#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.ComponentModel;
using System.Globalization;
using System.Windows.Forms;
using HeuristicLab.Core.Views;
using HeuristicLab.MainForm;

namespace HeuristicLab.Problems.DataAnalysis.Views {
  [View("Interval Constraint Detail View")]
  [Content(typeof(IntervalConstraint), true)]
  public partial class IntervalConstraintView : ItemView {

    public new IntervalConstraint Content {
      get => (IntervalConstraint) base.Content;
      set => base.Content = value;
    }

    public IntervalConstraintView() {
      InitializeComponent();
      int [] items = {1, 2, 3};
      expressionInput.ReadOnly = true;
      definitionInput.ReadOnly = true;
      derivationInput.Enabled = false;
      derivationInput.Checked = false;
      numberderivationInput.DataSource = items;
    }

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

    protected override void RegisterContentEvents() {
      base.RegisterContentEvents();
      Content.Changed += new EventHandler(Content_Changed);
    }

    protected override void DeregisterContentEvents() {
      base.DeregisterContentEvents();
      Content.Changed -= new EventHandler(Content_Changed);
    }

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



    #region helpers

    private double ParseDoubleValue(string input, Control control) {
      input = input.ToLower();
      switch (input) {
        case "inf.":
        case "+inf.":
        case "Infinity":
          return double.PositiveInfinity;
        case "-inf.":
        case "-Infinity":
          return double.NegativeInfinity;
        default: {
          if (double.TryParse(input, NumberStyles.Any, CultureInfo.InvariantCulture, out var value))
            return value;
          else {
            errorProvider.SetError(control, "Invalid Input: Value must be a double!");
            return double.NaN;
          }
        }
      }
    }

    private void UpdateControls() {
      if (Content == null) {
        expressionInput.Text = string.Empty;
        lowerboundInput.Text = string.Empty;
        upperboundInput.Text = string.Empty;
        incllowerboundInput.Checked = true;
        inclupperboundInput.Checked = true;
      } else {
        expressionInput.Text = Content.Expression;
        definitionInput.Text = Content.Definition;
        lowerboundInput.Text = Content.Interval.LowerBound.ToString(CultureInfo.InvariantCulture);
        upperboundInput.Text = Content.Interval.UpperBound.ToString(CultureInfo.InvariantCulture);
        incllowerboundInput.Checked = Content.InclusiveLowerBound;
        inclupperboundInput.Checked = Content.InclusiveUpperBound;
        derivationInput.Checked = Content.IsDerivation;
        variableInput.Text = Content.Variable;
        if (!Content.IsDerivation) {
          numberderivationInput.Enabled = false;
        } else {
          numberderivationInput.Enabled = true;
          numberderivationInput.SelectedItem = Content.NumberOfDerivation;
        }

        ischeckedCheckBox.Checked = Content.Enabled;
      }
      SetEnabledStateOfControls();
    }

    private static string UpdateExpression(IntervalConstraint constraint) {
      var expression = "";

      if (!constraint.IsDerivation) {
        expression = string.Format("{0} in {1}{2} .. {3}{4}",
          constraint.Variable, 
          (constraint.InclusiveLowerBound) ? "[" : "]",
          constraint.Interval.LowerBound,
          constraint.Interval.UpperBound,
          (constraint.InclusiveUpperBound) ? "]" : "[");
      } else {
        expression = string.Format("\u2202{5}Target/\u2202{0}{6} in {1}{2} .. {3}{4}",
          constraint.Variable,
          (constraint.InclusiveLowerBound) ? "[" : "]",
          constraint.Interval.LowerBound,
          constraint.Interval.UpperBound,
          (constraint.InclusiveUpperBound) ? "]" : "[",
          PrintNumberOfDerivation(constraint.numberOfDerivation),
          PrintNumberOfDerivation(constraint.numberOfDerivation));
      }

      return expression;
    }

    private static string PrintNumberOfDerivation(int derivation) {
      switch (derivation) {
        case 1:
          return "";
        case 2:
          return "²";
        case 3:
          return "³";
        default:
          return "";
      }
    }

    #endregion

    #region control event handlers
    private void lowerboundInput_Validating(object sender, CancelEventArgs e) {
      var value = ParseDoubleValue(lowerboundInput.Text, lowerboundInput);
      if (double.IsNaN(value)) {
        errorProvider.SetError(lowerboundInput, "Invalid Input: Lowerbound must be a double value!");
        e.Cancel = true;
        return;
      }

      if (value > Content.Interval.UpperBound) {
        errorProvider.SetError(lowerboundInput, "Invalid Input: Lowerbound must be smaller than Upperbound!");
        e.Cancel = true;
        return;
      }

      errorProvider.SetError(lowerboundInput, string.Empty);
      e.Cancel = false;
    }

    private void lowerboundInput_Validated(object sender, EventArgs e) {
      var value = ParseDoubleValue(lowerboundInput.Text, lowerboundInput);
      if (!double.IsNaN(value)) {
        Content.Interval = new Interval(value, Content.Interval.UpperBound);
        var exp = UpdateExpression(Content);
        Content.Name = exp;
        Content.Expression = exp;
      }
    }

    private void upperboundInput_Validating(object sender, CancelEventArgs e) {
      var value = ParseDoubleValue(upperboundInput.Text, upperboundInput);
      if (double.IsNaN(value)) {
        errorProvider.SetError(upperboundInput, "Invalid Input: Upperbound must be a double value!");
        e.Cancel = true;
        return;
      }

      if (value < Content.Interval.LowerBound) {
        errorProvider.SetError(upperboundInput, "Invalid Input: Upperbound must be bigger than Lowerbound!");
        e.Cancel = true;
        return;
      }

      errorProvider.SetError(upperboundInput, string.Empty);
      e.Cancel = false;
    }

    private void upperboundInput_Validated(object sender, EventArgs e) {
      var value = ParseDoubleValue(upperboundInput.Text, upperboundInput);
      if (!double.IsNaN(value)) {
        Content.Interval = new Interval(Content.Interval.LowerBound, value);
        var exp = UpdateExpression(Content);
        Content.Name = exp;
        Content.Expression = exp;
      }
    }

    private void incllowerboundInput_CheckedChanged(object sender, EventArgs e) {
      if (Content.InclusiveLowerBound != incllowerboundInput.Checked) {
        Content.InclusiveLowerBound = incllowerboundInput.Checked;
        var exp = UpdateExpression(Content);
        Content.Name = exp;
        Content.Expression = exp;
      }
      
      
    }

    private void inclupperboundInput_CheckedChanged(object sender, EventArgs e) {
      if (Content.InclusiveUpperBound != inclupperboundInput.Checked) { 
        Content.InclusiveUpperBound = inclupperboundInput.Checked;
        var exp = UpdateExpression(Content);
        Content.Name = exp;
        Content.Expression = exp;
      }
    }

    private void ischeckedCheckBox_CheckedChanged(object sender, EventArgs e) {
      if (Content.Enabled != ischeckedCheckBox.Checked) {
        Content.Enabled = ischeckedCheckBox.Checked;
        //UpdateControls();
      }
    }

    private void numberderivationInput_SelectedIndexChanged(object sender, EventArgs e) {
      if ((int)numberderivationInput.SelectedItem == 1)
        Content.numberOfDerivation = 1;
      else if ((int)numberderivationInput.SelectedItem == 2)
        Content.numberOfDerivation = 2;
      else if ((int)numberderivationInput.SelectedItem == 3)
        Content.numberOfDerivation = 3;

      var exp = UpdateExpression(Content);
      Content.Name = exp;
      Content.Expression = exp;
    }

    #endregion

    #region content event handlers

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


    #endregion

  }
}