@using Sandbox
@using Sandbox.UI
@using System
@using System.Collections.Generic
@namespace FieldGuide.DayNight
@inherits PanelComponent
@attribute [StyleSheet]

@*
	The demo's on-screen key card, up from the first frame. A scene with no visible instructions reads as
	a broken scene: you press nothing, nothing happens, you close it. So this says what the demo is and
	which keys do what, before you have touched anything.

	It also carries the one thing the demo could not otherwise show. The kit ships no sky shader and no
	sky art on purpose; the sky is a SEAM, four normalized crossfade weights per hour. Those weights have
	no picture, so the card prints them live and they visibly hand off from one slot to the next as the
	clock runs. That is the seam doing its job, on screen, with no art involved.

	Rows render in MAIN markup via @foreach per the fragment-undermeasure gotcha. H hides the card (a
	letter, never an F key, which the editor eats in play). No ESC anywhere: house law.

	Look and layout follow the Field Kit UI system: docs/design/ui-system/daynight-kit.dc.html for this
	screen, tokens.dc.html for the values. Font sizes come from the {12, 13, 14, 16} panel scale and there
	is no letter-spacing; the stylesheet head lists the rest of the engine-legality rules.

	Not part of the kit's runtime surface: delete Code/Demo when you drop the kit into your own project.
*@

<root>
@* DemoActive is the inert-by-construction gate (library law 11): only DayNightDemoBootstrap sets it, so
   this card cannot appear in a consumer's game even if Code/Demo was left in the project. *@
@if ( CardOpen && DayNightDemoBootstrap.DemoActive )
{
	<div class="dh-card">
		<div class="dh-hdr">
			<span class="dh-title">DAY / NIGHT KIT DEMO</span>
			<div class="dh-x" onclick=@(() => CardOpen = false)>×</div>
		</div>

		<div class="dh-lede">One directional light, one skybox, one clock. Watch the sun sweep and the colour grade follow it, or open the time panel and drive the cycle yourself.</div>

		<div class="dh-rows">
			@foreach ( var r in Keys )
			{
				string key = r.key;     // plain locals before interpolating: an inline tuple read can render blank
				string what = r.what;
				<div class="dh-row">
					<span class="dh-key">@key</span>
					<span class="dh-what">@what</span>
				</div>
			}
		</div>

		<div class="dh-live">
			@foreach ( var w in Weights )
			{
				string run = w;
				<span class="dh-lk">@run</span>
			}
		</div>

		<div class="dh-foot">Those four are the sky seam. The kit ships no sky shader and no sky art; you crossfade your own sky from these weights.</div>
	</div>
}
</root>

@code
{
	static bool _open = true;

	/// <summary>Console fallback: `daynight_hint 1` / `daynight_hint 0` shows or hides the card (H also
	/// toggles). Starts SHOWN, unlike the time panel, because it is the thing that tells you the time panel
	/// exists.</summary>
	[ConVar( "daynight_hint", Help = "Show or hide the demo scene's key card (same as the H key)" )]
	public static bool CardOpen { get => _open; set => _open = value; }

	static readonly List<(string key, string what)> Keys = new()
	{
		( "N", "Open the time panel: scrub the clock, change the pace, pin the weather" ),
		( "H", "Hide this card" ),
	};

	DayNightClock _clock;

	DayNightClock Clock
	{
		get
		{
			if ( _clock.IsValid() ) return _clock;
			_clock = DayNightClock.For( Scene );
			return _clock;
		}
	}

	/// <summary>The live sky weights as four short atomic runs. Split into separate spans rather than one
	/// sentence so a wrap breaks BETWEEN runs; a single long run wraps mid-word, which is a live bug class
	/// in this engine's text layout.</summary>
	List<string> Weights
	{
		get
		{
			var c = Clock;
			var cfg = c?.Config ?? DayNightConfig.Default;
			var w = SkyWeights.WeightsFor( c?.GetTimeHours() ?? 0f, cfg );
			return new List<string>
			{
				$"MORNING {w.x:0.00}",
				$"NOON {w.y:0.00}",
				$"EVENING {w.z:0.00}",
				$"NIGHT {w.w:0.00}",
			};
		}
	}

	protected override void OnUpdate()
	{
		if ( Input.Keyboard.Pressed( "H" ) )
			CardOpen = !CardOpen;
	}

	// Fold the card state and every printed weight (to the two decimals shown), or the strip freezes at
	// whatever it read on the first frame while the sun keeps moving.
	protected override int BuildHash()
	{
		var c = Clock;
		var cfg = c?.Config ?? DayNightConfig.Default;
		var w = SkyWeights.WeightsFor( c?.GetTimeHours() ?? 0f, cfg );
		return HashCode.Combine( CardOpen, DayNightDemoBootstrap.DemoActive,
			(int)MathF.Round( w.x * 100f ),
			(int)MathF.Round( w.y * 100f ),
			(int)MathF.Round( w.z * 100f ),
			(int)MathF.Round( w.w * 100f ) );
	}
}