feat: implement remove command with sequential removals

internal/remove/apply.go

@@ -0,0 +1,92 @@
+package remove
+
+import (
+	"context"
+	"errors"
+	"os"
+	"path/filepath"
+	"sort"
+
+	"github.com/rogeecn/renamer/internal/history"
+)
+
+// Apply executes planned removals and appends the result to the ledger.
+func Apply(ctx context.Context, req *Request, planned []PlannedOperation, summary Summary, orderedTokens []string) (history.Entry, error) {
+	entry := history.Entry{Command: "remove"}
+
+	if len(planned) == 0 {
+		return entry, nil
+	}
+
+	sort.SliceStable(planned, func(i, j int) bool {
+		return planned[i].Result.Candidate.Depth > planned[j].Result.Candidate.Depth
+	})
+
+	done := make([]history.Operation, 0, len(planned))
+
+	revert := func() error {
+		for i := len(done) - 1; i >= 0; i-- {
+			op := done[i]
+			source := filepath.Join(req.WorkingDir, op.To)
+			destination := filepath.Join(req.WorkingDir, op.From)
+			if err := os.Rename(source, destination); err != nil && !errors.Is(err, os.ErrNotExist) {
+				return err
+			}
+		}
+		return nil
+	}
+
+	for _, op := range planned {
+		if err := ctx.Err(); err != nil {
+			_ = revert()
+			return history.Entry{}, err
+		}
+
+		from := op.Result.Candidate.OriginalPath
+		to := op.TargetAbsolute
+
+		if from == to {
+			continue
+		}
+
+		if err := os.Rename(from, to); err != nil {
+			_ = revert()
+			return history.Entry{}, err
+		}
+
+		done = append(done, history.Operation{
+			From: filepath.ToSlash(op.Result.Candidate.RelativePath),
+			To:   filepath.ToSlash(op.TargetRelative),
+		})
+	}
+
+	if len(done) == 0 {
+		return entry, nil
+	}
+
+	entry.Operations = done
+
+	matchesCopy := make(map[string]int, len(summary.TokenMatches))
+	for token, count := range summary.TokenMatches {
+		matchesCopy[token] = count
+	}
+
+	tokensCopy := append([]string(nil), orderedTokens...)
+
+	entry.Metadata = map[string]any{
+		"tokens":          tokensCopy,
+		"matches":         matchesCopy,
+		"changed":         summary.ChangedCount,
+		"totalCandidates": summary.TotalCandidates,
+	}
+	if len(summary.Empties) > 0 {
+		entry.Metadata["empties"] = append([]string(nil), summary.Empties...)
+	}
+
+	if err := history.Append(req.WorkingDir, entry); err != nil {
+		_ = revert()
+		return history.Entry{}, err
+	}
+
+	return entry, nil
+}