// Copyright 2016 Google Inc. Use of this source code is governed by an
// MIT-style license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT.

import 'package:source_span/source_span.dart';

import 'expression.dart';
import 'node.dart';

/// A set of arguments passed in to a function or mixin.
class ArgumentInvocation implements SassNode {
  /// The arguments passed by position.
  final List<Expression> positional;

  /// The arguments passed by name.
  final Map<String, Expression> named;

  /// The first rest argument (as in `$args...`).
  final Expression rest;

  /// The second rest argument, which is expected to only contain a keyword map.
  final Expression keywordRest;

  final FileSpan span;

  ArgumentInvocation(
      Iterable<Expression> positional, Map<String, Expression> named, this.span,
      {this.rest, this.keywordRest})
      : positional = new List.unmodifiable(positional),
        named = new Map.unmodifiable(named) {
    assert(rest != null || keywordRest == null);
  }

  /// Creates an invocation that passes no arguments.
  ArgumentInvocation.empty(this.span)
      : positional = const [],
        named = const {},
        rest = null,
        keywordRest = null;

  String toString() {
    var components = new List<Object>.from(positional)
      ..addAll(named.keys.map((name) => "$name: ${named[name]}"));
    if (rest != null) components.add("$rest...");
    if (keywordRest != null) components.add("$keywordRest...");
    return "(${components.join(', ')})";
  }
}