using ConsoleApp2.Helpers;
using Microsoft.Extensions.Logging;
using System.IO;
using System.Text.RegularExpressions;
using ZstdSharp;
namespace ConsoleApp2.Services
{
    public class ZstSource : CsvSource
    {
        public ZstSource(string inputDir, string tableName, string delimiter = ",", char quoteChar = '"',
        ILogger? logger = null) : base(inputDir, tableName, delimiter = ",", quoteChar = '"', logger = null)
        {
            //throw new Exception("aaa");
            string pattern = $"^.*\\.{tableName}\\..*\\.sql.zst$";
             _sqlFilePath = Directory.GetFiles(_inputDir).FirstOrDefault(s => Regex.Match(s, pattern).Success);

        }
        private async Task<string> DecompressFile(string filePath)
        {
            using (var input = File.OpenRead(filePath))
            {
                using (var decopress = new DecompressionStream(input))
                {

                    var ms = new MemoryStream();
                    decopress.CopyTo(ms);
                    ms.Seek(0, SeekOrigin.Begin);
                    StreamReader reader = new StreamReader(ms);
                    var text = await reader.ReadToEndAsync();
                    return text;

                }
            }
        }
        public override async Task<string[]> GetHeaders()
        {
            var text = await DecompressFile(_sqlFilePath);
            return await DumpDataHelper.GetCsvHeadersFromSqlFileAsync(text);

        }
        public override async Task<string[]> GetCsvFiles()
        {
            var text = await DecompressFile(_sqlFilePath);
            return await DumpDataHelper.GetCsvFileNamesFromSqlFileAsync(text, new Regex(@"'.+\.dat.zst'"));
        }
        public override async Task DoEnqueue(Action<DataRecord> action)
        {
            var sourceFiles = await GetCsvFiles();
            var headers = await GetHeaders();
            foreach (var file in sourceFiles)
            {
                var filePath = Path.Combine(_inputDir, file);
                using (var input = File.OpenRead(filePath))
                {
                    using (var decopress = new DecompressionStream(input))
                    {

                        var ms = new MemoryStream();
                        decopress.CopyTo(ms);
                        ms.Seek(0, SeekOrigin.Begin);
                        StreamReader reader = new StreamReader(ms);
                        while (!reader.EndOfStream) 
                        {
                            var line = await reader.ReadLineAsync();
                            var fields = ParseRow2(line, QuoteChar, Delimiter);
                            var record = new DataRecord(fields, _tableName, headers);
                            action?.Invoke(record);
                        }
                    }
                }
                //var headers = await GetHeaders();
                //using (StreamReader sr = new StreamReader(file))
                //{
                //    while (!sr.EndOfStream)
                //    {
                //        var line = await sr.ReadLineAsync();
                //        var fields = ParseRow2(line, QuoteChar, Delimiter);
                //        var record = new DataRecord(fields, _tableName, headers);
                //        action?.Invoke(record);
                //    }
                //}
            }
        }
        public override async Task<DataRecord?> GetTestRecord()
        {
            var sourceFiles = await GetCsvFiles();
            var file = sourceFiles.FirstOrDefault();
            if (file != null)
            {
                var headers = await GetHeaders();
                var filePath = Path.Combine(_inputDir, file);
                using (var input = File.OpenRead(filePath))
                {
                    using (var decopress = new DecompressionStream(input))
                    {

                        var ms = new MemoryStream();
                        decopress.CopyTo(ms);
                        ms.Seek(0, SeekOrigin.Begin);
                        StreamReader reader = new StreamReader(ms);
                        var line = await reader.ReadLineAsync();
                        var fields = ParseRow2(line, QuoteChar, Delimiter);
                        var record = new DataRecord(fields, _tableName, headers);
                        return record;

                    }
                }
                //using (var fs = File.OpenRead(filePath))
                //{
                //    using (StreamReader sr = new StreamReader(fs))
                //    {
                //        var line = await sr.ReadLineAsync();
                //        var fields = ParseRow2(line, QuoteChar, Delimiter);
                //        var record = new DataRecord(fields, _tableName, headers);
                //        return record;
                //    }
                //}
            }
            return null;
        }
        public void Dispose()
        {
            //_reader.Dispose();
        }
    }
}