// 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.Runtime.Serialization.DataContracts;
using System.Xml;


namespace System.Runtime.Serialization
{
    internal sealed class XmlSerializableWriter : XmlWriter
    {
        private XmlWriter _xmlWriter = null!; // initialized in BeginWrite
        private int _depth;
        private object? _obj;

        internal void BeginWrite(XmlWriter xmlWriter, object obj)
        {
            _depth = 0;
            _xmlWriter = xmlWriter;
            _obj = obj;
        }

        internal void EndWrite()
        {
            if (_depth != 0)
                throw XmlObjectSerializer.CreateSerializationException(SR.Format(SR.IXmlSerializableMissingEndElements, (_obj == null ? string.Empty : DataContract.GetClrTypeFullName(_obj.GetType()))));
            _obj = null;
        }

        public override void WriteStartDocument()
        {
            if (WriteState == WriteState.Start)
                _xmlWriter.WriteStartDocument();
        }
        public override void WriteEndDocument() { _xmlWriter.WriteEndDocument(); }
        public override void WriteStartDocument(bool standalone)
        {
            if (WriteState == WriteState.Start)
                _xmlWriter.WriteStartDocument(standalone);
        }
        public override void WriteDocType(string name, string? pubid, string? sysid, string? subset)
        {
            // XmlSerializer does not write doc type
        }

        public override void WriteStartElement(string? prefix, string localName, string? ns)
        {
            _xmlWriter.WriteStartElement(prefix, localName, ns);
            _depth++;
        }

        public override void WriteEndElement()
        {
            if (_depth == 0)
                throw XmlObjectSerializer.CreateSerializationException(SR.Format(SR.IXmlSerializableWritePastSubTree, (_obj == null ? string.Empty : DataContract.GetClrTypeFullName(_obj.GetType()))));
            _xmlWriter.WriteEndElement();
            _depth--;
        }

        public override void WriteFullEndElement()
        {
            if (_depth == 0)
                throw XmlObjectSerializer.CreateSerializationException(SR.Format(SR.IXmlSerializableWritePastSubTree, (_obj == null ? string.Empty : DataContract.GetClrTypeFullName(_obj.GetType()))));
            _xmlWriter.WriteFullEndElement();
            _depth--;
        }

        public override void Close()
        {
            throw XmlObjectSerializer.CreateSerializationException(SR.IXmlSerializableIllegalOperation);
        }

        public override void WriteStartAttribute(string? prefix, string localName, string? ns)
        {
            _xmlWriter.WriteStartAttribute(prefix, localName, ns);
        }

        public override void WriteEndAttribute() { _xmlWriter.WriteEndAttribute(); }
        public override void WriteCData(string? text) { _xmlWriter.WriteCData(text); }
        public override void WriteComment(string? text) { _xmlWriter.WriteComment(text); }
        public override void WriteProcessingInstruction(string name, string? text) { _xmlWriter.WriteProcessingInstruction(name, text); }
        public override void WriteEntityRef(string name) { _xmlWriter.WriteEntityRef(name); }
        public override void WriteCharEntity(char ch) { _xmlWriter.WriteCharEntity(ch); }
        public override void WriteWhitespace(string? ws) { _xmlWriter.WriteWhitespace(ws); }
        public override void WriteString(string? text) { _xmlWriter.WriteString(text); }
        public override void WriteSurrogateCharEntity(char lowChar, char highChar) { _xmlWriter.WriteSurrogateCharEntity(lowChar, highChar); }
        public override void WriteChars(char[] buffer, int index, int count) { _xmlWriter.WriteChars(buffer, index, count); }
        public override void WriteRaw(char[] buffer, int index, int count) { _xmlWriter.WriteRaw(buffer, index, count); }
        public override void WriteRaw(string data) { _xmlWriter.WriteRaw(data); }
        public override void WriteBase64(byte[] buffer, int index, int count) { _xmlWriter.WriteBase64(buffer, index, count); }
        public override void WriteBinHex(byte[] buffer, int index, int count) { _xmlWriter.WriteBinHex(buffer, index, count); }
        public override WriteState WriteState { get { return _xmlWriter.WriteState; } }
        public override void Flush() { _xmlWriter.Flush(); }
        public override void WriteName(string name) { _xmlWriter.WriteName(name); }
        public override void WriteQualifiedName(string localName, string? ns) { _xmlWriter.WriteQualifiedName(localName, ns); }
        public override string? LookupPrefix(string ns) { return _xmlWriter.LookupPrefix(ns); }
        public override XmlSpace XmlSpace { get { return _xmlWriter.XmlSpace; } }
        public override string? XmlLang { get { return _xmlWriter.XmlLang; } }
        public override void WriteNmToken(string name) { _xmlWriter.WriteNmToken(name); }
    }
}