#region PDFsharp Charting - A .NET charting library based on PDFsharp
//
// Authors:
//   Niklas Schneider
//
// Copyright (c) 2005-2017 empira Software GmbH, Cologne Area (Germany)
//
// http://www.pdfsharp.com
// http://sourceforge.net/projects/pdfsharp
//
// 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.
#endregion

using PdfSharp.Drawing;

namespace PdfSharp.Charting.Renderers
{
    /// <summary>
    /// Represents a plot area renderer of clustered columns, i. e. all columns are drawn side by side.
    /// </summary>
    internal abstract class ColumnPlotAreaRenderer : ColumnLikePlotAreaRenderer
    {
        /// <summary>
        /// Initializes a new instance of the ColumnPlotAreaRenderer class with the
        /// specified renderer parameters.
        /// </summary>
        internal ColumnPlotAreaRenderer(RendererParameters parms)
            : base(parms)
        { }

        /// <summary>
        /// Layouts and calculates the space for each column.
        /// </summary>
        internal override void Format()
        {
            base.Format();
            CalcColumns();
        }

        /// <summary>
        /// Draws the content of the column plot area.
        /// </summary>
        internal override void Draw()
        {
            ChartRendererInfo cri = (ChartRendererInfo)_rendererParms.RendererInfo;

            XRect plotAreaBox = cri.plotAreaRendererInfo.Rect;
            if (plotAreaBox.IsEmpty)
                return;

            XGraphics gfx = _rendererParms.Graphics;

            double xMin = cri.xAxisRendererInfo.MinimumScale;
            double xMax = cri.xAxisRendererInfo.MaximumScale;
            double yMin = cri.yAxisRendererInfo.MinimumScale;
            double yMax = cri.yAxisRendererInfo.MaximumScale;

            LineFormatRenderer lineFormatRenderer;

            // Under some circumstances it is possible that no zero base line will be drawn,
            // e. g. because of unfavourable minimum/maximum scale and/or major tick, so force to draw
            // a zero base line if necessary.
            if (cri.yAxisRendererInfo.MajorGridlinesLineFormat != null ||
                cri.yAxisRendererInfo.MinorGridlinesLineFormat != null)
            {
                if (yMin < 0 && yMax > 0)
                {
                    XPoint[] points = new XPoint[2];
                    points[0].X = xMin;
                    points[0].Y = 0;
                    points[1].X = xMax;
                    points[1].Y = 0;
                    cri.plotAreaRendererInfo._matrix.TransformPoints(points);

                    if (cri.yAxisRendererInfo.MinorGridlinesLineFormat != null)
                        lineFormatRenderer = new LineFormatRenderer(gfx, cri.yAxisRendererInfo.MinorGridlinesLineFormat);
                    else
                        lineFormatRenderer = new LineFormatRenderer(gfx, cri.yAxisRendererInfo.MajorGridlinesLineFormat);

                    lineFormatRenderer.DrawLine(points[0], points[1]);
                }
            }

            // Draw columns
            XGraphicsState state = gfx.Save();
            foreach (SeriesRendererInfo sri in cri.seriesRendererInfos)
            {
                foreach (ColumnRendererInfo column in sri._pointRendererInfos)
                {
                    // Do not draw column if value is outside yMin/yMax range. Clipping does not make sense.
                    if (IsDataInside(yMin, yMax, column.Point._value))
                        gfx.DrawRectangle(column.FillFormat, column.Rect);
                }
            }

            // Draw borders around column.
            // A border can overlap neighbor columns, so it is important to draw borders at the end.
            foreach (SeriesRendererInfo sri in cri.seriesRendererInfos)
            {
                foreach (ColumnRendererInfo column in sri._pointRendererInfos)
                {
                    // Do not draw column if value is outside yMin/yMax range. Clipping does not make sense.
                    if (IsDataInside(yMin, yMax, column.Point._value) && column.LineFormat.Width > 0)
                    {
                        lineFormatRenderer = new LineFormatRenderer(gfx, column.LineFormat);
                        lineFormatRenderer.DrawRectangle(column.Rect);
                    }
                }
            }
            gfx.Restore(state);
        }

        /// <summary>
        /// Calculates the position, width and height of each column of all series.
        /// </summary>
        protected abstract void CalcColumns();

        /// <summary>
        /// If yValue is within the range from yMin to yMax returns true, otherwise false.
        /// </summary>
        protected abstract bool IsDataInside(double yMin, double yMax, double yValue);
    }
}