using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Net;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using NaiBa.Util.Extension;

namespace NaiBa.Util.Helper
{
    public class HtmlHelper
    {
        public static string HtmlEncode(string html)
        {
            if (string.IsNullOrEmpty(html))
            {
                return string.Empty;
            }
            else
            {
                return WebUtility.HtmlEncode(html);
            }
        }

        public static string HtmlDecode(string url)
        {
            if (string.IsNullOrEmpty(url))
            {
                return string.Empty;
            }
            else
            {
                return WebUtility.HtmlDecode(url);
            }
        }

        /// <summary>
        /// Unicode解码
        /// </summary>
        /// <param name="html"></param>
        /// <returns></returns>
        public static string UnicodeDecode(string html)
        {
            html = WebUtility.HtmlDecode(html);

            Regex reUnicode = new Regex(@"\\u([0-9a-fA-F]{4})", RegexOptions.Compiled);
            return reUnicode.Replace(html, m =>
            {
                short c;
                if (short.TryParse(m.Groups[1].Value, NumberStyles.HexNumber, CultureInfo.InvariantCulture, out c))
                {
                    return "" + (char)c;
                }
                return m.Value;
            });
        }

        #region Resove
        public static string Resove(string html, string prefix, string subfix = "")
        {
            int inl = html.IndexOf(prefix);
            if (inl == -1)
            {
                prefix = prefix.Replace("\"", "'");
                subfix = subfix.Replace("\"", "'");
                inl = html.IndexOf(prefix);
            }
            if (inl == -1)
            {
                return null;
            }
            inl += prefix.Length;
            if (!string.IsNullOrEmpty(subfix))
            {
                int inl2 = html.IndexOf(subfix, inl);
                if (inl2 == -1)
                {
                    return null;
                }
                string result = html.Substring(inl, inl2 - inl);
                return result;
            }
            else
            {
                string result = html.Substring(inl);
                return result;
            }
        }
        #endregion

        #region ResoveReverse
        public static string ResoveReverse(string html, string subfix, string prefix)
        {
            int inl = html.IndexOf(subfix);
            if (inl == -1)
            {
                return null;
            }
            string subString = html.Substring(0, inl);
            int inl2 = subString.LastIndexOf(prefix);
            if (inl2 == -1)
            {
                return null;
            }
            string s = subString.Substring(inl2 + prefix.Length, subString.Length - inl2 - prefix.Length);
            return s;
        }
        #endregion

        #region ResoveList
        public static List<string> ResoveList(string html, string prefix, string subfix)
        {
            List<string> list = new List<string>();
            int index = 0;
            do
            {
                index = html.IndexOf(prefix, index);
                if (index == -1)
                {
                    break;
                }
                index += prefix.Length;
                int indexEnd = html.IndexOf(subfix, index);
                if (indexEnd > 0)
                {
                    string content = html.Substring(index, indexEnd - index);
                    list.Add(content);
                }
                index = indexEnd;
            }
            while (index > -1);
            return list;
        }
        #endregion

        #region ResoveListByAT
        public static List<string> ResoveListByAT(string html)
        {
            List<string> list = new List<string>();

            int index = html.IndexOf('@');
            while (index > 0)
            {
                int indexx = html.LastIndexOf("'", index);  //向前一个单引号
                int indexy = html.IndexOf("'", index + 1); //向后一个单引号
                string s78 = html.Substring(indexx, indexy - indexx);
                s78 = s78.Replace("'", "");
                list.Add(s78);
                index = html.IndexOf('@', indexy);
            }
            return list;
        }
        #endregion

        /// <summary>
        /// 清除HTML代码
        /// </summary>
        /// <param name="html"></param>
        public static string ClearHtml(string html)
        {
            html = html.ParseToString();
            html = Regex.Replace(html, @"(<head[\w\W]*?</head>|<script[\w\W]*?</script>|<style[\w\W]*?</style>|<!--[\w\W]*?-->)", string.Empty);
            html = Regex.Replace(html, @"(<span[\w\W]*?</span>)", string.Empty);
            html = Regex.Replace(html, "(<[^>]*?>)", string.Empty);
            return html;
        }

        public static string GetHtmlText(string html)
        {
            html = html.ParseToString();
            html = Regex.Replace(html, "<.*?>", string.Empty);
            return html;
        }

        /// <summary>
        /// 清除HTML代码A标签
        /// </summary>
        /// <param name="html"></param>
        /// <returns></returns>
        public static string ClearHtmlA(string html)
        {
            html = html.ParseToString();
            html = Regex.Replace(html, "(</?a[^>]*>)", "", RegexOptions.IgnoreCase);
            return html.Trim();
        }

        public static string AddEscapeCharacter(string html)
        {
            html = html.ParseToString();
            html = html.Replace("\"", "\\\"");
            html = html.Replace("'", "\\'");
            return html;
        }

        public static string TrimBOM(string html)
        {
            html = html.Trim(new char[] { '\uFEFF' });
            return html;
        }

        public static string TrimJsonp(string json)
        {
            int start = json.IndexOf("{");
            int end = json.LastIndexOf("}");
            if (start > 0 && end > 0)
            {
                return json.Substring(start, end - start + 1);
            }
            return json;
        }
    }
}