using Events.FilesAPI.Infrastructure.Options;
using Events.WebAPI.Handlers.EF.Data.Postgres;
using Events.WebAPI.Handlers.EF.Models;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Options;

namespace Events.FilesAPI.Features.RegistrationsExcel.Synchronize;

public sealed class RegistrationsExcelFileGenerator(
  EventsContext context,
  IHostEnvironment hostEnvironment,
  IOptions<GeneratedFilesOptions> generatedFilesOptions,
  ILogger<RegistrationsExcelFileGenerator> logger)
{
  public async Task GenerateAsync(int eventId, CancellationToken cancellationToken)
  {
    var registrations = context.Set<Registration>()
      .AsNoTracking()
      .Where(r => r.EventId == eventId)
      .OrderBy(r => r.Person.LastName)
      .ThenBy(r => r.Person.FirstName)
      .ThenBy(r => r.Sport.Name)
      .Select(r => new EventRegistrationsExcelWriter.RowData
      {
        RegistrationId = r.Id,
        RegisteredAt = r.RegisteredAt,
        PersonId = r.PersonId,
        FirstName = r.Person.FirstName,
        LastName = r.Person.LastName,
        FirstNameTranscription = r.Person.FirstNameTranscription,
        LastNameTranscription = r.Person.LastNameTranscription,
        CountryName = r.Person.CountryCodeNavigation.Name,
        SportName = r.Sport.Name
      });

    string excelPath = GetPath(eventId);
    EventRegistrationsExcelWriter.RowData? firstRow = await registrations.FirstOrDefaultAsync(cancellationToken);
    if (firstRow == null)
    {
      DeleteFileIfExists(excelPath);
      return;
    }

    Directory.CreateDirectory(Path.GetDirectoryName(excelPath)!);
    await EventRegistrationsExcelWriter.WriteAsync(excelPath, registrations, firstRow, cancellationToken);

    logger.LogInformation(
      "Event registrations Excel generated for event #{EventId} at {Path}",
      eventId,
      excelPath);
  }

  private string GetPath(int eventId)
  {
    string rootPath = Path.IsPathRooted(generatedFilesOptions.Value.OutputPath)
      ? generatedFilesOptions.Value.OutputPath
      : Path.GetFullPath(Path.Combine(hostEnvironment.ContentRootPath, generatedFilesOptions.Value.OutputPath));

    return Path.Combine(rootPath, $"{eventId}.xlsx");
  }

  private void DeleteFileIfExists(string path)
  {
    if (!File.Exists(path))
      return;

    File.Delete(path);
    logger.LogInformation("Event registrations Excel deleted at {Path}", path);
  }
}