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.Authentication;
using Tango.Web.ActiveDirectory;
using Tango.MachineService.Filters;

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

        public static TokensManager<String> TokensManager { get; set; }

        #region Constructors

        /// <summary>
        /// Initializes the <see cref="MachineStudioController"/> class.
        /// </summary>
        static MachineStudioController()
        {
            TokensManager = new TokensManager<string>();
            TokensManager.ExpirationTime = TimeSpan.FromDays(10);
            _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]
        [MachineStudioLoginFilter]
        public CheckForUpdatesResponse CheckForUpdates(CheckForUpdatesRequest request)
        {
            LogManager.Log("Request received...");

            CheckForUpdatesResponse response = new CheckForUpdatesResponse();

            using (ObservablesContext db = ObservablesContextHelper.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 StorageManager();
                    var container = manager.GetContainer(MachineServiceConfig.MACHINE_STUDIO_VERSIONS_CONTAINER);
                    var blob = container.GetBlockBlobReference(latestVersion.BlobName);

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

                    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]
        [MachineStudioLoginFilter]
        public DownloadLatestVersionResponse DownloadLatestVersion(DownloadLatestVersionRequest request)
        {
            LogManager.Log("Request received...");

            DownloadLatestVersionResponse response = new DownloadLatestVersionResponse();

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

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

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

                    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]
        [MachineStudioLoginFilter]
        public UploadVersionResponse UploadVersion(UploadVersionRequest request)
        {
            UploadVersionResponse response = new UploadVersionResponse();

            using (ObservablesContext db = ObservablesContextHelper.CreateContext())
            {
                //Load relation first...
                db.Roles.ToList();
                db.Permissions.ToList();
                db.UsersRoles.ToList();
                db.RolesPermissions.ToList();

                String userID = TokensManager.GetTokenObject(request.AccessToken);

                var user = db.Users.SingleOrDefault(x => x.Guid == userID);

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

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

                        var manager = new StorageManager();
                        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));

                        _pendingUploads.Add(new MachineStudioPendingUpload()
                        {
                            UserGuid = user.Guid,
                            Comments = request.Comments,
                            Token = response.Token,
                            Version = request.Version,
                            BlobName = blob.Name,
                        });
                    }
                    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]
        [MachineStudioLoginFilter]
        public UploadCompletedResponse NotifyUploadCompleted(UploadCompletedRequest request)
        {
            MachineStudioPendingUpload upload = _pendingUploads.FirstOrDefault(x => x.Token == request.Token);

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

                using (ObservablesContext db = ObservablesContextHelper.CreateContext())
                {
                    db.MachineStudioVersions.Add(new MachineStudioVersion()
                    {
                        Comments = upload.Comments,
                        BlobName = upload.BlobName,
                        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 = ObservablesContextHelper.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)
        {
            var authResult = _ad_manager.ValidateUserCredentials(request.Email, request.Password);

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

            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;

            User user = null;

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

                user = db.Users.SingleOrDefault(x => x.Email.ToLower() == request.Email.ToLower());

                IHashGenerator g = new BasicHashGenerator();

                if (user == null)
                {
                    //Than add the user !!
                    User new_user = new User();
                    new_user.Email = request.Email;
                    new_user.Password = g.Encrypt(request.Password);
                    new_user.Organization = db.Organizations.Include(x => x.Address).Single(x => x.Name == "Twine");
                    new_user.Address = new_user.Organization.Address.Clone();
                    new_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 = new_user,
                        Role = db.Roles.Single(x => (Roles)x.Code == Roles.User),
                    });

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

                    new_user.LastLogin = DateTime.UtcNow;
                    db.Users.Add(new_user);
                }
                else
                {
                    user.LastLogin = DateTime.UtcNow;
                    user.Password = g.Encrypt(request.Password);
                }

                db.SaveChanges();

                if (MachineServiceConfig.ENFORCE_MACHINE_STUDIO_VERSION)
                {
                    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 new LoginResponse()
            {
                DataSource = new Core.DataSource()
                {
                    Address = MachineServiceConfig.DB_ADDRESS,
                    Catalog = MachineServiceConfig.DB_CATALOG,
                    Type = Core.DataSourceType.Azure,
                    IntegratedSecurity = false,
                    UserName = request.Email,
                    Password = request.Password,
                },

                AccessToken = TokensManager.GetOrCreate(user.Guid),
                VersionChangeRequired = versionChangeRequired,
                RequiredVersion = requiredVersion,
            };
        }

        #endregion
    }
}