#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2016 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
 *
 * This file is part of HeuristicLab.
 *
 * HeuristicLab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HeuristicLab is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using System;

namespace HeuristicLab.MainForm {
  public class Progress : IProgress {
    private ProgressState progressState;
    public ProgressState ProgressState {
      get { return progressState; }
      private set {
        if (progressState != value) {
          progressState = value;
          OnProgressStateChanged();
        }
      }
    }

    private string message;
    public string Message {
      get { return message; }
      set {
        if (message != value) {
          message = value;
          OnMessageChanged();
        }
      }
    }

    private ProgressBarMode progressBarMode;
    public ProgressBarMode ProgressBarMode {
      get { return progressBarMode; }
      set {
        if (progressBarMode != value) {
          progressBarMode = value;
          OnProgressBarModeChanged();
        }
      }
    }

    private double progressValue;
    public double ProgressValue {
      get { return progressValue; }
      set {
        if (progressBarMode == ProgressBarMode.Marquee)
          throw new InvalidOperationException("Cannot set ProgressValue while ProgressBar is in Marquee-Mode");
        if (progressValue != value) {
          progressValue = Math.Max(Math.Min(value, 1.0), 0.0);
          OnProgressChanged();
        }
      }
    }

    private bool canBeStopped;
    public bool CanBeStopped {
      get { return canBeStopped; }
      set {
        if (canBeStopped != value) {
          canBeStopped = value;
          OnCanBeStoppedChanged();
        }
      }
    }

    private bool canBeCanceled;
    public bool CanBeCanceled {
      get { return canBeCanceled; }
      set {
        if (canBeCanceled != value) {
          canBeCanceled = value;
          OnCanBeCanceledChanged();
        }
      }
    }

    public Progress() {
      progressState = ProgressState.Finished;
      canBeStopped = false;
      canBeCanceled = false;
      progressBarMode = ProgressBarMode.Marquee;
      progressValue = 0.0;
    }

    /// <summary>
    /// Starts or restarts an "undefined" progress in marquee-mode
    /// </summary>
    public void Start(string message) {
      ProgressState = ProgressState.Started;
      ProgressBarMode = ProgressBarMode.Marquee;
      Message = message;
    }
    /// <summary>
    /// Starts or restarts a progress in continuous-mode
    /// </summary>
    public void Start(string message, double progressValue) {
      ProgressState = ProgressState.Started;
      ProgressBarMode = ProgressBarMode.Continuous;
      ProgressValue = progressValue;
      Message = message;
    }

    public void Finish() {
      if (ProgressBarMode == ProgressBarMode.Continuous && ProgressValue != 1.0)
        ProgressValue = 1.0;
      ProgressState = ProgressState.Finished;
    }

    public void Stop() {
      if (canBeStopped) {
        ProgressState = ProgressState.StopRequested;
        OnStopRequested();
      } else throw new NotSupportedException("This progress cannot be stopped.");
    }
    public void Cancel() {
      if (canBeCanceled) {
        ProgressState = ProgressState.CancelRequested;
        OnCancelRequested();
      } else throw new NotSupportedException("This progress cannot be canceled.");
    }

    #region Event Handler
    public event EventHandler ProgressStateChanged;
    private void OnProgressStateChanged() {
      var handler = ProgressStateChanged;
      if (handler != null) handler(this, EventArgs.Empty);
    }

    public event EventHandler MessageChanged;
    private void OnMessageChanged() {
      var handler = MessageChanged;
      if (handler != null) handler(this, EventArgs.Empty);
    }

    public event EventHandler ProgressBarModeChanged;
    private void OnProgressBarModeChanged() {
      var handler = ProgressBarModeChanged;
      if (handler != null) handler(this, EventArgs.Empty);
    }

    public event EventHandler ProgressValueChanged;
    private void OnProgressChanged() {
      var handler = ProgressValueChanged;
      if (handler != null) handler(this, EventArgs.Empty);
    }

    public event EventHandler CanBeStoppedChanged;
    private void OnCanBeStoppedChanged() {
      var handler = CanBeStoppedChanged;
      if (handler != null) handler(this, EventArgs.Empty);
    }

    public event EventHandler CanBeCanceledChanged;
    private void OnCanBeCanceledChanged() {
      var handler = CanBeCanceledChanged;
      if (handler != null) handler(this, EventArgs.Empty);
    }

    public event EventHandler StopRequested;
    private void OnStopRequested() {
      var handler = StopRequested;
      if (handler != null) handler(this, EventArgs.Empty);
    }

    public event EventHandler CancelRequested;
    private void OnCancelRequested() {
      var handler = CancelRequested;
      if (handler != null) handler(this, EventArgs.Empty);
    }
    #endregion
  }
}