using Sandbox;
using System;

namespace NZombies;

/// <summary>
/// A BOSS'S PULL ON THIS PLAYER — Oberon's black hole dragging them toward him for as long as it is open.
///
/// ⛔ ON THE MACHINE THAT OWNS THE BODY, AS THE DAZE IS (`SonicDaze`). The hole used to drag every player from the host's
/// `OberonBoss.TickPull`, writing `WorldPosition` and the body's velocity straight onto them — which moves the host's own
/// player and no one else's: a body another machine simulates is written back within a frame (INSTRUCTIONS.md, `IsProxy`).
/// So the host now says where and for how long (`NZNet.OberonPull`) and each machine pulls its own player, here. Solo is
/// the same pull as before, which only ever pulled the one player there was.
///
/// ⚠️ THE SAME MATH AS THE OLD LOOP, ten times a second: inside the reach and more than 64u from the middle, the body lifted
/// off the floor by `Placeable.GroundBreak` first — a grounded controller cancels velocity and re-snaps — then given the
/// pull's speed toward the middle. It removes itself when the pull closes.
/// </summary>
public sealed class BossPull : Component
{
	Vector3 _at;
	float _radius, _speed, _rate = 10f;
	TimeUntil _from, _until, _next;

	/// <summary>
	/// Pull this machine's own player toward `at`, starting `delay` seconds from now and lasting `seconds`: `speed` a tick,
	/// ten ticks a second, anyone inside `radius`. LOCAL — `NZNet.OberonPull`. A second pull replaces the first.
	/// </summary>
	public static void Apply( NZPlayer player, Vector3 at, float radius, float speed, float delay, float seconds )
	{
		if ( !player.IsValid() || player.IsProxy || seconds <= 0f ) return;

		var p = player.Components.GetOrCreate<BossPull>();
		p._at = at;
		p._radius = MathF.Max( 1f, radius );
		p._speed = speed;
		p._from = MathF.Max( 0f, delay );
		p._until = MathF.Max( 0f, delay ) + seconds;
		p._next = 0f;
	}

	protected override void OnUpdate()
	{
		if ( _until <= 0f ) { Destroy(); return; }
		if ( _from > 0f || !_next ) return;
		_next = 1f / _rate;

		var player = Components.Get<NZPlayer>( FindMode.EverythingInSelf );
		if ( !player.IsValid() || player.IsProxy ) return;

		var d = player.WorldPosition.Distance( _at );
		if ( d > _radius || d < 64f ) return;

		var c = player.Components.Get<PlayerController>( FindMode.EverythingInSelfAndDescendants );
		var body = c.IsValid() ? c.Body : null;
		if ( !body.IsValid() ) return;

		var dir = (_at - player.WorldPosition).WithZ( 0f ).Normal;
		player.WorldPosition += Vector3.Up * Placeable.GroundBreak;
		body.Velocity += dir * _speed;
	}
}