//	Spludlow Software
//	Copyright © Samuel P. Ludlow 2020 All Rights Reserved
//	Distributed under the terms of the GNU General Public License version 3
//	Distributed WITHOUT ANY WARRANTY; without implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE
//	https://www.spludlow.co.uk/LICENCE.TXT
//	The Spludlow logo is a registered trademark of Samuel P. Ludlow and may not be used without permission
//	v1.14

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using System.Data;
using System.Drawing;

namespace Spludlow.Drawing
{
	public class PieChart
	{
		public static void Draw(Spludlow.Printing.PrintDoc doc, float x, float y, float radius, float stroke, DataTable table)
		{
			string keyColumnName = table.Columns[0].ColumnName;
			string valueColumnName = table.Columns[1].ColumnName;

			Draw(doc, x, y, radius, stroke, table, keyColumnName, valueColumnName);
		}

		public static void Draw(Spludlow.Printing.PrintDoc doc, float x, float y, float radius, float stroke, DataTable table, string keyColumnName, string valueColumnName)
		{
			Dictionary<string, decimal> values = new Dictionary<string, decimal>();

			foreach (DataRow row in table.Rows)
			{
				if (row.IsNull(valueColumnName) == true || row.IsNull(keyColumnName) == true)
					continue;

				decimal value = Math.Abs(Convert.ToDecimal(row[valueColumnName]));

				if (value == 0)
					continue;

				string key = Convert.ToString(row[keyColumnName]);

				if (values.ContainsKey(key) == false)
					values.Add(key, 0);

				values[key] = values[key] + value;
			}

			Draw(doc, x, y, radius, stroke, values);
		}

		public static void Draw(Spludlow.Printing.PrintDoc doc, float x, float y, float radius, float stroke, DataRow row)
		{
			List<string> columnNames = new List<string>();

			foreach (DataColumn column in row.Table.Columns)
				columnNames.Add(column.ColumnName);

			Draw(doc, x, y, radius, stroke, row, columnNames.ToArray());
		}

		public static void Draw(Spludlow.Printing.PrintDoc doc, float x, float y, float radius, float stroke, DataRow row, string[] columnNames)
		{
			Dictionary<string, decimal> values = new Dictionary<string, decimal>();

			foreach (string columnName in columnNames)
			{
				if (row.IsNull(columnName) == true)
					continue;

				decimal value = Math.Abs(Convert.ToDecimal(row[columnName]));

				if (value == 0)
					continue;

				string key = columnName;

				if (values.ContainsKey(key) == false)
					values.Add(key, 0);

				values[key] = values[key] + value;
			}

			Draw(doc, x, y, radius, stroke, values);
		}

		public static void Draw(Spludlow.Printing.PrintDoc doc, float x, float y, float radius, float stroke, Dictionary<string, decimal> values)
		{
			Color[] colourRange = Spludlow.Drawing.Colour.Range(values.Count < 9 ? 9 : values.Count);

			decimal total = 0;

			foreach (string key in values.Keys)
				total += values[key];

			decimal start = 0;

			int index = 0;
			foreach (string key in values.Keys)
			{
				decimal value = values[key];
				decimal end = start + value;

				decimal startAngle = start * (360 / total);
				decimal endAngle = end * (360 / total);

				doc.ArcSector(x, y, radius, radius, 0, 0, (float)startAngle, (float)endAngle, stroke, System.Drawing.Color.Black, colourRange[index]);

				//doc.Arc(x, y, radius + 2.5F, radius + 2.5F, (float)startAngle, (float)endAngle, 3.0F, colourRange[index]);
				//radius -= 2.5F;

				start = end;
				++index;

				//break;
			}
		}
	}
}