using Microsoft.EntityFrameworkCore.Storage;

namespace GamificationService.Database.UnitOfWork;

public class UnitOfWork : IUnitOfWork
{
    #region Fields
    private readonly ApplicationContext _context;
    private IDbContextTransaction? _transaction;

    #endregion

    public UnitOfWork(ApplicationContext context)
    {
        _context = context;
    }

    #region Repositories
    #endregion

    #region Save Methods
    public bool SaveChanges() => _context.SaveChanges() > 0;

    public async Task<bool> SaveChangesAsync() => (await _context.SaveChangesAsync()) > 0;
    #endregion

    #region Transactions
    public async Task BeginTransactionAsync()
    {
        if (_transaction is not null)
            throw new InvalidOperationException("A transaction has already been started.");

        _transaction = await _context.Database.BeginTransactionAsync();
    }

    public async Task CommitTransactionAsync()
    {
        if (_transaction is null)
            throw new InvalidOperationException("A transaction has not been started.");

        try
        {
            await _transaction.CommitAsync();
        }
        catch
        {
            await RollbackTransactionAsync();
            throw;
        }
        finally
        {
            await _transaction.DisposeAsync();
            _transaction = null;
        }
    }

    public async Task RollbackTransactionAsync()
    {
        if (_transaction is null)
            return;

        await _transaction.RollbackAsync();
        await _transaction.DisposeAsync();
        _transaction = null;
    }
    #endregion
    
}