#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2016 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 = 25;
    private const double YIncrement = 25;
    private const double Diameter = 20;
    private readonly Brush defaultBrush;
    private readonly Pen defaultPen;

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

    #region chart options
    public bool SimpleLineages { get; set; }
    public bool LockGenealogy { get; set; }
    public Func<IGenealogyGraphNode, Color> ColorSelector { get; set; }
    #endregion

    private bool DrawInProgress { get; set; } // do not try to update the chart while the drawing is not finished

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

    public IGenealogyGraphNode SelectedGraphNode {
      get {
        return SelectedVisualNode == null ? null : SelectedVisualNode.Data;
      }
      set {
        if (value == null || value == SelectedGraphNode)
          return;
        SelectedVisualNode = GetMappedNode(value);
        RedrawLineages();
      }
    }
    private void Clear() {
      nodeMap = new Dictionary<IGenealogyGraphNode, VisualGenealogyGraphNode>();
      arcMap = new Dictionary<Tuple<VisualGenealogyGraphNode, VisualGenealogyGraphNode>, VisualGenealogyGraphArc>();

      Chart.Group.Clear();
    }

    private Visualization.Rectangle TargetRectangle { get; set; }
    protected VisualGenealogyGraphNode SelectedVisualNode { get; set; }

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

    public 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(new GridlessChart(0, 0, 800, 600)) {
      InitializeComponent();
      AddChartModes(new PanChartMode(this), new ZoomInChartMode(this), new ZoomOutChartMode(this), new SelectChartMode(this));
      defaultBrush = new SolidBrush(Color.Transparent);
      defaultPen = new Pen(Color.DarkGray);

      ColorSelector = node => ColorGradient.Colors[(int)Math.Round(node.Quality * 255)];
    }

    protected virtual void DrawGraph(double xIncrement, double yIncrement, double diameter) {
      this.SuspendRendering();
      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 rect = new Visualization.Rectangle(Chart, new PointD(x, y), new PointD(x + diameter, y + diameter));
        var font = new Font(FontFamily.GenericSansSerif, 12);
        var genLabel = new LabeledPrimitive(rect, rank.Rank.ToString(), font);
        Chart.Group.Add(genLabel);

        x += xIncrement;

        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 brush = new SolidBrush(ColorSelector(node));
          var visualNode = new VisualGenealogyGraphNode(Chart, x, y, x + diameter, y + diameter, defaultPen, brush) {
            Data = node,
            ToolTipText = "Rank: " + node.Rank + nl +
                          "Quality: " + string.Format("{0:N4}", node.Quality) + nl +
                          "IsElite: " + node.IsElite + nl +
                          "In/Out Degree: " + node.InDegree + " " + node.OutDegree
          };
          Chart.Group.Add(visualNode);
          nodeMap.Add(node, visualNode);

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

      // add arcs
      foreach (var node in GenealogyGraph.Vertices) {
        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 = Pens.Transparent;
          var visualArc = AddArc(Chart, visualParent, visualNode, pen);
          Chart.OneLayerDown(visualArc); // send it behind the visual nodes
          if (!arcMap.ContainsKey(Tuple.Create(visualParent, visualNode))) {
            arcMap.Add(Tuple.Create(visualParent, visualNode), visualArc);
          }
        }
      }

      ResumeRendering();
      DrawInProgress = false;
    }

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

    public event MouseEventHandler GenealogyGraphNodeDoubleClicked;
    protected void OnGenealogyGraphNodeDoubleClicked(object sender, MouseEventArgs e) {
      var doubleClicked = GenealogyGraphNodeDoubleClicked;
      if (doubleClicked != null)
        doubleClicked(sender, e);
    }
    #region event handlers

    protected override void PictureBoxOnMouseUp(object sender, MouseEventArgs e) {
      if (Mode is SelectChartMode) {
        var primitive = Chart.GetAllPrimitives(e.Location).FirstOrDefault(p => p is VisualGenealogyGraphNode);
        if (primitive != null && primitive != SelectedVisualNode) {
          SelectedVisualNode = (VisualGenealogyGraphNode)primitive;
          RedrawLineages(); // redraw ancestries, mark node etc.

          if (SelectedVisualNode != null)
            OnGenealogyGraphNodeClicked(SelectedVisualNode, null); // emit clicked event
        }
      }
      base.PictureBoxOnMouseUp(sender, e);
    }

    private void RedrawLineages() {
      if (!LockGenealogy) {
        // new node has been selected, clean up
        SuspendRendering();
        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, ColorSelector);
        ((SolidBrush)visualNode.Brush).Color = Color.Transparent;
        DrawLineage(visualNode, n => n.OutgoingArcs, a => a.Target, ColorSelector);
      }

      MarkSelectedNode();

      // update
      ResumeRendering();
    }
    #endregion

    #region drawing routines
    private static void DrawLineage(VisualGenealogyGraphNode node, Func<VisualGenealogyGraphNode, IEnumerable<VisualGenealogyGraphArc>> arcSelector, Func<VisualGenealogyGraphArc, VisualGenealogyGraphNode> nodeSelector, Func<IGenealogyGraphNode, Color> getNodeColor) {
      var brush = (SolidBrush)node.Brush;
      if (brush.Color != Color.Transparent) return; // this lineage was already drawn (avoid redrawing common ancestors)
      brush.Color = getNodeColor(node.Data);
      var arcs = arcSelector(node);
      var pen = new Pen(Color.Transparent);
      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 = pen;
        arc.Pen.Brush = new LinearGradientBrush(start, end, getNodeColor(source), getNodeColor(target));
        DrawLineage(nodeSelector(arc), arcSelector, nodeSelector, getNodeColor);
      }
    }

    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) {
        var lowerLeft = new PointD(x1, y1);
        var upperRight = new PointD(x2, y2);
        TargetRectangle = new Visualization.Rectangle(Chart, lowerLeft, upperRight, new Pen(Color.Black), null);
        Chart.Group.Add(TargetRectangle);
      } else {
        var lowerLeft = new PointD(x1, y1);
        var upperRight = new PointD(x2, y2);
        TargetRectangle.SetPosition(lowerLeft, upperRight);
      }
    }

    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 void ClearArcs() {
      foreach (var primitive in Chart.Group.Primitives.OfType<VisualGenealogyGraphArc>()) {
        primitive.Pen = Pens.Transparent;
      }
    }

    public void ClearNodes() {
      foreach (var primitive in Chart.Group.Primitives.OfType<VisualGenealogyGraphNode>()) {
        primitive.Brush = new SolidBrush(Color.Transparent);
        primitive.Pen = new Pen(Color.LightGray);
      }
    }

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

    public void HighlightNodes(IEnumerable<IGenealogyGraphNode> nodes, bool clearPrimitives = true) {
      if (clearPrimitives)
        ClearPrimitives();

      foreach (var node in nodes) {
        var graphNode = GetMappedNode(node);
        graphNode.Brush = new SolidBrush(ColorSelector(node));
      }
    }

    public void HighlightNodes(IEnumerable<IGenealogyGraphNode> nodes, Color color, bool clearPrimitives = true) {
      if (clearPrimitives)
        ClearPrimitives();

      foreach (var node in nodes.Select(GetMappedNode)) {
        node.Brush = new SolidBrush(color);
      }
    }

    public void HighlightAll() {
      foreach (var visualNode in nodeMap.Values) {
        visualNode.Brush = new SolidBrush(ColorSelector(visualNode.Data));
        Chart.IntoForeground(visualNode);
      }
      // draw arcs first and then nodes
      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 = new Pen(new LinearGradientBrush(start, end, ColorSelector(source), ColorSelector(target)));
        Chart.IntoBackground(arc);
      }
    }

    public void HighlightArc(IGenealogyGraphNode source, IGenealogyGraphNode target) {
      var arc = GetMappedArc(source, target) ??
                AddArc(Chart, GetMappedNode(source), GetMappedNode(target), new Pen(Color.Transparent));
      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 = new Pen(Color.Transparent);
      arc.Pen = new Pen(new LinearGradientBrush(start, end, ColorSelector(source), ColorSelector(target)));
      Chart.IntoBackground(arc);
    }
    #endregion

    // workaround to disable the chart grid
    private class GridlessChart : Chart {
      public GridlessChart(PointD lowerLeft, PointD upperRight) : base(lowerLeft, upperRight) {
        Grid = null;
      }

      public GridlessChart(double x1, double y1, double x2, double y2) : this(new PointD(x1, y1), new PointD(x2, y2)) { }
    }
  }
}