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

namespace PayService
{
    class Utils
    {
        public static Dictionary<string, string> paraFilter(Dictionary<string, string> map)
        {

            Dictionary<string, string> result = new Dictionary<string, string>();

            if (map == null || map.Count() <= 0)
            {
                return result;
            }

            foreach (string key in map.Keys)
            {
                string value = map[key];
                if (key.Equals("sign", StringComparison.CurrentCultureIgnoreCase) || 
                    (key.Length >= 8 && key.Substring(0, 8).Equals("reserved", StringComparison.CurrentCultureIgnoreCase)))
                {
                    continue;
                }
                result.Add(key, value);
            }

            return result;
        }

        public static string createLinkstring(Dictionary<string, string> map)
        {

            List<string> keys = new List<string>(map.Keys);
            keys.Sort();

            string prestr = "";

            for (int i = 0; i < keys.Count; i++)
            {
                string key = keys[i];
                string value = map[key];

                if (i == keys.Count - 1)
                {
                    //拼接时，不包括最后一个&字符
                    prestr = prestr + key + "=" + value;
                }
                else
                {
                    prestr = prestr + key + "=" + value + "&";
                }
            }

            return prestr;
        }

        public static string getSign(Dictionary<string, string> map)
        {
            Dictionary<string, string> mapNew = paraFilter(map);

            string preSignStr = createLinkstring(mapNew);

            Console.WriteLine("==============================待签名字符串==============================\r\n" + preSignStr);
            
            string sign = Sign.sign(preSignStr, Const.privateKey);

            sign = sign.Replace("\r\n", "");

            Console.WriteLine("==============================签名字符串==============================\r\n" + sign);

            return sign;
        }

        public static string UrlEncode(string temp, Encoding encoding)
        {
            StringBuilder stringBuilder = new StringBuilder();
            for (int i = 0; i < temp.Length; i++)
            {
                string t = temp[i].ToString();
                string k = HttpUtility.UrlEncode(t, encoding);
                if (t == k)
                {
                    stringBuilder.Append(t);
                }
                else
                {
                    stringBuilder.Append(k.ToUpper());
                }
            }
            return stringBuilder.ToString();
        }
    }
}