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 * See CONTRIBUTORS.TXT for a full list of copyright holders.
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 * modification, are permitted provided that the following conditions are met:
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 *       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.
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 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

using System;
using System.Collections.Generic;
using OpenMetaverse;
using OpenSim.Framework;
using OpenSim.Services.Interfaces;

namespace OpenSim.Region.CoreModules.Avatar.Inventory.Archiver
{
    /// <summary>
    /// Utility methods for inventory archiving
    /// </summary>
    public static class InventoryArchiveUtils
    {
        public static readonly string PATH_DELIMITER = "/";

        /// <summary>
        /// Find a folder given a PATH_DELIMITER delimited path starting from a user's root 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="inventoryService">
        /// Inventory service to query
        /// </param>
        /// <param name="userId">
        /// User id to search
        /// </param>
        /// <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 static InventoryFolderBase FindFolderByPath(
            IInventoryService inventoryService, UUID userId, string path)
        {
            InventoryFolderBase rootFolder = inventoryService.GetRootFolder(userId);

            if (null == rootFolder)
                return null;

            return FindFolderByPath(inventoryService, rootFolder, path);
        }
        
        /// <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="inventoryService">
        /// Inventory service to query
        /// </param>
        /// <param name="startFolder">
        /// The folder from which the path starts
        /// </param>
        /// <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 static InventoryFolderBase FindFolderByPath(
            IInventoryService inventoryService, InventoryFolderBase startFolder, string path)
        {
            if (path == string.Empty)
                return startFolder;

            path = path.Trim();

            if (path == PATH_DELIMITER)
                return startFolder;

            string[] components = path.Split(new string[] { PATH_DELIMITER }, 2, StringSplitOptions.None);
            InventoryCollection contents = inventoryService.GetFolderContent(startFolder.Owner, startFolder.ID);

            foreach (InventoryFolderBase folder in contents.Folders)
            {
                if (folder.Name == components[0])
                {
                    if (components.Length > 1)
                        return FindFolderByPath(inventoryService, folder, components[1]);
                    else
                        return folder;
                }
            }

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

        /// <summary>
        /// Find an item given a PATH_DELIMITOR delimited path starting from the user's root 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="inventoryService">
        /// Inventory service to query
        /// </param>
        /// <param name="userId">
        /// The user to search
        /// </param>
        /// <param name="path">
        /// The path to the required item.
        /// </param>
        /// <returns>null if the item is not found</returns>
        public static InventoryItemBase FindItemByPath(
            IInventoryService inventoryService, UUID userId, string path)
        {
            InventoryFolderBase rootFolder = inventoryService.GetRootFolder(userId);

            if (null == rootFolder)
                return null;

            return FindItemByPath(inventoryService, rootFolder, path);
        }
        
        /// <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="inventoryService">
        /// Inventory service to query
        /// </param>
        /// <param name="startFolder">
        /// The folder from which the path starts
        /// </param>
        /// <param name="path">
        /// <param name="path">
        /// The path to the required item.
        /// </param>
        /// <returns>null if the item is not found</returns>
        public static InventoryItemBase FindItemByPath(
            IInventoryService inventoryService, InventoryFolderBase startFolder, string path)
        {
            string[] components = path.Split(new string[] { PATH_DELIMITER }, 2, StringSplitOptions.None);

            if (components.Length == 1)
            {
                List<InventoryItemBase> items = inventoryService.GetFolderItems(startFolder.Owner, startFolder.ID);
                foreach (InventoryItemBase item in items)
                {
                    if (item.Name == components[0])
                        return item;
                }
            }
            else
            {
                InventoryCollection contents = inventoryService.GetFolderContent(startFolder.Owner, startFolder.ID);
                
                foreach (InventoryFolderBase folder in contents.Folders)
                {
                    if (folder.Name == components[0])
                        return FindItemByPath(inventoryService, folder, components[1]);
                }
            }

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