// NpgsqlTypes.NpgsqlTypesHelper.cs
//
// Author:
//	Glen Parker <glenebob@nwlink.com>
//
//	Copyright (C) 2004 The Npgsql Development Team
//	npgsql-general@gborg.postgresql.org
//	http://gborg.postgresql.org/project/npgsql/projdisplay.php
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

// This file provides data type converters between PostgreSQL representations
// and .NET objects.

using System;
using System.Collections;
using System.Globalization;
using System.Text;
using System.IO;
using System.Text.RegularExpressions;

using Npgsql;

namespace NpgsqlTypes
{
    /// <summary>
    /// Provide event handlers to convert all native supported basic data types from their backend
    /// text representation to a .NET object.
    /// </summary>
    internal abstract class BasicBackendToNativeTypeConverter
    {
        private static readonly String[] DateFormats = new String[] 
        {
          "yyyy-MM-dd",
        };

        private static readonly String[] TimeFormats = new String[]
        {
          "HH:mm:ss.ffffff",
          "HH:mm:ss.fffff",	
          "HH:mm:ss.ffff",
          "HH:mm:ss.fff",
          "HH:mm:ss.ff",
          "HH:mm:ss.f",
          "HH:mm:ss",
          "HH:mm:ss.ffffffzz",
          "HH:mm:ss.fffffzz",	
          "HH:mm:ss.ffffzz",
          "HH:mm:ss.fffzz",
          "HH:mm:ss.ffzz",
          "HH:mm:ss.fzz",
          "HH:mm:sszz"
        };

        private static readonly String[] DateTimeFormats = new String[] 
        {
          "yyyy-MM-dd HH:mm:ss.ffffff",
          "yyyy-MM-dd HH:mm:ss.fffff",	
          "yyyy-MM-dd HH:mm:ss.ffff",
          "yyyy-MM-dd HH:mm:ss.fff",
          "yyyy-MM-dd HH:mm:ss.ff",
          "yyyy-MM-dd HH:mm:ss.f",
          "yyyy-MM-dd HH:mm:ss",
          "yyyy-MM-dd HH:mm:ss.ffffffzz",
          "yyyy-MM-dd HH:mm:ss.fffffzz",	
          "yyyy-MM-dd HH:mm:ss.ffffzz",
          "yyyy-MM-dd HH:mm:ss.fffzz",
          "yyyy-MM-dd HH:mm:ss.ffzz",
          "yyyy-MM-dd HH:mm:ss.fzz",
          "yyyy-MM-dd HH:mm:sszz"
        };

        /// <summary>
        /// Binary data.
        /// </summary>
        internal static Object ToBinary(NpgsqlBackendTypeInfo TypeInfo, String BackendData, Int16 TypeSize, Int32 TypeModifier)
        {
            Int32           octalValue = 0;
            Int32           byteAPosition = 0;
            Int32           byteAStringLength = BackendData.Length;
            MemoryStream    ms = new MemoryStream();

            while (byteAPosition < byteAStringLength)
            {
                // The IsDigit is necessary in case we receive a \ as the octal value and not
                // as the indicator of a following octal value in decimal format.
                // i.e.: \201\301P\A
                if (BackendData[byteAPosition] == '\\') {

                    if (byteAPosition + 1 == byteAStringLength)
                    {
                        octalValue = '\\';
                        byteAPosition++;
                    }
                    else if (Char.IsDigit(BackendData[byteAPosition + 1]))
                    {
                        octalValue = (Byte.Parse(BackendData[byteAPosition + 1].ToString()) << 6);
                        octalValue |= (Byte.Parse(BackendData[byteAPosition + 2].ToString()) << 3);
                        octalValue |= Byte.Parse(BackendData[byteAPosition + 3].ToString());
                        byteAPosition += 4;

                    }
                    else
                    {
                        octalValue = '\\';
                        byteAPosition += 2;
                    }

                } else {
                    octalValue = (Byte)BackendData[byteAPosition];
                    byteAPosition++;
                }


                ms.WriteByte((Byte)octalValue);

            }

            return ms.ToArray();
        }

        /// <summary>
        /// Convert a postgresql boolean to a System.Boolean.
        /// </summary>
        internal static Object ToBoolean(NpgsqlBackendTypeInfo TypeInfo, String BackendData, Int16 TypeSize, Int32 TypeModifier)
        {
            return (BackendData.ToLower() == "t" ? true : false);
        }

        /// <summary>
        /// Convert a postgresql datetime to a System.DateTime.
        /// </summary>
        internal static Object ToDateTime(NpgsqlBackendTypeInfo TypeInfo, String BackendData, Int16 TypeSize, Int32 TypeModifier)
        {
            // Get the date time parsed in all expected formats for timestamp.
            return DateTime.ParseExact(BackendData,
                                        DateTimeFormats,
                                        DateTimeFormatInfo.InvariantInfo,
                                        DateTimeStyles.NoCurrentDateDefault | DateTimeStyles.AllowWhiteSpaces);
        }

        /// <summary>
        /// Convert a postgresql date to a System.DateTime.
        /// </summary>
        internal static Object ToDate(NpgsqlBackendTypeInfo TypeInfo, String BackendData, Int16 TypeSize, Int32 TypeModifier)
        {
            return DateTime.ParseExact(BackendData,
                                        DateFormats,
                                        DateTimeFormatInfo.InvariantInfo,
                                        DateTimeStyles.AllowWhiteSpaces);
        }

        /// <summary>
        /// Convert a postgresql time to a System.DateTime.
        /// </summary>
        internal static Object ToTime(NpgsqlBackendTypeInfo TypeInfo, String BackendData, Int16 TypeSize, Int32 TypeModifier)
        {
            return DateTime.ParseExact(BackendData,
                                        TimeFormats,
                                        DateTimeFormatInfo.InvariantInfo,
                                        DateTimeStyles.NoCurrentDateDefault | DateTimeStyles.AllowWhiteSpaces);
        }

        /// <summary>
        /// Convert a postgresql money to a System.Decimal.
        /// </summary>
        internal static Object ToMoney(NpgsqlBackendTypeInfo TypeInfo, String BackendData, Int16 TypeSize, Int32 TypeModifier)
        {
            // It's a number with a $ on the beginning...
            return Convert.ToDecimal(BackendData.Substring(1, BackendData.Length - 1), CultureInfo.InvariantCulture);
        }
    }

    /// <summary>
    /// Provide event handlers to convert the basic native supported data types from
    /// native form to backend representation.
    /// </summary>
    internal abstract class BasicNativeToBackendTypeConverter
    {
        /// <summary>
        /// Binary data.
        /// </summary>
        internal static String ToBinary(NpgsqlNativeTypeInfo TypeInfo, Object NativeData)
        {
            Byte[]     byteArray = (Byte[])NativeData;
            int        len = byteArray.Length;
            char[]     res = new char[len * 5];

            for (int i = 0, o = 0; i < len; ++i, o += 5)
            {
                byte item = byteArray[i];
                res[o] = res[o + 1] = '\\';
                res[o + 2] = (char)('0' + (7 & (item >> 6)));
                res[o + 3] = (char)('0' + (7 & (item >> 3)));
                res[o + 4] = (char)('0' + (7 & item));
            }

            return new String(res);
        }

        /// <summary>
        /// Convert to a postgresql boolean.
        /// </summary>
        internal static String ToBoolean(NpgsqlNativeTypeInfo TypeInfo, Object NativeData)
        {
            return ((bool)NativeData) ? "TRUE" : "FALSE";
        }

        /// <summary>
        /// Convert to a postgresql timestamp.
        /// </summary>
        internal static String ToDateTime(NpgsqlNativeTypeInfo TypeInfo, Object NativeData)
        {
            return ((DateTime)NativeData).ToString("yyyy-MM-dd HH:mm:ss.fff", DateTimeFormatInfo.InvariantInfo);
        }

        /// <summary>
        /// Convert to a postgresql date.
        /// </summary>
        internal static String ToDate(NpgsqlNativeTypeInfo TypeInfo, Object NativeData)
        {
            return ((DateTime)NativeData).ToString("yyyy-MM-dd", DateTimeFormatInfo.InvariantInfo);
        }

        /// <summary>
        /// Convert to a postgresql time.
        /// </summary>
        internal static String ToTime(NpgsqlNativeTypeInfo TypeInfo, Object NativeData)
        {
            return ((DateTime)NativeData).ToString("HH:mm:ss.fff", DateTimeFormatInfo.InvariantInfo);
        }

        /// <summary>
        /// Convert to a postgres money.
        /// </summary>
        internal static String ToMoney(NpgsqlNativeTypeInfo TypeInfo, Object NativeData)
        {
            return "$" + ((Decimal)NativeData).ToString(DateTimeFormatInfo.InvariantInfo);
        }
    }


    /// <summary>
    /// Provide event handlers to convert extended native supported data types from their backend
    /// text representation to a .NET object.
    /// </summary>
    internal abstract class ExtendedBackendToNativeTypeConverter
    {
    
    	private static readonly Regex pointRegex = new Regex(@"\((-?\d+.?\d*),(-?\d+.?\d*)\)");
    	private static readonly Regex boxlsegRegex = new Regex(@"\((-?\d+.?\d*),(-?\d+.?\d*)\),\((-?\d+.?\d*),(-?\d+.?\d*)\)");
    	private static readonly Regex pathpolygonRegex = new Regex(@"\((-?\d+.?\d*),(-?\d+.?\d*)\)");
    	private static readonly Regex circleRegex = new Regex(@"<\((-?\d+.?\d*),(-?\d+.?\d*)\),(\d+.?\d*)>");
    	
    	
        /// <summary>
        /// Convert a postgresql point to a System.NpgsqlPoint.
        /// </summary>
        internal static Object ToPoint(NpgsqlBackendTypeInfo TypeInfo, String BackendData, Int16 TypeSize, Int32 TypeModifier)
        {
            
            Match m = pointRegex.Match(BackendData);
            
            return new NpgsqlPoint(Single.Parse(m.Groups[1].ToString()), Single.Parse(m.Groups[2].ToString()));
            
            
            
        }

        /// <summary>
        /// Convert a postgresql point to a System.RectangleF.
        /// </summary>
        internal static Object ToBox(NpgsqlBackendTypeInfo TypeInfo, String BackendData, Int16 TypeSize, Int32 TypeModifier)
        {
            
            Match m = boxlsegRegex.Match(BackendData);
            
            return new NpgsqlBox(new NpgsqlPoint(Single.Parse(m.Groups[1].ToString()), Single.Parse(m.Groups[2].ToString())),
            						new NpgsqlPoint(Single.Parse(m.Groups[3].ToString()), Single.Parse(m.Groups[4].ToString())));
        }

        /// <summary>
        /// LDeg.
        /// </summary>
        internal static Object ToLSeg(NpgsqlBackendTypeInfo TypeInfo, String BackendData, Int16 TypeSize, Int32 TypeModifier)
        {
            Match m = boxlsegRegex.Match(BackendData);
            
            return new NpgsqlLSeg(new NpgsqlPoint(Single.Parse(m.Groups[1].ToString()), Single.Parse(m.Groups[2].ToString())),
            						new NpgsqlPoint(Single.Parse(m.Groups[3].ToString()), Single.Parse(m.Groups[4].ToString())));
        }

        /// <summary>
        /// Path.
        /// </summary>
        internal static Object ToPath(NpgsqlBackendTypeInfo TypeInfo, String BackendData, Int16 TypeSize, Int32 TypeModifier)
        {
        	   	
        	Match m = pathpolygonRegex.Match(BackendData);
        	Boolean open = (BackendData[0] == '['); 
        	ArrayList points = new ArrayList();
        	    	
        	while (m.Success)
        	{
        		
        		if (open)
        			points.Add(new NpgsqlPoint(Single.Parse(m.Groups[1].ToString()), Single.Parse(m.Groups[2].ToString())));
        		else
        		{
        			// Here we have to do a little hack, because as of 2004-08-11 mono cvs version, the last group is returned with
        			// a trailling ')' only when the last character of the string is a ')' which is the case for closed paths
					// returned by backend. This gives parsing exception when converting to single. 
					// I still don't know if this is a bug in mono or in my regular expression.
        			// Check if there is this character and remove it.
        			
        			String group2 = m.Groups[2].ToString();
        			if (group2.EndsWith(")"))
        				group2 = group2.Remove(group2.Length - 1, 1);
        				
        			points.Add(new NpgsqlPoint(Single.Parse(m.Groups[1].ToString()), Single.Parse(group2)));
        		}
        			
        		m = m.NextMatch();
        		
        	}
        	
        	NpgsqlPath result = new NpgsqlPath((NpgsqlPoint[]) points.ToArray(typeof(NpgsqlPoint)));
			result.IsOpen = open; 
        	return result;
        	
            
        }

        /// <summary>
        /// Polygon.
        /// </summary>
        internal static Object ToPolygon(NpgsqlBackendTypeInfo TypeInfo, String BackendData, Int16 TypeSize, Int32 TypeModifier)
        {
            
        	Match m = pathpolygonRegex.Match(BackendData);
        	ArrayList points = new ArrayList();
        	    	
        	while (m.Success)
        	{
        		
	   			// Here we have to do a little hack, because as of 2004-08-11 mono cvs version, the last group is returned with
	   			// a trailling ')' only when the last character of the string is a ')' which is the case for closed paths
				// returned by backend. This gives parsing exception when converting to single. 
				// I still don't know if this is a bug in mono or in my regular expression.
	   			// Check if there is this character and remove it.
	   			
	   			String group2 = m.Groups[2].ToString();
	   			if (group2.EndsWith(")"))
	   				group2 = group2.Remove(group2.Length - 1, 1);
	   				
	   			points.Add(new NpgsqlPoint(Single.Parse(m.Groups[1].ToString()), Single.Parse(group2)));

	        			
	       		m = m.NextMatch();
        		
        	}
        	
        	return new NpgsqlPolygon((NpgsqlPoint[]) points.ToArray(typeof(NpgsqlPoint)));
			
        }

        /// <summary>
        /// Circle.
        /// </summary>
        internal static Object ToCircle(NpgsqlBackendTypeInfo TypeInfo, String BackendData, Int16 TypeSize, Int32 TypeModifier)
        {
        	Match m = circleRegex.Match(BackendData);
            return new NpgsqlCircle(new NpgsqlPoint(Single.Parse(m.Groups[1].ToString()), Single.Parse(m.Groups[2].ToString())), Single.Parse(m.Groups[3].ToString()));
            
        }
    }

    /// <summary>
    /// Provide event handlers to convert extended native supported data types from
    /// native form to backend representation.
    /// </summary>
    internal abstract class ExtendedNativeToBackendTypeConverter
    {
        /// <summary>
        /// Point.
        /// </summary>
        internal static String ToPoint(NpgsqlNativeTypeInfo TypeInfo, Object NativeData)
        {
            if (NativeData is NpgsqlPoint)
           	{
           		NpgsqlPoint	P = (NpgsqlPoint)NativeData;
                return String.Format(CultureInfo.InvariantCulture, "({0},{1})", P.X, P.Y);
           	} 
			else 
			{
                throw new InvalidCastException("Unable to cast data to NpgsqlPoint type");
            }
        }

        /// <summary>
        /// Box.
        /// </summary>
        internal static String ToBox(NpgsqlNativeTypeInfo TypeInfo, Object NativeData)
        {
            /*if (NativeData.GetType() == typeof(Rectangle)) {
                Rectangle       R = (Rectangle)NativeData;
                return String.Format(CultureInfo.InvariantCulture, "({0},{1}),({2},{3})", R.Left, R.Top, R.Left + R.Width, R.Top + R.Height);
            } else if (NativeData.GetType() == typeof(RectangleF)) {
                RectangleF      R = (RectangleF)NativeData;
                return String.Format(CultureInfo.InvariantCulture, "({0},{1}),({2},{3})", R.Left, R.Top, R.Left + R.Width, R.Top + R.Height);*/
                
            if (NativeData is NpgsqlBox)
			{
				NpgsqlBox box = (NpgsqlBox) NativeData;
				return String.Format(CultureInfo.InvariantCulture, "({0},{1}),({2},{3})", box.LowerLeft.X, box.LowerLeft.Y, box.UpperRight.X, box.UpperRight.Y);
			    
            } else {
                throw new InvalidCastException("Unable to cast data to Rectangle type");
            }
        }

        /// <summary>
        /// LSeg.
        /// </summary>
        internal static String ToLSeg(NpgsqlNativeTypeInfo TypeInfo, Object NativeData)
        {
            NpgsqlLSeg      S = (NpgsqlLSeg)NativeData;
            return String.Format(CultureInfo.InvariantCulture, "{0},{1},{2},{3}", S.Start.X, S.Start.Y, S.End.X, S.End.Y);
        }

        /// <summary>
        /// Open path.
        /// </summary>
        internal static String ToPath(NpgsqlNativeTypeInfo TypeInfo, Object NativeData)
        {
            StringBuilder   B = new StringBuilder();

            foreach (NpgsqlPoint P in ((NpgsqlPath)NativeData).Points) {
                B.AppendFormat(CultureInfo.InvariantCulture, "{0}({1},{2})", (B.Length > 0 ? "," : ""), P.X, P.Y);
            }

            return String.Format("[{0}]", B.ToString());
        }

        /// <summary>
        /// Polygon.
        /// </summary>
        internal static String ToPolygon(NpgsqlNativeTypeInfo TypeInfo, Object NativeData)
        {
            StringBuilder   B = new StringBuilder();

            foreach (NpgsqlPoint P in ((NpgsqlPolygon)NativeData).Points) {
                B.AppendFormat(CultureInfo.InvariantCulture, "{0}({1},{2})", (B.Length > 0 ? "," : ""), P.X, P.Y);
            }

            return String.Format("({0})", B.ToString());
        }

        /// <summary>
        /// Circle.
        /// </summary>
        internal static String ToCircle(NpgsqlNativeTypeInfo TypeInfo, Object NativeData)
        {
            NpgsqlCircle      C = (NpgsqlCircle)NativeData;
            return String.Format(CultureInfo.InvariantCulture, "{0},{1},{2}", C.Center.X, C.Center.Y, C.Radius);
        }
    }
}