using FluentAssertions;
using foodmarket.Application.Common;
using Xunit;

namespace foodmarket.UnitTests;

/// <summary>PagedRequest / PagedResult — простые helper'ы, но Skip/Take/Desc/
/// TotalPages нетривиальны на edge-кейсах. Sprint 15 — расширение покрытия.</summary>
public class PagedRequestTests
{
    [Theory]
    [InlineData(1, 50, 0)]    // первая страница → skip 0
    [InlineData(2, 50, 50)]   // вторая → skip 50
    [InlineData(5, 20, 80)]   // 5×20 = 80
    [InlineData(0, 50, 0)]    // невалидная страница ≤0 → skip 0 (Max)
    public void Skip_calculated_from_Page_and_PageSize(int page, int pageSize, int expectedSkip)
        => new PagedRequest { Page = page, PageSize = pageSize }.Skip.Should().Be(expectedSkip);

    [Theory]
    [InlineData(50, 50)]
    [InlineData(1, 1)]
    [InlineData(501, 500)]    // clamp на 500 сверху
    [InlineData(0, 1)]        // clamp на 1 снизу
    [InlineData(-1, 1)]       // отрицательные тоже клампим
    public void Take_clamps_to_1_500(int requested, int expected)
        => new PagedRequest { PageSize = requested }.Take.Should().Be(expected);

    [Theory]
    [InlineData("desc", true)]
    [InlineData("DESC", true)]
    [InlineData("asc", false)]
    [InlineData(null, false)]
    [InlineData("", false)]
    [InlineData("garbage", false)]
    public void Desc_only_for_explicit_desc(string? order, bool expected)
        => new PagedRequest { Order = order }.Desc.Should().Be(expected);

    [Theory]
    [InlineData(100, 50, 2)]
    [InlineData(101, 50, 3)]
    [InlineData(0, 50, 0)]
    [InlineData(7, 50, 1)]
    public void TotalPages_calculated_from_Total_and_PageSize(int total, int pageSize, int expected)
    {
        var result = new PagedResult<string>
        {
            Items = new List<string>(),
            Total = total,
            Page = 1,
            PageSize = pageSize,
        };
        result.TotalPages.Should().Be(expected);
    }

    [Fact]
    public void Default_Page_and_PageSize_sensible()
    {
        var r = new PagedRequest();
        r.Page.Should().Be(1);
        r.PageSize.Should().Be(50);
        r.Skip.Should().Be(0);
        r.Take.Should().Be(50);
    }
}