using System;
using System.Threading.Tasks;
using Microsoft.Owin.Security.OAuth;
using Step.Database.Controllers;
using Step.Model.DatabaseModels;
using System.Security.Claims;
using static Step.Utils.Constants;
using static Step.Config.ServerConfig;

namespace Step.Provider
{
    public class ApplicationOAuthProvider : OAuthAuthorizationServerProvider
    {
       public override async Task ValidateClientAuthentication(OAuthValidateClientAuthenticationContext context)
        {
            // Validate client
            context.Validated();
        }

        public override async Task GrantResourceOwnerCredentials(OAuthGrantResourceOwnerCredentialsContext context)
        {
            using (UsersController usersController = new UsersController())
            {
                try
                {
                    // Check if credentials are correct
                    UserModel user = usersController.FindByUsernameAndPassword(context.UserName, context.Password);
                    // If not
                    if (user == null)
                    {
                        // Return 401
                        context.SetError("invalid_grant", "The user name or password is incorrect.");
                        return;
                    }
                    // Create a new Identity and insert custom claims
                    var identity = new ClaimsIdentity(context.Options.AuthenticationType);

                    // Add claims to token
                    identity.AddClaim(new Claim(USER_ID_KEY, user.UserId.ToString()));

                    using (MachinesUsersController machinesUsersController = new MachinesUsersController())
                    {
                        // Check if user can access to the machine
                        MachinesUsersModel machineUser = machinesUsersController.FindByUserId(MachineConfig.MachineId, user.UserId);

                        if (machineUser == null)
                        {
                            // Return 401 bad request
                            context.SetError("invalid_grant", "User has no access to this machine");
                            return;
                        }

                        // Find machine unique id
                        using (MachineController machineController = new MachineController())
                        {
                            MachineModel machineModel = machineController.GetMachineById(machineUser.MachineId);
                            // Add machine id 
                            identity.AddClaim(new Claim(MACHINE_ID_KEY, machineModel.UniqueId));
                        }

                        // Add Role level key id
                        identity.AddClaim(new Claim(ROLE_LEVEL_KEY, machineUser.Role.Level.ToString()));
                    }

                    // Create Token with identity data
                    context.Validated(identity);

                    await base.GrantResourceOwnerCredentials(context);

                    return;
                }
                catch (Exception ex)
                {
                    // Return 401 bad request
                    context.SetError("invalid_grant", ex.Message);
                    return;
                }
               
            }
        }
    }
}