//
//  Class:			Extensions
//	Current CLR:	4.0.30319.34209
//	System:			Microsoft Visual Studio 10.0
//	Author:			dani
// 	Created:		5/13/2015 7:37:03 PM
//
//	Copyright (c) 2015 Informatikbüro Daniel Schick. All rights reserved.

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Text.RegularExpressions;
using log4net;

namespace bsmd.database
{
    /// <summary>
    /// sensible helpers
    /// </summary>
    public static class Extensions
    {
        private static ILog _log = LogManager.GetLogger(typeof(Extensions));

        public static bool IsNullOrEmpty(this String str)
        {
            if (str == null) return true;
            if (str.Trim().Length == 0) return true;
            if (str.Equals("00000000-0000-0000-0000-000000000000")) return true; // for null guids
            return false;
        }

        public static bool IsNullOrEmpty<T>(this List<T> items)
        {
            return (items == null) || (items.Count == 0);
        }

        public static bool IsNullOrEmpty<T>(this Dictionary<T, T> items)
        {
            return (items == null) || (items.Count == 0);
        }

        public static bool IsNumber(this String str)
        {
            string pattern = @"^[1-9]\d*(\.\d+)?$";
            if (str == null) return false;
            if (str.Trim().Length == 0) return false;
            return new Regex(pattern).IsMatch(str);
        }

        public static bool IsBoolean(this String str)
        {
            if (str == null) return false;
            if (str.Trim().Length == 0) return false;
            if (str.Trim().Equals("true", StringComparison.InvariantCultureIgnoreCase)) return true;
            if (str.Trim().Equals("false", StringComparison.InvariantCultureIgnoreCase)) return true;
            return false;
        }

        public static bool Contains(this string source, string toCheck, StringComparison comp)
        {
            return source.IndexOf(toCheck, comp) >= 0;
        }

        public static DateTime? TryParseDateTime(string text)
        {
            DateTime date;
            if(DateTime.TryParse(text, DateTimeFormatInfo.InvariantInfo,DateTimeStyles.AssumeUniversal, out date))
            {
                return date;
            }
            else
            {
                _log.WarnFormat("{0} cannot be parsed as datetime", text);
                return null;
            }
        }        

        public static double? TryParseDouble(string text)
        {
            double d;
            if (Double.TryParse(text, NumberStyles.Any, NumberFormatInfo.InvariantInfo, out d))
            {
                return d;
            }
            else
            {
                _log.WarnFormat("{0} cannot be parsed as double", text);
                return null;
            }
        }

    }
}