// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System.Diagnostics;
using System.Globalization;

namespace System.Xml.Schema
{
#pragma warning disable 618

    internal sealed class AutoValidator : BaseValidator
    {
        public AutoValidator(XmlValidatingReaderImpl reader, XmlSchemaCollection schemaCollection, IValidationEventHandling eventHandling) : base(reader, schemaCollection, eventHandling)
        {
            schemaInfo = new SchemaInfo();
        }

        public override bool PreserveWhitespace
        {
            get { return false; }
        }

        public override void Validate()
        {
            ValidationType valType = DetectValidationType();
            switch (valType)
            {
                case ValidationType.XDR:
                    reader.Validator = new XdrValidator(this);
                    reader.Validator.Validate();
                    break;

                case ValidationType.Schema:
                    reader.Validator = new XsdValidator(this);
                    reader.Validator.Validate();
                    break;

                case ValidationType.Auto:
                    break;
            }
        }

        public override void CompleteValidation() { }

        public override object? FindId(string name)
        {
            return null;
        }

        private ValidationType DetectValidationType()
        {
            //Type not yet detected : Check in Schema Collection
            if (reader.Schemas != null && reader.Schemas.Count > 0)
            {
                XmlSchemaCollectionEnumerator enumerator = reader.Schemas.GetEnumerator();
                while (enumerator.MoveNext())
                {
                    XmlSchemaCollectionNode node = enumerator.CurrentNode!;
                    SchemaInfo schemaInfo = node.SchemaInfo!;
                    if (schemaInfo.SchemaType == SchemaType.XSD)
                        return ValidationType.Schema;
                    else if (schemaInfo.SchemaType == SchemaType.XDR)
                        return ValidationType.XDR;
                }
            }

            if (reader.NodeType == XmlNodeType.Element)
            {
                SchemaType schemaType = SchemaNames.SchemaTypeFromRoot(reader.LocalName, reader.NamespaceURI);
                if (schemaType == SchemaType.XSD)
                {
                    return ValidationType.Schema;
                }
                else if (schemaType == SchemaType.XDR)
                {
                    return ValidationType.XDR;
                }
                else
                {
                    int count = reader.AttributeCount;
                    for (int i = 0; i < count; i++)
                    {
                        reader.MoveToAttribute(i);
                        string objectNs = reader.NamespaceURI;
                        string objectName = reader.LocalName;
                        if (Ref.Equal(objectNs, SchemaNames.NsXmlNs))
                        {
                            if (XdrBuilder.IsXdrSchema(reader.Value))
                            {
                                reader.MoveToElement();
                                return ValidationType.XDR;
                            }
                        }
                        else if (Ref.Equal(objectNs, SchemaNames.NsXsi))
                        {
                            reader.MoveToElement();
                            return ValidationType.Schema;
                        }
                        else if (Ref.Equal(objectNs, SchemaNames.QnDtDt.Namespace) && Ref.Equal(objectName, SchemaNames.QnDtDt.Name))
                        {
                            reader.SchemaTypeObject = XmlSchemaDatatype.FromXdrName(reader.Value);
                            reader.MoveToElement();
                            return ValidationType.XDR;
                        }
                    } //end of for
                    if (count > 0)
                    {
                        reader.MoveToElement();
                    }
                }
            }
            return ValidationType.Auto;
        }
    }
#pragma warning restore 618
}