using System;
using System.IO;
using System.Text;
using System.Collections.Generic;

namespace AniNIX.Shared {

    public class FileHandle : IDisposable {

        //Private variables
        private StreamReader _fileHandle = null;
        private String _path = null;
        private String _directory = null;
        private String _file = null;

        /// <summary> 
        /// Create an object to bundle my usual file operations.
        /// <summary>
        public FileHandle(String path) {
            this._path = path;
            this._directory = Path.GetDirectoryName(path);
            this._file = Path.GetFileName(path);
            this.Reset();
        }

        /// <summary>
        /// Read the next line.
        /// </summary>
        /// <returns>Next line</returns>
        public String NextLine() {
            return _fileHandle.ReadLine();
        }

        /// <summary>
        /// Get the next new line added to the file.
        /// </summary>
        /// <returns>Next new line</returns>
        public string NextNewLine() {
            FileSystemWatcher fsw = new FileSystemWatcher(_directory);
            fsw.Path = _directory;
            fsw.Filter = _file;
            fsw.NotifyFilter = NotifyFilters.LastWrite;
            fsw.WaitForChanged(WatcherChangeTypes.Changed);
            // Optionally, this could be accomplished with http://stackoverflow.com/questions/452902/how-to-read-a-text-file-reversely-with-iterator-in-c-sharp
            // Instead, we are using a syscall for sake of codespace and testing.
            return ExecuteCommand.Run(String.Format("tail -n 1 {0}",this._path));
        }

        /// <summary>
        /// Read all contents of the file.
        /// </summary>
        /// <returns>File contents</returns>
        public String ReadAll() {
            return _fileHandle.ReadToEnd();
        }

        /// <summary>
        /// Close the old handle, if applicable, and open new one.
        /// </summary>
        public void Reset() {
            if (this._fileHandle != null) { 
                this._fileHandle.Close(); 
                this._fileHandle.Dispose(); 
            }
            this._fileHandle = new StreamReader(_path);
        }

        /* IDisposable */ 

        /// <summary>
        /// Clean up this FileStream, implementing IDisposable
        /// </summary>
        public void Dispose() {
            this.Dispose(true);
            GC.SuppressFinalize(this);
        }
        /// <summary>
        /// Force the GarbageCollector to Dispose if programmer does not
        /// </summary>
        ~FileHandle() {
            Dispose(false);
            ReportMessage.Log(Verbosity.Error,"Programmer forgot to dispose of FileHandle. Marking for Garbage Collector");
        }

        // This bool indicates whether we have disposed of this Raven
        public bool _isDisposed = false;

        /// <summary>
        /// Dispose of this FileHandle's resources responsibly.
        /// </summary>
        private void Dispose(bool disposing) {
            if (!_isDisposed) {
                if (disposing) {
                    _path = null;
                    _file = null;
                    _directory = null;
                }
                if ( _fileHandle != null) {
                    _fileHandle.Close();
                    _fileHandle.Dispose();
                }
            }
            this._isDisposed = true;		
        }

    }
}