using System;
using System.Linq;
using System.Security.Claims;
using System.Security.Principal;
using Microsoft.AspNet.SignalR;
using Step.Config;
using Step.Database.Controllers;
using Step.Model.DatabaseModels;
using static Step.Utils.Constants;
using static Step.Config.ServerConfig;

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

        protected override bool UserAuthorized(IPrincipal user)
        {
            if (!base.UserAuthorized(user))
                return false;

            // Get user level stored in the bearer token   
            ClaimsIdentity identity = user.Identity as ClaimsIdentity;
            var userRoleLevel = identity.Claims.Where(c => c.Type == ROLE_LEVEL_KEY).SingleOrDefault();

            // Get machine unique id stored in the bearer token
            var machineUniqueId = identity.Claims.Where(c => c.Type == MACHINE_ID_KEY).SingleOrDefault();

            // User data not found -> not authorized
            if (userRoleLevel == null || machineUniqueId == null)
                return false;

            // check authorization
            if (!CheckAuthorization(machineUniqueId.ToString(), Convert.ToInt32(userRoleLevel.Value), FunctionAccess))
                return false;

            return true;
        }

        private bool CheckAuthorization(string machineUniqueId, int userLevel, string functionName)
        {
            using (FunctionAccessController acController = new FunctionAccessController())
            {
                // Check if the machine is the same where the user logged in
                if (machineUniqueId != MachineConfig.UniqueId)
                    return false;

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

            // Authorized
            return true;
        }
    }
}