#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2019 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;
using System.Collections.Generic;
using System.Drawing;
using HeuristicLab.Collections;
using HeuristicLab.Core;
using HeuristicLab.MainForm;
using HeuristicLab.MainForm.WindowsForms;

namespace HeuristicLab.Problems.DataAnalysis.Views {
  [View("ProblemDataConstraint View")]
  [Content(typeof(ProblemDataConstraint), true)]
  public partial class ProblemDataConstraintView : AsynchronousContentView {
    private readonly CheckedItemList<IntervalConstraint> intervalConstraints = new CheckedItemList<IntervalConstraint>();
    public new ProblemDataConstraint Content {
      get => (ProblemDataConstraint)base.Content;
      set => base.Content = value;
    }

    public ProblemDataConstraintView() {
      InitializeComponent();
      errorOutput.Text = "";
    }

    protected override void OnContentChanged() {
      base.OnContentChanged();
      UpdateControl();
    }

    protected override void RegisterContentEvents() {
      base.RegisterContentEvents();
      intervalConstraints.CheckedItemsChanged += constraint_CheckedItemChanged;
      intervalConstraints.ItemsAdded += constraints_Updated;
      intervalConstraints.ItemsRemoved += constraint_removed;
      Content.Changed += Content_Changed;
    }

    protected override void DeregisterContentEvents() {
      intervalConstraints.CheckedItemsChanged -= constraint_CheckedItemChanged;
      intervalConstraints.ItemsAdded -= constraints_Updated;
      intervalConstraints.ItemsRemoved -= constraint_removed;
      Content.Changed -= Content_Changed;
      base.DeregisterContentEvents();
    }

    protected override void SetEnabledStateOfControls() {
      constraintsInput.Enabled = Content != null && !Locked && !ReadOnly;
    }


    private IEnumerable<IntervalConstraint> ParseConstraints(string input) {
        return IntervalConstraintsParser.ParseInput(input, Content.ProblemData.TargetVariable,
          Content.ProblemData.AllowedInputVariables);
    }

    private void parseBtn_Click(object sender, EventArgs e) {
      if (constraintsInput.Text != null) {
        intervalConstraints.Clear();
        try {
          var parsedConstraints = ParseConstraints(constraintsInput.Text);
          Content.Constraints = parsedConstraints;
          Content.Input = constraintsInput.Text;
          Content.InfoText = "Constraints successfully parsed.";
          Content.InfoColor = Color.DarkGreen;
          //Catch the exception from the constraints parser and show it in the error dialog
        } catch(ArgumentException ex) {
          Content.Constraints = new List<IntervalConstraint>();
          Content.InfoText = ex.Message.Replace("Parameter name", "@Line");
          Content.InfoColor = Color.DarkRed;
        }
      } else {
        errorOutput.Text = "No constraints were found!";
      }
    }

    private void UpdateControl() {
      if (Content == null) {
        intervalConstraints.Clear();
        intervalConstraintsView.Content = intervalConstraints;
      } else {
        intervalConstraints.Clear();
        constraintsInput.Text = Content.Input;
        errorOutput.ForeColor = Content.InfoColor;
        errorOutput.Text = Content.InfoText;
        foreach (var constraint in Content.Constraints) {
          intervalConstraints.Add(constraint, constraint.Enabled);
        }

        intervalConstraintsView.Content = intervalConstraints;
      }
    }

    private void constraint_Changed(object sender, EventArgs e) {
      var constraint = (IntervalConstraint)sender;
      intervalConstraints.SetItemCheckedState(constraint, constraint.Enabled);
    }

    private void constraints_Updated(object sender, CollectionItemsChangedEventArgs<IndexedItem<IntervalConstraint>> e) {
      foreach (var addedItem in e.Items) {
        addedItem.Value.Changed += constraint_Changed;
      }
    }

    private void constraint_removed(object sender, CollectionItemsChangedEventArgs<IndexedItem<IntervalConstraint>> e) {
      foreach (var removedItem in e.Items) {
        removedItem.Value.Changed -= constraint_Changed;
      }
    }

    private void constraint_CheckedItemChanged(object sender,
      CollectionItemsChangedEventArgs<IndexedItem<IntervalConstraint>> e) {
      ICheckedItemList<IntervalConstraint> checkedItemList = (ICheckedItemList<IntervalConstraint>)sender;
      foreach (var indexedItem in e.Items) {
        indexedItem.Value.Enabled = checkedItemList.ItemChecked(indexedItem.Value);
      }
    }

    private void constraintsInput_TextChanged(object sender, EventArgs e) {
      if (Content.Input != constraintsInput.Text) {
       Content.Input = constraintsInput.Text;
       Content.InfoText = "Unparsed changes! Press parse button to save changes.";
       Content.InfoColor = Color.DarkOrange;
      } else {
        errorOutput.Text = "";
      }

    }

    private void Content_Changed(object sender, EventArgs e) {
      UpdateControl();
    }

  }
}