using System;
using System.IO;
using System.Windows.Forms;

namespace PrintApp
{
	/// <summary>
	/// Summary description for FileFun.
	/// </summary>
	internal class FileFun
	{
		private string m_strWorkDir;
		private string m_strDataFile;
		private string m_strBackFile;
		
		public FileFun()
		{
			m_strBackFile = "test.bak";
		}

		/// <summary>
		/// 傳入文件的相關信息
		/// </summary>
		/// <param name="strInDir">工作目錄</param>
		/// <param name="strInDataFile">數據文件名</param>
		/// <param name="strInBackFile">備份文件名</param>
		public void SetFilePath(string strInDir, string strInDataFile, string strInBackFile)
		{
			m_strWorkDir	= strInDir;
			m_strDataFile	= strInDataFile;
			m_strBackFile   = strInBackFile;
		}
		
		/// <summary>
		/// 處理文件的字符串
		/// </summary>
		/// <returns>成功返回true, 錯誤返回false</returns>
		public bool HandleFile()
		{
			bool bFlag = false;

			try
			{
				DirectoryInfo theFolder = new DirectoryInfo(m_strWorkDir);
				if(!theFolder.Exists)
					throw new DirectoryNotFoundException("Folder not found:" +  m_strWorkDir);

				bFlag = ifExist();
			}
			catch(Exception ex)
			{
				MessageBox.Show(ex.Message);
			}

			return bFlag;
		}

		/// <summary>
		/// 測試文件名存在
		/// </summary>
		/// <returns>返回測試結果，存在為TRUE, 不存在為FALSE</returns>
		private bool ifExist()
		{
			bool bFlag = false;

			try 
			{
				string strFullName = Path.Combine(m_strWorkDir, m_strBackFile);
				
				FileInfo bakFile = new FileInfo(strFullName);
				if(bakFile.Exists)
				{
					bakFile.Delete();
				}
				
				strFullName = Path.Combine(m_strWorkDir, m_strDataFile);
				FileInfo theFile =  new FileInfo(strFullName);
				if(theFile.Exists)
				{					
					theFile.CopyTo(bakFile.FullName);
					bFlag = true;
				}
				else
				{
					bFlag = false;
					throw new FileNotFoundException("File not found:" + "this name:" + m_strDataFile);
				}				
			}
			catch (Exception e) 
			{
				MessageBox.Show(e.Message);
			}
	
			return bFlag;
		}
	}
}