using System.Numerics;

namespace AcDream.UI.Abstractions.Tests;

/// <summary>
/// Tests the shape of the new Phase I.1 widget extensions on
/// <see cref="IPanelRenderer"/>. Every test dispatches through the
/// interface (not the concrete fake) so the test only compiles when
/// the interface actually has the method — that's the RED signal for
/// TDD when adding new widgets in the future.
/// </summary>
public sealed class IPanelRendererWidgetTests
{
    private static (IPanelRenderer Iface, FakePanelRenderer Fake) New()
    {
        var f = new FakePanelRenderer();
        return (f, f);
    }

    [Fact]
    public void TextColored_RecordsCallWithColorAndText()
    {
        var (r, fake) = New();
        var color = new Vector4(0.9f, 0.4f, 0.2f, 1f);

        r.TextColored(color, "ouch");

        var call = Assert.Single(fake.Calls);
        Assert.Equal("TextColored", call.Method);
        Assert.Equal(color, call.Args[0]);
        Assert.Equal("ouch", call.Args[1]);
    }

    [Fact]
    public void CollapsingHeader_RecordsLabelAndDefaultOpen_ReturnsBackingValue()
    {
        var (r, fake) = New();
        fake.CollapsingHeaderNextReturn = false;

        bool open = r.CollapsingHeader("Player Info");
        Assert.False(open);

        var call = Assert.Single(fake.Calls);
        Assert.Equal("CollapsingHeader", call.Method);
        Assert.Equal("Player Info", call.Args[0]);
        Assert.Equal(true, call.Args[1]); // default
    }

    [Fact]
    public void CollapsingHeader_PassesDefaultOpenFalse()
    {
        var (r, fake) = New();

        r.CollapsingHeader("Diagnostics", defaultOpen: false);

        var call = Assert.Single(fake.Calls);
        Assert.Equal(false, call.Args[1]);
    }

    [Fact]
    public void TreeNode_AndTreePop_FormPair()
    {
        var (r, fake) = New();
        fake.TreeNodeNextReturn = true;

        if (r.TreeNode("Inventory"))
        {
            r.Text("sword");
            r.TreePop();
        }

        Assert.Equal(3, fake.Calls.Count);
        Assert.Equal("TreeNode", fake.Calls[0].Method);
        Assert.Equal("Inventory", fake.Calls[0].Args[0]);
        Assert.Equal("Text", fake.Calls[1].Method);
        Assert.Equal("TreePop", fake.Calls[2].Method);
    }

    [Fact]
    public void Checkbox_AppliesNextValueToRefAndRecordsBefore()
    {
        var (r, fake) = New();
        fake.CheckboxNextReturn = true;
        fake.CheckboxNextValue = true;

        bool flag = false;
        bool changed = r.Checkbox("DumpMotion", ref flag);

        Assert.True(changed);
        Assert.True(flag); // fake mutated the ref
        var call = Assert.Single(fake.Calls);
        Assert.Equal("Checkbox", call.Method);
        Assert.Equal("DumpMotion", call.Args[0]);
        Assert.Equal(false, call.Args[1]); // value-before-the-call captured in trace
    }

    [Fact]
    public void Button_ReturnsBackingValueAndRecordsLabel()
    {
        var (r, fake) = New();
        fake.ButtonNextReturn = true;

        bool clicked = r.Button("Cycle Weather");

        Assert.True(clicked);
        var call = Assert.Single(fake.Calls);
        Assert.Equal("Button", call.Method);
        Assert.Equal("Cycle Weather", call.Args[0]);
    }

    [Fact]
    public void Combo_AppliesNextSelectedIndex_AndReturnsChanged()
    {
        var (r, fake) = New();
        fake.ComboNextReturn = true;
        fake.ComboNextSelectedIndex = 2;

        int idx = 0;
        var items = new[] { "Dawn", "Noon", "Dusk", "Night" };
        bool changed = r.Combo("Time", ref idx, items);

        Assert.True(changed);
        Assert.Equal(2, idx);
        var call = Assert.Single(fake.Calls);
        Assert.Equal("Combo", call.Method);
        Assert.Equal("Time", call.Args[0]);
        Assert.Equal(0, call.Args[1]);
        Assert.Same(items, call.Args[2]);
    }

    [Fact]
    public void SliderFloat_AppliesNextValueAndReturnsChanged()
    {
        var (r, fake) = New();
        fake.SliderFloatNextReturn = true;
        fake.SliderFloatNextValue = 0.7f;

        float v = 0.1f;
        bool changed = r.SliderFloat("Sensitivity", ref v, 0f, 1f);

        Assert.True(changed);
        Assert.Equal(0.7f, v);
        var call = Assert.Single(fake.Calls);
        Assert.Equal("SliderFloat", call.Method);
        Assert.Equal("Sensitivity", call.Args[0]);
        Assert.Equal(0.1f, call.Args[1]);
        Assert.Equal(0f, call.Args[2]);
        Assert.Equal(1f, call.Args[3]);
    }

    [Fact]
    public void PlotLines_RecordsAllOptionalArgs()
    {
        var (r, fake) = New();
        var values = new[] { 16f, 17f, 16.5f, 16.2f };

        r.PlotLines(
            "FrameMs",
            values,
            count: values.Length,
            offset: 1,
            overlay: "60 fps",
            min: 0f,
            max: 33f,
            size: new Vector2(120, 40));

        var call = Assert.Single(fake.Calls);
        Assert.Equal("PlotLines", call.Method);
        Assert.Equal("FrameMs", call.Args[0]);
        Assert.Same(values, call.Args[1]);
        Assert.Equal(values.Length, call.Args[2]);
        Assert.Equal(1, call.Args[3]);
        Assert.Equal("60 fps", call.Args[4]);
        Assert.Equal(0f, call.Args[5]);
        Assert.Equal(33f, call.Args[6]);
        Assert.Equal(new Vector2(120, 40), call.Args[7]);
    }

    [Fact]
    public void PlotLines_DefaultsApplied_WhenOptionalsOmitted()
    {
        var (r, fake) = New();
        var values = new[] { 1f, 2f, 3f };

        r.PlotLines("FPS", values, count: values.Length);

        var call = Assert.Single(fake.Calls);
        Assert.Equal(0, call.Args[3]);   // offset default
        Assert.Null(call.Args[4]);        // overlay default
        Assert.Null(call.Args[5]);        // min default
        Assert.Null(call.Args[6]);        // max default
        Assert.Null(call.Args[7]);        // size default
    }

    [Fact]
    public void Table_BeginNextColumnEnd_FormSequence()
    {
        var (r, fake) = New();

        r.BeginTable("Keybinds", 2);
        r.TableNextColumn();
        r.Text("F1");
        r.TableNextColumn();
        r.Text("Toggle Info");
        r.EndTable();

        Assert.Equal(6, fake.Calls.Count);
        Assert.Equal("BeginTable", fake.Calls[0].Method);
        Assert.Equal("Keybinds", fake.Calls[0].Args[0]);
        Assert.Equal(2, fake.Calls[0].Args[1]);
        Assert.Equal("TableNextColumn", fake.Calls[1].Method);
        Assert.Equal("Text", fake.Calls[2].Method);
        Assert.Equal("TableNextColumn", fake.Calls[3].Method);
        Assert.Equal("Text", fake.Calls[4].Method);
        Assert.Equal("EndTable", fake.Calls[5].Method);
    }

    [Fact]
    public void InputTextSubmit_NoSubmit_ReturnsFalseAndSubmittedNull()
    {
        var (r, fake) = New();
        // InputTextSubmitNextSubmitted left null → the buffer should be untouched
        // and the out arg should be null.

        string buf = "hel";
        bool submitted = r.InputTextSubmit("##chat", ref buf, 256, out var output);

        Assert.False(submitted);
        Assert.Null(output);
        Assert.Equal("hel", buf);

        var call = Assert.Single(fake.Calls);
        Assert.Equal("InputTextSubmit", call.Method);
        Assert.Equal("##chat", call.Args[0]);
        Assert.Equal("hel", call.Args[1]);
        Assert.Equal(256, call.Args[2]);
    }

    [Fact]
    public void InputTextSubmit_OnSubmit_OutputsTextAndClearsBuffer()
    {
        var (r, fake) = New();
        fake.InputTextSubmitNextSubmitted = "hello world";
        fake.InputTextSubmitNextBufferAfter = string.Empty;

        string buf = "hello world";
        bool submitted = r.InputTextSubmit("##chat", ref buf, 256, out var output);

        Assert.True(submitted);
        Assert.Equal("hello world", output);
        // Contract: on submit the impl clears the buffer for the next frame.
        Assert.Equal(string.Empty, buf);
    }

    [Fact]
    public void Spacing_RecordsCall()
    {
        var (r, fake) = New();
        r.Spacing();
        var call = Assert.Single(fake.Calls);
        Assert.Equal("Spacing", call.Method);
    }

    [Fact]
    public void Dummy_RecordsSize()
    {
        var (r, fake) = New();
        r.Dummy(new Vector2(8, 12));
        var call = Assert.Single(fake.Calls);
        Assert.Equal("Dummy", call.Method);
        Assert.Equal(new Vector2(8, 12), call.Args[0]);
    }

    [Fact]
    public void TextWrapped_RecordsText()
    {
        var (r, fake) = New();
        r.TextWrapped("a long description that wraps onto multiple lines");

        var call = Assert.Single(fake.Calls);
        Assert.Equal("TextWrapped", call.Method);
        Assert.Equal("a long description that wraps onto multiple lines", call.Args[0]);
    }

    // -- Sanity: existing widgets still recorded correctly via the fake -------

    [Fact]
    public void BeginEndTextSeparatorProgressBar_StillRecorded()
    {
        var (r, fake) = New();
        fake.BeginReturns = true;

        Assert.True(r.Begin("Window"));
        r.Text("hi");
        r.SameLine();
        r.Separator();
        r.ProgressBar(0.5f, 100f, "50%");
        r.End();

        Assert.Equal(6, fake.Calls.Count);
        Assert.Equal("Begin", fake.Calls[0].Method);
        Assert.Equal("Text", fake.Calls[1].Method);
        Assert.Equal("SameLine", fake.Calls[2].Method);
        Assert.Equal("Separator", fake.Calls[3].Method);
        Assert.Equal("ProgressBar", fake.Calls[4].Method);
        Assert.Equal("End", fake.Calls[5].Method);
    }
}