using System;
using System.Runtime.InteropServices;

namespace LibGPhoto2
{
	public enum ErrorCode
	{
		/* IO Errors */
		GeneraError		= -1,
		BadParameters		= -2,
		NoMemory		= -3,
		Library			= -4,
		UnknownPort		= -5,
		NotSupported		= -6,
		IO			= -7,
		Timout			= -10,
		SupportedSerial		= -20,
		SupportedUSB		= -21,
		Init			= -31,
		Read			= -34,
		Write			= -35,
		Update			= -37,
		SerialSpeed		= -41,
		USBClearHalt		= -51,
		USBFind			= -52,
		USBClaim		= -53,
		Lock			= -60,

		/* Other Errors*/
		CorruptedData		= -102,
		PathNotAbsolute		= -111,
		DirectoryExists		= -109,
		FileExists		= -103,
		FileNotFound		= -108,
		DirectoryNotFound	= -107,
		ModelNotFound		= -105
	}

	public class Error
	{
		private static string GetErrorAsString(ErrorCode e)
		{
			IntPtr raw_message = gp_result_as_string(e);
			return Marshal.PtrToStringAnsi(raw_message);
		}

		private static string GetIOErrorAsString(ErrorCode e)
		{
			IntPtr raw_message = gp_port_result_as_string(e);
			return Marshal.PtrToStringAnsi(raw_message);
		}
		
		public static bool IsError (ErrorCode error_code)
		{
			return (error_code < 0);
		}
		
		public static GPhotoException ErrorException (ErrorCode error_code)
		{
			string message = "Unknown Error";
			int error_code_int = (int)error_code;
			
			if (error_code_int <= -102 && error_code_int >= -111)
				message = GetErrorAsString(error_code);
			else if (error_code_int <= -1 && error_code_int >= -60)
				message = GetIOErrorAsString(error_code);

			return new GPhotoException(error_code, message);
		}
		
		public static ErrorCode CheckError (ErrorCode error)
		{
			if (IsError (error))
				throw ErrorException (error);
			
			return error;
		}
		
		[DllImport ("libgphoto2.so")]
		internal static extern IntPtr gp_result_as_string (ErrorCode result);
		
		[DllImport ("libgphoto2_port.so")]
		internal static extern IntPtr gp_port_result_as_string (ErrorCode result);
	}
	
	public class GPhotoException : Exception
	{
		private ErrorCode error;
		
		public GPhotoException(ErrorCode error_code)
		: base ("Unknown Error.")
		{
			error = error_code;
		}
		
		public GPhotoException (ErrorCode error_code, string message)
		: base (message)
		{
			error = error_code;
		}
		
		public override string ToString()
		{
			return ("Error " + error.ToString() + ": " + base.ToString());
		}

		public ErrorCode Error {
			get {
				return error;
			}
		}
	}
}