#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 HeuristicLab.Collections;
using HeuristicLab.Core;
using HeuristicLab.MainForm;
using HeuristicLab.MainForm.WindowsForms;

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

    public ParsedConstraintView() {
      InitializeComponent();
      errorOutput.Text = "";
      intervalConstraints = new CheckedItemList<IntervalConstraint>();
      intervalConstraints.CheckedItemsChanged += constraint_CheckedItemChanged;
    }

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

    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) {
        ClearConstraints();
        var parsedConstraints = ParseConstraints(constraintsInput.Text);
        foreach (var constraint in parsedConstraints) {
          constraint.Changed += constraint_Changed;
          intervalConstraints.Add(constraint, constraint.Enabled);
        }
        constraintsOutput.Content = intervalConstraints;
        Content.Constraints = intervalConstraints;
        Content.Input = constraintsInput.Text;
        errorOutput.Text = "";
      } else {
        errorOutput.Text = "No constraints were found!";
      }
    }

    private void UpdateControl() {
      if (Content == null) {
        ClearConstraints();
        constraintsOutput.Content = intervalConstraints.AsReadOnly();
      } else {
        ClearConstraints();
        constraintsInput.Text = Content.Input;
        foreach (var constraint in Content.Constraints) {
          constraint.Changed += constraint_Changed;
          intervalConstraints.Add(constraint, constraint.Enabled);
        }

        constraintsOutput.Content = intervalConstraints.AsReadOnly();
      }
      SetEnabledStateOfControls();
    }

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

    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) {
      errorOutput.Text = "Unparsed changes! Press parse button to save changes.";
    }

    private void ClearConstraints() {
      foreach (var constraint in intervalConstraints) {
        constraint.Changed -= constraint_Changed;
      }
      intervalConstraints.Clear();
    }

  }
}