using ExcelDataReader;
using System;
using System.Collections.Generic;
using System.Data;
using System.IO;

namespace etoy
{
    class CmdReadMetadataTable : Command
    {
        const string SEARCH_PATTERN = "*.metadata";

        ExcelReaderConfiguration _excelReaderConfiguration;

        MetadataTableCsvParser _parser = new MetadataTableCsvParser();

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

        protected override void OnProcess()
        {
            SetProgress(0.1f);

            _excelReaderConfiguration = new ExcelReaderConfiguration() { AutodetectSeparators = new char[] { ',' } };

            var metedatas = Directory.GetFiles(Context.Option.CsvOutput, SEARCH_PATTERN, SearchOption.TopDirectoryOnly);

            if(metedatas.Length > 0)
            {
                List<MetadataTable> metadatas = new List<MetadataTable>();

                SetProgress(0.4f);

                foreach (var metedata in metedatas)
                    ReadSingle(metedata.ToPath(), metadatas);

                SetProgress(0.8f);

                Context.Blackboard.MetadataTables = metadatas;

                Completed();
            }
            else
            {
                SetException(new Exception("找不到Metadata表"));
            }
        }

        void ReadSingle(string file, List<MetadataTable> metadatas)
        {
            using Stream metadata = new FileStream(file, FileMode.Open, FileAccess.Read);

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

            DataSet dataSet = reader.AsDataSet();
            if (dataSet.Tables.Count != 1)
                throw new Exception($"Metadata表 Table数量不为1, {file}");


            DataTable dt = dataSet.Tables[0];
            if (dt == null)
                throw new Exception($"Metadata表 DataTable等于空, {file}");


            MetadataTable table = _parser.Parser(dt, file);

            metadatas.Add(table);

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