//	Spludlow Software
//	Copyright © Samuel P. Ludlow 2020 All Rights Reserved
//	Distributed under the terms of the GNU General Public License version 3
//	Distributed WITHOUT ANY WARRANTY; without implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE
//	https://www.spludlow.co.uk/LICENCE.TXT
//	The Spludlow logo is a registered trademark of Samuel P. Ludlow and may not be used without permission
//	v1.14

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using System.IO;
using System.Data;

namespace Spludlow
{
	/// <summary>
	/// EWS Folder ID lookup with caching. Used by Spludlow.Exchange
	/// </summary>
	public class ExchangeFolders
	{
		private DataSet DataSet = null;

		private Spludlow.Exchange ExchangeService;
		private string CacheDirectory;

		public ExchangeFolders(Spludlow.Exchange exchangeService, string cacheDirectory)
		{
			this.ExchangeService = exchangeService;
			this.CacheDirectory = cacheDirectory;

			this.DataSet = Spludlow.Data.TextTable.ReadDirectory(this.CacheDirectory);

			foreach (DataTable table in this.DataSet.Tables)
				table.CaseSensitive = true;
		}

		private void SaveChanges(string userEmailAddress)
		{
			DataTable table = this.DataSet.Tables[userEmailAddress];

			Spludlow.Data.TextTable.Write(this.CacheDirectory + @"\" + table.TableName + ".txt", table);
		}

		public string FolderId(string userEmailAddress, string path)
		{
			DataTable table;

			if (this.DataSet.Tables.Contains(userEmailAddress) == false)
			{
				string rootFolderId = this.ExchangeService.MailBoxRootUniqueFolderId(userEmailAddress);

				table = this.ExchangeService.QueryFolders(rootFolderId).Tables[0];
				table.TableName = userEmailAddress;

				table.DataSet.Tables.Remove(table);

				table.CaseSensitive = true;

				this.DataSet.Tables.Add(table);

				this.SaveChanges(userEmailAddress);
			}

			table = this.DataSet.Tables[userEmailAddress];

			DataRow[] rows = table.Select("Path = '" + path.Replace("'", "''") + "'");

			if (rows.Length == 0)
				return null;

			if (rows.Length > 1)
				throw new ApplicationException("ExchangeFolders; Looking up FolderId, more that one folder with same path: " + userEmailAddress + ", " + path);

			return (string)rows[0]["UniqueId"];
		}

		public bool FolderExists(string userEmailAddress, string path)
		{
			return (this.FolderId(userEmailAddress, path) != null);
		}

		//	UniqueId	DisplayName	Depth	Path	FolderType	ChildFolderCount	TotalCount

		public string CreateFolder(string userEmailAddress, string path)
		{
			string folderId = this.FolderId(userEmailAddress, path);
			if (folderId != null)
				return folderId;

			string parentPath = Path.GetDirectoryName(path).Replace("\\", "/");
			string name = Path.GetFileName(path);

			//throw new ApplicationException(">" + parentPath + "<");

			string parentFolderId = this.FolderId(userEmailAddress, parentPath);

			if (parentFolderId == null)
				throw new ApplicationException("ExchangeFolders; Create Folder, Can't find parent folder: " + userEmailAddress + ", " + path);

			folderId = this.ExchangeService.CreateFolder(parentFolderId, name);

			int depth = 0;
			foreach (char ch in path)
				if (ch == '/')
					++depth;

			DataTable table = this.DataSet.Tables[userEmailAddress];

			table.Rows.Add(folderId, name, depth, path, "Folder", 0, 0);

			//	Add to parent's ChildFolderCount
			DataRow[] rows = table.Select("UniqueId = '" + parentFolderId + "'");
			if (rows.Length != 1)
				throw new ApplicationException("ExchangeFolders; Create Folder, Did not find one parent row: " + userEmailAddress + ", " + path + ", " + rows.Length);
			DataRow parentRow = rows[0];
			parentRow["ChildFolderCount"] = (int)parentRow["ChildFolderCount"] + 1;

			this.SaveChanges(userEmailAddress);

			return folderId;
		}

		public static void DeleteFolder(string userEmailAddress, string path)
		{
			throw new NotImplementedException("Delete not implimentd yet!");
		}
	}
}