using System;
using System.Text.RegularExpressions;
using System.Threading;

namespace iWare_SCADA_BusinessLogical
{
    public static class RegexExtension
    {
        /// <summary>
        /// 启动一个线程执行操作，同时设置超时时间。
        /// var r = WithTimeout(() => regex.Match(foo), 1000);
        /// </summary>
        /// <typeparam name="TR"></typeparam>
        /// <param name="proc"></param>
        /// <param name="duration"></param>
        /// <returns></returns>
        private static TR WithTimeout<TR>(Func<TR> proc, int duration)
        {
            var reset = new AutoResetEvent(false);
            var r = default(TR);
            Exception ex = null;

            var t = new Thread(() =>
            {
                try
                {
                    r = proc();
                }
                catch (Exception e)
                {
                    ex = e;
                }
                reset.Set();
            });
            
            t.Start();

            if (!reset.WaitOne(duration))
            {
                t.Abort();
                throw new TimeoutException();
            }

            if (ex != null)
            {
                throw ex;
            }

            return r;
        }

        /// <summary>
        /// 判断正则是否匹配, duration毫秒后报超时异常
        /// </summary>
        /// <param name="regex"></param>
        /// <param name="input"></param>
        /// <param name="startat"></param>
        /// <param name="duration"></param>
        /// <returns></returns>
        public static bool IsMatchWithTimeout(this Regex regex, string input, int startat, int duration)
        {
            return regex.IsMatchWithTimeout(input, 0, duration);
        }

        /// <summary>
        /// 判断正则是否匹配, duration毫秒后报超时异常
        /// </summary>
        /// <param name="regex"></param>
        /// <param name="input"></param>
        /// <param name="duration"></param>
        /// <returns></returns>
        public static bool IsMatchWithTimeout(this Regex regex, string input, int duration)
        {
            if (regex == null)
                throw new NullReferenceException();

            return WithTimeout(() => regex.IsMatch(input), duration);
        }
        /// <summary>
        /// 匹配正则, duration毫秒后报超时异常
        /// </summary>
        /// <param name="regex"></param>
        /// <param name="input"></param>
        /// <param name="startat"></param>
        /// <param name="duration"></param>
        /// <returns></returns>
        public static Match MatchWithTimeout(this Regex regex, string input, int startat, int duration)
        {
            if (regex == null)
                throw new NullReferenceException();

            return WithTimeout(() => regex.Match(input, startat), duration);
        }

        /// <summary>
        /// 匹配正则, duration毫秒后报超时异常
        /// </summary>
        /// <param name="regex"></param>
        /// <param name="input"></param>
        /// <param name="duration"></param>
        /// <returns></returns>
        public static Match MatchWithTimeout(this Regex regex, string input, int duration)
        {
            return regex.MatchWithTimeout(input, 0, duration);
        }

        /// <summary>
        /// 匹配正则, duration毫秒后报超时异常
        /// </summary>
        /// <param name="regex"></param>
        /// <param name="input"></param>
        /// <param name="startat"></param>
        /// <param name="duration"></param>
        /// <returns></returns>
        public static MatchCollection MatchesWithTimeout(this Regex regex, string input, int startat, int duration)
        {
            if (regex == null)
                throw new NullReferenceException();

            return WithTimeout(() => regex.Matches(input, startat), duration);
        }

        /// <summary>
        /// 匹配正则, duration毫秒后报超时异常
        /// </summary>
        /// <param name="regex"></param>
        /// <param name="input"></param>
        /// <param name="duration"></param>
        /// <returns></returns>
        public static MatchCollection MatchesWithTimeout(this Regex regex, string input, int duration)
        {
            return regex.MatchesWithTimeout(input, 0, duration);
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="input"></param>
        /// <param name="pattern"></param>
        /// <param name="options"></param>
        /// <param name="duration"></param>
        /// <returns></returns>
        public static bool IsMatch(string input, string pattern, RegexOptions options, int duration)
        {
            var regex = new Regex(pattern, options);
            return regex.IsMatchWithTimeout(input, duration);
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="input"></param>
        /// <param name="pattern"></param>
        /// <param name="duration"></param>
        /// <returns></returns>
        public static bool IsMatch(string input, string pattern, int duration)
        {
            return IsMatch(input, pattern, RegexOptions.None, duration);
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="input"></param>
        /// <param name="pattern"></param>
        /// <param name="options"></param>
        /// <param name="duration"></param>
        /// <returns></returns>
        public static Match Match(string input, string pattern, RegexOptions options, int duration)
        {
            var regex = new Regex(pattern, options);
            return regex.MatchWithTimeout(input, duration);
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="input"></param>
        /// <param name="pattern"></param>
        /// <param name="duration"></param>
        /// <returns></returns>
        public static Match Match(string input, string pattern, int duration)
        {
            return Match(input, pattern, RegexOptions.None, duration);
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="input"></param>
        /// <param name="pattern"></param>
        /// <param name="options"></param>
        /// <param name="duration"></param>
        /// <returns></returns>
        public static MatchCollection Matches(string input, string pattern, RegexOptions options, int duration)
        {
            var regex = new Regex(pattern, options);
            return regex.MatchesWithTimeout(input, duration);
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="input"></param>
        /// <param name="pattern"></param>
        /// <param name="duration"></param>
        /// <returns></returns>
        public static MatchCollection Matches(string input, string pattern, int duration)
        {
            return Matches(input, pattern, RegexOptions.None, duration);
        }
    }
}