using Microsoft.IdentityModel.Clients.ActiveDirectory;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Security.Authentication;
using System.Web.Http;
using Tango.BL;
using Tango.BL.Builders;
using Tango.BL.Entities;
using Tango.BL.Enumerations;
using Tango.Core.Cryptography;
using Tango.MachineService.Models;
using Tango.MachineStudio.Common.Authentication;
using System.Data.Entity;
using Tango.MachineStudio.Common.Web;
using Tango.Web.Controllers;
using Tango.Web.Helpers;
using Tango.Web.Storage;
using Tango.Web.Security;
using Tango.Web.ActiveDirectory;
using Tango.MachineService.Filters;
using Tango.MachineService.Security;
using Tango.Web.SQLServer;
using Tango.Core;
using Tango.Web.SMO;
using Tango.Core.DB;
using System.Threading.Tasks;

namespace Tango.MachineService.Controllers
{
    public class MachineStudioController : TangoController<MachineStudioController.TokenObject>
    {
        private static List<MachineStudioPendingUpload> _pendingUploads;
        private ActiveDirectoryManager _ad_manager;

        public class TokenObject
        {
            public String UserGuid { get; set; }
        }

        #region Constructors

        /// <summary>
        /// Initializes the <see cref="MachineStudioController"/> class.
        /// </summary>
        static MachineStudioController()
        {
            _pendingUploads = new List<MachineStudioPendingUpload>();
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="MachineStudioController"/> class.
        /// </summary>
        public MachineStudioController() : base()
        {
            _ad_manager = new ActiveDirectoryManager();
        }

        #endregion

        #region Actions

        /// <summary>
        /// Checks for updates.
        /// </summary>
        /// <param name="request">The request.</param>
        /// <returns></returns>
        [HttpPost]
        [JwtTokenFilter]
        public CheckForUpdatesResponse CheckForUpdates(CheckForUpdatesRequest request)
        {
            LogManager.Log("Request received...");

            var userID = RequestToken.Object.UserGuid;

            CheckForUpdatesResponse response = new CheckForUpdatesResponse();

            using (ObservablesContext db = ObservablesWebContext.CreateContext())
            {
                var versions = db.MachineStudioVersions.ToList();

                MachineStudioVersion latestVersion = null;

                latestVersion = versions.OrderByDescending(x => Version.Parse(x.Version)).FirstOrDefault();

                Version currentVersion = Version.Parse(request.Version);

                String comments = String.Join(Environment.NewLine, versions.OrderBy(x => Version.Parse(x.Version)).Where(x => Version.Parse(x.Version) > currentVersion).Select(x => x.Comments));

                if (latestVersion != null && Version.Parse(latestVersion.Version) != currentVersion)
                {
                    var manager = new BlobStorageManager();
                    var container = manager.GetContainer(MachineServiceConfig.MACHINE_STUDIO_VERSIONS_CONTAINER);
                    var blob = container.GetBlockBlobReference(latestVersion.BlobName);

                    response.BlobAddress = blob.GenerateReadSignature(TimeSpan.FromMinutes(60));

                    if (!String.IsNullOrWhiteSpace(MachineServiceConfig.CDN_ENDPOINT))
                    {
                        response.CdnAddress = MachineServiceConfig.CDN_ENDPOINT + blob.Uri.AbsolutePath;
                    }

                    response.IsUpdateAvailable = true;
                    response.Version = latestVersion.Version;
                    response.Comments = latestVersion.Comments;
                }
            }

            return response;
        }

        /// <summary>
        /// Downloads the latest version.
        /// </summary>
        /// <param name="request">The request.</param>
        /// <returns></returns>
        [HttpPost]
        [JwtTokenFilter]
        public DownloadLatestVersionResponse DownloadLatestVersion(DownloadLatestVersionRequest request)
        {
            DownloadLatestVersionResponse response = new DownloadLatestVersionResponse();

            using (ObservablesContext db = ObservablesWebContext.CreateContext())
            {
                var versions = db.MachineStudioVersions.ToList();

                MachineStudioVersion latestVersion = versions.OrderByDescending(x => Version.Parse(x.Version)).FirstOrDefault();

                if (latestVersion != null)
                {
                    var manager = new BlobStorageManager();
                    var container = manager.GetContainer(MachineServiceConfig.MACHINE_STUDIO_VERSIONS_CONTAINER);
                    var blob = container.GetBlockBlobReference(latestVersion.BlobName);

                    if (!String.IsNullOrWhiteSpace(MachineServiceConfig.CDN_ENDPOINT))
                    {
                        response.CdnAddress = MachineServiceConfig.CDN_ENDPOINT + blob.Uri.AbsolutePath;
                    }

                    response.BlobAddress = blob.GenerateReadSignature(TimeSpan.FromMinutes(60));
                    response.Version = latestVersion.Version;
                }
            }

            return response;
        }

        /// <summary>
        /// Uploads a version.
        /// </summary>
        /// <param name="request">The request.</param>
        /// <returns></returns>
        /// <exception cref="System.ArgumentException">New version must be greater than latest version.</exception>
        /// <exception cref="AuthenticationException">Invalid user credentials.</exception>
        [HttpPost]
        [JwtTokenFilter]
        public UploadVersionResponse UploadVersion(UploadVersionRequest request)
        {
            UploadVersionResponse response = new UploadVersionResponse();

            using (ObservablesContext db = ObservablesWebContext.CreateContext())
            {
                String userID = RequestToken.Object.UserGuid;

                var user = new UserBuilder(db).Set(userID).WithRolesAndPermissions().Build();

                if (user != null && user.HasPermission(Permissions.PublishMachineStudioVersions))
                {
                    var latestVersion = db.MachineStudioVersions.ToList().OrderByDescending(x => Version.Parse(x.Version)).FirstOrDefault();
                    Version local_version = Version.Parse(request.Version);

                    if (latestVersion == null || local_version > Version.Parse(latestVersion.Version))
                    {
                        String newVersionFileName = "Machine Studio v" + local_version.ToString() + ".zip";

                        var manager = new BlobStorageManager();
                        var container = manager.GetContainer(MachineServiceConfig.MACHINE_STUDIO_VERSIONS_CONTAINER);
                        var blob = container.CreateEmptyBlob(newVersionFileName);

                        response.Token = Guid.NewGuid().ToString();
                        response.BlobAddress = blob.GenerateWriteSignature(TimeSpan.FromMinutes(30));

                        MachineStudioPendingUpload pending_upload = new MachineStudioPendingUpload()
                        {
                            UserGuid = user.Guid,
                            Comments = request.Comments,
                            Token = response.Token,
                            Version = request.Version,
                            BlobName = blob.Name,
                        };

                        if (request.WithInstaller)
                        {
                            String installerVersionFileName = "Machine Studio v" + local_version.ToString() + ".exe";
                            var installerBlob = container.CreateEmptyBlob(installerVersionFileName);
                            response.InstallerBlobAddress = installerBlob.GenerateWriteSignature(TimeSpan.FromMinutes(30));
                            pending_upload.InstallerBlobName = installerBlob.Name;
                        }

                        _pendingUploads.Add(pending_upload);
                    }
                    else
                    {
                        throw new ArgumentException("New version must be greater than latest version.");
                    }
                }
                else
                {
                    throw new AuthenticationException("Invalid user credentials.");
                }
            }

            return response;
        }

        /// <summary>
        /// Notifies about a version upload completion.
        /// </summary>
        /// <param name="request">The request.</param>
        /// <returns></returns>
        /// <exception cref="System.ArgumentException">Invalid Token.</exception>
        [HttpPost]
        [JwtTokenFilter]
        public UploadCompletedResponse NotifyVersionUploadCompleted(UploadCompletedRequest request)
        {
            MachineStudioPendingUpload upload = _pendingUploads.FirstOrDefault(x => x.Token == request.Token);

            if (upload != null)
            {
                _pendingUploads.RemoveAll(x => x.Token == upload.Token);

                using (ObservablesContext db = ObservablesWebContext.CreateContext())
                {
                    db.MachineStudioVersions.Add(new MachineStudioVersion()
                    {
                        Comments = upload.Comments,
                        BlobName = upload.BlobName,
                        InstallerBlobName = upload.InstallerBlobName,
                        UserGuid = upload.UserGuid,
                        Version = upload.Version,
                    });

                    db.SaveChanges();
                }

                return new UploadCompletedResponse();
            }
            else
            {
                throw new ArgumentException("Invalid Token.");
            }
        }

        /// <summary>
        /// Gets the latest version.
        /// </summary>
        /// <param name="request">The request.</param>
        /// <returns></returns>
        [HttpPost]
        public LatestVersionResponse GetLatestVersion(LatestVersionRequest request)
        {
            using (ObservablesContext db = ObservablesWebContext.CreateContext())
            {
                var version = db.MachineStudioVersions.ToList().OrderByDescending(x => Version.Parse(x.Version)).FirstOrDefault();
                return new LatestVersionResponse() { Version = version != null ? version.Version : "0.0.0.0" };
            }
        }

        /// <summary>
        /// Login to the service.
        /// </summary>
        /// <param name="request">The request.</param>
        /// <returns></returns>
        /// <exception cref="AuthenticationException"></exception>
        [HttpPost]
        public LoginResponse Login(LoginRequest request)
        {
            AuthenticationResult authResult = null;
            User user = null;
            DataSource dataSource = null;
            IHashGenerator hash = new BasicHashGenerator();

            Version client_version;

            if (!Version.TryParse(request.Version, out client_version))
            {
                client_version = new Version("1.0.0.0");
            }

            bool versionChangeRequired = false;
            String requiredVersion = null;
            bool isPasswordOK = false;

            try
            {
                authResult = _ad_manager.ValidateUserCredentials(request.Email, request.Password);
                isPasswordOK = true;
            }
            catch { }

            //Login via Active Directory
            if (request.Method == LoginMethod.ActiveDirectory)
            {
                try
                {
                    authResult = _ad_manager.ValidateUserCredentials(request.Email, request.Password);
                }
                catch (Exception ex)
                {
                    throw new AuthenticationException(ex.FlattenMessage());
                }

                if (!_ad_manager.CanUserAccessCurrentEnvironment(request.Email))
                {
                    throw new AuthenticationException($"You do not have permissions to access the {MachineServiceConfig.DEPLOYMENT_SLOT.ToDescription()} environment.");
                }

                using (ObservablesContext db = ObservablesWebContext.CreateContext())
                {
                    db.Roles.ToList();
                    db.Permissions.ToList();
                    db.UsersRoles.ToList();
                    db.RolesPermissions.ToList();

                    user = new UserBuilder(db).Set(x => x.Email.ToLower() == request.Email.ToLower()).WithRolesAndPermissions().WithDeleted().Build();

                    if (user == null)
                    {
                        user = new User();
                        user.Email = request.Email;
                        user.Password = hash.Encrypt(request.Password);
                        user.Organization = db.Organizations.Include(x => x.Address).Single(x => x.Name == "Twine");
                        user.Address = user.Organization.Address.Clone();
                        user.Contact = new Contact()
                        {
                            FirstName = authResult.UserInfo.GivenName,
                            LastName = authResult.UserInfo.FamilyName,
                            FullName = authResult.UserInfo.GivenName + " " + authResult.UserInfo.FamilyName,
                            Email = request.Email,
                        };

                        db.UsersRoles.Add(new UsersRole()
                        {
                            User = user,
                            Role = db.Roles.Single(x => (Roles)x.Code == Roles.User),
                        });

                        db.UsersRoles.Add(new UsersRole()
                        {
                            User = user,
                            Role = db.Roles.Single(x => (Roles)x.Code == Roles.MachineStudioUser),
                        });

                        user.Password = hash.Encrypt(request.Password);

                        db.Users.Add(user);
                    }
                    else
                    {
                        if (user.Deleted)
                        {
                            throw new AuthenticationException("Your account has been disabled. Please contact your administrator.");
                        }
                    }

                    user.LastLogin = DateTime.UtcNow;

                    db.SaveChanges();
                }

                dataSource = new DataSource()
                {
                    Address = MachineServiceConfig.DB_ADDRESS,
                    Catalog = MachineServiceConfig.DB_CATALOG,
                    Type = Core.DataSourceType.Azure,
                    IntegratedSecurity = false,
                    UserName = request.Email,
                    Password = request.Password,
                };
            }
            //Login via Database standard user
            else
            {
                var password = hash.Encrypt(request.Password);

                using (var db = ObservablesWebContext.CreateContext())
                {
                    user = new UserBuilder(db).Set(x => x.Email.ToLower() == request.Email.ToLower() && (isPasswordOK || x.Password == password)).WithRolesAndPermissions().WithDeleted().Build();

                    if (user == null)
                    {
                        throw new AuthenticationException("Invalid email or password.");
                    }

                    if (user.Deleted)
                    {
                        throw new AuthenticationException("Your account has been disabled. Please contact your administrator.");
                    }

                    user.LastLogin = DateTime.UtcNow;
                    db.SaveChanges();
                }

                SQLServerManager sqlServer = new SQLServerManager();
                var accessToken = sqlServer.GetAccessToken();

                dataSource = new DataSource()
                {
                    Address = MachineServiceConfig.DB_ADDRESS,
                    Catalog = MachineServiceConfig.DB_CATALOG,
                    Type = Core.DataSourceType.AccessToken,
                    IntegratedSecurity = false,
                    AccessToken = accessToken.AccessToken,
                    AccessTokenExpiration = accessToken.ExpiresOn.UtcDateTime
                };
            }

            //Enforce Machine Studio Version ?
            if (MachineServiceConfig.ENFORCE_MACHINE_STUDIO_VERSION)
            {
                using (var db = ObservablesWebContext.CreateContext())
                {
                    var latest_version = db.MachineStudioVersions.ToList().OrderByDescending(x => Version.Parse(x.Version)).FirstOrDefault();

                    if (latest_version != null && Version.Parse(latest_version.Version) != client_version)
                    {
                        versionChangeRequired = true;
                        requiredVersion = latest_version.Version;
                    }
                }
            }

            //Return data source
            return new LoginResponse()
            {
                DataSource = dataSource,
                AccessToken = WebToken<TokenObject>.CreateNew(MachineServiceConfig.JWT_TOKEN_SECRET, new TokenObject()
                {
                    UserGuid = user.Guid,
                }, DateTime.UtcNow.AddDays(1)).AccessToken,
                VersionChangeRequired = versionChangeRequired,
                RequiredVersion = requiredVersion,
                PasswordChangeRequired = request.Method == LoginMethod.StandardUser && user.PasswordChangeRequired
            };
        }

        [JwtTokenFilter]
        public RefreshTokenResponse RefreshToken(RefreshTokenRequest request)
        {
            SQLServerManager sqlServer = new SQLServerManager();
            var accessToken = sqlServer.GetAccessToken();

            //TokenManager tokenManager = new TokenManager();
            //tokenManager.UpdateToken(request.AccessToken, accessToken.AccessToken, accessToken.ExpiresOn.UtcDateTime);

            return new RefreshTokenResponse()
            {
                AccessToken = accessToken.AccessToken,
                Expiration = accessToken.ExpiresOn.UtcDateTime,
            };
        }

        [HttpPost]
        [JwtTokenFilter]
        public DownloadLatestPPCVersionResponse DownloadLatestPPCVersion(DownloadLatestPPCVersionRequest request)
        {
            DownloadLatestPPCVersionResponse response = new DownloadLatestPPCVersionResponse();

            using (ObservablesContext db = ObservablesWebContext.CreateContext())
            {
                var machine = db.Machines.SingleOrDefault(x => x.SerialNumber == request.SerialNumber);

                if (machine == null)
                {
                    throw new AuthenticationException("The specified serial number could not be found.");
                }

                var machine_version = db.MachineVersions.SingleOrDefault(x => x.Guid == machine.MachineVersionGuid);

                var latest_machine_version = db.TangoVersions.Where(x => x.MachineVersionGuid == machine_version.Guid).ToList().OrderByDescending(x => Version.Parse(x.Version)).FirstOrDefault();

                response.Version = latest_machine_version.Version;

                var manager = new BlobStorageManager();
                var container = manager.GetContainer(MachineServiceConfig.TANGO_VERSIONS_CONTAINER);
                var blob = container.GetBlockBlobReference(latest_machine_version.BlobName);

                response.BlobAddress = blob.GenerateReadSignature(TimeSpan.FromMinutes(60));

                if (!String.IsNullOrWhiteSpace(MachineServiceConfig.CDN_ENDPOINT))
                {
                    response.CdnAddress = MachineServiceConfig.CDN_ENDPOINT + blob.Uri.AbsolutePath;
                }

                DbCredentials credentials = new DbCredentials();

                using (SmoManager smo = new SmoManager())
                {
                    credentials = smo.CreateRandomLoginAndUser();

                    Task.Delay(TimeSpan.FromMinutes(PPCController.SQL_TEMP_CREDENTIALS_EXP_MINUTS)).ContinueWith((x) =>
                    {
                        using (SmoManager m = new SmoManager())
                        {
                            m.DeleteLoginAndUser(credentials.UserName);
                        }
                    });
                }

                response.DataSource = new DataSource()
                {
                    Address = MachineServiceConfig.DB_ADDRESS,
                    Catalog = MachineServiceConfig.DB_CATALOG,
                    UserName = credentials.UserName,
                    Password = credentials.Password,
                    IntegratedSecurity = false,
                    Type = DataSourceType.SQLServer,
                };
            }

            return response;
        }

        #endregion
    }
}