/*

* Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

*

* Redistribution and use in source and binary forms, with or without

* modification, are permitted provided that the following conditions are met:

*

* - Redistributions of source code must retain the above copyright notice,

*   this list of conditions and the following disclaimer.

* - Redistributions in binary form must reproduce the above copyright notice,

*   this list of conditions and the following disclaimer in the documentation

*   and/or other materials provided with the distribution.

* - Neither the name of Nokia Corporation nor the names of its contributors

*   may be used to endorse or promote products derived from this software

*   without specific prior written permission.

*

* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE

* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

* POSSIBILITY OF SUCH DAMAGE.

* 

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

*

*/

using System;

using System.Collections;

using System.Collections.Generic;

using System.Text;

using SymbianUtils.RawItems;

using SymbianUtils.Utilities;

using HeapLib.Array;

using HeapLib.Cells;

namespace HeapLib.Relationships

{

    public class RelationshipManager

    {

        #region Constructors & destructor

        internal RelationshipManager( HeapCell aCell )

        {

            iCell = aCell;

        }

        #endregion

        #region API

        internal void AddReferencedBy( HeapCell aCell )

        {

            iReferencedBy.Add( aCell );

        }

        internal void AddEmbeddedReferenceTo( RawItem aRawItemInThisCell, HeapCell aToCell )

        {

            System.Diagnostics.Debug.Assert( aRawItemInThisCell.Tag == null );

            if ( ContainsEmbeddedReference( aToCell ) == false )

            {

                // Make reference description

                RelationshipInfo referenceTo = new RelationshipInfo( iCell, aRawItemInThisCell, aToCell );

                // Set up relationship between a raw item in this cell and

                // the specified other cell.

                aRawItemInThisCell.Tag = referenceTo;

                // This cell now contains a reference to the other cell.

                iEmbeddedReferencesTo.Add( aToCell.Address, referenceTo );

                // aAnotherCell has been referenced by 'me'

                aToCell.RelationshipManager.ReferencedBy.Add( Parent );

            }

            else

            {

                //System.Diagnostics.Debug.WriteLine( "PREVENTING CYCLIC LINK - Cell: 0x" + aCell.Address.ToString("x8") + " already contains a linkRef to: 0x" + cell.Address.ToString("x8") );

            }

        }

        public HeapCell EmbeddedReference( uint aAddress )

        {

            HeapCell ret = null;

            //

            if ( ContainsEmbeddedReference( aAddress ) )

            {

                RelationshipInfo info = iEmbeddedReferencesTo[ aAddress ];

                ret = info.ToCell;

            }

            //

            return ret;

        }

        public bool ContainsEmbeddedReference( uint aAddress )

        {

            bool found = iEmbeddedReferencesTo.ContainsKey( aAddress );

            return found;

        }

        public bool ContainsEmbeddedReference( HeapCell aCell )

        {

            return ContainsEmbeddedReference( aCell.Address );

        }

        #endregion

        #region Properties

        public HeapCell Parent

        {

            get { return iCell; }

        }

        // <summary>

        // The array of cells that this particular cell contains references

        // to within it's raw item array (i.e. it's payload section).

        // </summary>

        public RelationshipCollection EmbeddedReferencesTo

        {

            get { return new RelationshipCollection( iEmbeddedReferencesTo ); }

        }

        // <summary>

        // The array of cells that are referencing this cell, i.e. the

        // list of other cells that contain addresses that point to 'me'

        // </summary>

        public HeapCellArrayBase ReferencedBy

        {

            get { return iReferencedBy; }

        }

        public HeapCell ReferencedByUnique

        {

            get

            {

                if (iReferencedBy.Count == 1)

                    return iReferencedBy[0];

                if (iReferencedBy.Count > 1)

                {

                    HeapCell firstHeapCell = iReferencedBy[0];

                    for (int i = 1; i < iReferencedBy.Count; i++)

                    {

                        if (!firstHeapCell.Equals(iReferencedBy[i]))

                        {

                            return null;

                        }

                    }

                    return iReferencedBy[0];

                }

                return null;

            }

        }

        public uint PayloadLengthOfEmbeddedCells

        {

            get

            {

                uint ret = 0;

                //

                foreach ( RelationshipInfo info in EmbeddedReferencesTo )

                {

                    ret += info.ToCell.PayloadLength;

                }

                //

                return ret;

            }

        }

        #endregion

        #region Data members

        private readonly HeapCell iCell;

        private Dictionary<uint, RelationshipInfo> iEmbeddedReferencesTo = new Dictionary<uint, RelationshipInfo>();

        private HeapCellArrayUnsorted iReferencedBy = new HeapCellArrayUnsorted();

        #endregion

    }

}