using XFESystem.Browser;
using XFESystem.Core;
using XFESystem.Desktop;
using Xunit;

namespace XFESystem.Desktop.Tests;

public sealed class DesktopRenderYieldTests
{
    [Fact]
    public void PreviewSkipsStartPageAndCannotRunScriptsFromAnAbortedFirstFrame()
    {
        var canvas = new YieldCanvas { YieldOnWebPainting = false };
        var storage = new MemoryWorkspace(seed: false);
        string path = SystemPaths.Combine(SystemPaths.Documents, "First.md");
        storage.WriteText(path, "# Actual preview heading\n\nThis paragraph comes from the file.");
        var trace = new List<string>();
        var desktop = new DesktopSession(canvas, storage, new BrowserService { Trace = trace.Add });
        desktop.Open(DesktopApplication.Editor, path);
        desktop.Key(DesktopKey.Run);
        var preview = Assert.IsType<BrowserService>(desktop.ActiveWindow!.PreviewSession);
        Assert.DoesNotContain(trace, line => line.StartsWith("XFE_BROWSER_SCRIPT_BEGIN", StringComparison.Ordinal));
        Assert.DoesNotContain(trace, line => line.Contains("JavaScript ready", StringComparison.Ordinal));
        canvas.YieldOnWebPainting = true;
        desktop.Render();
        Assert.False(desktop.LastFrameCompleted);
        Assert.False(preview.DocumentFirstFramePresented);
        desktop.AdvanceFeedback(20);
        Assert.DoesNotContain(preview.LoadedResources, resource => resource.Kind == "script");
        canvas.YieldOnWebPainting = canvas.YieldPending = false;
        desktop.Render();
        Assert.True(desktop.LastFrameCompleted);
        Assert.True(preview.DocumentFirstFramePresented);
        Assert.Contains(canvas.Texts, value => value.Contains("Actual", StringComparison.Ordinal));
        desktop.AdvanceFeedback(40); // Construct Jint after physical presentation.
        desktop.AdvanceFeedback(60); // Run the first original script.
        Assert.Single(preview.LoadedResources, resource => resource.Kind == "script");
    }
    [Fact]
    public void WebViewportResizeRepaintsItsReflowButPureWindowTranslationStillReusesBody()
    {
        var canvas=new YieldCanvas{YieldOnWebPainting=false};var desktop=new DesktopSession(canvas,new MemoryWorkspace(),new BrowserService(new Transport()));
        var window=desktop.Open(DesktopApplication.Browser,"http://yield.test/Index.html");desktop.Render();
        var bounds=window.Bounds;int x=bounds.X+bounds.Width-5,y=bounds.Y+bounds.Height-5;
        desktop.Pointer(x,y,true,timestampMs:1000);desktop.Render();
        desktop.Pointer(x+20,y+20,true,timestampMs:1020);desktop.Render();
        Assert.NotEqual(bounds,window.Bounds);Assert.Equal(0,canvas.PreservedRegions);
        desktop.Pointer(x+20,y+20,false,timestampMs:1040);desktop.Render();
        bounds=window.Bounds;x=bounds.X+bounds.Width/2;y=bounds.Y+14;
        desktop.Pointer(x,y,true,timestampMs:2000);desktop.Render();
        desktop.Pointer(x+20,y+8,true,timestampMs:2020);desktop.Render();
        Assert.True(canvas.PreservedRegions>0);Assert.Equal(bounds.Width,window.Bounds.Width);Assert.Equal(bounds.Height,window.Bounds.Height);
    }
    [Fact]
    public void CancelledWebFrameIsNotCachedOrPresentedAndDirtyFrameRetriesSuccessfully()
    {
        var canvas=new YieldCanvas();var browser=new BrowserService(new Transport());var desktop=new DesktopSession(canvas,new MemoryWorkspace(),browser);
        var window=desktop.Open(DesktopApplication.Browser,"http://yield.test/Index.html");
        desktop.Render();
        Assert.False(desktop.LastFrameCompleted);Assert.True(desktop.NeedsRender);Assert.Equal(1,desktop.RenderYieldCount);
        Assert.Equal(0,canvas.Presents);Assert.Equal(0,canvas.StoredFrames);Assert.Equal(0,canvas.SavedScenes);
        Assert.True(canvas.YieldPending);Assert.True(canvas.EndedPreservation>0);Assert.Equal(new DesktopBounds(0,0,canvas.Width,canvas.Height),canvas.LastScene);
        Assert.Equal(1,canvas.AbortedPreservation);Assert.False(canvas.PendingScanoutSkip);
        Assert.Same(window,desktop.ActiveWindow);Assert.DoesNotContain("Rendering failed",canvas.Texts);

        canvas.YieldOnWebPainting=false;canvas.YieldPending=false;
        desktop.Render();
        Assert.True(desktop.LastFrameCompleted);Assert.False(desktop.NeedsRender);Assert.Equal(1,desktop.RenderYieldCount);
        Assert.Equal(1,canvas.Presents);Assert.Equal(1,canvas.StoredFrames);Assert.Equal(1,canvas.SavedScenes);
        Assert.Same(window,desktop.ActiveWindow);Assert.DoesNotContain("Rendering failed",canvas.Texts);
        desktop.Render();Assert.False(desktop.LastFrameCompleted);Assert.Equal(1,canvas.Presents);
    }
    private sealed class Transport:IWebTransport
    {
        public WebResponse Get(Uri address,BrowserLimits limits)=>new(address,200,"text/html",
            "<style>body{margin:0}article{width:500px;height:400px;border-radius:12px;background:linear-gradient(90deg,red,blue)}</style><article>Actual web paint</article>");
    }
    private sealed class YieldCanvas:IDesktopCoverageCanvas,IDesktopWebFrameCache,IDesktopSceneMotionCanvas,IDesktopRenderYieldCanvas,IDesktopWebCanvas
    {
        public int Width=>1280;public int Height=>800;public bool SupportsSceneCache=>true;
        public bool YieldPending, YieldOnWebPainting=true,PendingScanoutSkip;public int Presents,StoredFrames,SavedScenes,EndedPreservation,AbortedPreservation,PreservedRegions;
        public DesktopBounds LastScene;public List<string> Texts=[];
        public bool RenderYieldRequested=>YieldPending;
        public DesktopBounds WebPaintClip{get{if(YieldOnWebPainting){YieldPending=true;PendingScanoutSkip=true;}return LastScene;}}
        public void BeginScene(DesktopBounds bounds){LastScene=bounds;}
        public void BlendCoverage(uint rgb,int x,int y,int width,int height,ReadOnlySpan<byte> source)
        {if(YieldPending)throw new DesktopRenderYieldException();}
        public bool TryRestoreWebFrame(long pageId,long revision,long layoutVersion,DesktopBounds bounds,double scrollX,double scrollY)=>false;
        public void StoreWebFrame(long pageId,long revision,long layoutVersion,DesktopBounds bounds,double scrollX,double scrollY){StoredFrames++;}
        public void SaveScene(DesktopBounds bounds){SavedScenes++;}
        public void EndScenePreservation(){EndedPreservation++;}
        public void AbortScenePreservation(){AbortedPreservation++;PendingScanoutSkip=false;EndScenePreservation();}
        public void PreserveTranslatedSceneRegion(DesktopBounds source,int x,int y){PreservedRegions++;}
        public void Fill(uint rgb,int x,int y,int width,int height){}
        public void Line(uint rgb,int x1,int y1,int x2,int y2){}
        public void Text(string text,uint rgb,int x,int y){Texts.Add(text);}
        public void PushClip(DesktopBounds bounds) { }
        public void PopClip() { }
        public double MeasureWebText(string text, double size, string family, int weight) => text.Length * size * .6;
        public (int Width, int Height, byte[] Alpha) RasterizeWebText(string text, double size, string family, int weight)
        { Texts.Add(text); return (1, 1, [255]); }
        public void WebText(string text, uint color, double x, double y, double size, string family, int weight, double opacity = 1)
        { if (YieldPending) throw new DesktopRenderYieldException(); Texts.Add(text); }
        public void Present(){Presents++;}
    }
}