using System;
using System.ComponentModel;
using FastReport.Utils;

namespace FastReport
{
    /// <summary>
    /// The layout of the data band columns.
    /// </summary>
    public enum ColumnLayout
    {
        /// <summary>
        /// Print columns across then down.
        /// </summary>
        AcrossThenDown,

        /// <summary>
        /// Print columns down then across.
        /// </summary>
        DownThenAcross
    }

    /// <summary>
    /// This class holds the band columns settings. It is used in the <see cref="DataBand.Columns"/> property.
    /// </summary>
    [TypeConverter(typeof(FastReport.TypeConverters.FRExpandableObjectConverter))]
    public class BandColumns
    {
        private int count;
        private float width;
        private ColumnLayout layout;
        private int minRowCount;
        private DataBand band;

        /// <summary>
        /// Gets or sets the number of columns.
        /// </summary>
        /// <remarks>
        /// Set this property to 0 or 1 if you don't want to use columns.
        /// </remarks>
        [DefaultValue(0)]
        public int Count
        {
            get { return count; }
            set
            {
                if (value < 0)
                    throw new ArgumentOutOfRangeException("Count", "Value must be >= 0");
                count = value;
            }
        }

        /// <summary>
        /// The column width, in pixels.
        /// </summary>
        [DefaultValue(0f)]
        [TypeConverter("FastReport.TypeConverters.UnitsConverter, FastReport")]
        public float Width
        {
            get { return width; }
            set { width = value; }
        }

        /// <summary>
        /// Gets or sets the layout of the columns.
        /// </summary>
        [DefaultValue(ColumnLayout.AcrossThenDown)]
        public ColumnLayout Layout
        {
            get { return layout; }
            set { layout = value; }
        }

        /// <summary>
        /// Gets or sets the minimum row count that must be printed.
        /// </summary>
        /// <remarks>
        /// This property is used if the <b>Layout</b> property is set to <b>DownThenAcross</b>. 0 means that
        /// FastReport should calculate the optimal number of rows.
        /// </remarks>
        [DefaultValue(0)]
        public int MinRowCount
        {
            get { return minRowCount; }
            set { minRowCount = value; }
        }

        internal float ActualWidth
        {
            get
            {
                ReportPage page = band.Page as ReportPage;
                if (Width == 0 && page != null)
                    return (page.PaperWidth - page.LeftMargin - page.RightMargin) * Units.Millimeters / (Count == 0 ? 1 : Count);
                return Width;
            }
        }

        internal FloatCollection Positions
        {
            get
            {
                FloatCollection positions = new FloatCollection();
                float columnWidth = ActualWidth;
                for (int i = 0; i < Count; i++)
                {
                    positions.Add(i * columnWidth);
                }
                return positions;
            }
        }

        /// <summary>
        /// Assigns values from another source.
        /// </summary>
        /// <param name="source">Source to assign from.</param>
        public void Assign(BandColumns source)
        {
            Count = source.Count;
            Width = source.Width;
            Layout = source.Layout;
            MinRowCount = source.MinRowCount;
        }

        internal void Serialize(FRWriter writer, BandColumns c)
        {
            if (Count != c.Count)
                writer.WriteInt("Columns.Count", Count);
            if (Width != c.Width)
                writer.WriteFloat("Columns.Width", Width);
            if (Layout != c.Layout)
                writer.WriteValue("Columns.Layout", Layout);
            if (MinRowCount != c.MinRowCount)
                writer.WriteInt("Columns.MinRowCount", MinRowCount);
        }

        /// <summary>
        /// Initializes a new instance of the <b>BandColumns</b> class with default settings. 
        /// </summary>
        public BandColumns(DataBand band)
        {
            this.band = band;
        }
    }
}