using System;
using System.Drawing;
using System.Drawing.Imaging;

namespace mikejorgensen.Photography
{
	/// <summary>
	/// Provides access to EXIF data
	/// </summary>
	public class EXIFData
	{
		private string _Equipment, _ShutterSpeed, _Aperture, _ISO, _FocalLength, _ExposureDate, _Flash;
		private bool _IsEXIF = false;

		public EXIFData( System.Drawing.Image image)
		{
			this.ExtractEXIF(image);
		}

		public EXIFData( string filePath )
		{
			try
			{
				System.Drawing.Image image = System.Drawing.Image.FromFile(filePath, true);
				this.ExtractEXIF(image);
			}
			catch (Exception exp)
			{
				throw new ArgumentException("The file does not exist", exp);
			}
		}


		#region Private Helper Methods
		private void ExtractEXIF( System.Drawing.Image image)
		{
			foreach(System.Drawing.Imaging.PropertyItem Property in image.PropertyItems)
			{
				switch (Property.Id)
				{
					case (272):
						//Canon EOS 10D
						_Equipment = System.Text.Encoding.ASCII.GetString(image.GetPropertyItem(272).Value);
						_IsEXIF = true;
						break;
					case (36867):
						//Exposure Date
						_ExposureDate = System.Text.Encoding.ASCII.GetString(image.GetPropertyItem(36867).Value);
						_IsEXIF = true;
						break;
					case (33434):
						//Shutter
						_ShutterSpeed = (System.BitConverter.ToInt32(image.GetPropertyItem(33434).Value,0)).ToString() + "/" + (System.BitConverter.ToInt32(image.GetPropertyItem(33434).Value,4)).ToString();
						_IsEXIF = true;
						break;
					case (33437):
						//Aperture
						_Aperture = (Convert.ToDecimal(System.BitConverter.ToInt32(image.GetPropertyItem(33437).Value,0))/Convert.ToDecimal(System.BitConverter.ToInt32(image.GetPropertyItem(33437).Value,4))).ToString();
						_IsEXIF = true;
						break;
					case (37386):
						//Focal Length
						_FocalLength = (System.BitConverter.ToInt32(image.GetPropertyItem(37386).Value,0)/System.BitConverter.ToInt32(image.GetPropertyItem(37386).Value,4)).ToString() + "mm";
						_IsEXIF = true;
						break;
					case (34855):
						//ISO
						_ISO = System.BitConverter.ToUInt16(image.GetPropertyItem(34855).Value,0).ToString();
						_IsEXIF = true;
						break;
					case (37385):
						//Flash
						_Flash = System.BitConverter.ToUInt16(image.GetPropertyItem(37385).Value,0).ToString();
						break;
				}
			}	

			image.Dispose();
		}
		#endregion

		#region Properties
		public bool IsEXIF
		{
			get { return _IsEXIF; }
		}
		public string Equipment
		{
			get { return _Equipment.Remove(_Equipment.Length-1,1); }
		}
		public string ShutterSpeed
		{
			get { return _ShutterSpeed; }
		}
		public string Aperture
		{
			get { return _Aperture; }
		}
		public string ISO
		{
			get { return _ISO; }
		}
		public string Flash
		{
			get { return _Flash; }
		}
		public string FocalLength
		{
			get { return _FocalLength; }
		}
		public string ExposureDate
		{
			get
			{ 
				return _ExposureDate.Substring(5,2) + "/" + _ExposureDate.Substring(8,2) + "/" + _ExposureDate.Substring(0,4) + " " + _ExposureDate.Substring(11,5);
					
			}
		}
		#endregion
	}
}