using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Tango.Core;
using Tango.FileSystem;

namespace Tango.FSE.Common.FileSystem
{
    public class FileSystemHandler : ExtendedObject
    {
        private Action _abortAction;
        private FileSystemHandlerStatus _statusBeforePause;

        public FileSystemHandlerType Type { get; set; }

        private FileSystemHandlerStatus _status;
        public FileSystemHandlerStatus Status
        {
            get { return _status; }
            set
            {
                _status = value;
                RaisePropertyChangedAuto();
            }
        }

        private bool _isPaused;
        public bool IsPaused
        {
            get { return _isPaused; }
            set
            {
                if (_isPaused != value)
                {
                    _isPaused = value;

                    if (_isPaused)
                    {
                        _statusBeforePause = Status;
                        Status = FileSystemHandlerStatus.Paused;
                    }
                    else
                    {
                        Status = _statusBeforePause;
                    }

                    RaisePropertyChangedAuto();
                }
            }
        }

        private double _position;
        public double Position
        {
            get { return _position; }
            set { _position = value; RaisePropertyChangedAuto(); }
        }

        private double _length;
        public double Length
        {
            get { return _length; }
            set { _length = value; RaisePropertyChangedAuto(); }
        }

        private Exception _failedException;
        public Exception FailedException
        {
            get { return _failedException; }
            set { _failedException = value; RaisePropertyChangedAuto(); }
        }

        public FileSystemItem FileSystemItem { get; set; }
        public String Destination { get; set; }
        public String OperationId { get; set; }

        public FileSystemHandler(FileSystemItem fileSystemItem, String destination, Action abortAction)
        {
            FileSystemItem = fileSystemItem;
            Destination = destination;
            _abortAction = abortAction;
        }

        internal void InvalidateProgress(double position, double length)
        {
            Position = position;
            Length = length;

            if (!IsPaused)
            {
                Status = (Type == FileSystemHandlerType.FileDownload || Type == FileSystemHandlerType.FolderDownload) ? FileSystemHandlerStatus.Downloading : FileSystemHandlerStatus.Uploading;
            }
        }

        internal void RaiseFailed(Exception exception)
        {
            Status = FileSystemHandlerStatus.Failed;
            FailedException = exception;
        }

        internal void RaiseAborted()
        {
            Status = FileSystemHandlerStatus.Aborted;
        }

        internal void RaiseCompleted()
        {
            Status = FileSystemHandlerStatus.Completed;
        }

        public void Abort()
        {
            Status = FileSystemHandlerStatus.Aborted;
            _abortAction?.Invoke();
        }
    }
}