using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Data.OracleClient;
using System.IO;
using System.Runtime.CompilerServices;
using System.Threading;
using System.Web;
using System.Xml;
using Amib.Threading;
using CCSTrace.CCS.Domain;
using CCSTrace.CCS.Object;
using NLog;

namespace CCSTrace.CCS
{
    public class CcsMain
    {
        private const string DbConfigFilename = "DBConfig.xml";

        private static Logger _logger = LogManager.GetCurrentClassLogger();
        private static CcsMain _instance;

        public static ArrayList ProcessCases = new ArrayList();
        public static Queue<int> ProcessCaseQueue = new Queue<int>();
        public static Hashtable ProcessFdr = new Hashtable();//Record the processing FDR
        public static ArrayList WaitingCases = new ArrayList();//Record the case when the case's FDR processed by another

        private int _connectionCount = 1;
        private OracleConnection _mainConn = null;
        private SEventLog _mainLog = null;

        private SmartThreadPool _mainjobThreadPool = null;
        private readonly object _syncDbQueue = new object();
        private readonly Queue<OracleConnection> _dbQueue = new Queue<OracleConnection>();

        public CcsMain()
        {
            _mainjobThreadPool = new SmartThreadPool();
            // Startup();
        }

        public string AppDataPath { get; set; }

        public static CcsMain Instance()
        {
            // Uses lazy initialization.

            // Note: this is not thread safe.

            if (_instance == null)
            {
                _instance = new CcsMain();
            }
            return _instance;
        }

        public void Startup()
        {
            _mainLog = new SEventLog();

            try
            {
                ReadXml();

                if (_mainConn == null)
                    _mainConn = CreateConnection();
                //MainConn = CreateMainConnection();

                GlobalVariable.CcsCodelist = new CcsCodelist(_mainConn);
                GlobalVariable.EosCodelist = new EosCodelist(_mainConn);

                for (int i = 0; i < _connectionCount; i++)
                {
                    lock (_syncDbQueue) _dbQueue.Enqueue(CreateConnection());
                }
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
                Console.WriteLine(e.StackTrace);
                _mainLog.Error(e.Message);

                if (GlobalVariable.ShowError)
                    _mainLog.Error(e.StackTrace);

                throw;
            }
            finally
            {
                _mainLog.Close();
            }

            CcsRecord mRecord = GetWaitRecord(_mainConn);

            if (mRecord != null)
            {
                OracleConnection conn = null;
                lock (_syncDbQueue) conn = _dbQueue.Dequeue();
                ProcessCase(mRecord, conn);
            }

            STPStartInfo stpStartInfo = new STPStartInfo();
            stpStartInfo.IdleTimeout = GlobalVariable.IdleTimeout * 1000;
            stpStartInfo.MaxWorkerThreads = GlobalVariable.MaxThreadSize;
            stpStartInfo.MinWorkerThreads = GlobalVariable.MinThreadSize;
            _mainjobThreadPool = new SmartThreadPool(stpStartInfo);
        }

        public void Shutdown()
        {
            _mainjobThreadPool.Shutdown(true, 1000);
            _mainjobThreadPool.Dispose();
            _mainjobThreadPool = null;
            GC.Collect();
            GC.WaitForPendingFinalizers();
        }
        public void AcceptEvent(CcsRecord record)
        {
            int i = 0;
            int reConnectCount = 1;

            while (i <= reConnectCount)
            {
                try
                {
                    if (InsertEventRecord(record, _mainConn))
                    {
                        if (_dbQueue.Count > 0)
                        {
                            //將EVETNQUERY的案件狀態改為開始處理
                            CcsRecord mRecord = GetWaitRecord(_mainConn);

                            if (mRecord != null)
                            {
                                OracleConnection conn = _dbQueue.Dequeue();
                                ProcessCase(mRecord, conn);
                            }
                        }

                        break;
                    }
                }
                catch (Exception)
                {
                    if (_mainConn.State == ConnectionState.Closed)
                    {
                        i++;
                        if (i > reConnectCount)
                            throw;
                    }
                    else
                        throw;
                }
            }
        }

        private void ReadXml()
        {
            XmlReader reader = null;

            try
            {
                string file = Path.Combine(AppDataPath, DbConfigFilename);
                // 建立 XML 讀取器
                XmlReaderSettings settings = new XmlReaderSettings();
                settings.IgnoreComments = true; // 不處理註解
                settings.IgnoreWhitespace = true; // 跳過空白
                settings.ValidationType = ValidationType.None; // 不驗證任何資料
                reader = XmlReader.Create(file, settings);

                // 進入讀取主要部分
                while (reader.Read())
                {
                    switch (reader.NodeType)
                    {
                        case XmlNodeType.Element:
                            string localName = reader.LocalName; // 取得標籤名稱

                            // Step 3: 讀取 FileInfo 標籤的屬性
                            if (localName.Equals("DBSetting"))
                            {
                                GlobalVariable.ConnectionString =
                                    $"Data source={reader["DataSource"]};User Id={reader["UserId"]};Password={reader["Password"]};";
                                GlobalVariable.TraceConnectionString =
                                    $"{reader["UserId"]}/{reader["Password"]}@{reader["DataSource"]}";
                                string token = reader["ConnectionCount"];
                                if (token != null)
                                {
                                    GlobalVariable.MaxConnectionCount = int.Parse(token);
                                }
                                token = reader["ShowError"];
                                if (token != null)
                                {
                                    GlobalVariable.ShowError = bool.Parse(token);
                                }
                            } else if (localName.Equals("ThreadSetting"))
                            {
                                string token = reader["maxThreadSize"];
                                if (token != null)
                                {
                                    GlobalVariable.MaxThreadSize = int.Parse(token);
                                }
                                token = reader["minThreadSize"];
                                if (token != null)
                                {
                                    GlobalVariable.MinThreadSize = int.Parse(token);
                                }
                            }

                            break;
                    }
                }
                reader.Close();
            }
            catch (XmlException xe)
            {
                Console.WriteLine(xe.StackTrace);
                reader?.Close();
            }
        }

        private OracleConnection CreateConnection()
        {
            OracleConnection dbConn = new OracleConnection(GlobalVariable.ConnectionString);

            dbConn.Open();

            return dbConn;
        }

        [MethodImpl(MethodImplOptions.Synchronized)]
        private bool InsertEventRecord(CcsRecord record, OracleConnection conn)
        {
            OracleTransaction transaction = null;

            try
            {
                _mainLog = new SEventLog();

                if (conn.State.ToString().Equals("Closed"))
                    conn.Open();

                transaction = conn.BeginTransaction();

                if (record.InsertDb(conn, transaction, _mainLog))
                {
                    var eventQuery = new EventQuery
                    {
                        CcsId = record.CcsId,
                        Meter = record.Meter,
                        CaseStatus = (int) CCSCaseState.EventInitial,
                        ChangeTime = record.AcceptTime
                    };


                    if (eventQuery.Insert(_mainLog, conn, transaction))
                        transaction.Commit();
                    else
                    {
                        if (transaction.Connection.State.ToString().Equals("Open"))
                            transaction.Rollback();

                        throw new Exception("案件未受理成功。");
                    }
                }
                else
                {
                    if (transaction.Connection.State.ToString().Equals("Open"))
                        transaction.Rollback();

                    throw new Exception("案件未受理成功。");
                }
            }
            catch (OracleException e)
            {
                Console.WriteLine(e.Message);
                Console.WriteLine(e.StackTrace);
                _mainLog.Error(e.Message);

                if (GlobalVariable.ShowError)
                    _mainLog.Error(e.StackTrace);

                if (transaction != null && transaction.Connection.State.ToString().Equals("Open"))
                    transaction.Rollback();

                throw;
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
                Console.WriteLine(ex.StackTrace);
                _mainLog.Error(ex.Message);

                if (GlobalVariable.ShowError)
                    _mainLog.Error(ex.StackTrace);

                if (transaction != null && transaction.Connection.State.ToString().Equals("Open"))
                    transaction.Rollback();

                throw;
            }
            finally
            {
                _mainLog.Close();
            }

            return true;
        }

        private delegate void WorkerThreadHandler();

        private void ProcessCase(CcsRecord record, OracleConnection conn)
        {
            try
            {
                if (conn.State.ToString().Equals("Closed"))
                    conn.Open();

                ProcessEvent processEvent = new ProcessEvent(record, conn, GlobalVariable.TraceConnectionString);
                processEvent.ThreadFinish += ThreadEndEventProcess;

                ThreadStart threadStart = processEvent.Run;
                Thread thread = new Thread(threadStart);
                thread.Start();
            }
            catch
            {
                lock (_syncDbQueue) _dbQueue.Enqueue(conn);
            }
        }

        private void ThreadEndEventProcess(object sender, ThreadEndEvent e)
        {
            //將EVETNQUERY的案件狀態改為開始處理
            CcsRecord mRecord = GetWaitRecord(e.GetConnection());

            try
            {
                if (mRecord != null)
                    ProcessCase(mRecord, e.GetConnection());
            }
            finally 
            {
                lock (_syncDbQueue) _dbQueue.Enqueue(e.GetConnection());
            }
        }

        [MethodImpl(MethodImplOptions.Synchronized)]
        private CcsRecord GetWaitRecord(OracleConnection conn)
        {
            string processCcsid = "";
            string ccsid = "";
            CcsRecord record = null;

            foreach (string[] obj in WaitingCases)
            {
                string ccsId = obj[0];
                string fdrid = obj[1];

                if (ProcessFdr.ContainsKey(fdrid)) //該條饋線仍有案件在處理中
                    processCcsid = processCcsid + "'" + ccsid + "',";
                else
                {
                    ccsid = ccsId;
                    WaitingCases.Remove(obj);
                    break;
                }
            }

            if (ccsid.Length == 0)  //沒有因同饋線而在等候中的案件
            {
                string sqlStmt = "SELECT Q.CCSID AS CCSID FROM CCS.EVENTQUERY Q,CCS.EVENTRECORD R WHERE Q.CASESTATUS IN (" + (int) CCSCaseState.EventInitial + "," + (int) CCSCaseState.EventProcess + ")";
                IEnumerator Enum = ProcessCases.GetEnumerator();

                while (Enum.MoveNext())
                    if (Enum.Current != null) processCcsid = processCcsid + "'" + Enum.Current + "',";

                if (processCcsid.Length != 0)
                    sqlStmt = sqlStmt + " AND Q.CCSID NOT IN (" + processCcsid.Substring(0, processCcsid.Length - 1) + ")";

                sqlStmt = sqlStmt + " AND Q.CCSID = R.CCSID AND ROWNUM < 2 ORDER BY Q.ChangeTime";
                OracleCommand command = new OracleCommand(sqlStmt, conn);
                OracleDataReader reader = command.ExecuteReader();

                try
                {
                    if (reader.Read())
                        ccsid = reader["CCSID"].ToString();
                }
                catch (Exception e)
                {
                    Log(e.Message);
                    _mainLog.Error("無法取得等候處理CCS案件資料。錯誤訊息 = " + e.Message);

                    if (GlobalVariable.ShowError)
                        _mainLog.Error(e.StackTrace);
                }
                finally
                {
                    reader.Close();
                    command.Dispose();
                }
            }

            if (ccsid.Length != 0)
                record = new CcsRecord(ccsid, conn, _mainLog);

            if (record != null)
            {
                EventQuery eventQuery = new EventQuery();
                //先將EVETNQUERY的案件狀態改為開始處理
                eventQuery.CcsId = record.CcsId;
                eventQuery.CaseStatus = (int) CCSCaseState.EventProcess;

                OracleTransaction transaction = conn.BeginTransaction();

                try
                {
                    if (eventQuery.UpdateCaseStatus(_mainLog, conn, transaction))
                    {
                        _mainLog.Info("更新EVENTQUERY的案件狀態為處理中.(CCSID = " + record.CcsId + ")");
                        transaction.Commit();
                        ProcessCases.Add(record.CcsId);
                    }
                    else
                    {
                        _mainLog.Error("無法更新EVENTQUERY的案件狀態.(CCSID = " + record.CcsId + ")");

                        if (transaction.Connection.State.ToString().Equals("Open"))
                            transaction.Rollback();
                    }
                }
                catch (Exception e)
                {
                    if (transaction.Connection.State.ToString().Equals("Open"))
                        transaction.Rollback();

                    Log(e.Message);
                    record = null;
                }
            }

            return record;
        }

        private void Log(string message)
        {
            RecordLog pLog = null;
            try
            {
                pLog = new RecordLog(GlobalVariable.CcsListPath + "MAIN.txt");
                pLog.Error(message);
            }
            finally
            {
                if (pLog != null)
                {
                    pLog.Close();
                }
            }
        }
    }
}