using System;
using System.Data.OracleClient;
using System.Runtime.CompilerServices;
using NLog;

namespace CCSTrace.CCS.Function
{
    public class InitialEventData
    {
        private static readonly Logger Logger = LogManager.GetCurrentClassLogger();

        private string _acceptNum = "";
        private int _caseId = 0;
        private int _mYear = 0;
        private bool _isChangeYear = false;
        private string _nowYear = string.Empty;
        private readonly string _acceptTime = "";
        private readonly OracleConnection _connectionTpc;

        //New CaseID and New AcceptNum must be seen by others,so it need not controled by transaction
        [MethodImpl(MethodImplOptions.Synchronized)]
        public InitialEventData(OracleConnection conn)
        {
            _connectionTpc = conn;

            var sqlStmt = "SELECT ACCEPTNUM,CASEID,YEAR,TO_CHAR(SYSDATE,'YYYY/MM/DD') as ACCEPTTIME FROM EOS.EVENTNUM";

            OracleCommand command = new OracleCommand(sqlStmt, _connectionTpc);
            OracleDataReader reader = command.ExecuteReader();

            try
            {
                if (reader.Read())
                {
                    _acceptNum = reader["ACCEPTNUM"].ToString();
                    _caseId = Convert.ToInt32(reader["CASEID"].ToString());
                    _mYear = Convert.ToInt32(reader["YEAR"].ToString());
                    _acceptTime = reader["ACCEPTTIME"].ToString();
                }
                else
                {
                    Logger.Error("起始號碼資料遺失!");
                    return;
                }
            }
            catch (Exception e)
            {
                Logger.Error(e, "Problems occur when Initializing EventData: " + e.Message);
                return;
            }
            finally
            {
                reader.Close();
                command.Dispose();
            }

            CheckAcceptNum();

            while (!UpdateDataBase(_isChangeYear))
            {
                RegetNumber();
                CheckAcceptNum();
            }
        }

        public int GetNewCaseId()
        {
            return _caseId;
        }

        public string GetNewAcceptNum()
        {
            return _acceptNum;
        }

        private bool UpdateDataBase(bool mChangeYear)
        {
            string sqlStmt;
            bool mResult = false;

            if (mChangeYear)
                sqlStmt = "UPDATE EOS.EVENTNUM SET ACCEPTNUM = '" + (Convert.ToInt32(_acceptNum) + 1) + "',CASEID = "
                        + (_caseId + 1) + ",YEAR = " + _nowYear + " WHERE CASEID = " + _caseId;
            else
                sqlStmt = "UPDATE EOS.EVENTNUM SET ACCEPTNUM = '" + (Convert.ToInt32(_acceptNum) + 1) + "',CASEID = "
                        + (_caseId + 1) + " WHERE CASEID = " + _caseId + " AND ACCEPTNUM = '" + _acceptNum + "'";

            OracleCommand command = new OracleCommand(sqlStmt, _connectionTpc);

            try
            {
                if (command.ExecuteNonQuery() > 0)
                    mResult = true;
            }
            catch (Exception e)
            {
                Logger.Error(e, "Problems occur during EventNumCreating: " + e.Message);
                throw;
            }
            finally
            {
                command.Dispose();
            }

            return mResult;
        }

        private void CheckAcceptNum()
        {
            int nowYear = Convert.ToInt32(_acceptTime.Substring(0, 4)) - 1911;
            int nowMonth = Convert.ToInt32(_acceptTime.Substring(5, 2));
            string tmp = _acceptNum;

            if (Convert.ToInt32(tmp.Substring(0, 3)) == nowYear)
            {
                if (Convert.ToInt32(tmp.Substring(3, 2)) != nowMonth)
                {
                    // 新月份
                    if (nowMonth < 10)
                        _acceptNum = nowYear + "0" + nowMonth + "0001";
                    else
                        _acceptNum = nowYear + nowMonth.ToString() + "0001";
                }
            }
            else
            {
                _acceptNum = nowYear + "010001"; // 新年度
                _nowYear = nowYear.ToString();
                _isChangeYear = true;
            }

            if (!_isChangeYear)
            {
            }
        }

        private void RegetNumber()
        {
            var sqlStmt = "SELECT ACCEPTNUM,CASEID,YEAR FROM EOS.EVENTNUM";
            OracleCommand command = new OracleCommand(sqlStmt, _connectionTpc);
            OracleDataReader reader = command.ExecuteReader();

            try
            {
                if (reader.Read())
                {
                    _acceptNum = reader["ACCEPTNUM"].ToString();
                    _caseId = Convert.ToInt32(reader["CASEID"].ToString());
                    _mYear = Convert.ToInt32(reader["YEAR"].ToString());
                }
            }
            catch (Exception e)
            {
                Logger.Error(e, e.Message);
            }
            finally
            {
                reader.Close();
                command.Dispose();
            }
        }
    }
}