#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.Windows.Forms;
using HeuristicLab.Core.Views;
using HeuristicLab.MainForm;

namespace HeuristicLab.Problems.DataAnalysis.Views {
  [View("Interval Constraint Detail View")]
  [Content(typeof(IntervalConstraint), true)]
  public sealed 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;
      numberderivationInput.DataSource = items;
    }

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

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

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

    protected override void SetEnabledStateOfControls() {
      base.SetEnabledStateOfControls();
      expressionInput.Enabled       = Content != null && !Locked && !ReadOnly;
      variableInput.Enabled         = Content != null && !Locked && !ReadOnly;
      numberderivationInput.Enabled = Content != null && !Locked && !ReadOnly;
      lowerboundInput.Enabled       = Content != null && !Locked && !ReadOnly;
      upperboundInput.Enabled       = Content != null && !Locked && !ReadOnly;
      ischeckedCheckBox.Enabled     = Content != null && !Locked && !ReadOnly;
    }


    #region helpers

    private static double ParseDoubleValue(string input, Control control, ErrorProvider errorProvider) {
      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, out var value)) {
            return value;
          }

          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;
        return;
      }

      expressionInput.Text = Content.Expression;
      lowerboundInput.Text = Content.Interval.LowerBound.ToString();
      upperboundInput.Text = Content.Interval.UpperBound.ToString();

      variableInput.Text = Content.Variable;
      if (!Content.IsDerivative) {
        numberderivationInput.Enabled      = false;
        numberderivationInput.SelectedItem = null;
        numberderivationInput.Text         = "0";
      }
      else {
        numberderivationLabel.Visible      = true;
        numberderivationInput.Visible      = true;
        numberderivationInput.Enabled      = true;
        numberderivationInput.SelectedItem = Content.NumberOfDerivations;
      }

      ischeckedCheckBox.Checked = Content.Enabled;
    }

    #endregion

    #region control event handlers

    private void lowerboundInput_Validating(object sender, CancelEventArgs e) {
      var value = ParseDoubleValue(lowerboundInput.Text, lowerboundInput, errorProvider);
      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, errorProvider);
      if (!double.IsNaN(value)) Content.Interval = new Interval(value, Content.Interval.UpperBound);
    }

    private void upperboundInput_Validating(object sender, CancelEventArgs e) {
      var value = ParseDoubleValue(upperboundInput.Text, upperboundInput, errorProvider);
      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, errorProvider);
      if (!double.IsNaN(value)) Content.Interval = new Interval(Content.Interval.LowerBound, value);
    }

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

    private void numberderivationInput_SelectedIndexChanged(object sender, EventArgs e) {
      if (numberderivationInput.SelectedItem == null) {
        Content.NumberOfDerivations   = 0;
        numberderivationInput.Enabled = false;
        return;
      }

      if ((int) numberderivationInput.SelectedItem == 1)
        Content.NumberOfDerivations = 1;
      else if ((int) numberderivationInput.SelectedItem == 2)
        Content.NumberOfDerivations = 2;
      else if ((int) numberderivationInput.SelectedItem == 3)
        Content.NumberOfDerivations = 3;
    }

    #endregion

    #region content event handlers

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

    #endregion
  }
}