using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace NaiBa.Util.Helper
{
    public class RegexHelper
    {
        // <span\\sclass=\"rantings-num\".*?>(.+?)</span>

        /// <summary>
        /// 返回正则对象所有结果
        /// </summary>
        /// <param name="html"></param>
        /// <param name="regex"></param>
        /// <returns></returns>
        public static MatchCollection GetMatchCollection(string html, string regex)
        {
            if (string.IsNullOrEmpty(html))
            {
                return null;
            }
            return Regex.Matches(html, regex, RegexOptions.IgnoreCase);
        }

        /// <summary>
        /// 返回单个正则分析结果
        /// </summary>
        /// <param name="html"></param>
        /// <param name="regex"></param>
        /// <returns></returns>
        public static string GetMatch(string html, string regex, int index = 0)
        {
            if (string.IsNullOrEmpty(html))
            {
                return string.Empty;
            }
            MatchCollection mc = Regex.Matches(html, regex, RegexOptions.IgnoreCase);
            if (mc.Count > 0)
            {
                return mc[index].Groups[1].Value.ToString();
            }
            return string.Empty;
        }

        public static string GetMatchWithSingleLine(string html, string regex)
        {
            if (string.IsNullOrEmpty(html))
            {
                return string.Empty;
            }
            MatchCollection mc = Regex.Matches(html, regex, RegexOptions.IgnoreCase | RegexOptions.Singleline);
            if (mc.Count > 0)
            {
                return mc[0].Groups[1].ToString();
            }
            return string.Empty;
        }

        public static bool IsNumber(string str)
        {
            Regex regex = new Regex(@"^[0-9\.]+$");
            return regex.IsMatch(str);
        }

        public static bool IsAlphabet(string str)
        {
            Regex regex = new Regex(@"^[A-Za-z]+$");
            return regex.IsMatch(str);
        }

        public static bool IsAlphabetOrNumber(string str)
        {
            Regex regex = new Regex(@"^[A-Za-z0-9]+$");
            return regex.IsMatch(str);
        }
    }
}