using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;

namespace CommonLib.DB
{
    public class InfluxDBHelper
    { 
        static string _baseAddress;  //地址
        static string _username;  //用户名
        static string _password;  //密码
        static string _database;  //数据库名

        static string _proxyUri;    // 服务器地址
        static int _proxyPort;   //服务器端口


        public InfluxDBHelper(
            string baseAddress,
            string username,
            string password,
            string database
            )
        {
            _baseAddress = baseAddress;
            _username = username;
            _password = password;
            _database = database; 
        }

        public InfluxDBHelper(string baseAddress,
            string username,
            string password,
            string database,
            string proxyUri,
            int proxyPort
            )
        {
            _baseAddress = baseAddress;
            _username = username;
            _password = password;
            _database = database;
            _proxyUri = proxyUri;
            _proxyPort = proxyPort;
        }

        /// <summary>
        /// 读
        /// </summary>
        /// <param name="sql"></param>
        /// <returns></returns>
        public string Query(string sql)
        {
            string pathAndQuery = string.Format("/query?db={0}&epoch=u&q={1}", _database, sql);
            string url = _baseAddress + pathAndQuery;

            string result = HttpHelperGet(url);
            return result;
        }

        /// <summary>
        /// 写
        /// </summary>
        /// <param name="sql"></param>
        /// <returns></returns>
        public string Write(string paramStr)
        {
            string result = string.Empty; 
                string pathAndQuery = string.Format("/write?db={0}", _database);
                string url = _baseAddress + pathAndQuery;
                result = HttpHelperPost(url, paramStr); 
            return result;
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="uri"></param>
        /// <param name="username"></param>
        /// <param name="password"></param>
        /// <returns></returns>
        public static string HttpHelperGet(string uri)
        {
            try
            {
                string result = string.Empty;
                HttpWebRequest wbRequest = (HttpWebRequest)WebRequest.Create(uri);
                if (string.IsNullOrEmpty(_proxyUri))
                {
                    wbRequest.Proxy = null;
                }
                else
                {
                    wbRequest.Proxy = new WebProxy(_proxyUri, _proxyPort);
                }

                if (!string.IsNullOrEmpty(_username) && !string.IsNullOrEmpty(_password))
                {
                    wbRequest.Credentials = GetCredentialCache(uri, _username, _password);
                    //wbRequest.Headers.Add(_username, _password); 
                    wbRequest.Headers.Add("Authorization", GetAuthorization(_username, _password));
                }
                wbRequest.Method = "GET";
                HttpWebResponse wbResponse = (HttpWebResponse)wbRequest.GetResponse();
                using (Stream responseStream = wbResponse.GetResponseStream())
                {
                    using (StreamReader sReader = new StreamReader(responseStream))
                    {
                        result = sReader.ReadToEnd();
                    }
                }
                return result;
            }
            catch (Exception ex)
            {
                return ex.Message;
            }
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="uri"></param>
        /// <param name="paramStr"></param>
        /// <param name="username"></param>
        /// <param name="password"></param>
        /// <returns></returns>
        public static string HttpHelperPost(string uri, string paramStr)
        {
            string result = string.Empty;
            try
            {
                HttpWebRequest wbRequest = (HttpWebRequest)WebRequest.Create(uri);

                if(string.IsNullOrEmpty(_proxyUri)) 
                {
                    wbRequest.Proxy = null;
                }
                else
                {
                    wbRequest.Proxy = new WebProxy(_proxyUri, _proxyPort);
                }
                wbRequest.Method = "POST";
                wbRequest.ContentType = "application/x-www-form-urlencoded";
                wbRequest.ContentLength = Encoding.UTF8.GetByteCount(paramStr);
                if (!string.IsNullOrEmpty(_username) && !string.IsNullOrEmpty(_password))
                {
                    wbRequest.Credentials = GetCredentialCache(uri, _username, _password);
                   // wbRequest.Headers.Add(_username, _password); 
                    wbRequest.Headers.Add("Authorization", GetAuthorization(_username, _password)); 
                }
                byte[] data = Encoding.ASCII.GetBytes(paramStr);
                using (Stream requestStream = wbRequest.GetRequestStream())
                {
                    using (StreamWriter swrite = new StreamWriter(requestStream))
                    {
                        swrite.Write(paramStr);
                    }
                }
                HttpWebResponse wbResponse = (HttpWebResponse)wbRequest.GetResponse();
                using (Stream responseStream = wbResponse.GetResponseStream())
                {
                    using (StreamReader sread = new StreamReader(responseStream))
                    {
                        result = sread.ReadToEnd();
                    }
                }

                return result;
            }
            catch (Exception ex)
            {
                result = $"{ex.Message} \n{uri} \n{paramStr}\n{ex.StackTrace}";
                throw; 
            }
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="uri"></param>
        /// <param name="username"></param>
        /// <param name="password"></param>
        /// <returns></returns>
        private static CredentialCache GetCredentialCache(string uri, string username, string password)
        {
            string authorization = string.Format("{0}:{1}", username, password);
            CredentialCache credCache = new CredentialCache();
            credCache.Add(new Uri(uri), "Basic", new NetworkCredential(username, password));
            return credCache;
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="username"></param>
        /// <param name="password"></param>
        /// <returns></returns>
        private static string GetAuthorization(string username, string password)
        {
            string authorization = string.Format("{0}:{1}", username, password);
            return "Basic " + Convert.ToBase64String(new ASCIIEncoding().GetBytes(authorization));
        }
    }
}