#region License Information
// Copyright (c) 2014 AlphaSierraPapa for the SharpDevelop Team
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
// software and associated documentation files (the "Software"), to deal in the Software
// without restriction, including without limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
// to whom the Software is furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in all copies or
// substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

/* HeuristicLab
 * Copyright (C) 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.Diagnostics;
using System.Linq;
using System.Windows;
using System.Windows.Media;
using System.Windows.Threading;
using ICSharpCode.AvalonEdit.Document;
using ICSharpCode.AvalonEdit.Rendering;
using ICSharpCode.NRefactory.Editor;
using ICSharpCode.SharpDevelop.Editor;

namespace ICSharpCode.AvalonEdit.AddIn {
  /// <summary>
  /// Handles the text markers for a code editor.
  /// </summary>
  public sealed class TextMarkerService : DocumentColorizingTransformer, IBackgroundRenderer, ITextMarkerService, ITextViewConnect {
    TextSegmentCollection<TextMarker> markers;
    TextDocument document;

    public TextMarkerService(TextDocument document) {
      if (document == null)
        throw new ArgumentNullException("document");
      this.document = document;
      this.markers = new TextSegmentCollection<TextMarker>(document);
    }

    #region ITextMarkerService
    public ITextMarker Create(int startOffset, int length) {
      if (markers == null)
        throw new InvalidOperationException("Cannot create a marker when not attached to a document");

      int textLength = document.TextLength;
      if (startOffset < 0 || startOffset > textLength)
        throw new ArgumentOutOfRangeException("startOffset", startOffset, "Value must be between 0 and " + textLength);
      if (length < 0 || startOffset + length > textLength)
        throw new ArgumentOutOfRangeException("length", length, "length must not be negative and startOffset+length must not be after the end of the document");

      TextMarker m = new TextMarker(this, startOffset, length);
      markers.Add(m);
      // no need to mark segment for redraw: the text marker is invisible until a property is set
      return m;
    }

    public IEnumerable<ITextMarker> GetMarkersAtOffset(int offset) {
      if (markers == null)
        return Enumerable.Empty<ITextMarker>();
      else
        return markers.FindSegmentsContaining(offset);
    }

    public IEnumerable<ITextMarker> TextMarkers {
      get { return markers ?? Enumerable.Empty<ITextMarker>(); }
    }

    public void RemoveAll(Predicate<ITextMarker> predicate) {
      if (predicate == null)
        throw new ArgumentNullException("predicate");
      if (markers != null) {
        foreach (TextMarker m in markers.ToArray()) {
          if (predicate(m))
            Remove(m);
        }
      }
    }

    public void Remove(ITextMarker marker) {
      if (marker == null)
        throw new ArgumentNullException("marker");
      TextMarker m = marker as TextMarker;
      if (markers != null && markers.Remove(m)) {
        Redraw(m);
        m.OnDeleted();
      }
    }

    /// <summary>
    /// Redraws the specified text segment.
    /// </summary>
    internal void Redraw(ISegment segment) {
      foreach (var view in textViews) {
        view.Redraw(segment, DispatcherPriority.Normal);
      }
      if (RedrawRequested != null)
        RedrawRequested(this, EventArgs.Empty);
    }

    public event EventHandler RedrawRequested;
    #endregion

    #region DocumentColorizingTransformer
    protected override void ColorizeLine(DocumentLine line) {
      if (markers == null)
        return;
      int lineStart = line.Offset;
      int lineEnd = lineStart + line.Length;
      foreach (TextMarker marker in markers.FindOverlappingSegments(lineStart, line.Length)) {
        Brush foregroundBrush = null;
        if (marker.ForegroundColor != null) {
          foregroundBrush = new SolidColorBrush(marker.ForegroundColor.Value);
          foregroundBrush.Freeze();
        }
        ChangeLinePart(
          Math.Max(marker.StartOffset, lineStart),
          Math.Min(marker.EndOffset, lineEnd),
          element => {
            if (foregroundBrush != null) {
              element.TextRunProperties.SetForegroundBrush(foregroundBrush);
            }
            Typeface tf = element.TextRunProperties.Typeface;
            element.TextRunProperties.SetTypeface(new Typeface(
              tf.FontFamily,
              marker.FontStyle ?? tf.Style,
              marker.FontWeight ?? tf.Weight,
              tf.Stretch
            ));
          }
        );
      }
    }
    #endregion

    #region IBackgroundRenderer
    public KnownLayer Layer {
      get {
        // draw behind selection
        return KnownLayer.Selection;
      }
    }

    public void Draw(TextView textView, DrawingContext drawingContext) {
      if (textView == null)
        throw new ArgumentNullException("textView");
      if (drawingContext == null)
        throw new ArgumentNullException("drawingContext");
      if (markers == null || !textView.VisualLinesValid)
        return;
      var visualLines = textView.VisualLines;
      if (visualLines.Count == 0)
        return;
      int viewStart = visualLines.First().FirstDocumentLine.Offset;
      int viewEnd = visualLines.Last().LastDocumentLine.EndOffset;
      foreach (TextMarker marker in markers.FindOverlappingSegments(viewStart, viewEnd - viewStart)) {
        if (marker.BackgroundColor != null) {
          BackgroundGeometryBuilder geoBuilder = new BackgroundGeometryBuilder();
          geoBuilder.AlignToWholePixels = true;
          geoBuilder.CornerRadius = 3;
          geoBuilder.AddSegment(textView, marker);
          Geometry geometry = geoBuilder.CreateGeometry();
          if (geometry != null) {
            Color color = marker.BackgroundColor.Value;
            SolidColorBrush brush = new SolidColorBrush(color);
            brush.Freeze();
            drawingContext.DrawGeometry(brush, null, geometry);
          }
        }
        var underlineMarkerTypes = TextMarkerTypes.SquigglyUnderline | TextMarkerTypes.NormalUnderline | TextMarkerTypes.DottedUnderline;
        if ((marker.MarkerTypes & underlineMarkerTypes) != 0) {
          foreach (Rect r in BackgroundGeometryBuilder.GetRectsForSegment(textView, marker)) {
            Point startPoint = r.BottomLeft;
            Point endPoint = r.BottomRight;

            Brush usedBrush = new SolidColorBrush(marker.MarkerColor);
            usedBrush.Freeze();
            if ((marker.MarkerTypes & TextMarkerTypes.SquigglyUnderline) != 0) {
              double offset = 2.5;

              int count = Math.Max((int)((endPoint.X - startPoint.X) / offset) + 1, 4);

              StreamGeometry geometry = new StreamGeometry();

              using (StreamGeometryContext ctx = geometry.Open()) {
                ctx.BeginFigure(startPoint, false, false);
                ctx.PolyLineTo(CreatePoints(startPoint, endPoint, offset, count).ToArray(), true, false);
              }

              geometry.Freeze();

              Pen usedPen = new Pen(usedBrush, 1);
              usedPen.Freeze();
              drawingContext.DrawGeometry(Brushes.Transparent, usedPen, geometry);
            }
            if ((marker.MarkerTypes & TextMarkerTypes.NormalUnderline) != 0) {
              Pen usedPen = new Pen(usedBrush, 1);
              usedPen.Freeze();
              drawingContext.DrawLine(usedPen, startPoint, endPoint);
            }
            if ((marker.MarkerTypes & TextMarkerTypes.DottedUnderline) != 0) {
              Pen usedPen = new Pen(usedBrush, 1);
              usedPen.DashStyle = DashStyles.Dot;
              usedPen.Freeze();
              drawingContext.DrawLine(usedPen, startPoint, endPoint);
            }
          }
        }
      }
    }

    IEnumerable<Point> CreatePoints(Point start, Point end, double offset, int count) {
      for (int i = 0; i < count; i++)
        yield return new Point(start.X + i * offset, start.Y - ((i + 1) % 2 == 0 ? offset : 0));
    }
    #endregion

    #region ITextViewConnect
    readonly List<TextView> textViews = new List<TextView>();

    void ITextViewConnect.AddToTextView(TextView textView) {
      if (textView != null && !textViews.Contains(textView)) {
        Debug.Assert(textView.Document == document);
        textViews.Add(textView);
      }
    }

    void ITextViewConnect.RemoveFromTextView(TextView textView) {
      if (textView != null) {
        Debug.Assert(textView.Document == document);
        textViews.Remove(textView);
      }
    }
    #endregion
  }

  public sealed class TextMarker : TextSegment, ITextMarker {
    readonly TextMarkerService service;

    public TextMarker(TextMarkerService service, int startOffset, int length) {
      if (service == null)
        throw new ArgumentNullException("service");
      this.service = service;
      this.StartOffset = startOffset;
      this.Length = length;
      this.markerTypes = TextMarkerTypes.None;
    }

    public event EventHandler Deleted;

    public bool IsDeleted {
      get { return !this.IsConnectedToCollection; }
    }

    public void Delete() {
      service.Remove(this);
    }

    internal void OnDeleted() {
      if (Deleted != null)
        Deleted(this, EventArgs.Empty);
    }

    void Redraw() {
      service.Redraw(this);
    }

    Color? backgroundColor;

    public Color? BackgroundColor {
      get { return backgroundColor; }
      set {
        if (backgroundColor != value) {
          backgroundColor = value;
          Redraw();
        }
      }
    }

    Color? foregroundColor;

    public Color? ForegroundColor {
      get { return foregroundColor; }
      set {
        if (foregroundColor != value) {
          foregroundColor = value;
          Redraw();
        }
      }
    }

    FontWeight? fontWeight;

    public FontWeight? FontWeight {
      get { return fontWeight; }
      set {
        if (fontWeight != value) {
          fontWeight = value;
          Redraw();
        }
      }
    }

    FontStyle? fontStyle;

    public FontStyle? FontStyle {
      get { return fontStyle; }
      set {
        if (fontStyle != value) {
          fontStyle = value;
          Redraw();
        }
      }
    }

    public object Tag { get; set; }

    TextMarkerTypes markerTypes;

    public TextMarkerTypes MarkerTypes {
      get { return markerTypes; }
      set {
        if (markerTypes != value) {
          markerTypes = value;
          Redraw();
        }
      }
    }

    Color markerColor;

    public Color MarkerColor {
      get { return markerColor; }
      set {
        if (markerColor != value) {
          markerColor = value;
          Redraw();
        }
      }
    }

    public object ToolTip { get; set; }
  }
}