using Force.Crc32;
using LANCommander.SDK.Enums;
using LANCommander.SDK.Exceptions;
using LANCommander.SDK.Extensions;
using LANCommander.SDK.Helpers;
using LANCommander.SDK.Models;
using Microsoft.Extensions.Logging;
using SharpCompress.Common;
using SharpCompress.Readers;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;

namespace LANCommander.SDK
{
    public class GameService
    {
        private readonly ILogger Logger;
        private Client Client { get; set; }
        private string DefaultInstallDirectory { get; set; }

        public delegate void OnArchiveEntryExtractionProgressHandler(object sender, ArchiveEntryExtractionProgressArgs e);
        public event OnArchiveEntryExtractionProgressHandler OnArchiveEntryExtractionProgress;

        public delegate void OnArchiveExtractionProgressHandler(long position, long length, Game game);
        public event OnArchiveExtractionProgressHandler OnArchiveExtractionProgress;

        public const string PlayerAliasFilename = "PlayerAlias";
        public const string KeyFilename = "Key";

        private TrackableStream DownloadStream;
        private IReader Reader;

        public GameService(Client client, string defaultInstallDirectory)
        {
            Client = client;
            DefaultInstallDirectory = defaultInstallDirectory;
        }

        public GameService(Client client, string defaultInstallDirectory, ILogger logger)
        {
            Client = client;
            DefaultInstallDirectory = defaultInstallDirectory;
            Logger = logger;
        }

        public IEnumerable<Game> Get()
        {
            return Client.GetRequest<IEnumerable<Game>>("/api/Games");
        }

        public Game Get(Guid id)
        {
            return Client.GetRequest<Game>($"/api/Games/{id}");
        }

        public GameManifest GetManifest(Guid id)
        {
            return Client.GetRequest<GameManifest>($"/api/Games/{id}/Manifest");
        }

        private TrackableStream Stream(Guid id)
        {
            return Client.StreamRequest($"/api/Games/{id}/Download");
        }

        public void StartPlaySession(Guid id)
        {
            Logger?.LogTrace("Starting a game session...");

            Client.PostRequest<object>($"/api/PlaySessions/Start/{id}");
        }

        public void EndPlaySession(Guid id)
        {
            Logger?.LogTrace("Ending a game session...");

            Client.PostRequest<object>($"/api/PlaySessions/End/{id}");
        }

        public string GetAllocatedKey(Guid id)
        {
            Logger?.LogTrace("Requesting allocated key...");

            var macAddress = Client.GetMacAddress();

            var request = new KeyRequest()
            {
                GameId = id,
                MacAddress = macAddress,
                ComputerName = Environment.MachineName,
                IpAddress = Client.GetIpAddress(),
            };

            var response = Client.PostRequest<Key>($"/api/Keys/GetAllocated/{id}", request);

            if (response == null)
                return String.Empty;

            return response.Value;
        }

        public string GetNewKey(Guid id)
        {
            Logger?.LogTrace("Requesting new key allocation...");

            var macAddress = Client.GetMacAddress();

            var request = new KeyRequest()
            {
                GameId = id,
                MacAddress = macAddress,
                ComputerName = Environment.MachineName,
                IpAddress = Client.GetIpAddress(),
            };

            var response = Client.PostRequest<Key>($"/api/Keys/Allocate/{id}", request);

            if (response == null)
                return String.Empty;

            return response.Value;
        }

        /// <summary>
        /// Downloads, extracts, and runs post-install scripts for the specified game
        /// </summary>
        /// <param name="game">Game to install</param>
        /// <param name="maxAttempts">Maximum attempts in case of transmission error</param>
        /// <returns>Final install path</returns>
        /// <exception cref="Exception"></exception>
        public string Install(Guid gameId, int maxAttempts = 10)
        {
            GameManifest manifest = null;

            var game = Get(gameId);
            var destination = GetInstallDirectory(game);

            if ((game.Type == GameType.StandaloneExpansion || game.Type == GameType.StandaloneMod) && game.BaseGame != null)
            {
                destination = GetInstallDirectory(game.BaseGame);

                if (!Directory.Exists(destination))
                    destination = Install(game.BaseGame.Id, maxAttempts);
            }

            try
            {
                if (ManifestHelper.Exists(destination, game.Id))
                    manifest = ManifestHelper.Read(destination, game.Id);
            }
            catch (Exception ex)
            {
                Logger?.LogTrace(ex, "Error reading manifest before install");
            }

            Logger?.LogTrace("Installing game {GameTitle} ({GameId})", game.Title, game.Id);

            var result = RetryHelper.RetryOnException<ExtractionResult>(maxAttempts, TimeSpan.FromMilliseconds(500), new ExtractionResult(), () =>
            {
                Logger?.LogTrace("Attempting to download and extract game");

                return DownloadAndExtract(game, destination);
            });

            if (!result.Success && !result.Canceled)
                throw new InstallException("Could not extract the installer. Retry the install or check your connection");
            else if (result.Canceled)
                throw new InstallCanceledException("Game install was canceled");

            game.InstallDirectory = result.Directory;

            var writeManifestSuccess = RetryHelper.RetryOnException(maxAttempts, TimeSpan.FromSeconds(1), false, () =>
            {
                Logger?.LogTrace("Attempting to get game manifest");

                manifest = GetManifest(game.Id);

                ManifestHelper.Write(manifest, game.InstallDirectory);

                return true;
            });

            if (!writeManifestSuccess)
                throw new InstallException("Could not grab the manifest file. Retry the install or check your connection");

            Logger?.LogTrace("Saving scripts");

            ScriptHelper.SaveScript(game, ScriptType.Install);
            ScriptHelper.SaveScript(game, ScriptType.Uninstall);
            ScriptHelper.SaveScript(game, ScriptType.NameChange);
            ScriptHelper.SaveScript(game, ScriptType.KeyChange);

            return game.InstallDirectory;
        }

        public void Uninstall(string installDirectory, Guid gameId)
        {
            var fileListPath = GameService.GetMetadataFilePath(installDirectory, gameId, "FileList.txt");

            if (File.Exists(fileListPath))
            {
                var fileList = File.ReadAllLines(fileListPath);
                var files = fileList.Select(l => l.Split('|').FirstOrDefault().Trim());

                Logger?.LogTrace("Attempting to delete the install files");

                foreach (var file in files.Where(f => !f.EndsWith("/")))
                {
                    var localPath = Path.Combine(installDirectory, file);

                    try
                    {
                        if (File.Exists(localPath))
                            File.Delete(localPath);
                    }
                    catch (Exception ex)
                    {
                        Logger?.LogWarning(ex, "Could not remove file {LocalPath}", localPath);
                    }
                }

                Logger?.LogTrace("Attempting to delete any empty directories");

                DirectoryHelper.DeleteEmptyDirectories(installDirectory);

                if (!Directory.Exists(installDirectory))
                    Logger?.LogTrace("Deleted install directory {InstallDirectory}", installDirectory);
                else
                    Logger?.LogTrace("Removed game files for {GameId}", gameId);
            }
            else
            {
                Directory.Delete(installDirectory, true);
            }
        }

        private ExtractionResult DownloadAndExtract(Game game, string destination)
        {
            if (game == null)
            {
                Logger?.LogTrace("Game failed to download, no game was specified");

                throw new ArgumentNullException("No game was specified");
            }

            Logger?.LogTrace("Downloading and extracting {Game} to path {Destination}", game.Title, destination);

            var extractionResult = new ExtractionResult
            {
                Canceled = false,
            };

            var fileManifest = new StringBuilder();

            try
            {
                Directory.CreateDirectory(destination);

                DownloadStream = Stream(game.Id);
                Reader = ReaderFactory.Open(DownloadStream);

                DownloadStream.OnProgress += (pos, len) =>
                {
                    OnArchiveExtractionProgress?.Invoke(pos, len, game);
                };

                Reader.EntryExtractionProgress += (object sender, ReaderExtractionEventArgs<IEntry> e) =>
                {
                    OnArchiveEntryExtractionProgress?.Invoke(this, new ArchiveEntryExtractionProgressArgs
                    {
                        Entry = e.Item,
                        Progress = e.ReaderProgress,
                        Game = game,
                    });
                };

                while (Reader.MoveToNextEntry())
                {
                    if (Reader.Cancelled)
                        break;

                    var localFile = Path.Combine(destination, Reader.Entry.Key);

                    uint crc = 0;

                    if (File.Exists(localFile))
                    {
                        using (FileStream fs = File.Open(localFile, FileMode.Open))
                        {
                            var buffer = new byte[65536];

                            while (true)
                            {
                                var count = fs.Read(buffer, 0, buffer.Length);

                                if (count == 0)
                                    break;

                                crc = Crc32Algorithm.Append(crc, buffer, 0, count);
                            }
                        }
                    }

                    fileManifest.AppendLine($"{Reader.Entry.Key} | {Reader.Entry.Crc.ToString("X")}");

                    if (crc == 0 || crc != Reader.Entry.Crc)
                        Reader.WriteEntryToDirectory(destination, new ExtractionOptions()
                        {
                            ExtractFullPath = true,
                            Overwrite = true,
                            PreserveFileTime = true
                        });
                    else
                        Reader.OpenEntryStream().Dispose();
                }

                Reader.Dispose();
                DownloadStream.Dispose();
            }
            catch (ReaderCancelledException ex)
            {
                Logger?.LogTrace("User cancelled the download");

                extractionResult.Canceled = true;

                if (Directory.Exists(destination))
                {
                    Logger?.LogTrace("Cleaning up orphaned files after cancelled install");

                    Directory.Delete(destination, true);
                }
            }
            catch (Exception ex)
            {
                Logger?.LogError(ex, "Could not extract to path {Destination}", destination);

                if (Directory.Exists(destination))
                {
                    Logger?.LogTrace("Cleaning up orphaned install files after bad install");

                    Directory.Delete(destination, true);
                }

                throw new Exception("The game archive could not be extracted, is it corrupted? Please try again");
            }

            if (!extractionResult.Canceled)
            {
                extractionResult.Success = true;
                extractionResult.Directory = destination;

                var fileListDestination = Path.Combine(destination, ".lancommander", game.Id.ToString(), "FileList.txt");

                if (!Directory.Exists(Path.GetDirectoryName(fileListDestination)))
                    Directory.CreateDirectory(Path.GetDirectoryName(fileListDestination));

                File.WriteAllText(fileListDestination, fileManifest.ToString());

                Logger?.LogTrace("Game {Game} successfully downloaded and extracted to {Destination}", game.Title, destination);
            }

            return extractionResult;
        }

        public string GetInstallDirectory(Game game)
        {
            if ((game.Type == GameType.Expansion || game.Type == GameType.StandaloneExpansion || game.Type == GameType.Mod || game.Type == GameType.StandaloneMod) && game.BaseGame != null)
                return GetInstallDirectory(game.BaseGame);
            else
                return Path.Combine(DefaultInstallDirectory, game.Title.SanitizeFilename());
        }

        public void CancelInstall()
        {
            Reader?.Cancel();
        }

        public static string GetMetadataDirectoryPath(string installDirectory, Guid gameId)
        {
            return Path.Combine(installDirectory, ".lancommander", gameId.ToString());
        }

        public static string GetMetadataFilePath(string installDirectory, Guid gameId, string fileName)
        {
            return Path.Combine(GetMetadataDirectoryPath(installDirectory, gameId), fileName);
        }

        public static string GetPlayerAlias(string installDirectory, Guid gameId)
        {
            var aliasFilePath = GameService.GetMetadataFilePath(installDirectory, gameId, GameService.PlayerAliasFilename);

            if (File.Exists(aliasFilePath))
                return File.ReadAllText(aliasFilePath);
            else
                return String.Empty;
        }

        public static void UpdatePlayerAlias(string installDirectory, Guid gameId, string newName)
        {
            File.WriteAllText(GameService.GetMetadataFilePath(installDirectory, gameId, GameService.PlayerAliasFilename), newName);
        }

        public static string GetCurrentKey(string installDirectory, Guid gameId)
        {
            var keyFilePath = GameService.GetMetadataFilePath(installDirectory, gameId, GameService.KeyFilename);

            if (File.Exists(keyFilePath))
                return File.ReadAllText(keyFilePath);
            else
                return String.Empty;
        }

        public static void UpdateCurrentKey(string installDirectory, Guid gameId, string newKey)
        {
            File.WriteAllText(GameService.GetMetadataFilePath(installDirectory, gameId, GameService.KeyFilename), newKey);
        }
    }
}