using System.Linq;
using Dpz.Core.Entity.Base.Image;
using Dpz.Core.Public.ViewModel.Request;
using Dpz.Core.Service.Mediator.Features.Media.Contracts;

namespace Dpz.Core.ServiceTest;

[TestFixture]
public class ImageMetadataBackfillHelperTest
{
    [Test]
    public void CreateCandidate_WhenAllUrlsHaveMetadata_ReturnsNull()
    {
        var candidate = ImageMetadataBackfillHelper.CreateCandidate(
            "id",
            ["https://cdn.example.com/a.jpg"],
            [
                new ImageMetadata
                {
                    Url = "https://cdn.example.com/a.jpg",
                    Width = 100,
                    Height = 100,
                },
            ]
        );

        Assert.That(candidate, Is.Null);
    }

    [Test]
    public void CreateCandidate_WhenForced_ReturnsCandidateEvenIfAllUrlsHaveMetadata()
    {
        var candidate = ImageMetadataBackfillHelper.CreateCandidate(
            "id",
            ["https://cdn.example.com/a.jpg"],
            [
                new ImageMetadata
                {
                    Url = "https://cdn.example.com/a.jpg",
                    Width = 100,
                    Height = 100,
                },
            ],
            forceCreate: true
        );

        Assert.That(candidate, Is.Not.Null);
        Assert.That(candidate.Urls, Is.EqualTo(["https://cdn.example.com/a.jpg"]));
    }

    [Test]
    public void CreateCandidate_WhenAnyUrlMissesMetadata_ReturnsAllTargetUrls()
    {
        var candidate = ImageMetadataBackfillHelper.CreateCandidate(
            "id",
            ["https://cdn.example.com/a.jpg", "https://cdn.example.com/b.jpg"],
            [
                new ImageMetadata
                {
                    Url = "https://cdn.example.com/a.jpg",
                    Width = 100,
                    Height = 100,
                },
            ]
        );

        Assert.That(candidate, Is.Not.Null);
        Assert.That(
            candidate.Urls,
            Is.EqualTo(["https://cdn.example.com/a.jpg", "https://cdn.example.com/b.jpg"])
        );
    }

    [Test]
    public void FilterObjectStorageUrls_WhenHostMissing_ReturnsEmptyList()
    {
        var urls = ImageMetadataBackfillHelper.FilterObjectStorageUrls(
            ["https://cdn.example.com/a.jpg"],
            ""
        );

        Assert.That(urls, Is.Empty);
    }

    [Test]
    public void FilterObjectStorageUrls_OnlyReturnsUrlsUnderConfiguredHost()
    {
        var urls = ImageMetadataBackfillHelper.FilterObjectStorageUrls(
            [
                "https://cdn.example.com/a.jpg",
                "https://cdn.example.com.evil/a.jpg",
                "https://other.example.com/a.jpg",
            ],
            "https://cdn.example.com/"
        );

        Assert.That(urls, Is.EqualTo(new[] { "https://cdn.example.com/a.jpg" }));
    }

    [Test]
    public void MergeByUrl_PreservesTargetOrderAndCollectedMetadataWins()
    {
        var result = ImageMetadataBackfillHelper.MergeByUrl(
            ["https://cdn.example.com/b.jpg", "https://cdn.example.com/a.jpg"],
            [
                new ImageMetadata
                {
                    Url = "https://cdn.example.com/a.jpg",
                    Width = 100,
                    Height = 100,
                },
                new ImageMetadata
                {
                    Url = "https://cdn.example.com/b.jpg",
                    Width = 200,
                    Height = 200,
                },
            ],
            [
                new ImageMetadata
                {
                    Url = "https://cdn.example.com/a.jpg",
                    Width = 300,
                    Height = 300,
                },
            ]
        );

        Assert.That(
            result.Select(x => x.Url),
            Is.EqualTo(new[] { "https://cdn.example.com/b.jpg", "https://cdn.example.com/a.jpg" })
        );
        Assert.That(result[1].Width, Is.EqualTo(300));
    }

    [Test]
    public void EditMumbleRequest_ImagesDefaultIsNullAndEmptyListMeansClear()
    {
        var keepExisting = new EditMumbleRequest { Id = "id", Markdown = "content" };
        var clear = new EditMumbleRequest
        {
            Id = "id",
            Markdown = "content",
            Images = [],
        };

        Assert.That(keepExisting.Images, Is.Null);
        Assert.That(clear.Images, Is.Empty);
    }
}