using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Tango.PMR.Printing;

namespace Tango.Integration.Operation
{
    /// <summary>
    /// Represents a <see cref="MachineOperator.Print(Observables.Job, Observables.ProcessParametersTable)"/> handler.
    /// </summary>
    public class JobHandler
    {
        private Action _cancelAction;

        #region Events

        /// <summary>
        /// Occurs when a job status has been received.
        /// </summary>
        public event EventHandler<JobStatus> StatusReceived;

        /// <summary>
        /// Occurs when the job has failed.
        /// </summary>
        public event EventHandler<Exception> Failed;

        /// <summary>
        /// Occurs when the job has completed successfully.
        /// </summary>
        public event EventHandler Completed;

        /// <summary>
        /// Occurs when the job has been canceled.
        /// </summary>
        public event EventHandler Canceled;

        #endregion

        #region Properties

        /// <summary>
        /// Gets a value indicating whether this handler job has been canceled.
        /// </summary>
        public bool IsCanceled { get; internal set; }

        #endregion

        #region Constructors

        /// <summary>
        /// Initializes a new instance of the <see cref="JobHandler"/> class.
        /// </summary>
        public JobHandler()
        {

        }

        /// <summary>
        /// Initializes a new instance of the <see cref="JobHandler"/> class.
        /// </summary>
        /// <param name="cancelAction">The cancel action.</param>
        internal JobHandler(Action cancelAction) : this()
        {
            _cancelAction = () => { IsCanceled = true; cancelAction(); };
        }

        #endregion

        #region Internal Methods

        /// <summary>
        /// Raises the status received event.
        /// </summary>
        /// <param name="status">The status.</param>
        internal void RaiseStatusReceived(JobStatus status)
        {
            StatusReceived?.Invoke(this, status);
        }

        /// <summary>
        /// Raises the failed event.
        /// </summary>
        /// <param name="ex">The ex.</param>
        internal void RaiseFailed(Exception ex)
        {
            Failed?.Invoke(this, ex);
        }

        /// <summary>
        /// Raises the completed event.
        /// </summary>
        internal void RaiseCompleted()
        {
            Completed?.Invoke(this, new EventArgs());
        }

        /// <summary>
        /// Raises the canceled event.
        /// </summary>
        internal void RaiseCanceled()
        {
            Canceled?.Invoke(this, new EventArgs());
        }

        #endregion

        #region Public Methods

        /// <summary>
        /// Cancels the associated job.
        /// </summary>
        public void Cancel()
        {
            _cancelAction();
        }

        #endregion
    }
}