using System;
using System.Collections.Generic;
using System.Text;
using Duplicati.Library.Backend;

namespace Duplicati.CommandLine.BackendTester
{
    class Program
    {
        class TempFile
        {
            public string filename;
            public byte[] hash;
            public long length;
            public bool found = false;

            public TempFile(string filename, byte[] hash, long length)
            {
                this.filename = filename;
                this.hash = hash;
                this.length = length;
            }
        }

        private const string ValidFilenameChars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ123456789";
        private const string ExtendedChars = "-_',=)(&%$#@!";


        static void Main(string[] _args)
        {
            List<string> args = new List<string>(_args);
            Dictionary<string, string> options = CommandLineParser.ExtractOptions(args);

            if (!options.ContainsKey("ftp_password") && !string.IsNullOrEmpty(System.Environment.GetEnvironmentVariable("FTP_PASSWORD")))
                options["ftp_password"] = System.Environment.GetEnvironmentVariable("FTP_PASSWORD");

            if (!options.ContainsKey("ftp_username") && !string.IsNullOrEmpty(System.Environment.GetEnvironmentVariable("FTP_USERNAME")))
                options["ftp_username"] = System.Environment.GetEnvironmentVariable("FTP_USERNAME");

            if (args.Count != 1 || args[0].ToLower() == "help" || args[0] == "?")
            {
                Console.WriteLine("Usage: <protocol>://<username>:<password>@<path>");
                Console.WriteLine("Example: ftp://user:pass@server/folder");
                Console.WriteLine();
                Console.WriteLine("Supported backends: " + string.Join(",", Duplicati.Library.Backend.BackendLoader.Backends));

                Console.WriteLine();
                List<string> lines = new List<string>();
                foreach (Library.Backend.ICommandLineArgument arg in SupportedCommands)
                    Library.Backend.CommandLineArgument.PrintArgument(lines, arg);

                foreach (string s in lines)
                    Console.WriteLine(s);

                return;
            }

            int reruns = 5;
            if (options.ContainsKey("reruns"))
                reruns = int.Parse(options["reruns"]);

            for (int i = 0; i < reruns; i++)
            {
                Console.WriteLine("Starting run no {0}", i);
                if (!Run(args, options))
                    return;
            }
            Console.WriteLine("Unittest complete!");
        }

        static bool Run(List<string> args, Dictionary<string, string> options)
        {
            string allowedChars = ValidFilenameChars;
            if (options.ContainsKey("extended-chars"))
                allowedChars += options["extended-chars"];
            else
                allowedChars += ExtendedChars;

            Uri url = new Uri(args[0]);
            Library.Backend.IBackend backend = Library.Backend.BackendLoader.GetBackend(args[0], options);
            if (backend == null)
            {
                Console.WriteLine("Unsupported backend");
                Console.WriteLine();
                Console.WriteLine("Supported backends: " + string.Join(",", Duplicati.Library.Backend.BackendLoader.Backends));
                return false;
            }

            List<Library.Backend.FileEntry> curlist = backend.List();
            foreach (Library.Backend.FileEntry fe in curlist)
                if (!fe.IsFolder)
                {
                    Console.WriteLine("*** Remote folder is not empty, aborting");
                    return false;
                }


            int number_of_files = 10;
            int min_file_size = 1024;
            int max_file_size = 1024 * 1024 * 50;
            int min_filename_size = 5;
            int max_filename_size = 80;

            if (options.ContainsKey("number-of-files"))
                number_of_files = int.Parse(options["number-of-files"]);
            if (options.ContainsKey("min-file-size"))
                min_file_size = (int)Duplicati.Library.Core.Sizeparser.ParseSize(options["min-file-size"], "mb");
            if (options.ContainsKey("max-file-size"))
                max_file_size = (int)Duplicati.Library.Core.Sizeparser.ParseSize(options["max-file-size"]);

            if (options.ContainsKey("min-filename-length"))
                min_filename_size = int.Parse(options["min-filename-length"]);
            if (options.ContainsKey("max-filename-length"))
                max_filename_size = int.Parse(options["max-filename-length"]);

            Random rnd = new Random();
            System.Security.Cryptography.SHA256 sha = System.Security.Cryptography.SHA256.Create();

            //Create random files
            using (Library.Core.TempFolder tf = new Duplicati.Library.Core.TempFolder())
            {
                List<TempFile> files = new List<TempFile>();
                for (int i = 0; i < number_of_files; i++)
                {
                    Console.WriteLine("Generating file {0}", i);
                    StringBuilder filename = new StringBuilder();
                    int filenamelen = rnd.Next(min_filename_size, max_filename_size);
                    for (int j = 0; j < filenamelen; j++)
                        filename.Append(allowedChars[rnd.Next(0, allowedChars.Length)]);

                    using (System.IO.FileStream fs = new System.IO.FileStream(System.IO.Path.Combine(tf, i.ToString()), System.IO.FileMode.CreateNew, System.IO.FileAccess.Write))
                    {
                        //Random size
                        byte[] buf = new byte[1024];
                        int size = rnd.Next(min_file_size, max_file_size);
                        while (size > 0)
                        {
                            rnd.NextBytes(buf);
                            fs.Write(buf, 0, Math.Min(buf.Length, size));
                            size -= buf.Length;
                        }
                    }

                    //Calculate local hash and length
                    using (System.IO.FileStream fs = new System.IO.FileStream(System.IO.Path.Combine(tf, i.ToString()), System.IO.FileMode.Open, System.IO.FileAccess.Read))
                        files.Add(new TempFile(filename.ToString(), sha.ComputeHash(fs), fs.Length));
                }


                Console.WriteLine("Uploading files ...");

                for (int i = 0; i < files.Count; i++)
                {
                    Console.Write("Uploading file {0}, {1} ... ", i, Duplicati.Library.Core.Utility.FormatSizeString(new System.IO.FileInfo(System.IO.Path.Combine(tf, i.ToString())).Length));
                    try { backend.Put(files[i].filename, System.IO.Path.Combine(tf, i.ToString())); }
                    catch (Exception ex)
                    {
                        Console.WriteLine("Failed to upload file {0}, error message: {1}", i, ex.ToString());
                    }
                    Console.WriteLine(" done!");
                }

                Console.WriteLine("Verifying file list ...");

                curlist = backend.List();
                foreach (Library.Backend.FileEntry fe in curlist)
                    if (!fe.IsFolder)
                    {
                        bool found = false;
                        foreach (TempFile tx in files)
                            if (tx.filename == fe.Name)
                            {
                                if (tx.found)
                                    Console.WriteLine("*** File with name {0} was found more than once", tx.filename);
                                found = true;
                                tx.found = true;
                                break;
                            }

                        if (!found)
                            Console.WriteLine("*** File with name {0} was found on server but not uploaded!", fe.Name);
                    }

                foreach (TempFile tx in files)
                    if (!tx.found)
                        Console.WriteLine("*** File with name {0} was uploaded but not found afterwards", tx.filename);

                Console.WriteLine("Downloading files");

                for(int i = 0; i < files.Count; i++)
                {
                    using (Duplicati.Library.Core.TempFile cf = new Duplicati.Library.Core.TempFile())
                    {
                        Exception e = null;
                        Console.Write("Downloading file {0} ... ", i);
                        try { backend.Get(files[i].filename, cf); }
                        catch (Exception ex) { e = ex; }

                        if (e != null)
                            Console.WriteLine("failed\n*** Error: {0}", e.ToString());
                        else
                            Console.WriteLine("done");

                        Console.Write("Checking hash ... ");

                        using (System.IO.FileStream fs = new System.IO.FileStream(cf, System.IO.FileMode.Open, System.IO.FileAccess.Read))
                            if (Convert.ToBase64String(sha.ComputeHash(fs)) != Convert.ToBase64String(files[i].hash))
                                Console.WriteLine("failed\n*** Downloaded file was corrupt");
                            else
                                Console.WriteLine("done");
                    }
                }

                Console.WriteLine("Deleting files...");

                foreach (TempFile tx in files)
                    try { backend.Delete(tx.filename); }
                    catch (Exception ex)
                    {
                        Console.WriteLine("*** Failed to delete file {0}, message: {1}", tx.filename, ex.ToString());
                    }

                curlist = backend.List();
                foreach (Library.Backend.FileEntry fe in curlist)
                    if (!fe.IsFolder)
                    {
                        Console.WriteLine("*** Remote folder contains {0} after cleanup", fe.Name);
                    }

            }

            return true;
        }

        public static IList<ICommandLineArgument> SupportedCommands
        {
            get
            {
                return new List<ICommandLineArgument>(new ICommandLineArgument[] {
                    new CommandLineArgument("reruns", CommandLineArgument.ArgumentType.Integer, "The number of test runs to perform", "A number that describes how many times the test is performed", "5"),
                    new CommandLineArgument("extended-chars", CommandLineArgument.ArgumentType.String, "A list of allowed extended filename chars", "A list of characters besides {a-z, A-Z, 0-9} to use when generating filenames", ExtendedChars),
                    new CommandLineArgument("number-of-files", CommandLineArgument.ArgumentType.Integer, "The number of files to test with", "An integer describing how many files to upload during a test run", "10"),
                    new CommandLineArgument("min-file-size", CommandLineArgument.ArgumentType.Size, "The minimum allowed file size", "File sizes are chosen at random, this valus is the lower bound", "1kb"),
                    new CommandLineArgument("max-file-size", CommandLineArgument.ArgumentType.Size, "The maximum allowed file size", "File sizes are chosen at random, this valus is the upper bound", "50mb"),
                    new CommandLineArgument("min-filename-length", CommandLineArgument.ArgumentType.Integer, "The minimum allowed filename length", "File name lengths are chosen at random, this valus is the lower bound", "5"),
                    new CommandLineArgument("max-filename-length", CommandLineArgument.ArgumentType.Integer, "The minimum allowed filename length", "File name lengths are chosen at random, this valus is the upper bound", "80")
                });

            }
        }
    }
}