using System;

namespace GisSharpBlog.NetTopologySuite.IO
{
	/// <summary>
	/// Class for holding the information assicated with a dbase field.
	/// </summary>
	public class DbaseFieldDescriptor
	{
		// Field Name
		private string _name;
        
		// Field Type (C N L D or M)
		private char _type;
        
		// Field Data Address offset from the start of the record.
		private int _dataAddress;
        
		// Length of the data in bytes
		private int _length;
        
		// Field decimal count in Binary, indicating where the decimal is
		private int _decimalCount;

        /// <summary>
        /// 
        /// </summary>
        /// <param name="type"></param>
        /// <returns></returns>
		public static char GetDbaseType(Type type)
		{
			DbaseFieldDescriptor dbaseColumn = new DbaseFieldDescriptor();
            if (type == typeof(Char))
                return 'C';
            if (type == typeof(string))
                return 'C';
            else if (type == typeof(Double))
                return 'N';
            else if (type == typeof(Single))
                return 'N';
            else if (type == typeof(Int16))
                return 'N';
            else if (type == typeof(Int32))
                return 'N';
            else if (type == typeof(Int64))
                return 'N';
            else if (type == typeof(UInt16))
                return 'N';
            else if (type == typeof(UInt32))
                return 'N';
            else if (type == typeof(UInt64))
                return 'N';
            else if (type == typeof(Decimal))
                return 'N';
            else if (type == typeof(Boolean))
                return 'L';
            else if (type == typeof(DateTime))
                return 'D';

			throw new NotSupportedException(String.Format("{0} does not have a corresponding dbase type.", type.Name));
		}

        /// <summary>
        /// 
        /// </summary>
        /// <returns></returns>
		public static DbaseFieldDescriptor ShapeField()
		{
			DbaseFieldDescriptor shpfield = new DbaseFieldDescriptor();
			shpfield.Name="Geometry";
			shpfield._type='B';
			return shpfield;
		}

        /// <summary>
        /// 
        /// </summary>
        /// <returns></returns>
		public static DbaseFieldDescriptor IdField()
		{
			DbaseFieldDescriptor shpfield = new DbaseFieldDescriptor();
			shpfield.Name="Row";
			shpfield._type='I';
			return shpfield;
		}

        /// <summary>
        /// Field Name.
        /// </summary>
		public string Name
		{
			get
			{
				return _name;
			}
			set
			{
				_name = value;
			}
		}
        		
        /// <summary>
        /// Field Type (C N L D or M).
        /// </summary>
		public char DbaseType
		{
			get
			{
				return _type;
			}
			set
			{
				_type = value;
			}
		}
        
        /// <summary>
        /// Field Data Address offset from the start of the record.
        /// </summary>
		public int DataAddress
		{
			get
			{
				return _dataAddress;
			}
			set
			{
				_dataAddress = value;
			}
		}
        
        /// <summary>
        /// Length of the data in bytes.
        /// </summary>
		public int Length
		{
			get
			{
				return _length;
			}
			set
			{
				_length = value;
			}
		}
        
        /// <summary>
        /// Field decimal count in Binary, indicating where the decimal is.
        /// </summary>
		public int DecimalCount
		{
			get
			{
				return _decimalCount;
			}
			set
			{
				_decimalCount = value;
			}
		}

		/// <summary>
		/// Returns the equivalent CLR type for this field.
		/// </summary>
		public Type Type
		{
			get
			{
				Type type;
				switch (_type)
				{
					case 'L': // logical data type, one character (T,t,F,f,Y,y,N,n)
						type = typeof(bool);
						break;
					case 'C': // char or string
						type = typeof(string);
						break;
					case 'D': // date
						type = typeof(DateTime);
						break;
					case 'N': // numeric
						type = typeof(double);
						break;
					case 'F': // double
						type = typeof(float);
						break;
					case 'B': // BLOB - not a dbase but this will hold the WKB for a geometry object.
						type = typeof(byte[]);
							break;
					default:
						throw new NotSupportedException("Do not know how to parse Field type "+_type);
				}
				return type;
			}	
		}
	}
}