using Microsoft.AspNet.SignalR;
using Microsoft.AspNet.SignalR.Hubs;
using Microsoft.AspNet.SignalR.Owin;
using System.Collections.Generic;
using System.Linq;
using System.Security.Claims;
using System.Security.Principal;
using Thermo.Active.Config;
using Thermo.Active.Database.Controllers;
using Thermo.Active.Model.DatabaseModels;
using static Thermo.Active.Config.ServerConfig;
using static Thermo.Active.Listeners.SignalRStaticObjects;
using static Thermo.Active.Model.Constants;

namespace Thermo.Active.Attributes
{
    public class SignalRAuthorizeAttribute : AuthorizeAttribute
    {
        public string FunctionAccess;
        public ACTIONS Action;

        public override bool AuthorizeHubConnection(HubDescriptor hubDescriptor, IRequest request)
        {
            string token = request.QueryString["Authorization"];

            using (SessionsController sessionsController = new SessionsController())
            {
                // Find user session on this machine
                SessionModel session = sessionsController.FindSessionByToken(token);
                if (session == null)
                    return false;
            }

            return base.AuthorizeHubConnection(hubDescriptor, request);
        }

        public override bool AuthorizeHubMethodInvocation(IHubIncomingInvokerContext hubIncomingInvokerContext, bool appliesToMethod)
        {
            var connectionId = hubIncomingInvokerContext.Hub.Context.ConnectionId;
            var request = hubIncomingInvokerContext.Hub.Context.Request;
            var token = request.QueryString.Get("Authorization");
            if (!string.IsNullOrEmpty(token))
            {
                // check authorization
                if (!CheckAuthorization(FunctionAccess, token, out int machineId, out int userId))
                    return false;

                var claims = new ClaimsIdentity(AUTHENTICATION_TYPE);
                claims.AddClaim(new Claim(USER_ID_KEY, userId.ToString()));
                claims.AddClaim(new Claim(MACHINE_ID_KEY, machineId.ToString()));

                Dictionary<string, object> _DCI = new Dictionary<string, object>();
                _DCI.Add("server.User", claims as IPrincipal);
                hubIncomingInvokerContext.Hub.Context = new HubCallerContext(new ServerRequest(_DCI), connectionId);
                return true;
            }
            return false;
        }


        private bool CheckAuthorization(string functionName, string token, out int machineId, out int userId)
        {
            machineId = userId = 0;
            using (SessionsController sessionsController = new SessionsController())
            {
                // Find user session on this machine
                SessionModel session = sessionsController.FindSessionByToken(token);
                if (session == null)
                    return false;

                // Check if the machine is the same where the user logged in
                if (session.MachineUser.MachineId != MachineConfig.MachineId)
                    return false;

                machineId = session.MachineUser.MachineId;
                userId = session.MachineUser.UserId;

                MachineUserModel machineUser = new MachineUserModel();
                using (MachinesUsersController machineUsersController = new MachinesUsersController())
                {
                    // Find machineUser data and joined to user data, role data, machine data 
                    machineUser = machineUsersController.FindByIdWithData(session.MachineUserId);
                }

                using (FunctionsAccessController acController = new FunctionsAccessController())
                {
                    // Read from db function levels
                    FunctionAccessModel functionAccess = acController.FindEnabledFunctionByName(functionName);
                    if (functionAccess != null && ServerConfigController.CheckAreaStatus(functionAccess.Area))
                    {
                        if (Action == ACTIONS.READ)
                        {   // Check read permissions 
                            if (functionAccess.ReadLevelMin > machineUser.Role.Level)
                                return false; // Not authorized
                        }
                        else
                        {   // Check write permissions
                            if (functionAccess.WriteLevelMin > machineUser.Role.Level)
                                return false; // Not authorized
                        }

                        // Check if PLC bit exists
                        if (functionAccess.PlcId != 0)
                        {
                            // Check if functionality is enabled by PLC
                            var functionalityIsEnabled = LastRuntimeFunctionality.Where(x => x.Name == functionName).FirstOrDefault();
                            if (functionalityIsEnabled == null || functionalityIsEnabled.Enabled == false)
                                return false;
                        }
                    }
                    else
                        return false;

                    // Authorized
                    return true;
                }
            }
        }
    }
}