using System.Diagnostics;
using ConsoleApp2.Helpers;
using ConsoleApp2.Services;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;

namespace ConsoleApp2;

public class CsvConversion : BackgroundService
{
    private readonly ILogger _logger;
    private readonly IOptions<CsvOptions> _csvOptions;
    private readonly DataTransformService _transform;
    private readonly TaskManager _taskManager;


    public CsvConversion(ILogger<CsvConversion> logger, 
        IOptions<CsvOptions> csvOptions, 
        DataTransformService transform, 
        TaskManager taskManager)
    {
        _logger = logger;
        _csvOptions = csvOptions;
        _transform = transform;
        _taskManager = taskManager;
    }

    protected override async Task ExecuteAsync(CancellationToken cancellationToken)
    {
        var sw = Stopwatch.StartNew();
        var inputDir = _csvOptions.Value.InputDir;
        _logger.LogInformation("Working dir: {InputDir}", inputDir);
        var files = Directory.GetFiles(inputDir).Where(s => s.EndsWith(".sql") && !s.Contains("schema")).ToArray();
        if (files.Length == 0)
        {
            _logger.LogInformation("No sql files found in {InputDir}", inputDir);
            return;
        }

        foreach(var sqlPath in files)
        {
            _logger.LogInformation("Working sql file: {SqlPath}", sqlPath);
            var headers = await DumpDataHelper.GetCsvHeadersFromSqlFileAsync(sqlPath);
            var csvFiles = await DumpDataHelper.GetCsvFileNamesFromSqlFileAsync(sqlPath);

            var queue = new DataRecordQueue();
            foreach (var csvFile in csvFiles)
            {
                var csvPath = Path.Combine(inputDir, csvFile);
                var source = new JsvSource(csvPath, headers, _logger);

                while (await source.ReadAsync())
                {
                    queue.Enqueue(source.Current);
                }

                if (queue.Count > 200)
                {
                    var queue1 = queue;
                    await _taskManager.CreateTask(async () => await _transform.ExecuteAsync(queue1, cancellationToken));
                    queue = new DataRecordQueue();
                }

                if (cancellationToken.IsCancellationRequested)
                    return;
            }
            
            _logger.LogInformation("File '{File}' input completed", Path.GetFileName(sqlPath));
        }

        _logger.LogInformation("***** Csv input service completed *****");
        _logger.LogInformation("Elapsed: {Elapsed}", sw.Elapsed);
        _taskManager.MainTaskCompleted = true;
    }
}