#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2014 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 System.Drawing.Drawing2D;
using System.Linq;
using System.Windows.Forms;
using HeuristicLab.Common;
using HeuristicLab.Visualization;

namespace HeuristicLab.EvolutionTracking.Views {
  public partial class GenealogyGraphChart : ChartControl {
    private IGenealogyGraph genealogyGraph;

    private const double XIncrement = 30;
    private const double YIncrement = 30;
    private const double Diameter = 20;

    public IGenealogyGraph GenealogyGraph {
      get { return genealogyGraph; }
      set {
        if (value == null) return;
        genealogyGraph = value;
        Clear();
        DrawGraph(XIncrement, YIncrement, Diameter);
      }
    }

    public IGenealogyGraphNode SelectedGraphNode { get; private set; }

    private void Clear() {
      if (nodeMap == null)
        nodeMap = new Dictionary<IGenealogyGraphNode, VisualGenealogyGraphNode>();
      else nodeMap.Clear();

      if (arcMap == null)
        arcMap = new Dictionary<Tuple<VisualGenealogyGraphNode, VisualGenealogyGraphNode>, VisualGenealogyGraphArc>();
      else arcMap.Clear();

      Chart.Group.Clear();
    }

    private Dictionary<IGenealogyGraphNode, VisualGenealogyGraphNode> nodeMap;
    private Dictionary<Tuple<VisualGenealogyGraphNode, VisualGenealogyGraphNode>, VisualGenealogyGraphArc> arcMap;

    #region chart modes
    public bool SimpleLineages { get; set; }
    public bool LockGenealogy { get; set; }
    public bool TraceFragments { get; set; }
    #endregion

    private Visualization.Rectangle TargetRectangle { get; set; }
    private bool DrawInProgress { get; set; } // do not try to update the chart while the drawing is not finished
    private VisualGenealogyGraphNode SelectedVisualNode { get; set; }

    private VisualGenealogyGraphNode GetMappedNode(IGenealogyGraphNode node) {
      VisualGenealogyGraphNode v;
      nodeMap.TryGetValue(node, out v);
      return v;
    }

    private VisualGenealogyGraphArc GetMappedArc(IGenealogyGraphNode source, IGenealogyGraphNode target) {
      VisualGenealogyGraphNode visualSource, visualTarget;
      nodeMap.TryGetValue(source, out visualSource);
      nodeMap.TryGetValue(target, out visualTarget);

      if (visualSource == null || visualTarget == null) return null;

      VisualGenealogyGraphArc arc;
      arcMap.TryGetValue(new Tuple<VisualGenealogyGraphNode, VisualGenealogyGraphNode>(visualSource, visualTarget), out arc);
      return arc;
    }

    public GenealogyGraphChart()
      : base() {
      InitializeComponent();
    }

    protected virtual void DrawGraph(double xIncrement, double yIncrement, double diameter) {
      Chart.UpdateEnabled = false;
      DrawInProgress = true;

      var ranks = GenealogyGraph.Ranks.Select(t => new { Rank = t.Key, Nodes = t.Value }).OrderBy(p => p.Rank).ToList();
      double x = 0;
      double y = PreferredSize.Height + yIncrement + 2 * diameter;

      foreach (var rank in ranks) {
        var nodes = rank.Nodes.ToList();
        nodes.Sort((a, b) => b.CompareTo(a)); // sort descending by quality
        var nl = Environment.NewLine;

        foreach (var node in nodes) {
          var pen = new Pen(Color.DarkGray);
          var brush = new SolidBrush(node.GetColor());

          var visualNode = new VisualGenealogyGraphNode(Chart, x, y, x + diameter, y + diameter, pen, brush) {
            Data = node,
            ToolTipText = "Rank: " + node.Rank + nl +
                          "Quality: " + String.Format("{0:0.0000}", node.Quality) + nl +
                          "IsElite: " + node.IsElite
          };
          Chart.Group.Add(visualNode);
          nodeMap.Add(node, visualNode);

          x += xIncrement;
        }
        y -= yIncrement;
        x = 0;
      }

      // add arcs
      foreach (var node in GenealogyGraph.Nodes) {
        if (!node.InArcs.Any()) continue;
        var visualNode = GetMappedNode(node);
        if (visualNode == null) continue;
        foreach (var arc in node.InArcs) {
          var parent = arc.Source;
          var visualParent = GetMappedNode(parent);
          if (visualParent == null) continue;
          var pen = new Pen(Color.Transparent);
          var visualArc = AddArc(Chart, visualParent, visualNode, pen);
          if (!arcMap.ContainsKey(Tuple.Create(visualParent, visualNode)))
            arcMap.Add(Tuple.Create(visualParent, visualNode), visualArc);
        }
      }
      // TODO: connect elites

      Chart.UpdateEnabled = true;
      Chart.EnforceUpdate();

      DrawInProgress = false;
    }

    public event MouseEventHandler GenealogyGraphNodeClicked;
    private void OnGenealogyGraphNodeClicked(object sender, MouseEventArgs e) {
      var clicked = GenealogyGraphNodeClicked;
      if (clicked != null) clicked(sender, e);
    }

    #region event handlers
    protected override void pictureBox_MouseMove(object sender, MouseEventArgs e) {
      if (!DrawInProgress) {
        switch (e.Button) {
          case MouseButtons.Left:
            Chart.Mode = ChartMode.Select;
            Cursor = Cursors.Default;
            break;
          case MouseButtons.Middle:
            Chart.Mode = ChartMode.Move;
            Cursor = Cursors.Hand;
            break;
        }
      }
      base.pictureBox_MouseMove(sender, e);
    }
    protected override void pictureBox_MouseUp(object sender, MouseEventArgs e) {
      Cursor = Cursors.Default;
      if (Chart.Mode == ChartMode.Move) {
        Chart.Mode = ChartMode.Select;
        return;
      }
      if (Chart.Mode != ChartMode.Select) {
        base.pictureBox_MouseUp(sender, e);
        return;
      }
      var visualNodes = Chart.GetAllPrimitives(e.Location).Where(p => p is VisualGenealogyGraphNode).ToList();
      if (!visualNodes.Any()) {
        SelectedVisualNode = null;
        return;
      }
      if (SelectedVisualNode == visualNodes[0]) return;
      SelectedVisualNode = visualNodes[0] as VisualGenealogyGraphNode;
      if (SelectedVisualNode == null) return;
      SelectedGraphNode = SelectedVisualNode.Data;

      if (!LockGenealogy) {
        // new node has been selected, clean up
        Chart.UpdateEnabled = false;
        if (ModifierKeys != Keys.Shift) {
          // clear colors
          ClearPrimitives();
        }
        // use a rectangle to highlight the currently selected genealogy graph node
        var graphNode = SelectedVisualNode.Data;
        var visualNode = GetMappedNode(graphNode);

        DrawLineage(visualNode, n => SimpleLineages ? n.IncomingArcs.Take(1) : n.IncomingArcs, a => a.Source);
        DrawLineage(visualNode, n => n.OutgoingArcs, a => a.Target);
      }

      MarkSelectedNode();

      // update
      Chart.UpdateEnabled = true;
      Chart.EnforceUpdate();

      if (SelectedVisualNode != null)
        /* emit clicked event */
        OnGenealogyGraphNodeClicked(SelectedVisualNode, e);

      base.pictureBox_MouseUp(sender, e);
    }
    #endregion

    private static void DrawLineage(VisualGenealogyGraphNode node, Func<VisualGenealogyGraphNode, IEnumerable<VisualGenealogyGraphArc>> arcSelector, Func<VisualGenealogyGraphArc, VisualGenealogyGraphNode> nodeSelector) {
      var brush = (SolidBrush)node.Brush;
      brush.Color = node.Data.GetColor();
      var arcs = arcSelector(node).ToList();
      foreach (var arc in arcs) {
        var source = arc.Source.Data;
        var target = arc.Target.Data;
        var start = new Point((int)arc.Start.X, (int)arc.Start.Y);
        var end = new Point((int)arc.End.X, (int)arc.End.Y);
        arc.Pen.Brush = new LinearGradientBrush(start, end, source.GetColor(), target.GetColor());
        arc.Pen.Color = Color.Transparent;
        //        if (arc == arcs[0]) { arc.Pen.Width = 2; } // mark connection to the root parent
        DrawLineage(nodeSelector(arc), arcSelector, nodeSelector);
      }
    }

    void MarkSelectedNode() {
      var center = SelectedVisualNode.Center;
      var size = SelectedVisualNode.Size;
      double x1 = center.X - size.Width / 2;
      double x2 = x1 + size.Width;
      double y1 = center.Y - size.Height / 2;
      double y2 = y1 + size.Height;
      if (TargetRectangle == null) {
        TargetRectangle = new Visualization.Rectangle(Chart, x1, y1, x2, y2, new Pen(Color.Black), null);
        Chart.Group.Add(TargetRectangle);
      } else {
        TargetRectangle.SetPosition(x1, y1, x2, y2);
      }
    }

    private static VisualGenealogyGraphArc AddArc(IChart chart, VisualGenealogyGraphNode source, VisualGenealogyGraphNode target, Pen pen, Brush brush = null) {
      var arc = new VisualGenealogyGraphArc(chart, source, target, pen) { Brush = brush };
      arc.UpdatePosition();
      source.OutgoingArcs.Add(arc);
      target.IncomingArcs.Add(arc);
      chart.Group.Add(arc);
      return arc;
    }

    public virtual void ClearPrimitives() {
      foreach (var primitive in Chart.Group.Primitives) {
        if (primitive is VisualGenealogyGraphArc) {
          primitive.Pen.Brush = new SolidBrush(Color.Transparent);
        } else if (primitive is VisualGenealogyGraphNode) {
          var brush = (SolidBrush)primitive.Brush;
          brush.Color = Color.Transparent;
          primitive.Pen.Color = Color.DarkGray;
        }
      }
    }

    public void HighlightNodes(IEnumerable<IGenealogyGraphNode> nodes) {
      Chart.UpdateEnabled = false;
      ClearPrimitives();
      foreach (var node in nodes) {
        var graphNode = GetMappedNode(node);
        graphNode.Brush = new SolidBrush(node.GetColor());
      }
      Chart.UpdateEnabled = true;
      Chart.EnforceUpdate();
    }

    public void HighlightAll() {
      Chart.UpdateEnabled = false;
      foreach (var visualNode in nodeMap.Values) {
        visualNode.Brush = new SolidBrush(visualNode.Data.GetColor());
      }
      foreach (var arc in arcMap.Values) {
        var source = arc.Source.Data;
        var target = arc.Target.Data;
        var start = new Point((int)arc.Start.X, (int)arc.Start.Y);
        var end = new Point((int)arc.End.X, (int)arc.End.Y);
        arc.Pen.Brush = new LinearGradientBrush(start, end, source.GetColor(), target.GetColor());
      }
      Chart.UpdateEnabled = true;
      Chart.EnforceUpdate();
    }
  }

  internal static class Util {
    public static Color GetColor(this IGenealogyGraphNode node) {
      var colorIndex = (int)Math.Round(node.Quality * ColorGradient.Colors.Count);
      if (colorIndex >= ColorGradient.Colors.Count) return ColorGradient.Colors.Last();
      return ColorGradient.Colors[colorIndex];
    }
  }
}