// -*- mode: typescript; indent-tabs-mode: nil; js-basic-offset: 4 -*-
//
// This file is part of Genie
//
// Copyright 2020 The Board of Trustees of the Leland Stanford Junior University
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Author: Giovanni Campagna <gcampagn@cs.stanford.edu>

import { Ast, } from 'thingtalk';

class UsesParamVisitor extends Ast.NodeVisitor {
    used = false;
    constructor(private pname : string) {
        super();
    }

    visitExternalBooleanExpression() {
        // do not recurse
        return false;
    }
    visitValue() {
        // do not recurse
        return false;
    }

    visitAtomBooleanExpression(atom : Ast.AtomBooleanExpression) {
        this.used = this.used ||
            (this.pname === atom.name && atom.operator === '=~');
        return true;
    }
}

export function expressionUsesIDFilter(expr : Ast.Expression) {
    const visitor = new UsesParamVisitor('id');
    expr.visit(visitor);
    return visitor.used;
}