using Sandbox;
using System.Collections.Generic;
using System.Linq;

namespace NZombies;

/// <summary>
/// PHOTO MODE — the map and nothing else, for screenshots: `nz_photo`. Asked for as *"a command that sets all hud and placed stuff
/// invisible so i only see the map and can take some screenshots"* (2026-09-28), to replace a map's images — its lobby background and
/// its thumbnail, named in `Assets/maps/manifest.json`.
///
/// ⛔ "THE MAP" IS WHAT THE MAP INSTANCE LOADED: every object under `NZMap.Instance`. Everything else that draws is the game's — the
/// placed buyables and barriers, the box, the marker objects, players and the weapon in hand, zombies, pickups, effects — and every
/// screen and world panel is too. Each is switched off, remembered, and put back exactly as it was.
///
/// ⚠️ SWEPT EVERY FRAME WHILE ON (`LobbyMenu.OnUpdate`), so a zombie that spawns or a particle that fires afterwards is hidden too.
/// ⚠️ LIGHTS, FOG AND THE SKY ARE LEFT ALONE: they are how the map looks, not something standing in it.
/// ⚠️ THE EDITOR'S OVERLAYS stop through `NZGame.ShowAuthoringVisuals`, and the pending corners with them.
/// ⚠️ BEST FROM SPECTATE OR CREATIVE — a body to fly, and no zombies clawing at you while you frame a shot.
/// </summary>
public static class MapPhotoMode
{
	/// <summary>Is the map on its own?</summary>
	public static bool On { get; private set; }

	/// <summary>What photo mode switched off, to switch back on — only what was on when it was found.</summary>
	static List<Component> Hidden => _hidden ??= new();
	static List<Component> _hidden;

	/// <summary>Each screen panel faded, with the opacity it had.</summary>
	static List<(ScreenPanel Panel, float Opacity)> Faded => _faded ??= new();
	static List<(ScreenPanel Panel, float Opacity)> _faded;

	/// <summary>Every frame (`LobbyMenu.OnUpdate`): while on, anything new that draws is hidden as well.</summary>
	public static void Tick()
	{
		if ( On ) Sweep();
	}

	/// <summary>On — the map alone — or off, everything back.</summary>
	public static void Set( bool on )
	{
		if ( on == On ) return;

		On = on;
		if ( on )
		{
			Sweep();
			return;
		}

		var back = 0;
		foreach ( var c in Hidden )
		{
			if ( !c.IsValid() ) continue;
			c.Enabled = true;
			back++;
		}

		foreach ( var (panel, opacity) in Faded )
			if ( panel.IsValid() ) panel.Opacity = opacity;

		Log.Info( $"[nz-photo] off — {back} thing(s) and {Faded.Count} screen panel(s) back" );
		Hidden.Clear();
		Faded.Clear();
	}

	static void Sweep()
	{
		var scene = Game.ActiveScene;
		if ( !scene.IsValid() ) return;

		var map = NZMap.Instance?.GameObject;

		foreach ( var r in scene.GetAllComponents<Renderer>().ToList() ) Hide( r, map );
		foreach ( var p in scene.GetAllComponents<ParticleEffect>().ToList() ) Hide( p, map );
		foreach ( var p in scene.GetAllComponents<ParticleSpriteRenderer>().ToList() ) Hide( p, map );
		foreach ( var p in scene.GetAllComponents<ParticleTrailRenderer>().ToList() ) Hide( p, map );
		foreach ( var w in scene.GetAllComponents<WorldPanel>().ToList() ) Hide( w, null );

		foreach ( var s in scene.GetAllComponents<ScreenPanel>().ToList() )
		{
			if ( !s.IsValid() || s.Opacity <= 0f ) continue;
			Faded.Add( (s, s.Opacity) );
			s.Opacity = 0f;
		}
	}

	/// <summary>Off, and remembered — unless it is part of the map, or already off.</summary>
	static void Hide( Component c, GameObject map )
	{
		if ( !c.IsValid() || !c.Enabled ) return;
		if ( map.IsValid() && IsUnder( c.GameObject, map ) ) return;

		c.Enabled = false;
		Hidden.Add( c );
	}

	static bool IsUnder( GameObject go, GameObject root )
	{
		for ( var g = go; g is not null; g = g.Parent )
			if ( g == root ) return true;

		return false;
	}

	/// <summary>
	/// `nz_photo [0|1]` — the map alone, for screenshots: the HUD and every panel faded out, everything the game placed switched off,
	/// the editor's markers stopped. Bare, it toggles. `nz_photo 0` puts everything back as it was.
	/// </summary>
	[ConCmd( "nz_photo" )]
	public static void Cmd( int on = -1 )
	{
		Set( on < 0 ? !On : on != 0 );

		if ( On )
			Log.Info( $"[nz-photo] ON — the map alone: {Hidden.Count} thing(s) switched off, {Faded.Count} screen panel(s) faded"
				+ $"{(NZMap.Instance.IsValid() ? "" : " · ⚠ no map instance found, so NOTHING counts as the map")}"
				+ " · nz_photo 0 brings it all back" );
	}
}