//------------------------------------------------------------------------------
// <copyright file="SqlBulkCopyMappingCollection.cs" company="Microsoft">
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// </copyright>
// <owner current="true" primary="true">[....]</owner>
// <owner current="true" primary="false">[....]</owner>
//------------------------------------------------------------------------------

// todo: rename the file
// Caution! ndp\fx\src\data\netmodule\sources needs to follow this name change

namespace System.Data.SqlClient
{
    using System;
    using System.Data;
    using System.Data.Common;
    using System.ComponentModel;

    using System.Collections;
    using System.Diagnostics;

    public sealed class SqlBulkCopyColumnMappingCollection : CollectionBase  {

        private enum MappingSchema {
            Undefined = 0,
            NamesNames = 1,
            NemesOrdinals = 2,
            OrdinalsNames = 3,
            OrdinalsOrdinals = 4,
        }

        private bool _readOnly;
        private MappingSchema _mappingSchema = MappingSchema.Undefined;

        internal SqlBulkCopyColumnMappingCollection() {
        }

        public SqlBulkCopyColumnMapping this [int index] {
            get {
                return (SqlBulkCopyColumnMapping)this.List[index];
            }
        }

        internal bool ReadOnly {
            get {
                return _readOnly;
            }
            set {
                _readOnly = value;
            }
        }


        public SqlBulkCopyColumnMapping Add(SqlBulkCopyColumnMapping bulkCopyColumnMapping) {
            AssertWriteAccess();
            Debug.Assert(ADP.IsEmpty(bulkCopyColumnMapping.SourceColumn) || bulkCopyColumnMapping._internalSourceColumnOrdinal == -1, "BulkLoadAmbigousSourceColumn");
            if (((ADP.IsEmpty(bulkCopyColumnMapping.SourceColumn)) && (bulkCopyColumnMapping.SourceOrdinal == -1))
                || ((ADP.IsEmpty(bulkCopyColumnMapping.DestinationColumn))&&(bulkCopyColumnMapping.DestinationOrdinal == -1))) {
                throw SQL.BulkLoadNonMatchingColumnMapping();
            }
            InnerList.Add(bulkCopyColumnMapping);
            return bulkCopyColumnMapping;
        }

        public SqlBulkCopyColumnMapping Add(string sourceColumn, string destinationColumn) {
            AssertWriteAccess();
            SqlBulkCopyColumnMapping column = new SqlBulkCopyColumnMapping (sourceColumn, destinationColumn);
            return Add(column);
        }

        public SqlBulkCopyColumnMapping Add(int sourceColumnIndex, string destinationColumn) {
            AssertWriteAccess();
            SqlBulkCopyColumnMapping column = new SqlBulkCopyColumnMapping (sourceColumnIndex, destinationColumn);
            return Add(column);
        }

        public SqlBulkCopyColumnMapping Add(string sourceColumn, int destinationColumnIndex) {
            AssertWriteAccess();
            SqlBulkCopyColumnMapping column = new SqlBulkCopyColumnMapping (sourceColumn, destinationColumnIndex);
            return Add(column);
        }
        public SqlBulkCopyColumnMapping Add(int sourceColumnIndex, int destinationColumnIndex) {
            AssertWriteAccess();
            SqlBulkCopyColumnMapping column = new SqlBulkCopyColumnMapping (sourceColumnIndex, destinationColumnIndex);
            return Add(column);
        }

        private void AssertWriteAccess () {
            if (ReadOnly) {
                throw SQL.BulkLoadMappingInaccessible();
            }
        }

        new public void Clear() {
            AssertWriteAccess();
            base.Clear();
        }

        public bool Contains(SqlBulkCopyColumnMapping value) {
            return (-1 != InnerList.IndexOf(value));
        }

        public void CopyTo(SqlBulkCopyColumnMapping[] array, int index) {
            InnerList.CopyTo(array, index);
        }

        internal void CreateDefaultMapping (int columnCount) {
            for (int i=0; i<columnCount; i++) {
                InnerList.Add(new SqlBulkCopyColumnMapping (i,i));
            }
        }

        public int IndexOf(SqlBulkCopyColumnMapping value) {
            return InnerList.IndexOf(value);
        }

        public void Insert(int index, SqlBulkCopyColumnMapping value) {
            AssertWriteAccess();
            InnerList.Insert(index, value);
        }

        public void Remove(SqlBulkCopyColumnMapping value) {
            AssertWriteAccess();
            InnerList.Remove(value);
        }

        new public void RemoveAt(int index) {
            AssertWriteAccess();
            base.RemoveAt(index);
        }

        internal void ValidateCollection () {
            MappingSchema mappingSchema;
            foreach (SqlBulkCopyColumnMapping a in this) {
                if (a.SourceOrdinal != -1) {
                    if(a.DestinationOrdinal != -1) {
                        mappingSchema = MappingSchema.OrdinalsOrdinals;
                    }
                    else {
                        mappingSchema = MappingSchema.OrdinalsNames;
                    }
                }
                else {
                    if(a.DestinationOrdinal != -1) {
                        mappingSchema = MappingSchema.NemesOrdinals;
                    }
                    else {
                        mappingSchema = MappingSchema.NamesNames;
                    }
                }

                if (_mappingSchema == MappingSchema.Undefined) {
                    _mappingSchema = mappingSchema;
                }
                else {
                    if (_mappingSchema != mappingSchema) {
                          throw SQL.BulkLoadMappingsNamesOrOrdinalsOnly();
                    }
                }
            }
        }
    }
}