using Microsoft.EntityFrameworkCore;
using mws.backend.dotnet.application.Common;

namespace mws.backend.dotnet.infrastructure.Persistence;

public static class PaginationExtensions
{
    public const int DefaultPageSize = 20;
    public const int MaxPageSize = 100;

    public static async Task<PagedResult<T>> ToPagedResultAsync<T>(
        this IQueryable<T> query, int page, int pageSize, CancellationToken ct = default)
    {
        page = page < 1 ? 1 : page;
        pageSize = pageSize < 1 ? DefaultPageSize : Math.Min(pageSize, MaxPageSize);

        var totalCount = await query.CountAsync(ct);
        var items = await query.Skip((page - 1) * pageSize).Take(pageSize).ToListAsync(ct);

        return new PagedResult<T> { Items = items, TotalCount = totalCount, Page = page, PageSize = pageSize };
    }
}