using System.Xml;

namespace Compat.Runtime.Serialization
{
    internal class XmlSerializableWriter : XmlWriter
    {
        private XmlWriter _xmlWriter;
        private int _depth = 0;
        private object _obj;

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

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

            _xmlWriter.WriteFullEndElement();
            _depth--;
        }

        public override void Close()
        {
            throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(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 => _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 => _xmlWriter.XmlSpace;
        public override string XmlLang => _xmlWriter.XmlLang;
        public override void WriteNmToken(string name) { _xmlWriter.WriteNmToken(name); }
    }
}