using Explorer.Application;
using Explorer.Domain;

namespace Explorer.Application.Tests;

public class FolderDisplayRefreshTests
{
    [Fact]
    public void Pick_prefers_visible_then_largest()
    {
        var items = new[]
        {
            Dir(@"C:\a", "a", 50_000_000),
            Dir(@"C:\b", "b", 90_000_000),
            Dir(@"C:\c", "c", 5_000),
            Dir(@"C:\d", "d", 20_000_000)
        };
        var picked = FolderDisplayRefresh.Pick(items, [@"C:\d", @"C:\a"]);
        Assert.Equal(3, picked.Count);
        Assert.Equal(@"C:\a", picked[0].FullPath);
        Assert.Equal(@"C:\d", picked[1].FullPath);
        Assert.Equal(@"C:\b", picked[2].FullPath);
    }

    [Fact]
    public void Pick_caps_and_skips_tiny_or_cloud()
    {
        var items = Enumerable.Range(0, 12)
            .Select(i => Dir($@"C:\f{i}", $"f{i}", (13 - i) * 2_000_000L))
            .Append(Dir(@"C:\tiny", "tiny", 100))
            .Append(Dir(@"C:\cloud", "cloud", 80_000_000, hydrate: true))
            .ToList();
        var picked = FolderDisplayRefresh.Pick(items);
        Assert.Equal(FolderDisplayRefresh.MaxProbes, picked.Count);
        Assert.Equal(@"C:\f0", picked[0].FullPath);
        Assert.DoesNotContain(picked, item => item.Name is "tiny" or "cloud");
    }

    [Fact]
    public void NeedsVerify_compares_child_counts()
    {
        Assert.True(FolderDisplayRefresh.NeedsVerify(10, 2000));
        Assert.False(FolderDisplayRefresh.NeedsVerify(10, 10));
        Assert.False(FolderDisplayRefresh.NeedsVerify(-1, 2000));
    }

    [Fact]
    public void HasIndexCounts_requires_index_hydration()
    {
        var live = Dir(@"C:\a", "a", 50_000_000, hydration: ItemHydrationFlags.Shell | ItemHydrationFlags.Metadata);
        Assert.False(FolderDisplayRefresh.HasIndexCounts(live));
        Assert.True(FolderDisplayRefresh.HasIndexCounts(live.Overlay(hydration: ItemHydrationFlags.Index)));
    }

    private static FileSystemItem Dir(string path, string name, long size, bool hydrate = false, ItemHydrationFlags? hydration = null)
        => new()
        {
            FullPath = path,
            Name = name,
            IsDirectory = true,
            SizeBytes = size,
            IndexedChildCount = 4,
            Hydration = hydration ?? ItemHydrationFlags.All,
            Cloud = hydrate
                ? new CloudPresence("x", CloudAvailability.OnlineOnly, size, null, true)
                : null
        };
}