using ExcelDataReader;
using System.Collections.Concurrent;
using System.Data;

namespace etoy
{
    class CmdReadCommonTable : Command
    {
        const string SEARCH_PATTERN = "*.csv";

        ConcurrentQueue<DataTableWrapper> _waitingParses = new ConcurrentQueue<DataTableWrapper>();
        ConcurrentQueue<Table> _parseDones = new ConcurrentQueue<Table>();
        ExcelReaderConfiguration _excelReaderConfiguration;
        ConcurrentQueue<ErrorData> _errorConfigs = new ConcurrentQueue<ErrorData>();
        CommonTableCsvParser _parser = new CommonTableCsvParser();

        object _locker = new object();
        int _totalCount;
        public int TotalCount
        {
            get { lock (_locker) return _totalCount; }
            set { lock (_locker) _totalCount = value; }
        }


        public override string Description => "读取Common表";

        protected override void OnProcess()
        {
            var csvs = Directory.GetFiles(Context.Option.CsvOutput, SEARCH_PATTERN, SearchOption.TopDirectoryOnly);
            if (csvs.Length <= 0)
                throw new Exception($"{Context.Option.CsvOutput} 没有*.csv文件...");
            TotalCount = csvs.Length;

            _excelReaderConfiguration = new ExcelReaderConfiguration() { AutodetectSeparators = new char[] { ',' } };
            _parseDones.Clear();
            _waitingParses.Clear();

            foreach (var file in csvs)
                Task.Factory.StartNew(OnThreadIO, file.ToPath());

            Task.Factory.StartNew(OnThreadParse);
        }


        void OnThreadParse()
        {
            while (_parseDones.Count < TotalCount)
            {
                while (_waitingParses.TryDequeue(out var wrapper))
                {
                    try
                    {
                        var table = _parser.Parse(wrapper.Table, wrapper.Path);
                        _parseDones.Enqueue(table);

                        SetProgress(_parseDones.Count / (float)TotalCount);
                    }
                    catch (Exception e)
                    {
                        TotalCount--;
                        _errorConfigs.Enqueue(new ErrorData() { Exception = e, Path = wrapper.Path });
                    }
                }
                Thread.Sleep(5);
            }

            if (_errorConfigs.Count > 0)
            {
                SetException(new Exception(string.Join('\n', (from e in _errorConfigs select $"## ERROR: {e}").ToArray())));
            }
            else
            {
                while (_parseDones.TryDequeue(out var table))
                    Context.Blackboard.Tables.Add(table);

                // 排序一下
                Context.Blackboard.Tables.Sort((a, b) => a.Name.CompareTo(b.Name));

                Completed();
            }
        }

        void OnThreadIO(object state)
        {
            try
            {
                ReadSingle(state as string);
            }
            catch (Exception e)
            {
                TotalCount--;
                _errorConfigs.Enqueue(new ErrorData() { Exception = e, Path = state as string });
            }
        }

        void ReadSingle(string file)
        {
            using Stream csv = new FileStream(file, FileMode.Open, FileAccess.Read);

            IExcelDataReader reader = ExcelReaderFactory.CreateCsvReader(csv, _excelReaderConfiguration);

            DataSet dataSet = reader.AsDataSet();

            foreach (DataTable dt in dataSet.Tables)
            {
                _waitingParses.Enqueue(new DataTableWrapper()
                {
                    Table = dt,
                    Path = file,
                });
            }

            csv.Close();
            reader.Close();
            reader.Dispose();
        }

        struct DataTableWrapper
        {
            public DataTable Table;
            public string Path;
        }

        struct ErrorData
        {
            public Exception Exception;
            public string Path;

            public override string ToString()
            {
                return $"{Exception?.Message} {Path}";
            }
        }

    }
}