/*
 * OCPP.Core - https://github.com/dallmann-consulting/OCPP.Core
 * Copyright (C) 2020-2021 dallmann consulting GmbH.
 * All Rights Reserved.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Http;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;
using OCPP.Core.Database;
using OCPP.Core.Server.Messages_OCPP16;

namespace OCPP.Core.Server
{
    public partial class ControllerOCPP16 : ControllerBase
    {
        /// <summary>
        /// Internal string for OCPP protocol version
        /// </summary>
        protected override string ProtocolVersion
        {
            get { return "16"; }
        }

        /// <summary>
        /// Constructor
        /// </summary>
        public ControllerOCPP16(IConfiguration config, ILoggerFactory loggerFactory, ChargePointStatus chargePointStatus, OCPPCoreContext dbContext) :
            base(config, loggerFactory, chargePointStatus, dbContext)
        {
            Logger = loggerFactory.CreateLogger(typeof(ControllerOCPP16));
        }

        /// <summary>
        /// Processes the charge point message and returns the answer message
        /// </summary>
        public OCPPMessage ProcessRequest(OCPPMessage msgIn)
        {
            OCPPMessage msgOut = new OCPPMessage();
            msgOut.MessageType = "3";
            msgOut.UniqueId = msgIn.UniqueId;

            string errorCode = null;

            switch (msgIn.Action)
            {
                case "BootNotification":
                    errorCode = HandleBootNotification(msgIn, msgOut);
                    break;

                case "Heartbeat":
                    errorCode = HandleHeartBeat(msgIn, msgOut);
                    break;

                case "Authorize":
                    errorCode = HandleAuthorize(msgIn, msgOut);
                    break;

                case "StartTransaction":
                    errorCode = HandleStartTransaction(msgIn, msgOut);
                    break;

                case "StopTransaction":
                    errorCode = HandleStopTransaction(msgIn, msgOut);
                    break;

                case "MeterValues":
                    errorCode = HandleMeterValues(msgIn, msgOut);
                    break;

                case "StatusNotification":
                    errorCode = HandleStatusNotification(msgIn, msgOut);
                    break;

                case "DataTransfer":
                    errorCode = HandleDataTransfer(msgIn, msgOut);
                    break;

                default:
                    errorCode = ErrorCodes.NotSupported;
                    WriteMessageLog(ChargePointStatus.Id, null, msgIn.Action, msgIn.JsonPayload, errorCode);
                    break;
            }

            if (!string.IsNullOrEmpty(errorCode))
            {
                // Inavlid message type => return type "4" (CALLERROR)
                msgOut.MessageType = "4";
                msgOut.ErrorCode = errorCode;
                Logger.LogDebug("ControllerOCPP16 => Return error code messge: ErrorCode={0}", errorCode);
            }

            return msgOut;
        }


        /// <summary>
        /// Processes the charge point message and returns the answer message
        /// </summary>
        public void ProcessAnswer(OCPPMessage msgIn, OCPPMessage msgOut)
        {
            // The response (msgIn) has no action => check action in original request (msgOut)
            switch (msgOut.Action)
            {
                case "Reset":
                    HandleReset(msgIn, msgOut);
                    break;

                case "UnlockConnector":
                    HandleUnlockConnector(msgIn, msgOut);
                    break;

                default:
                    WriteMessageLog(ChargePointStatus.Id, null, msgIn.Action, msgIn.JsonPayload, "Unknown answer");
                    break;
            }
        }

        /// <summary>
        /// Helper function for writing a log entry in database
        /// </summary>
        private bool WriteMessageLog(string chargePointId, int? connectorId, string message, string result, string errorCode)
        {
            try
            {
                int dbMessageLog = Configuration.GetValue<int>("DbMessageLog", 0);
                if (dbMessageLog > 0 && !string.IsNullOrWhiteSpace(chargePointId))
                {
                    bool doLog = (dbMessageLog > 1 ||
                                    (message != "BootNotification" &&
                                     message != "Heartbeat" &&
                                     message != "DataTransfer" &&
                                     message != "StatusNotification"));

                    if (doLog)
                    {
                        MessageLog msgLog = new MessageLog();
                        msgLog.ChargePointId = chargePointId;
                        msgLog.ConnectorId = connectorId;
                        msgLog.LogTime = DateTime.UtcNow;
                        msgLog.Message = message;
                        msgLog.Result = result;
                        msgLog.ErrorCode = errorCode;
                        DbContext.MessageLogs.Add(msgLog);
                        Logger.LogTrace("MessageLog => Writing entry '{0}'", message);
                        DbContext.SaveChanges();
                        return true;
                    }
                }
            }
            catch (Exception exp)
            {
                Logger.LogError(exp, "MessageLog => Error writing entry '{0}'", message);
            }
            return false;
        }
    }
}