feat: complete v0.3.1 agent workflow

internal/tools/file_edit.go

@@ -8,6 +8,7 @@ import (
 	"os"
 	"strings"
 
+	"agentu/internal/safeio"
 	"agentu/pkg/llm"
 )
 
@@ -21,6 +22,36 @@ func NewFileEditTool(workingDir string) *FileEditTool {
 
 func (*FileEditTool) Mutates() bool { return true }
 
+func (t *FileEditTool) Preview(ctx context.Context, raw json.RawMessage) (string, error) {
+	var args fileEditArgs
+	if err := json.Unmarshal(raw, &args); err != nil {
+		return "", fmt.Errorf("parse arguments: %w", err)
+	}
+	if args.StartLine > 0 {
+		end := args.EndLine
+		if end == 0 {
+			end = args.StartLine
+		}
+		return fmt.Sprintf("edit %s lines %d-%d", args.Path, args.StartLine, end), ctx.Err()
+	}
+	return fmt.Sprintf("replace text in %s", args.Path), ctx.Err()
+}
+
+func (t *FileEditTool) TargetPaths(raw json.RawMessage) ([]string, error) {
+	var args fileEditArgs
+	if err := json.Unmarshal(raw, &args); err != nil {
+		return nil, fmt.Errorf("parse arguments: %w", err)
+	}
+	if strings.TrimSpace(args.Path) == "" {
+		return nil, errors.New("path is required")
+	}
+	path, err := resolvePath(t.workingDir, args.Path)
+	if err != nil {
+		return nil, err
+	}
+	return []string{path}, nil
+}
+
 func (t *FileEditTool) Definition() llm.Tool {
 	return llm.Tool{
 		Type: "function",
@@ -111,7 +142,7 @@ func (t *FileEditTool) Execute(ctx context.Context, raw json.RawMessage) (string
 	if err := ctx.Err(); err != nil {
 		return "", err
 	}
-	if err := os.WriteFile(path, []byte(result), perm); err != nil {
+	if err := safeio.AtomicWriteFile(path, []byte(result), perm); err != nil {
 		return "", err
 	}