using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Threading;
using System.Threading.Tasks;
using PoweredSoft.Data.Core;

namespace Svrnty.CQRS.DynamicQuery;

/// <summary>
/// In-memory implementation of IAsyncQueryableService.
/// For EF Core projects, use AddDynamicQueryServices().UseEntityFramework() instead.
/// </summary>
public class InMemoryAsyncQueryableService : IAsyncQueryableService
{
    public IEnumerable<IAsyncQueryableHandlerService> Handlers { get; } = Array.Empty<IAsyncQueryableHandlerService>();

    public Task<List<TSource>> ToListAsync<TSource>(IQueryable<TSource> queryable, CancellationToken cancellationToken = default)
    {
        return Task.FromResult(queryable.ToList());
    }

    public Task<TSource?> FirstOrDefaultAsync<TSource>(IQueryable<TSource> queryable, CancellationToken cancellationToken = default)
    {
        return Task.FromResult(queryable.FirstOrDefault());
    }

    public Task<TSource?> FirstOrDefaultAsync<TSource>(IQueryable<TSource> queryable, Expression<Func<TSource, bool>> predicate, CancellationToken cancellationToken = default)
    {
        return Task.FromResult(queryable.FirstOrDefault(predicate));
    }

    public Task<TSource?> LastOrDefaultAsync<TSource>(IQueryable<TSource> queryable, CancellationToken cancellationToken = default)
    {
        return Task.FromResult(queryable.LastOrDefault());
    }

    public Task<TSource?> LastOrDefaultAsync<TSource>(IQueryable<TSource> queryable, Expression<Func<TSource, bool>> predicate, CancellationToken cancellationToken = default)
    {
        return Task.FromResult(queryable.LastOrDefault(predicate));
    }

    public Task<bool> AnyAsync<TSource>(IQueryable<TSource> queryable, CancellationToken cancellationToken = default)
    {
        return Task.FromResult(queryable.Any());
    }

    public Task<bool> AnyAsync<TSource>(IQueryable<TSource> queryable, Expression<Func<TSource, bool>> predicate, CancellationToken cancellationToken = default)
    {
        return Task.FromResult(queryable.Any(predicate));
    }

    public Task<bool> AllAsync<TSource>(IQueryable<TSource> queryable, Expression<Func<TSource, bool>> predicate, CancellationToken cancellationToken = default)
    {
        return Task.FromResult(queryable.All(predicate));
    }

    public Task<int> CountAsync<TSource>(IQueryable<TSource> queryable, CancellationToken cancellationToken = default)
    {
        return Task.FromResult(queryable.Count());
    }

    public Task<long> LongCountAsync<TSource>(IQueryable<TSource> queryable, CancellationToken cancellationToken = default)
    {
        return Task.FromResult(queryable.LongCount());
    }

    public Task<TSource?> SingleOrDefaultAsync<TSource>(IQueryable<TSource> queryable, Expression<Func<TSource, bool>> predicate, CancellationToken cancellationToken = default)
    {
        return Task.FromResult(queryable.SingleOrDefault(predicate));
    }

    public IAsyncQueryableHandlerService? GetAsyncQueryableHandler<TSource>(IQueryable<TSource> queryable)
    {
        return null;
    }
}