// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System;
using System.Diagnostics;
using System.Xml;
using System.Xml.XPath;
 
namespace System.Xml.Xsl.XsltOld
{
    internal class DocumentScope
    {
        protected NamespaceDecl? scopes;
 
        internal NamespaceDecl? Scopes
        {
            get { return this.scopes; }
        }
 
        internal NamespaceDecl AddNamespace(string prefix, string uri, string prevDefaultNsUri)
        {
            this.scopes = new NamespaceDecl(prefix, uri, prevDefaultNsUri, this.scopes);
            return this.scopes;
        }
 
        internal string? ResolveAtom(string prefix)
        {
            Debug.Assert(prefix != null && prefix.Length > 0);
 
            for (NamespaceDecl? scope = this.scopes; scope != null; scope = scope.Next)
            {
                if (Ref.Equal(scope.Prefix, prefix))
                {
                    Debug.Assert(scope.Uri != null);
                    return scope.Uri;
                }
            }
 
            return null;
        }
 
        internal string? ResolveNonAtom(string prefix)
        {
            Debug.Assert(prefix != null && prefix.Length > 0);
 
            for (NamespaceDecl? scope = this.scopes; scope != null; scope = scope.Next)
            {
                if (scope.Prefix == prefix)
                {
                    Debug.Assert(scope.Uri != null);
                    return scope.Uri;
                }
            }
            return null;
        }
    }
}