserted text %q removed\n", insertText)
+						}
+					}
 				}
 			}