/*
 * Copyright (c) Contributors, http://opensimulator.org/
 * See CONTRIBUTORS.TXT for a full list of copyright holders.
 *
 * 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 the OpenSimulator Project 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 DEVELOPERS ``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 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.
 */

using System;
using System.Collections.Generic;
using System.Reflection;
using log4net;
using OpenMetaverse;

namespace OpenSim.Framework
{
    public class InventoryFolderImpl : InventoryFolderBase
    {
        //private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

        public static readonly string PATH_DELIMITER = "/";

        /// <summary>
        /// Items that are contained in this folder
        /// </summary>
        public Dictionary<UUID, InventoryItemBase> Items = new Dictionary<UUID, InventoryItemBase>();

        /// <summary>
        /// Child folders that are contained in this folder
        /// </summary>
        protected Dictionary<UUID, InventoryFolderImpl> m_childFolders = new Dictionary<UUID, InventoryFolderImpl>();

        // Constructors
        public InventoryFolderImpl(InventoryFolderBase folderbase)
        {
            Owner = folderbase.Owner;
            ID = folderbase.ID;
            Name = folderbase.Name;
            ParentID = folderbase.ParentID;
            Type = folderbase.Type;
            Version = folderbase.Version;
        }

        public InventoryFolderImpl()
        {
        }

        /// <summary>
        /// Create a new subfolder.
        /// </summary>
        /// <param name="folderID"></param>
        /// <param name="folderName"></param>
        /// <param name="type"></param>
        /// <returns>The newly created subfolder.  Returns null if the folder already exists</returns>
        public InventoryFolderImpl CreateChildFolder(UUID folderID, string folderName, ushort type)
        {
            lock (m_childFolders)
            {
                if (!m_childFolders.ContainsKey(folderID))
                {
                    InventoryFolderImpl subFold = new InventoryFolderImpl()
                    {
                        Name = folderName,
                        ID = folderID,
                        Type = (short)type,
                        ParentID = this.ID,
                        Owner = Owner
                    };
                    m_childFolders.Add(subFold.ID, subFold);

                    return subFold;
                }
            }

            return null;
        }

        /// <summary>
        /// Add a folder that already exists.
        /// </summary>
        /// <param name="folder"></param>
        public void AddChildFolder(InventoryFolderImpl folder)
        {
            lock (m_childFolders)
            {
                folder.ParentID = ID;
                m_childFolders[folder.ID] = folder;
            }
        }

        /// <summary>
        /// Does this folder contain the given child folder?
        /// </summary>
        /// <param name="folderID"></param>
        /// <returns></returns>
        public bool ContainsChildFolder(UUID folderID)
        {
            return m_childFolders.ContainsKey(folderID);
        }

        /// <summary>
        /// Get a child folder
        /// </summary>
        /// <param name="folderID"></param>
        /// <returns>The folder if it exists, null if it doesn't</returns>
        public InventoryFolderImpl GetChildFolder(UUID folderID)
        {
            lock (m_childFolders)
            {
                m_childFolders.TryGetValue(folderID, out InventoryFolderImpl folder);
                return folder;
            }
        }

        /// <summary>
        /// Removes the given child subfolder.
        /// </summary>
        /// <param name="folderID"></param>
        /// <returns>
        /// The folder removed, or null if the folder was not present.
        /// </returns>
        public InventoryFolderImpl RemoveChildFolder(UUID folderID)
        {
            lock (m_childFolders)
            {
                if (m_childFolders.TryGetValue(folderID, out InventoryFolderImpl removedFolder))
                {
                    m_childFolders.Remove(folderID);
                    return removedFolder;
                }
            }
            return null;
        }

        /// <summary>
        /// Delete all the folders and items in this folder.
        /// </summary>
        public void Purge()
        {
            foreach (InventoryFolderImpl folder in m_childFolders.Values)
            {
                folder.Purge();
            }

            m_childFolders.Clear();
            Items.Clear();
        }

        /// <summary>
        /// Returns the item if it exists in this folder or in any of this folder's descendant folders
        /// </summary>
        /// <param name="itemID"></param>
        /// <returns>null if the item is not found</returns>
        public InventoryItemBase FindItem(UUID itemID)
        {
            lock (Items)
            {
                if (Items.TryGetValue(itemID, out InventoryItemBase it))
                    return it;
            }

            lock (m_childFolders)
            {
                foreach (InventoryFolderImpl folder in m_childFolders.Values)
                {
                    InventoryItemBase item = folder.FindItem(itemID);
                    if (item != null)
                        return item;
                }
            }
            return null;
        }

        public InventoryItemBase FindAsset(UUID assetID)
        {
            lock (Items)
            {
                foreach (InventoryItemBase item in Items.Values)
                {
                    if (item.AssetID.Equals(assetID))
                        return item;
                }
            }

            lock (m_childFolders)
            {
                foreach (InventoryFolderImpl folder in m_childFolders.Values)
                {
                    InventoryItemBase item = folder.FindAsset(assetID);
                    if (item != null)
                        return item;
                }
            }

            return null;
        }

        /// <summary>
        /// Deletes an item if it exists in this folder or any children
        /// </summary>
        /// <param name="folderID"></param>
        /// <returns></returns>
        public bool DeleteItem(UUID itemID)
        {
            lock (Items)
            {
                if (Items.Remove(itemID))
                    return true;
            }

            lock (m_childFolders)
            {
                foreach (InventoryFolderImpl folder in m_childFolders.Values)
                {
                    if(folder.DeleteItem(itemID))
                        return true;
                }
            }
            return false;
        }

        /// <summary>
        /// Returns the folder requested if it is this folder or is a descendent of this folder.  The search is depth
        /// first.
        /// </summary>
        /// <returns>The requested folder if it exists, null if it does not.</returns>
        public InventoryFolderImpl FindFolder(UUID folderID)
        {
            if (folderID.Equals(ID))
                return this;

            lock (m_childFolders)
            {
                foreach (InventoryFolderImpl folder in m_childFolders.Values)
                {
                    InventoryFolderImpl returnFolder = folder.FindFolder(folderID);
                    if (returnFolder != null)
                        return returnFolder;
                }
            }
            return null;
        }

        /// <summary>
        /// Look through all child subfolders for a folder marked as one for a particular asset type, and return it.
        /// </summary>
        /// <param name="type"></param>
        /// <returns>Returns null if no such folder is found</returns>
        public InventoryFolderImpl FindFolderForType(int type)
        {
            lock (m_childFolders)
            {
                foreach (InventoryFolderImpl f in m_childFolders.Values)
                {
                    if (f.Type == type)
                        return f;
                }
            }

            return null;
        }

        /// <summary>
        /// Find a folder given a PATH_DELIMITER delimited path starting from this folder
        /// </summary>
        ///
        /// This method does not handle paths that contain multiple delimitors
        ///
        /// FIXME: We do not yet handle situations where folders have the same name.  We could handle this by some
        /// XPath like expression
        ///
        /// FIXME: Delimitors which occur in names themselves are not currently escapable.
        ///
        /// <param name="path">
        /// The path to the required folder.
        /// It this is empty or consists only of the PATH_DELIMTER then this folder itself is returned.
        /// </param>
        /// <returns>null if the folder is not found</returns>
        public InventoryFolderImpl FindFolderByPath(string path)
        {
            path = path.Trim();
            if (path.Length == 0)
                return this;

            if (path == PATH_DELIMITER)
                return this;

            string[] components = path.Split(new string[] { PATH_DELIMITER }, 2, StringSplitOptions.None);

            lock (m_childFolders)
            {
                foreach (InventoryFolderImpl folder in m_childFolders.Values)
                {
                    if (folder.Name == components[0])
                        if (components.Length > 1)
                            return folder.FindFolderByPath(components[1]);
                        else
                            return folder;
                }
            }

            // We didn't find a folder with the given name
            return null;
        }

        /// <summary>
        /// Find an item given a PATH_DELIMITOR delimited path starting from this folder.
        ///
        /// This method does not handle paths that contain multiple delimitors
        ///
        /// FIXME: We do not yet handle situations where folders or items have the same name.  We could handle this by some
        /// XPath like expression
        ///
        /// FIXME: Delimitors which occur in names themselves are not currently escapable.
        /// </summary>
        /// <param name="path">
        /// The path to the required item.
        /// </param>
        /// <returns>null if the item is not found</returns>
        public InventoryItemBase FindItemByPath(string path)
        {
            string[] components = path.Split(new string[] { PATH_DELIMITER }, 2, StringSplitOptions.None);

            if (components.Length == 1)
            {
                lock (Items)
                {
                    foreach (InventoryItemBase item in Items.Values)
                    {
                        if (item.Name == components[0])
                            return item;
                    }
                }
            }
            else
            {
                lock (m_childFolders)
                {
                    foreach (InventoryFolderImpl folder in m_childFolders.Values)
                    {
                        if (folder.Name == components[0])
                            return folder.FindItemByPath(components[1]);
                    }
                }
            }

            // We didn't find an item or intermediate folder with the given name
            return null;
        }

        /// <summary>
        /// Return a copy of the list of child items in this folder.  The items themselves are the originals.
        /// </summary>
        public List<InventoryItemBase> RequestListOfItems()
        {
            List<InventoryItemBase> itemList = new List<InventoryItemBase>();

            lock (Items)
            {
                foreach (InventoryItemBase item in Items.Values)
                {
                    //m_log.DebugFormat(
                    //    "[INVENTORY FOLDER IMPL]: Returning item {0} {1}, OwnerPermissions {2:X}",
                    //    item.Name, item.ID, item.CurrentPermissions);

                    itemList.Add(item);
                }
            }

            //m_log.DebugFormat("[INVENTORY FOLDER IMPL]: Found {0} items", itemList.Count);

            return itemList;
        }

        /// <summary>
        /// Return a copy of the list of child folders in this folder.  The folders themselves are the originals.
        /// </summary>
        public List<InventoryFolderBase> RequestListOfFolders()
        {
            List<InventoryFolderBase> folderList = new List<InventoryFolderBase>(m_childFolders.Count);

            lock (m_childFolders)
            {
                foreach (InventoryFolderBase folder in m_childFolders.Values)
                {
                    folderList.Add(folder);
                }
            }

            return folderList;
        }

        public List<InventoryFolderImpl> RequestListOfFolderImpls()
        {
            List<InventoryFolderImpl> folderList = new List<InventoryFolderImpl>(m_childFolders.Count);

            lock (m_childFolders)
            {
                foreach (InventoryFolderImpl folder in m_childFolders.Values)
                {
                    folderList.Add(folder);
                }
            }

            return folderList;
        }

        /// <value>
        /// The total number of items in this folder and in the immediate child folders (though not from other
        /// descendants).
        /// </value>
        public int TotalCount
        {
            get
            {
                int total = Items.Count;
                foreach (InventoryFolderImpl folder in m_childFolders.Values)
                {
                    total += folder.TotalCount;
                }
                return total;
            }
        }
    }
}