using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Cryptography;
using System.Text;

namespace POSV.OtherMember.Utils
{
    class MemberApiUtils
    {
        static NLog.Logger logger = NLog.LogManager.GetCurrentClassLogger();

        private static object _lock = new object();

        public static string URL = "https://openapi.qimai.shop/api/v2";

        public static string OPEN_KEY = "HrXrZCwlQ3rKVvfiNoVMPNsUHiqTnZUeY7EGpMQQyqK3m7zEwt";

        private static MemberApiUtils _instance = null;

        public static MemberApiUtils Instance
        {
            get
            {
                if (_instance == null)
                {
                    lock (_lock)
                    {
                        _instance = new MemberApiUtils();
                    }
                }
                return _instance;
            }
        }

        public string Sign(SortedList<string, string> parameters)
        {
            return Sign(parameters, null);
        }

        public string Sign(SortedList<string, string> parameters, List<string> ignoreParameters)
        {
            IList<string> keys = parameters.Keys;

            var paramNames = new List<string>(keys.Count);
            paramNames.AddRange(keys);
            if (ignoreParameters != null && ignoreParameters.Count > 0)
            {
                foreach (string ignore in ignoreParameters)
                {
                    paramNames.Remove(ignore);
                }
            }

            StringBuilder sb = new StringBuilder();
            foreach (string key in paramNames)
            {
                sb.Append(key +"="+ parameters[key]+"&");
            }

            string input = sb.ToString();

            Console.WriteLine("签名字符串:" + input.Substring(0, input.Length - 1));
            var encoding = Encoding.UTF8;
            HMACSHA1 hmac = new HMACSHA1(encoding.GetBytes(OPEN_KEY));
            hmac.Initialize();
            
            byte[] buffer = encoding.GetBytes(input.Substring(0,input.Length - 1));

            byte[] hash = hmac.ComputeHash(buffer);


            Console.WriteLine("Open Key:" + OPEN_KEY);

            Console.WriteLine("签名后的Token:" + Convert.ToBase64String(hash));

            return Convert.ToBase64String(hash);

        }

        /// <summary>
        /// 获取当前时间戳，兼容Java服务端
        /// </summary>
        /// <returns></returns>
        public string GetTimestamp()
        {
            TimeSpan ts = new TimeSpan(DateTime.UtcNow.Ticks - new DateTime(1970, 1, 1, 0, 0, 0).Ticks);

            return Convert.ToString((long)ts.TotalMilliseconds);
        }


        public string GetNonce()
        {
            Random random = new Random();
            return Convert.ToString(random.Next(10000, 99999));
        }

        public SortedList<string, string> NewParameters()
        {
            SortedList<string, string> parameters = new SortedList<string, string>();

#if DEBUG
            parameters.Add("OpenId", "9275b5818f8659c30442fcb7b21da30a");
            parameters.Add("GrantCode", "bcf53b6bec");
            parameters.Add("Timestamp", GetTimestamp());
            parameters.Add("Nonce", GetNonce());
#else
            parameters.Add("OpenId", "9275b5818f8659c30442fcb7b21da30a");
            parameters.Add("GrantCode", "bcf53b6bec");
            parameters.Add("Timestamp", GetTimestamp());            
            parameters.Add("Nonce", GetNonce());
#endif


            return parameters;
        }

    }
}