// (c) Copyright Ascensio System SIA 2010-2022
//
// This program is a free software product.
// You can redistribute it and/or modify it under the terms
// of the GNU Affero General Public License (AGPL) version 3 as published by the Free Software
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// to the effect that Ascensio System SIA expressly excludes the warranty of non-infringement of
// any third-party rights.
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namespace ASC.Data.Backup.Tasks;

[Scope]
public class TransferPortalTask : PortalTaskBase
{
    public const string DefaultDirectoryName = "backup";

    public string BackupDirectory { get; set; }
    public bool DeleteBackupFileAfterCompletion { get; set; }
    public bool BlockOldPortalAfterStart { get; set; }
    public bool DeleteOldPortalAfterCompletion { get; set; }
    public string ToConfigPath { get; private set; }
    public int ToTenantId { get; private set; }
    public int Limit { get; private set; }

    private readonly IOptionsMonitor<ILog> _options;
    private readonly TempStream _tempStream;
    private readonly TempPath _tempPath;
    private readonly IServiceProvider _serviceProvider;


    public TransferPortalTask(
        DbFactory dbFactory,
        IServiceProvider serviceProvider,
        IOptionsMonitor<ILog> options,
        StorageFactory storageFactory,
        StorageFactoryConfig storageFactoryConfig,
        ModuleProvider moduleProvider,
        TempStream tempStream,
        TempPath tempPath)
        : base(dbFactory, options, storageFactory, storageFactoryConfig, moduleProvider)
    {
        DeleteBackupFileAfterCompletion = true;
        BlockOldPortalAfterStart = true;
        DeleteOldPortalAfterCompletion = true;
        _options = options;
        _tempStream = tempStream;
        _tempPath = tempPath;
        _serviceProvider = serviceProvider;
    }

    public void Init(int tenantId, string fromConfigPath, string toConfigPath, int limit, string backupDirectory)
    {
        Limit = limit;
        ToConfigPath = toConfigPath ?? throw new ArgumentNullException(nameof(toConfigPath));
        Init(tenantId, fromConfigPath);

        BackupDirectory = backupDirectory;
    }

    public override void RunJob()
    {
        Logger.DebugFormat("begin transfer {0}", TenantId);
        var fromDbFactory = new DbFactory(null, null);
        var toDbFactory = new DbFactory(null, null);
        var tenantAlias = GetTenantAlias(fromDbFactory);
        var backupFilePath = GetBackupFilePath(tenantAlias);
        var columnMapper = new ColumnMapper();
        try
        {
            //target db can have error tenant from the previous attempts
            SaveTenant(toDbFactory, tenantAlias, TenantStatus.RemovePending, tenantAlias + "_error", "status = " + TenantStatus.Restoring.ToString("d"));

            if (BlockOldPortalAfterStart)
            {
                SaveTenant(fromDbFactory, tenantAlias, TenantStatus.Transfering);
            }

            SetStepsCount(ProcessStorage ? 3 : 2);

            //save db data to temporary file
            var backupTask = _serviceProvider.GetService<BackupPortalTask>();
            backupTask.Init(TenantId, ConfigPath, backupFilePath, Limit);
            backupTask.ProcessStorage = false;
            backupTask.ProgressChanged += (sender, args) => SetCurrentStepProgress(args.Progress);
            foreach (var moduleName in _ignoredModules)
            {
                backupTask.IgnoreModule(moduleName);
            }
            backupTask.RunJob();

            //restore db data from temporary file
            var restoreTask = _serviceProvider.GetService<RestorePortalTask>();
            restoreTask.Init(ToConfigPath, backupFilePath, columnMapper: columnMapper);
            restoreTask.ProcessStorage = false;
            restoreTask.ProgressChanged += (sender, args) => SetCurrentStepProgress(args.Progress);
            foreach (var moduleName in _ignoredModules)
            {
                restoreTask.IgnoreModule(moduleName);
            }
            restoreTask.RunJob();

            //transfer files
            if (ProcessStorage)
            {
                DoTransferStorage(columnMapper);
            }

            SaveTenant(toDbFactory, tenantAlias, TenantStatus.Active);
            if (DeleteOldPortalAfterCompletion)
            {
                SaveTenant(fromDbFactory, tenantAlias, TenantStatus.RemovePending, tenantAlias + "_deleted");
            }
            else if (BlockOldPortalAfterStart)
            {
                SaveTenant(fromDbFactory, tenantAlias, TenantStatus.Active);
            }

            ToTenantId = columnMapper.GetTenantMapping();
        }
        catch
        {
            SaveTenant(fromDbFactory, tenantAlias, TenantStatus.Active);
            if (columnMapper.GetTenantMapping() > 0)
            {
                SaveTenant(toDbFactory, tenantAlias, TenantStatus.RemovePending, tenantAlias + "_error");
            }
            throw;
        }
        finally
        {
            if (DeleteBackupFileAfterCompletion)
            {
                File.Delete(backupFilePath);
            }
            Logger.DebugFormat("end transfer {0}", TenantId);
        }
    }

    private void DoTransferStorage(ColumnMapper columnMapper)
    {
        Logger.Debug("begin transfer storage");
        var fileGroups = GetFilesToProcess(TenantId).GroupBy(file => file.Module).ToList();
        var groupsProcessed = 0;
        foreach (var group in fileGroups)
        {
            var baseStorage = StorageFactory.GetStorage(ConfigPath, TenantId.ToString(), group.Key);
            var destStorage = StorageFactory.GetStorage(ToConfigPath, columnMapper.GetTenantMapping().ToString(), group.Key);
            var utility = new CrossModuleTransferUtility(_options, _tempStream, _tempPath, baseStorage, destStorage);

            foreach (var file in group)
            {
                var adjustedPath = file.Path;

                var module = ModuleProvider.GetByStorageModule(file.Module, file.Domain);
                if (module == null || module.TryAdjustFilePath(false, columnMapper, ref adjustedPath))
                {
                    try
                    {
                        utility.CopyFileAsync(file.Domain, file.Path, file.Domain, adjustedPath).Wait();
                    }
                    catch (Exception error)
                    {
                        Logger.WarnFormat("Can't copy file ({0}:{1}): {2}", file.Module, file.Path, error);
                    }
                }
                else
                {
                    Logger.WarnFormat("Can't adjust file path \"{0}\".", file.Path);
                }
            }
            SetCurrentStepProgress((int)(++groupsProcessed * 100 / (double)fileGroups.Count));
        }

        if (fileGroups.Count == 0)
        {
            SetStepCompleted();
        }

        Logger.Debug("end transfer storage");
    }

    private void SaveTenant(DbFactory dbFactory, string alias, TenantStatus status, string newAlias = null, string whereCondition = null)
    {
        using var connection = dbFactory.OpenConnection();
        if (newAlias == null)
        {
            newAlias = alias;
        }
        else if (newAlias != alias)
        {
            newAlias = GetUniqAlias(connection, newAlias);
        }

        var commandText = "update tenants_tenants " +
        "set " +
            $"  status={status:d}, " +
            $"  alias = '{newAlias}', " +
            $"  last_modified='{DateTime.UtcNow:yyyy-MM-dd HH:mm:ss}', " +
            $"  statuschanged='{DateTime.UtcNow:yyyy-MM-dd HH:mm:ss}' " +
            $"where alias = '{alias}'";

        if (!string.IsNullOrEmpty(whereCondition))
        {
            commandText += " and " + whereCondition;
        }

        var command = connection.CreateCommand();
        command.CommandText = commandText;
        command.WithTimeout(120).ExecuteNonQuery();
    }

    private string GetTenantAlias(DbFactory dbFactory)
    {
        using var connection = dbFactory.OpenConnection();
        var command = connection.CreateCommand();
        command.CommandText = "select alias from tenants_tenants where id = " + TenantId;
        return (string)command.WithTimeout(120).ExecuteScalar();
    }

    private static string GetUniqAlias(DbConnection connection, string alias)
    {
        var command = connection.CreateCommand();
        command.CommandText = "select count(*) from tenants_tenants where alias like '" + alias + "%'";
        return alias + command.WithTimeout(120).ExecuteScalar();
    }

    private string GetBackupFilePath(string tenantAlias)
    {
        if (!Directory.Exists(BackupDirectory ?? DefaultDirectoryName))
        {
            Directory.CreateDirectory(BackupDirectory ?? DefaultDirectoryName);
        }

        return CrossPlatform.PathCombine(BackupDirectory ?? DefaultDirectoryName, tenantAlias + DateTime.UtcNow.ToString("(yyyy-MM-dd HH-mm-ss)") + ".backup");
    }

}