using System;
using System.Linq;
using System.Collections.Generic;
using System.Net;

using Duplicati.Library.Interface;
using Duplicati.Library.Utility;
using Newtonsoft.Json;

namespace Duplicati.Library.Backend.Sia
{
    public class Sia : IBackend
    {
        private const string SIA_PASSWORD = "sia-password";
        private const string SIA_TARGETPATH = "sia-targetpath";
        private const string SIA_REDUNDANCY = "sia-redundancy";

        private string m_apihost;
        private int m_apiport;
        private string m_targetpath;
        private float m_redundancy;
        private System.Net.NetworkCredential m_user;

        public Sia() {

        }

        public Sia(string url, Dictionary<string, string> options)
        {
            var uri = new Utility.Uri(url);

            m_apihost = uri.Host;
            m_apiport = uri.Port;
            m_targetpath = uri.Path;

            m_redundancy = 1.5F;
            if (options.ContainsKey(SIA_REDUNDANCY))
                m_redundancy = float.Parse(options[SIA_REDUNDANCY]);

            if (m_apiport <= 0)
                m_apiport = 9980;

            if (options.ContainsKey(SIA_TARGETPATH))
            {
                m_targetpath = options[SIA_TARGETPATH];
            }
            while(m_targetpath.Contains("//"))
                m_targetpath = m_targetpath.Replace("//","/");
            while (m_targetpath.StartsWith("/"))
                m_targetpath = m_targetpath.Substring(1);
            while (m_targetpath.EndsWith("/"))
                m_targetpath = m_targetpath.Remove(m_targetpath.Length - 1);

            if (m_targetpath.Length == 0)
                m_targetpath = "backup";

            m_user = new System.Net.NetworkCredential();
            if (options.ContainsKey(SIA_PASSWORD))
            {             
                m_user.Password = options[SIA_PASSWORD];
            }
        }

        private System.Net.HttpWebRequest CreateRequest(string endpoint)
        {
            string baseurl = "http://" + m_apihost + ":" + m_apiport;
            System.Net.HttpWebRequest req = (System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create(baseurl + endpoint);

            if (!string.IsNullOrEmpty(m_user.Password))
            {
                req.Credentials = m_user;
                req.PreAuthenticate = true;
            }

            req.KeepAlive = false;
            req.UserAgent = string.Format("Sia-Agent (Duplicati SIA client {0})", System.Reflection.Assembly.GetExecutingAssembly().GetName().Version.ToString());

            return req;
        }

        private string getResponseBodyOnError(string context, System.Net.WebException wex)
        {
            string body = "";
            System.Net.HttpWebResponse response = (System.Net.HttpWebResponse)wex.Response;
            using (System.IO.Stream data = response.GetResponseStream())
            using (var reader = new System.IO.StreamReader(data))
            {
                body = reader.ReadToEnd();
            }
            return string.Format("{0} failed, response: {1}", context, body);
        }

        public class SiaFile
        {
            [JsonProperty("siapath")]
            public string Siapath { get; set; }
            [JsonProperty("available")]
            public bool Available { get; set; }
            [JsonProperty("filesize")]
            public long Filesize { get; set; }
            [JsonProperty("uploadprogress")]
            public float Uploadprogress { get; set; }
            [JsonProperty("redundancy")]
            public float Redundancy { get; set; }
        }

        public class SiaFileList
        {
            [JsonProperty("files")]
            public SiaFile[] Files { get; set; }
        }

        public class SiaDownloadFile
        {
            [JsonProperty("siapath")]
            public string Siapath { get; set; }
            [JsonProperty("destination")]
            public string Destination { get; set; }
            [JsonProperty("filesize")]
            public long Filesize { get; set; }
            [JsonProperty("received")]
            public long Received { get; set; }
            [JsonProperty("starttime")]
            public string Starttime { get; set; }
            [JsonProperty("error")]
            public string Error { get; set; }
        }

        public class SiaDownloadList
        {
            [JsonProperty("downloads")]
            public SiaDownloadFile[] Files { get; set; }
        }

        private SiaFileList GetFiles()
        {
            var fl = new SiaFileList();
            string endpoint = string.Format("/renter/files");

            try
            {
                System.Net.HttpWebRequest req = CreateRequest(endpoint);
                req.Method = System.Net.WebRequestMethods.Http.Get;

                Utility.AsyncHttpRequest areq = new Utility.AsyncHttpRequest(req);

                using (System.Net.HttpWebResponse resp = (System.Net.HttpWebResponse)areq.GetResponse())
                {
                    int code = (int)resp.StatusCode;
                    if (code < 200 || code >= 300)
                        throw new System.Net.WebException(resp.StatusDescription, null, System.Net.WebExceptionStatus.ProtocolError, resp);

                    var serializer = new JsonSerializer();

                    using (var rs = areq.GetResponseStream())
                    using (var sr = new System.IO.StreamReader(rs))
                    using (var jr = new Newtonsoft.Json.JsonTextReader(sr))
                    {
                        fl = (SiaFileList)serializer.Deserialize(jr, typeof(SiaFileList));
                    }
                }
            }
            catch (System.Net.WebException wex)
            {
                throw new Exception(getResponseBodyOnError(endpoint, wex));
            }
            return fl;
        }

        private bool IsUploadComplete(string siafilename)
        {
            SiaFileList fl = GetFiles();
            if (fl.Files == null)
                return false;

            foreach (var f in fl.Files)
            {
                if (f.Siapath == siafilename)
                {
                    if (f.Available == true && f.Redundancy >= m_redundancy /* && f.Uploadprogress >= 100 */ )
                    {
                        return true;
                    }
                }
            }
            return false;
        }

        private SiaDownloadList GetDownloads()
        {
            var fl = new SiaDownloadList();
            string endpoint = string.Format("/renter/downloads");

            try
            {
                System.Net.HttpWebRequest req = CreateRequest(endpoint);
                req.Method = System.Net.WebRequestMethods.Http.Get;

                Utility.AsyncHttpRequest areq = new Utility.AsyncHttpRequest(req);

                using (System.Net.HttpWebResponse resp = (System.Net.HttpWebResponse)areq.GetResponse())
                {
                    int code = (int)resp.StatusCode;
                    if (code < 200 || code >= 300)
                        throw new System.Net.WebException(resp.StatusDescription, null, System.Net.WebExceptionStatus.ProtocolError, resp);

                    var serializer = new JsonSerializer();

                    using (var rs = areq.GetResponseStream())
                    using (var sr = new System.IO.StreamReader(rs))
                    using (var jr = new Newtonsoft.Json.JsonTextReader(sr))
                    {
                        fl = (SiaDownloadList)serializer.Deserialize(jr, typeof(SiaDownloadList));
                    }
                }
            }
            catch (System.Net.WebException wex)
            {
                throw new Exception(getResponseBodyOnError(endpoint, wex));
            }
            return fl;
        }

        private bool IsDownloadComplete(string siafilename, string localname)
        {
            SiaDownloadList fl = GetDownloads();
            if (fl.Files == null)
                return false;

            foreach (var f in fl.Files)
            {
                if (f.Siapath == siafilename)
                {
                    if (f.Error != "")
                    {
                        throw new Exception("failed to download " + siafilename + "err: " + f.Error);
                    }
                    if (f.Filesize == f.Received)
                    {
                        try
                        {
                            // Sia seems to keep the file open/locked for a while, make sure we can open it
                            System.IO.FileStream fs = new System.IO.FileStream(localname, System.IO.FileMode.Open, System.IO.FileAccess.Read, System.IO.FileShare.ReadWrite);
                            fs.Close();
                        }
                        catch (System.IO.IOException)
                        {
                            return false;
                        }
                        return true;
                    }
                }
            }
            return false;
        }

        #region IBackend Members

        public void Test()
        {
            List();
        }

        public void CreateFolder()
        {
            // Dummy method, Sia doesn't have folders
        }

        public string DisplayName
        {
            get { return Strings.Sia.DisplayName; }
        }

        public string ProtocolKey
        {
            get { return "sia"; }
        }

         
        public List<IFileEntry> List()
        {
            var files = new List<IFileEntry>();
            try
            {
                SiaFileList fl = GetFiles();
                if (fl.Files == null)
                    return files;

                foreach (var f in fl.Files)
                {
                    // Sia returns a complete file list, but we're only interested in files that are
                    // in our target path
                    if (f.Siapath.StartsWith(m_targetpath))
                    {
                        FileEntry fe = new FileEntry(f.Siapath.Substring(m_targetpath.Length + 1));
                        fe.Size = f.Filesize;
                        fe.IsFolder = false;
                        files.Add(fe);
                    }
                }
            }
            catch (System.Net.WebException wex)
            {
                throw new Exception("failed to call /renter/files "+wex.Message);
            }

            return files;
        }

        public void Put(string remotename, string filename)
        {
            string endpoint ="";
            string siafile = m_targetpath + "/" + remotename;

            try {
                endpoint = string.Format("/renter/upload/{0}/{1}?source={2}",
                    m_targetpath, 
                    Library.Utility.Uri.UrlEncode(remotename).Replace("+", "%20"),
                    Library.Utility.Uri.UrlEncode(filename).Replace("+", "%20")
                );

                System.Net.HttpWebRequest req = CreateRequest(endpoint);
                req.Method = System.Net.WebRequestMethods.Http.Post;

                Utility.AsyncHttpRequest areq = new Utility.AsyncHttpRequest(req);

                using (System.Net.HttpWebResponse resp = (System.Net.HttpWebResponse)areq.GetResponse())
                {
                    int code = (int)resp.StatusCode;
                    if (code < 200 || code >= 300)
                        throw new System.Net.WebException(resp.StatusDescription, null, System.Net.WebExceptionStatus.ProtocolError, resp);

                    while (! IsUploadComplete( siafile ))
                    {
                        System.Threading.Thread.Sleep(5000);
                    }
                }
            }
            catch (System.Net.WebException wex)
            {
                throw new Exception(getResponseBodyOnError(endpoint, wex));
            }
        }

        public void Get(string remotename, string localname)
        {
            string endpoint = "";
            string siafile = m_targetpath + "/" + remotename;
            string tmpfilename = localname + ".tmp";

            try
            {
                endpoint = string.Format("/renter/download/{0}/{1}?destination={2}",
                    m_targetpath,
                    Library.Utility.Uri.UrlEncode(remotename).Replace("+", "%20"),
                    Library.Utility.Uri.UrlEncode(tmpfilename).Replace("+", "%20")
                );
                System.Net.HttpWebRequest req = CreateRequest(endpoint);
                req.Method = System.Net.WebRequestMethods.Http.Get;

                Utility.AsyncHttpRequest areq = new Utility.AsyncHttpRequest(req);

                using (System.Net.HttpWebResponse resp = (System.Net.HttpWebResponse)areq.GetResponse())
                {
                    int code = (int)resp.StatusCode;
                    if (code < 200 || code >= 300)
                        throw new System.Net.WebException(resp.StatusDescription, null, System.Net.WebExceptionStatus.ProtocolError, resp);

                    while (!IsDownloadComplete(siafile, localname))
                    {
                        System.Threading.Thread.Sleep(5000);
                    }
                   
                    System.IO.File.Copy(tmpfilename, localname, true);
                    try
                    {
                        System.IO.File.Delete(tmpfilename);
                    } catch (Exception)
                    {

                    }
                }
            }
            catch (System.Net.WebException wex)
            {
                if (wex.Response is System.Net.HttpWebResponse && ((System.Net.HttpWebResponse)wex.Response).StatusCode == System.Net.HttpStatusCode.NotFound)
                    throw new FileMissingException(wex);
                else
                    throw new Exception(getResponseBodyOnError(endpoint, wex));
            }
        }

        public void Delete(string remotename)
        {
            string endpoint = "";

            try
            {
                endpoint = string.Format("/renter/delete/{0}/{1}",
                    m_targetpath,
                    Library.Utility.Uri.UrlEncode(remotename).Replace("+", "%20")
                );
                System.Net.HttpWebRequest req = CreateRequest(endpoint);
                req.Method = System.Net.WebRequestMethods.Http.Post;

                Utility.AsyncHttpRequest areq = new Utility.AsyncHttpRequest(req);

                using (System.Net.HttpWebResponse resp = (System.Net.HttpWebResponse)areq.GetResponse())
                {
                    int code = (int)resp.StatusCode;
                    if (code < 200 || code >= 300)
                        throw new System.Net.WebException(resp.StatusDescription, null, System.Net.WebExceptionStatus.ProtocolError, resp);
                }
            }
            catch (System.Net.WebException wex)
            {
                if (wex.Response is System.Net.HttpWebResponse && ((System.Net.HttpWebResponse)wex.Response).StatusCode == System.Net.HttpStatusCode.NotFound)
                    throw new FileMissingException(wex);
                else
                    throw new Exception(getResponseBodyOnError(endpoint, wex));
            }
        }


        public IList<ICommandLineArgument> SupportedCommands
        {
            get
            {    
                return new List<ICommandLineArgument>(new ICommandLineArgument[] {
                    new CommandLineArgument(SIA_TARGETPATH, CommandLineArgument.ArgumentType.String, Strings.Sia.SiaPathDescriptionShort, Strings.Sia.SiaPathDescriptionLong, "/backup"),
                    new CommandLineArgument(SIA_PASSWORD, CommandLineArgument.ArgumentType.Password, Strings.Sia.SiaPasswordShort, Strings.Sia.SiaPasswordLong, null),
                    new CommandLineArgument(SIA_REDUNDANCY, CommandLineArgument.ArgumentType.String, Strings.Sia.SiaRedundancyDescriptionShort, Strings.Sia.SiaRedundancyDescriptionLong, "1.5"),
                });
            }
        }

        public string Description
        {
            get
            {
                return Strings.Sia.Description;
            }
        }

        #endregion

        #region IDisposable Members

        public void Dispose()
        {

        }

        #endregion


    }


}