using System;
using System.IO;
using Xunit;
using ytLive.Services;

namespace ytLive.Tests;

/// <summary>
/// TASK 55·2–3 — the two disk debts a free app must not leave: the temp alert clip it materialises and
/// never deletes, and a recording that starts with no room to finish.
///
/// <para>Both are tested as policy, because the alternative — filling a real drive — is not a test.</para>
/// </summary>
public sealed class DiskHygieneTests : IDisposable
{
    private readonly string _dir = Path.Combine(Path.GetTempPath(), $"ytLlive-disk-{Guid.NewGuid():N}");

    public DiskHygieneTests() => Directory.CreateDirectory(_dir);

    public void Dispose()
    {
        try { Directory.Delete(_dir, recursive: true); } catch { /* best effort */ }
    }

    [Fact]
    public void Sweep_RemovesOnlyTheClipsWeCreated()
    {
        var ours1 = Path.Combine(_dir, "ytLive-alert-abc.mp4");
        var ours2 = Path.Combine(_dir, "ytLive-alert-def.mp4");
        var theirs = Path.Combine(_dir, "someone-elses-recording.mp4");
        File.WriteAllText(ours1, "x");
        File.WriteAllText(ours2, "x");
        File.WriteAllText(theirs, "x");

        var removed = AlertClipCleanup.Sweep(_dir);

        Assert.Equal(2, removed);
        Assert.False(File.Exists(ours1));
        Assert.False(File.Exists(ours2));
        Assert.True(File.Exists(theirs));      // never touch anything that isn't ours
    }

    [Fact]
    public void Delete_IsSafeOnMissingBlankAndNull()
    {
        Assert.False(AlertClipCleanup.Delete(null));
        Assert.False(AlertClipCleanup.Delete(""));
        Assert.False(AlertClipCleanup.Delete(Path.Combine(_dir, "not-there.mp4")));

        var file = Path.Combine(_dir, "ytLive-alert-gone.mp4");
        File.WriteAllText(file, "x");
        Assert.True(AlertClipCleanup.Delete(file));
        Assert.False(File.Exists(file));
    }

    [Fact]
    public void RecordingIsRefusedBelowAGigabyte_WarnedBelowFive_AndQuietAbove()
    {
        Assert.Equal(DiskSpaceGuard.StartDecision.Block, DiskSpaceGuard.ForStart(500L * 1024 * 1024));
        Assert.Equal(DiskSpaceGuard.StartDecision.Warn, DiskSpaceGuard.ForStart(2L * 1024 * 1024 * 1024));
        Assert.Equal(DiskSpaceGuard.StartDecision.Ok, DiskSpaceGuard.ForStart(20L * 1024 * 1024 * 1024));
    }

    [Fact]
    public void MidRecordingWarnsOnceBelowTwoGigabytes()
    {
        Assert.False(DiskSpaceGuard.ShouldWarnDuring(3L * 1024 * 1024 * 1024));
        Assert.True(DiskSpaceGuard.ShouldWarnDuring(1L * 1024 * 1024 * 1024));
    }
}