using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Aitex.Core.RT.DataCenter;
using Aitex.Core.RT.DBCore;
using Aitex.Core.RT.Event;
using Aitex.Core.RT.Log;
using Aitex.Core.RT.SCCore;
using Aitex.Core.Util;
using MECF.Framework.Common.Equipment;

namespace Aitex.Core.RT.DataCollection.HighPerformance
{ 

    public class DataRecorderManager : Singleton<DataRecorderManager>
    {
        #region Variables

        /// <summary>
        /// 当前记录器支持的数据类型。
        /// </summary>
        private readonly Type[] _supportedDataTypes =
            { typeof(bool), typeof(double), typeof(float), typeof(int), typeof(ushort), typeof(short) };

        private IDataBase _db;
        private readonly object _lock = new();
        private readonly int _dataRecorderInterval;
        private readonly int _dataRecorderCacheSize;
        private readonly int _dataRecorderCachePeriodMs;
        private string[] _modules = { "Data" };
        private readonly Dictionary<string, Func<object>> _subscribedRecordedDataGetter = new();
        private Dictionary<string, DataRecorderCache> _dictCachePerModule;
        private DateTime _dateOfTableName;
        private IDataRecorderCallback _callback;

        #endregion


        #region Constructors

        public DataRecorderManager()
        {
            _dataRecorderInterval = (SC.ContainsItem("System.DataRecorderInterval")
                ? SC.GetValue<int>("System.DataCollectionInterval")
                : 1000);

            _dataRecorderCacheSize = (SC.ContainsItem("System.DataRecorderCacheSize")
                ? SC.GetValue<int>("System.DataRecorderCacheSize")
                : DataRecorderCache.MIN_CACHE_SIZE);

            _dataRecorderCachePeriodMs = (SC.ContainsItem("System.DataRecorderCachePeriod")
                ? SC.GetValue<int>("System.DataRecorderCachePeriod")
                : DataRecorderCache.MIN_CACHE_PERIOD_MS);
        }

        #endregion

        #region Methods

        public void Initialize(IDataRecorderCallback callback)
        {
            IDataRecorderCallback callback2;
            if (callback != null)
            {
                callback2 = callback;
            }
            else
            {
                IDataRecorderCallback dataCollectionCallback = new DefaultDataRecorderCallback();
                callback2 = dataCollectionCallback;
            }

            _callback = callback2;
            Task.Factory.StartNew(DataRecorderThread);
        }

        public void Initialize(string[] modules, string dbName)
        {
            _callback = new DefaultDataRecorderCallback(dbName);
            if (modules != null && modules.Length != 0 && !string.IsNullOrEmpty(modules[0]))
            {
                _modules = modules;
            }

            Task.Factory.StartNew(DataRecorderThread);
        }

        public void Initialize(string dbName)
        {
            _callback = new DefaultDataRecorderCallback(dbName);
            Task.Factory.StartNew(DataRecorderThread);
        }

        /// <summary>
        /// 立即缓存所有模组的数据。
        /// </summary>
        public void ImmediateCache()
        {
            DoCache();
        }

        private void DataRecorderThread()
        {
            while (true)
            {
                Thread.Sleep(_dataRecorderInterval);
                try
                {
                    CreateCache();

                    // 开始周期性数据采集
                    var lastFlushTime = DateTime.Now;
                    while (true)
                    {
                        Thread.Sleep((int)(_dataRecorderInterval * 0.99));

                        // 跨天，退出循环并创建新表
                        if (DateTime.Now.Date != _dateOfTableName)
                            break;

                        // 立即缓存一次数据
                        DoCache();

                        // 每隔5秒钟将缓存写入数据库
                        if (lastFlushTime.AddSeconds(5) < DateTime.Now)
                        {
                            var ret = Persist();
                            lastFlushTime = DateTime.Now;
                            if (ret < 0) //  插入数据错误，退出
                                break;
                        }
                    }
                }
                catch (Exception ex)
                {
                    LOG.Write(ex, "数据库操作记录发生异常");
                }
            }
        }

        /// <summary>
        /// 扫描<see cref="DataManager"/>，获取所有可记录的数据。
        /// </summary>
        /// <remarks>
        /// 仅数据管理器中注册的数据，且类型为<see cref="bool"/>、<see cref="double"/>、<see cref="float"/>、<see cref="int"/>、<see cref="ushort"/>、<see cref="short"/>的数据支持保存到数据库。
        /// </remarks>>
        private void GetRecordableDataSource()
        {
            var dBRecorderList = DATA.GetDBRecorderList();
            foreach (var item in dBRecorderList)
            {
                if (_subscribedRecordedDataGetter.ContainsKey(item.Key))
                {
                    continue;
                }

                var obj = item.Value();
                if (obj != null)
                {
                    var type = obj.GetType();
                    if (type == typeof(bool) || type == typeof(double) || type == typeof(float) ||
                        type == typeof(int) || type == typeof(ushort) || type == typeof(short))
                    {
                        _subscribedRecordedDataGetter[item.Key] = item.Value;
                    }
                }
            }
        }

        /// <summary>
        /// 创建数据缓存对象。
        /// </summary>
        private void CreateCache()
        {
            lock (_lock)
            {
                GetRecordableDataSource();

                _dictCachePerModule = new();
                Dictionary<string, List<DataHolder>> dictModules = new();

                var defaultModuleName = (_modules.Contains(ModuleName.System.ToString())
                    ? ModuleName.System.ToString()
                    : (_modules.Contains("Data") ? "Data" : _modules[0]));


                if (_subscribedRecordedDataGetter is { Count: > 0 })
                {
                    foreach (var dataName in _subscribedRecordedDataGetter.Keys)
                    {
                        var isAvailableModuleName = false;
                        foreach (var module in _modules)
                        {
                            if (dataName.StartsWith(module + ".") ||
                                dataName.StartsWith("IO." + module + "."))
                            {
                                if (!dictModules.ContainsKey(module))
                                    dictModules[module] = new List<DataHolder>();

                                dictModules[module].Add(new DataHolder(dictModules[module].Count,
                                    dataName, _subscribedRecordedDataGetter[dataName]));
                                isAvailableModuleName = true;
                                break;
                            }
                        }

                        if (!isAvailableModuleName)
                        {

                            if (!dictModules.ContainsKey(defaultModuleName))
                                dictModules[defaultModuleName] = new List<DataHolder>();

                            dictModules[defaultModuleName].Add(new DataHolder(
                                dictModules[defaultModuleName].Count,
                                dataName, _subscribedRecordedDataGetter[dataName]));
                        }
                    }
                }

                _dateOfTableName = DateTime.Now.Date;
                foreach (var module in dictModules.Keys)
                {
                    var dhs = dictModules[module];
                    var tableName = $"{_dateOfTableName:yyyyMMdd}.{module}";
                    _dictCachePerModule[module] =
                        new DataRecorderCache(tableName, module, dhs, minCachePeriodMs: _dataRecorderCachePeriodMs,
                            maxCacheSize: _dataRecorderCacheSize);
                    
                    UpdateTableSchema(tableName, dhs);
                }
            }
        }

        /// <summary>
        /// 立即缓存所有模组的数据。
        /// </summary>
        /// <returns></returns>
        private void DoCache()
        {
            lock (_lock)
            {
                // DO调用ForceCache方法可能发生在当前对象初始化之前，此时_dictCachePerModule为null
                if (_dictCachePerModule == null)
                    return;


                // 立即缓存一次数据
                foreach (var drc in _dictCachePerModule.Values)
                    drc.Cache();
            }
            
        }

        /// <summary>
        /// 缓存写入数据库。
        /// </summary>
        /// <returns>插入数据库的行数。-1 表示写入数据库错误。</returns>
        public int Persist()
        {
            var num = 0;

            lock (_lock)
            {
                foreach (var dcc in _dictCachePerModule.Values)
                {
                    var sql = dcc.GetInsertSql();

                    if (!string.IsNullOrEmpty(sql))
                    {
                        try
                        {
                            num = DB.ExecuteNonQuery(sql);
                        }
                        catch (Exception ex)
                        {
                            LOG.Write(ex, $"{ModuleName.System.ToString()}写入数据库发生异常");
                            num = -1;
                        }
                    }
                }
            }

            return num;
        }

        private bool UpdateTableSchema(string tblName, IEnumerable<DataHolder> dataCollectors)
        {
            var cmdText = $"select column_name from information_schema.columns where table_name = '{tblName}';";
            var reader = DB.ExecuteReader(cmdText);
            var sqlExprAddColumn = string.Empty;
            var existedColumns = new List<string>();
            while (reader.Read())
            {
                for (var i = 0; i < reader.FieldCount; i++)
                {
                    existedColumns.Add(reader[i].ToString());
                }
            }

            reader.Close();
            if (existedColumns.Count > 0)
            {
                foreach (var dataItem in dataCollectors)
                {
                    var colName = dataItem.Name;
                    if (!existedColumns.Contains(colName))
                    {
                        var type = dataItem.Read().GetType();
                        if (type == typeof(bool))
                        {
                            sqlExprAddColumn += $"ALTER TABLE \"{tblName}\" ADD COLUMN \"{colName}\" {"Boolean"};";
                        }
                        else if (_supportedDataTypes.Contains(type))
                        {
                            sqlExprAddColumn += $"ALTER TABLE \"{tblName}\" ADD COLUMN \"{colName}\" {"Real"};";
                        }
                    }
                }

                if (!string.IsNullOrEmpty(sqlExprAddColumn))
                {
                    try
                    {
                        DB.ExecuteNonQuery(sqlExprAddColumn);
                    }
                    catch (Exception ex)
                    {
                        LOG.Write(ex);
                        return false;
                    }
                }
            }
            else
            {
                var sqlExprCreateTable = $"CREATE TABLE \"{tblName}\"(Time bigint NOT NULL,";
                foreach (var dataItem in dataCollectors)
                {
                    var colName = dataItem.Name;
                    var dataType = dataItem.Read().GetType();
                    if (dataType == typeof(bool))
                    {
                        sqlExprCreateTable += $"\"{colName}\" Boolean,\n";
                    }
                    else if (_supportedDataTypes.Contains(dataType))
                    {
                        sqlExprCreateTable += $"\"{colName}\" Real,\n";
                    }
                }

                sqlExprCreateTable += $"CONSTRAINT \"{tblName}_pkey\" PRIMARY KEY (Time));";
                sqlExprCreateTable += $"GRANT SELECT ON TABLE \"{tblName}\" TO postgres;";
                try
                {
                    DB.ExecuteNonQuery(sqlExprCreateTable.ToString());
                }
                catch (Exception ex2)
                {
                    LOG.Write(ex2, "创建数据库表格失败");
                    return false;
                }
            }

            return true;
        }
    }

    #endregion

}