using B2Classes;
using CommandLine;
using Newtonsoft.Json;
using NLog;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Security.Cryptography;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace B2Uploader
{
    class CmdLineOptions
    {
        [Option('i', "accountid", HelpText = "Account ID", Required=true)]
        public string AccountId { get; set; }

        [Option('a', "appkey", HelpText = "Application Key", Required=true)]
        public string ApplicationKey { get; set; }

        [Option('d', "directory", HelpText = "Directory you want to upload", Required = true)]
        public string Directory { get; set; }

        [Option('m', "multithreads", HelpText = "Number of uploads you want to use at a time. Default is 2", Required = false)]
        public int Threads { get; set; }

        [Option('r', "recursive", HelpText = "Uploads the directory in Recursive mode. Any sub folders will also be uploaded", Required = false)]
        public bool recursive { get; set; }
        
        [Option('v', "verbose", HelpText="Verbose Output")]
        public bool Verbose{get;set;}
    }

    class Program
    {

        static Logger logger = LogManager.GetCurrentClassLogger();
        static void Main(string[] args)
        {
            var result = CommandLine.Parser.Default.ParseArguments<CmdLineOptions>(args);                      

            logger.Debug("Starting B2Uploader Version: {0}", System.Reflection.Assembly.GetExecutingAssembly().GetName().Version);

            var existCode = result.MapResult(options => {
                if (!Directory.Exists(options.Directory))
                {
                    Console.WriteLine("Directory to upload MUST EXIST!");
                    return 0;
                }

                
                if (options.Verbose)
                {
                    logger.Debug("Authorizing User");
                }
                var auth = AuthorizeUser(options.AccountId, options.ApplicationKey);
                if (options.Verbose)
                {
                    logger.Debug("Listing Buckets");
                }
                var buckets = ListBuckets(new ListBucketsRequest() { accountId = auth.accountId }, auth.authorizationToken, auth.apiUrl).Result;

                var bucket = buckets.buckets.First();

                logger.Debug("Using Bucket Named {0} for uploads", bucket.bucketName);


                SearchOption so = SearchOption.TopDirectoryOnly;
                if (options.recursive)
                {
                    if (options.Verbose)
                    {
                        logger.Debug("Using Reurisve mode for uploads");
                    }
                    so = SearchOption.AllDirectories;
                }

                string[] FilesToProcess = Directory.GetFiles(options.Directory, "*", so);

                if (options.Verbose)
                {
                    logger.Debug("Found {0} files to upload", FilesToProcess.Length);
                }

                int maxParallel = 2;

                if(options.Threads > 0)
                {
                    if (options.Verbose)
                    {
                        logger.Debug("Mutliple threads for upload: {0}", options.Threads);
                    }   
                    maxParallel = options.Threads;
                }

                Parallel.ForEach(FilesToProcess, new ParallelOptions() { MaxDegreeOfParallelism = maxParallel }, s =>
                {
                    //check if file already exists

                    string fileName = getValidFilename(s);

                    var existingFiles = ListFileNames(new ListFileNamesRequest() { bucketId = bucket.bucketId, startFileName = fileName }, auth.apiUrl, auth.authorizationToken);
                    bool found = false;
                    foreach (var x in existingFiles.files)
                    {
                        if (x.fileName == fileName)
                        {
                            //check the file size
                            System.IO.FileInfo fi = new System.IO.FileInfo(s);
                            
                            if (fi.Length == x.size)
                            {
                                found = true;
                                break;
                            }
                            else
                            {
                                //delete old file? could just be an older version... going to upload again...
                                break;
                            }
                        }
                    }
                    if (found)
                    {
                       logger.Debug("File {0} exists already, skipping", fileName);
                    }
                    else
                    {
                        bool uploaded = false;
                        int retries = 0;
                        while (!uploaded && retries < 3)
                        {
                            try {
                                logger.Debug("Getting Upload URL");
                                var uploadURL = GetUploadURL(new GetUploadURLRequest { bucketId = bucket.bucketId }, auth.apiUrl, auth.authorizationToken).Result;
                                logger.Debug("Starting upload");
                                var response = UploadFile(uploadURL.authorizationToken, "b2/x-auto", s, uploadURL.uploadUrl);
                                if(response != null)
                                {
                                    uploaded = true;
                                }
                            }
                            catch(Exception ex)
                            {
                                logger.Error("Uploaded Failed. {0}, Retrying",ex.Message);
                                var innerEx = ex.InnerException;
                                while(innerEx != null)
                                {
                                    logger.Error("Inner Ex: {0}", innerEx.Message);
                                    innerEx = innerEx.InnerException;
                                }
                                logger.Error(ex.Message);
                                uploaded = false;
                                retries += 1;
                                Thread.Sleep(TimeSpan.FromSeconds(30));
                            }
                        }
                        if (!uploaded)
                        {
                            logger.Error("Uploaded Failed 3 times... Please retry later!");
                        }
                    }
                });
                return 1;
            },
            errors =>{
                Console.WriteLine(errors);
                return 1;
            });
        }

        static AuthorizeResponse AuthorizeUser(string accountId, string applicationKey)
        {
            HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create("https://api.backblaze.com/b2api/v1/b2_authorize_account");
            string credentials = Convert.ToBase64String(Encoding.UTF8.GetBytes(string.Format("{0}:{1}", accountId, applicationKey)));
            webRequest.Headers.Add("Authorization", "Basic " + credentials);
            webRequest.ContentType = "application/json; charset=utf-8";
            WebResponse response = (HttpWebResponse)webRequest.GetResponse();
            var responseString = new StreamReader(response.GetResponseStream()).ReadToEnd();
            response.Close();
            return JsonConvert.DeserializeObject<AuthorizeResponse>(responseString);
        }

        static async Task<ListBucketsResponse> ListBuckets(ListBucketsRequest request, string authToken, string apiUrl)
        {
            var headers = GetAuthHeaders(authToken);

            string responseString = await MakeRequest2(apiUrl + "/b2api/v1/b2_list_buckets", headers, JsonConvert.SerializeObject(request));
            
            return  await Task.Factory.StartNew(() => JsonConvert.DeserializeObject<ListBucketsResponse>(responseString));
        }

        static List<Tuple<string,string>> GetAuthHeaders(string authToken)
        {
            List<Tuple<string, string>> headers = new List<Tuple<string, string>>();
            headers.Add(new Tuple<string, string>("Authorization", authToken));
            return headers;
        }

        static async Task<GetUploadURLResponse> GetUploadURL(GetUploadURLRequest request, string apiUrl, string authToken)
        {
            var headers = GetAuthHeaders(authToken); 
            string responseString = await MakeRequest2(apiUrl + "/b2api/v1/b2_get_upload_url", headers, JsonConvert.SerializeObject(request));

            return await Task.Factory.StartNew(() => JsonConvert.DeserializeObject<GetUploadURLResponse>(responseString));
        }
        static string getValidFilename(string input)
        {
            string fileName = input.Replace('\\', '/');
            fileName = fileName.Replace(' ', '_');
            if (fileName.StartsWith("/"))
            {
                fileName = fileName.Substring(1);
            }
            return fileName;
        }

        static UploadFileResponse UploadFile(string authToken, string contentType, string filePath, string uploadUrl)
        {
            logger.Debug("Starting Uploading {0}", filePath);

            String sha1 = GetSha1(filePath);

            var headers = GetAuthHeaders(authToken);

            string fileName = getValidFilename(filePath);

            headers.Add(new Tuple<string, string>("X-Bz-File-Name", fileName));
            headers.Add(new Tuple<string, string>("X-Bz-Content-Sha1", sha1));

            
            string responseString = MakeRequest2(uploadUrl, headers, filePath, true, contentType).Result;

            var resp = JsonConvert.DeserializeObject<UploadFileResponse>(responseString);

            if (resp.contentSha1 == sha1)
            {
                Console.WriteLine(responseString);
                return resp;
            }
            else
            {
                //something went wrong!
                return null;
            }
            
        }

        static ListFileNamesResponse ListFileNames(ListFileNamesRequest request, string apiUrl, string authToken)
        {
            var headers = GetAuthHeaders(authToken);
            string responseString =  MakeRequest2(string.Format("{0}/b2api/v1/b2_list_file_names", apiUrl), headers, JsonConvert.SerializeObject(request)).Result;

            return JsonConvert.DeserializeObject<ListFileNamesResponse>(responseString);
        }


        static async Task<string> MakeRequest2(string url, List<Tuple<string, string>> headers, string data, bool isFile = false, string contentType = "application/json; charset=utf-8")
        {
            var client = new HttpClient();
            if (isFile)
            {
                client.Timeout = TimeSpan.FromMinutes(60);
            }
           
            foreach (var head in headers)
            {
                client.DefaultRequestHeaders.Add(head.Item1, head.Item2);
            }

            HttpContent content = null;
            if (isFile)
            {
                content = new StreamContent(System.IO.File.OpenRead(data));
                content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue(contentType);
            }
            else
            {
                content = new StringContent(data);
            }
            var resp = await client.PostAsync(url, content);
            try {
            resp.EnsureSuccessStatusCode();
            return await resp.Content.ReadAsStringAsync();          
        }
            catch(Exception ex)
            {
                logger.Error("Error getting respoonse: {0} {1}", ex.Message, ex.StackTrace);
                throw;
            }
        }
        

        private static string GetSha1(string fileName)
        {
            using (SHA1Managed sha1 = new SHA1Managed())
            {
                using (FileStream fs = System.IO.File.OpenRead(fileName))
                {
                    var hash = sha1.ComputeHash(fs);
                    var sb = new StringBuilder(hash.Length * 2);

                    foreach (byte b in hash)
                    {
                        // can be "x2" if you want lowercase
                        sb.Append(b.ToString("X2"));
                    }
                    return sb.ToString();
                }
            }
        }
    }

    
}