using System.CodeDom.Compiler;
using System.Globalization;
using System.IO;
using System.Text;
using GeoAPI.Geometries;
using HeuristicLab.BioBoost.Representation;
using HeuristicLab.BioBoost.Utils;
using HeuristicLab.BioBoost.Views.MapViews;
using HeuristicLab.Common;
using HeuristicLab.Core.Views;
using HeuristicLab.Data;
using HeuristicLab.MainForm;
using HeuristicLab.MainForm.WindowsForms;
using NetTopologySuite.Geometries;
using SharpMap.Data;
using SharpMap.Forms;
using SharpMap.Layers;
using SharpMap.Rendering.Decoration;
using SharpMap.Rendering.Decoration.ScaleBar;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.Linq;
using System.Threading;
using System.Windows.Forms;
using System.Windows.Forms.VisualStyles;
using HeuristicLab.BioBoost.Evaluators;
using HeuristicLab.PluginInfrastructure;
using Point = System.Drawing.Point;

namespace HeuristicLab.BioBoost.Views {

  [Content(typeof(BioBoostCompoundSolution), IsDefaultView = true)]
  public partial class BioBoostCompoundSolutionView : ItemView {

    private readonly Dictionary<String, ILazyLayerGenerator> layerCache;
    private readonly GradientLegend legend;
    private readonly Disclaimer disclaimer;
    private Thread mapUpdateThread;
    private Thread costsUpdateThread;
    private ManualResetEventSlim updateMap;
    private ManualResetEventSlim updateCosts;

    private SharpMap.Rendering.Thematics.ColorBlend vectorColorBlend =
      new SharpMap.Rendering.Thematics.ColorBlend(new[] {
        Color.FromArgb(0, 0, 255),
        Color.FromArgb(128, 0, 128),
        Color.FromArgb(255, 0, 0),
      }, new[] { 0f, .5f, 1f });
    private string currentRegion;
    public const string AllRegionsName = "All";

    public new BioBoostCompoundSolution Content {
      get { return (BioBoostCompoundSolution)base.Content; }
      set { base.Content = value; }
    }

    public BioBoostCompoundSolutionView() {
      InitializeComponent();
      layerCache = new Dictionary<string, ILazyLayerGenerator>();
      mapBox.Map.Decorations.Add(new ScaleBar {
        Anchor = MapDecorationAnchor.RightBottom,
        BarColor1 = Color.White,
        BarColor2 = Color.Black,
        BarStyle = ScaleBarStyle.Meridian,
        MapUnit = (int)Unit.Degree,
        BarUnit = (int)Unit.Kilometer,
      });
      disclaimer = new Disclaimer {
        Anchor = MapDecorationAnchor.RightTop,
        Text = "ForestryResidues Utilization",
        Enabled = true,
        BackgroundColor = Color.FromArgb(128, 255, 255, 255),
        ForeColor = Color.Black,
        BorderColor = Color.Transparent,
        Font = new Font(FontFamily.GenericSansSerif, 10, FontStyle.Regular)
      };
      legend = new GradientLegend {Size = new Size(300, 20)};
      mapBox.Map.Decorations.Add(legend);
      mapBox.Map.Decorations.Add(new NorthArrow());
      mapBox.Map.Decorations.Add(disclaimer);
        
      updateMap = new ManualResetEventSlim(true);
      mapUpdateThread = new Thread(UpdateMap);
      mapUpdateThread.Start();
      updateCosts = new ManualResetEventSlim(true);
      costsUpdateThread = new Thread(UpdateCosts);
      costsUpdateThread.Start();
      currentRegion = AllRegionsName;
    }


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

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

    #region Event Handlers (Content)

    private void SolutionChanged(object sender, EventArgs e) {
      if (InvokeRequired) {
        Invoke(new EventHandler<EventArgs>(SolutionChanged), sender, e);
      } else {
        UpgradeSolution();
        InitializeLayers();
        DiscoverLayerNames();
        summaryView.Content = new RegionDetailData {RegionName = null, Solution = Content};
        ShowSelectedLayers(false);
        ShowCosts();
      }
    }
    #endregion

    protected override void OnContentChanged() {
      base.OnContentChanged();
      if (Content == null) {
        ClearAllLayerNames();
        ClearCostsSummary();
      } else {
        UpgradeSolution();
        InitializeLayers();
        DiscoverLayerNames();
        summaryView.Content = new RegionDetailData {RegionName = null, Solution = Content};
        ShowSelectedLayers(true);
        ShowCosts();
      }
    }

    private bool upgradeInProgress = false;
    private void UpgradeSolution() {
      if (Content != null && !upgradeInProgress) {
        upgradeInProgress = true;
        Content.UpdateTo(new BioBoostCompoundSolution(
          AggregateEvaluator.Evaluate(Content.ProblemDataReference, Content.DoubleValues, Content.IntValues),
          Content.ProblemDataReference));
        upgradeInProgress = false;
      }
    }

    #region Main Logic
    private void ResetZoom() {
      if (mapBox.Map.Layers.Count > 0)
        mapBox.Map.ZoomToExtents();
      mapBox.ActiveTool = MapBox.Tools.Pan;
      mapBox.Refresh();
    }

    private void DiscoverLayerNames() {
      DiscoverValueLayers();
      DiscoverVectorLayers();
    }

    private class ListBoxItem {
      public Color Color;
      public String Text;
    }

    private void DiscoverVectorLayers() {
      var layerNames = vectorLayerNamesListBox.Items.Cast<ListBoxItem>().Select(l => l.Text).ToList();
      if (layerNames.SequenceEqual(Content.IntValues.Keys)) return;
      vectorLayerNamesListBox.BeginUpdate();
      vectorLayerNamesListBox.Items.Clear();
      int i = 0, n = Math.Max(1, Content.IntValues.Count - 1);
      foreach (var values in Content.IntValues) {
        var newItem = new ListBoxItem {
          Color = vectorColorBlend.GetColor(1f * i++ / n),
          Text = values.Key
        };
        vectorLayerNamesListBox.Items.Add(newItem);
        if (layerNames.Any(name => name == values.Key) || layerNames.Count == 0)
          vectorLayerNamesListBox.SelectedItems.Add(newItem);
      }
      vectorLayerNamesListBox.EndUpdate();
    }

    private void DiscoverValueLayers() {
      var layerNames = AddRelativePotentials(Content.DoubleValues.Keys).ToList();
      layerNames.Sort();
      if (valueLayerNamesListBox.Items.Cast<string>().SequenceEqual(layerNames))
        return;
      valueLayerNamesListBox.BeginUpdate();
      var selectedValueLayerName = (string)valueLayerNamesListBox.SelectedItem;
      var firstFinalProduct = Content.ProblemDataReference.FinalProducts.FirstOrDefault();
      if (selectedValueLayerName == null && firstFinalProduct != null)
        selectedValueLayerName = LayerDescriptor.RelativeCostAtSource.NameWithPrefix(firstFinalProduct.Value);
      valueLayerNamesListBox.Items.Clear();
      foreach (var name in layerNames) {
        var i = valueLayerNamesListBox.Items.Add(name);
        if (name == selectedValueLayerName)
          valueLayerNamesListBox.SelectedIndex = i;
      }
      if (valueLayerNamesListBox.SelectedIndex == -1)
        valueLayerNamesListBox.SelectedIndex = 0;
      valueLayerNamesListBox.EndUpdate();
    }

    private IEnumerable<string> AddRelativePotentials(IEnumerable<string> names) {
      foreach (var name in names) {
        if (LayerDescriptor.PotentialsFromProblemData.IsSuffixOf(name)) {
          var formattedName = name.Replace(LayerDescriptor.PotentialsFromProblemData.FullName, " Potentials");
          yield return formattedName;
          yield return formattedName + " Relative";
        } else {
          yield return name;
        }
      }
    }

    private void ClearAllLayerNames() {
      valueLayerNamesListBox.Items.Clear();
      vectorLayerNamesListBox.Items.Clear();
    }

    private void ShowSelectedLayers(bool resetZoom) {
      lock (updateMap) {
        if (pendingUpdate != null) {
          pendingUpdate.ResetZoom |= resetZoom;
        } else {
          pendingUpdate = new BackgroundArguments { ResetZoom = resetZoom };
        }
        updateMap.Set();
      }
    }

    private void ShowCosts() {
      updateCosts.Set();
    }

    private sealed class BackgroundArguments {
      public bool ResetZoom;
      public LazyValueLayerGenerator ValueLayerGenerator;
      public List<LazyVectorLayerGenerator> VectorLayerGenerators;
      public ILayer ValueLayer;
      public List<ILayer> TransportLayers;
    }

    private BackgroundArguments pendingUpdate;
    private bool runningUpdateMap = true;
    private bool runningUpdateCosts = true;

    private void UpdateMap() {
      while (runningUpdateMap) {
        BackgroundArguments currentUpdate = null;
        // wait for a signal to update the map
        while (!updateMap.Wait(2000)) {
          if (!runningUpdateMap) return; // stop thread if requested
        }
        lock (updateMap) {
          updateMap.Reset();
          currentUpdate = pendingUpdate;
          pendingUpdate = null;
        }

        // only do something if the map-tab is active
        if (currentUpdate != null) {
          DoShowSelectedLayers(currentUpdate);
        }
        Thread.Sleep(500);
      }
    }

    private void UpdateCosts() {
      while (runningUpdateCosts) {
        // wait for signal to update the costs
        while (!updateCosts.Wait(2000)) {
          if (!runningUpdateCosts) return; // stop the thread if requested
        }
        updateCosts.Reset();

        ClearCostsSummary();
        PopulateRegionTree();
        PopulateCostsSummary();

        Thread.Sleep(500);
      }
    }

    private void DoShowSelectedLayers(BackgroundArguments args) {
      if (InvokeRequired) {
        try {
          var result = BeginInvoke(new Action<BackgroundArguments>(DoShowSelectedLayers), args);
          result.AsyncWaitHandle.WaitOne();
          EndInvoke(result);
        } catch (ObjectDisposedException) { }
      } else {
        // only do something if the map-tab is active
        if (tabControl1.SelectedTab != tabPage1) return;

        GetConfigFromUI(args);
        var generator = args.ValueLayerGenerator;
        if (generator == null) return;
        args.ValueLayer = generator.Layer; // this might take a while
        args.TransportLayers = new List<ILayer>();
        foreach (var g in args.VectorLayerGenerators) {
          args.TransportLayers.Add(g.Layer); // TODO: cycle colors of vectors
        }
        UpdateUI(args);
      }
    }

    private void GetConfigFromUI(BackgroundArguments args) {
      var valueLayerName = (string)valueLayerNamesListBox.SelectedItem;
      var vectorLayerNames = vectorLayerNamesListBox.SelectedItems.Cast<ListBoxItem>().Select(i => i.Text);
      if (String.IsNullOrEmpty(valueLayerName)) return;
      var generator = layerCache[valueLayerName] as LazyValueLayerGenerator;
      if (generator == null) return;
      args.ValueLayerGenerator = generator;
      args.VectorLayerGenerators =
        vectorLayerNames.Select(n => layerCache[n] as LazyVectorLayerGenerator).Where(g => g != null).ToList();

    }

    private void UpdateUI(BackgroundArguments args) {
      if (IsDisposed || Disposing) return;
      try {
        var currentZoom = mapBox.Map.Zoom;
        var currentCenter = mapBox.Map.Center;
        mapBox.Map.Layers.Clear();
        mapBox.Map.Layers.Add(args.ValueLayer);
        foreach (var tl in args.TransportLayers)
          mapBox.Map.Layers.Add(tl);
        legend.MinValue = args.ValueLayerGenerator.ActualMinValue;
        legend.MaxValue = args.ValueLayerGenerator.ActualMaxValue;
        legend.Unit = args.ValueLayerGenerator.Unit;
        legend.ColorBlend = new ColorBlend {
          Colors = args.ValueLayerGenerator.ColorBlend.Colors,
          Positions = args.ValueLayerGenerator.ColorBlend.Positions,
        };
        disclaimer.Text = args.ValueLayer.LayerName;
        if (args.ResetZoom) {
          ResetZoom();
        } else {
          mapBox.ActiveTool = MapBox.Tools.Pan;
          mapBox.Map.Zoom = currentZoom;
          mapBox.Map.Center = currentCenter;
          mapBox.Refresh();
        }
      } catch (Exception x) {
        MessageBox.Show(this, "Could not update UI, please try again:\n" + x);
      }
    }

    private void InitializeLayers() {
      lock (updateMap) {
        layerCache.Clear();
        var geom = Content.Geometry;
        var locs = Content.LocationNames;
        foreach (var kvp in Content.DoubleValues) {
          var generator = new LazyValueLayerGenerator(geom, locs, kvp.Value, kvp.Key);
          var name = kvp.Key;
          if (kvp.Value.Min() > 0) generator.MinValue = 0;
          if (kvp.Value.Max() < 0) generator.MaxValue = 0;
          var layer = LayerDescriptor.GetLayer(name);
          if (layer == LayerDescriptor.Utilizations || layer == LayerDescriptor.UtilizationsEffective) {
            generator.MaxValue = 1;
          } else if (layer == Representation.LayerDescriptor.PotentialsFromProblemData) {
            generator.Unit = "t/a";
            name = name.Replace(LayerDescriptor.PotentialsFromProblemData.FullName, " Potentials");
            layerCache.Add(name + " Relative", new LazyValueLayerGenerator(geom, locs, kvp.Value, name + " Relative") {
              MinValue = 0,
              RealtiveToSize = true,
              Unit = "t/ha/a"
            });
          } else {
            if (layer != null)
              generator.Unit = layer.Unit;
          }
          layerCache.Add(name, generator);
        }
        int i = 0, n = Math.Max(1, Content.IntValues.Count - 1);
        foreach (var kvp in Content.IntValues) {
          var name = kvp.Key;
          var targets = kvp.Value;
          var amounts = BioBoostCompoundSolution.FindAmountsTransportedFromSource(Content.DoubleValues, name);
          if (amounts != null) {
            for (int j = 0; j < amounts.Length; j++) {
              if (amounts[j] <= 0) {
                targets[j] = -1;
              }
            }
          }
          layerCache.Add(
            name,
            new LazyVectorLayerGenerator(geom, locs, targets,  amounts, vectorColorBlend.GetColor(1.0f * i / n), name) {
              LineOffset = i * 2
            });
          i++;
        }
      }
    }

    private void ClearCostsSummary() {
      if (InvokeRequired) {
        try {
          var result = BeginInvoke(new Action(ClearCostsSummary));
          result.AsyncWaitHandle.WaitOne();
          EndInvoke(result);
        } catch (ObjectDisposedException) { }
      } else {
        if (IsDisposed || Disposing) return;
        bioBoostSolutionCostsView1.Content = null;
      }
    }

    private void PopulateCostsSummary() {
      if (InvokeRequired) {
        try {
          var result = BeginInvoke(new Action(PopulateCostsSummary));
          result.AsyncWaitHandle.WaitOne();
          EndInvoke(result);
        } catch (ObjectDisposedException) { }
      } else {
        if (IsDisposed || Disposing) return;
        // only do something if the costs-tab is active
        if (tabControl1.SelectedTab != tabPage2) return;

        regionsTreeView.SelectedNode = regionsTreeView.Nodes.Find(currentRegion, true).FirstOrDefault();
        regionsTreeView.Focus();
        if (IsDisposed) return;
        bioBoostSolutionCostsView1.Content = new RegionDetailData {
          RegionName = currentRegion,
          Solution = Content,
        };
      }
    }

    private void PopulateRegionTree() {
      if (InvokeRequired) {
        try {
          var result = BeginInvoke(new Action(PopulateRegionTree));
          result.AsyncWaitHandle.WaitOne();
          EndInvoke(result);
        } catch (ObjectDisposedException) { }
      } else {
        if (IsDisposed || Disposing) return;
        regionsTreeView.Nodes.Clear();
        if (Content == null) return;
        regionsTreeView.Nodes.Add(AllRegionsName, AllRegionsName);
        var allRegionsNodes = regionsTreeView.Nodes[AllRegionsName].Nodes;
        foreach (var location in Content.LocationNames) {
          var country = location.Substring(0, 2);
          if (!allRegionsNodes.ContainsKey(country)) {
            allRegionsNodes.Add(country, country);
          }
          allRegionsNodes[country].Nodes.Add(location, location);
        }
        regionsTreeView.HideSelection = false;
        regionsTreeView.Nodes[AllRegionsName].Expand();
      }
    }

    #endregion

    public void SetFocus(string regionName) {
      var row = Content.Geometry.Features.Rows.Cast<FeatureDataRow>().FirstOrDefault(r => (string)r["NUTS_ID"] == regionName);
      if (row == null) return;
      var coords = row.Geometry.Envelope.Buffer(1).Coordinates;
      var env = new Envelope(coords.Min(c => c.X), coords.Max(c => c.X),
                   coords.Min(c => c.Y), coords.Max(c => c.Y));
      mapBox.Map.ZoomToBox(env);
      mapBox.Refresh();
    }

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

    #region Auxiliary Methods
    private string GetRegionAtWorldPos(Coordinate loc) {
      var ds = new FeatureDataSet();
      Content.Geometry.ExecuteIntersectionQuery(new NetTopologySuite.Geometries.Point(loc), ds);
      return (from FeatureDataRow row in ds.Tables[0]
              select row["NUTS_ID"] as string).FirstOrDefault();
    }

    private string GetRegionDescription(string regionName) {
      if (regionName != null && Content.Geometry.Features.Columns.Contains("name")) {
        var row = Content.Geometry.Features.Rows.Cast<FeatureDataRow>().FirstOrDefault(r => (string)r["NUTS_ID"] == regionName);
        if (row != null)
          return row["name"].ToString();
      }
      return "";
    }

    private string GetCurrentValueLayerValue(string regionName) {
      if (regionName == null) return "";
      var layerName = valueLayerNamesListBox.SelectedItem as string;
      if (layerName == null) return "";
      var generator = layerCache[layerName] as LazyValueLayerGenerator;
      if (generator == null) return "";
      var mapping = generator.Mapping;
      if (mapping == null) return "";
      double value;
      if (!mapping.TryGetValue(regionName, out value)) return "";
      var v = Math.Abs(value);
      //var format = v > 1000 ? "F0" : v > 100 ? "F1" : v > 10 ? "F2" : value < 0.01 ? "G" : "F3";
      var format = v > 1000 ? "F0" : v > 100 ? "F1" : v > 10 ? "F2" : value < 0.01 ? "G" : "F3";
      var info = (NumberFormatInfo)NumberFormatInfo.InvariantInfo.Clone();
      info.NumberGroupSeparator = " ";
      return string.Format("{0} {1}", value.ToString(format, info), generator.Unit);
    }

    #endregion

    #region Event Handlers (child controls)
    private void vectorLayerNamesListBox_SelectedIndexChanged(object sender, EventArgs e) {
      ShowSelectedLayers(false);
      vectorLayerNamesListBox.Invalidate();
    }

    private void valueLayerNamesListBox_SelectedIndexChanged(object sender, EventArgs e) {
      ShowSelectedLayers(false);
    }

    private void mapBox_MouseMove(Coordinate worldPos, MouseEventArgs imagePos) {
      var nuts_id = GetRegionAtWorldPos(worldPos);
      var nuts_name = GetRegionDescription(nuts_id);
      regionNameLabel.Text = nuts_id;
      regionDescriptionLabel.Text = nuts_name;
      valueLayerValueLabel.Text = GetCurrentValueLayerValue(nuts_id);
      mapBox.Cursor = String.IsNullOrEmpty(nuts_id) ? Cursors.Default : Cursors.Hand;
    }

    private Point startPos = new Point(0, 0);
    private void mapBox_MouseDown(Coordinate worldPos, MouseEventArgs imagePos) {
      if (imagePos.Button == MouseButtons.Left) {
        startPos = imagePos.Location;
      }
    }

    private void mapBox_MouseUp(Coordinate worldPos, MouseEventArgs imagePos) {
      if (imagePos.Button == MouseButtons.Left
          && Util.Distance(imagePos.Location, startPos) < 4) {
        currentRegion = GetRegionAtWorldPos(worldPos);
        if (!String.IsNullOrEmpty(currentRegion)) {
          regionDetailView.Content = new RegionDetailData {
            RegionName = currentRegion,
            Solution = Content,
          };
        }
      }
    }

    private void solutionDetailView_RegionLabelClicked(object sender, EventArgs e) {
      if (regionDetailView.Content != null)
        SetFocus(regionDetailView.Content.RegionName);
    }

    private void vectorLayerNamesListBox_DrawItem(object sender, DrawItemEventArgs e) {
      var item = vectorLayerNamesListBox.Items[e.Index];
      var listBoxItem = item as ListBoxItem;
      var foreColor = Color.Black;
      if (listBoxItem != null) {
        foreColor = listBoxItem.Color;
      }
      var backColor = vectorLayerNamesListBox.BackColor;
      if (vectorLayerNamesListBox.SelectedItems.Contains(item)) {
        backColor = foreColor;
        foreColor = Color.White;
      }
      using (var backBrush = new SolidBrush(backColor)) {
        e.Graphics.FillRectangle(backBrush, e.Bounds);
      }
      using (var foreBrush = new SolidBrush(foreColor)) {
        e.Graphics.DrawString(
          listBoxItem != null ? listBoxItem.Text : item.ToString(),
          vectorLayerNamesListBox.Font, foreBrush, e.Bounds);
      }
    }
    #endregion

    private void tabControl1_Selected(object sender, TabControlEventArgs e) {
      switch (e.TabPageIndex) {
        case 0:
          ShowSelectedLayers(false); // prepare for the map update
          updateMap.Set(); // signal that the map should be updated once
          break;
        case 1:
          updateCosts.Set(); // signal that the costs should be updated once
          break;
      }
    }

    private void regionsTreeView_AfterSelect(object sender, TreeViewEventArgs e) {
      var labeltext = e.Node.Text.Split(' ');
      if (labeltext.Length > 0)
        currentRegion = labeltext[0];
      if (e.Node.GetNodeCount(true) == 0) {
        regionDetailView.Content = new RegionDetailData {
          RegionName = currentRegion,
          Solution = Content,
        };
      }

      ClearCostsSummary();
      PopulateCostsSummary();
    }

    private void openSolutionEditorButton_Click(object sender, EventArgs e) {
      // clone solution and also clone problem-data separately (solution does not clone problem data itself)
      var cloner = new Cloner();
      var clonedSolution = cloner.Clone(Content);
      var clonedProblemData = cloner.Clone(Content.ProblemDataReference);
      clonedSolution.ProblemDataReference = clonedProblemData;

      // create and open editor view for content
      var vh = new ViewHost();
      vh.Content = clonedSolution;
      vh.ViewType = typeof (BioBoostCompoundSolutionEditor);
      vh.Show();
    }

    public void SaveMapViewToPNG(string filename) {
      var bitmap = new Bitmap(mapBox.Width, mapBox.Height);
      mapBox.DrawToBitmap(bitmap, new Rectangle(0, 0, mapBox.Width, mapBox.Height));
      bitmap.Save(filename);
    }

    private void saveMapImageButton_Click(object sender, EventArgs e) {
      if (saveFileDialog.ShowDialog() == DialogResult.OK) {
        try {
          Enabled = false;
          SaveMapViewToPNG(saveFileDialog.FileName);
        } catch (Exception x) {
          ErrorHandling.ShowErrorDialog(this, x);
        } finally {
          Enabled = true;
        }
      }
    }

  }
}