//------------------------------------------------------------------------------
// <copyright file="SQLStringStorage.cs" company="Microsoft">
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// </copyright>
// <owner current="true" primary="true">Microsoft</owner>
// <owner current="true" primary="false">Microsoft</owner>
// <owner current="false" primary="false">Microsoft</owner>
//------------------------------------------------------------------------------
 
namespace System.Data.Common {
    using System;
    using System.Xml;
    using System.Globalization;
    using System.Data.SqlTypes;
    using System.Diagnostics;
    using System.IO;
    using System.Xml.Serialization;
    using System.Collections;
 
    internal sealed class SqlStringStorage : DataStorage {
 
        private SqlString[] values;
 
        public SqlStringStorage(DataColumn column)
        : base(column, typeof(SqlString), SqlString.Null, SqlString.Null, StorageType.SqlString) {
        }
 
        override public Object Aggregate(int[] recordNos, AggregateType kind) {
            try {
            	int i;
                switch (kind) {
                case AggregateType.Min:
                    int min = -1;
                    for (i = 0; i < recordNos.Length; i++) {
                        if (IsNull(recordNos[i]))
                            continue;
                        min = recordNos[i];
                        break;
                    }
                    if (min >= 0) {
                        for (i = i+1; i < recordNos.Length; i++) {
                            if (IsNull(recordNos[i]))
                                continue;
                            if (Compare(min, recordNos[i]) > 0) {
                                min = recordNos[i];
                            }
                        }
                        return Get(min);
                    }
                    return NullValue;
 
 
                case AggregateType.Max:
                    int max = -1;
                    for (i = 0; i < recordNos.Length; i++) {
                        if (IsNull(recordNos[i]))
                            continue;
                        max = recordNos[i];
                        break;
                    }
                    if (max >= 0) {
                        for (i = i+1; i < recordNos.Length; i++) {
                            if (Compare(max, recordNos[i]) < 0) {
                                max = recordNos[i];
                            }
                        }
                        return Get(max);
                    }
                    return NullValue;
 
                case AggregateType.Count:
                    int count = 0;
                    for (i = 0; i < recordNos.Length; i++) {
                        if (!IsNull(recordNos[i]))
                            count++;
                    }
                    return count;
 
                }
            }
            catch (OverflowException) {
                throw ExprException.Overflow(typeof(SqlString));
            }
            throw ExceptionBuilder.AggregateException(kind, DataType);
        }
 
        override public int Compare(int recordNo1, int recordNo2) {
            return Compare(values[recordNo1], values[recordNo2]);
        }
 
        public int Compare(SqlString valueNo1, SqlString valueNo2) {
 
            if (valueNo1.IsNull  && valueNo2.IsNull)
                return 0;
 
            if (valueNo1.IsNull)
                return -1;
 
            if (valueNo2.IsNull)
                return 1;
 
            return Table.Compare(valueNo1.Value, valueNo2.Value);
        }
 
        override public int CompareValueTo(int recordNo, Object value) {
            return Compare(values[recordNo], (SqlString)value);
        }
 
        override public object ConvertValue(object value) {
            if (null != value) {
                return SqlConvert.ConvertToSqlString(value);
            }
            return NullValue;
        }
 
        override public void Copy(int recordNo1, int recordNo2) {
            values[recordNo2] = values[recordNo1];
        }
 
        override public Object Get(int record) {
            return values[record];
        }
 
        override public int GetStringLength(int record) {
            SqlString value = values[record];
            return ((value.IsNull) ? 0 : value.Value.Length);
        }
 
        override public bool IsNull(int record) {
            return (values[record].IsNull);
        }
 
        override public void Set(int record, Object value) {
            values[record] =  SqlConvert.ConvertToSqlString(value);
        }
 
        override public void SetCapacity(int capacity) {
            SqlString[] newValues = new SqlString[capacity];
            if (null != values) {
                Array.Copy(values, 0, newValues, 0, Math.Min(capacity, values.Length));
            }
            values = newValues;
        }
 
        override public object ConvertXmlToObject(string s) {
            SqlString newValue = new SqlString();
            string tempStr =string.Concat("<col>", s, "</col>"); // this is done since you can give fragmet to reader, bug 98767
            StringReader strReader = new  StringReader(tempStr);
 
            IXmlSerializable tmp = newValue;
            
            using (XmlTextReader xmlTextReader = new XmlTextReader(strReader)) {
                tmp.ReadXml(xmlTextReader);
            }
            return ((SqlString)tmp);
        }
 
        override public string ConvertObjectToXml(object value) {
            Debug.Assert(!DataStorage.IsObjectNull(value), "we shouldn't have null here");
            Debug.Assert((value.GetType() == typeof(SqlString)), "wrong input type");
 
            StringWriter strwriter = new StringWriter(FormatProvider); // consider passing cultureinfo with CultureInfo.InvariantCulture
 
            using (XmlTextWriter xmlTextWriter = new XmlTextWriter (strwriter)) {
                ((IXmlSerializable)value).WriteXml(xmlTextWriter);
            }
            return (strwriter.ToString ());
        }
        
        override protected object GetEmptyStorage(int recordCount) {
            return new SqlString[recordCount];
        }
 
        override protected void CopyValue(int record, object store, BitArray nullbits, int storeIndex) {
            SqlString[] typedStore = (SqlString[]) store; 
            typedStore[storeIndex] = values[record];
            nullbits.Set(storeIndex, IsNull(record));
        }
 
        override protected void SetStorage(object store, BitArray nullbits) {
            values = (SqlString[]) store; 
            //SetNullStorage(nullbits);
        }            
    }
}