using System.Collections.Generic;
using Godot;
using GodotHostTest.Helpers;
using GodotHostTest.Interfaces;
using R3;

namespace GodotHostTest.Game;

public partial class TargetSpawner : Node2D, ITargetCollector, ITargetSpawner
{
    [Export] public double TimeBetweenSpawns;

    [Export] public required Timer Timer;

    private readonly List<ITarget> _availableTargets = [];

    public override void _Ready()
    {
        Spawn();
        Timer.Start(TimeBetweenSpawns);
    }

    private void MakeTargetAvailable(ITarget target)
    {
        _availableTargets.Add(target);
    }

    private void OnTimer()
    {
        Spawn();
    }

    private void Spawn()
    {
        // pick a random target
        var randomIndex = GD.RandRange(0, _availableTargets.Count - 1);
        var target = _availableTargets[randomIndex];
        _availableTargets.RemoveAt(randomIndex);

        // enable it
        target.Enable();

        // notify that a target has been spawned
        _targetSpawned.OnNext(target);
    }

    public void NewTarget(ITarget target)
    {
        _availableTargets.Add(target);
        target.Hit.Merge(target.TimedOut).Select(_ => target).Subscribe(MakeTargetAvailable).AddTo(this);
    }

    protected override void Dispose(bool disposing)
    {
        base.Dispose(disposing);
        _targetSpawned.Dispose();
    }

    private readonly Subject<ITarget> _targetSpawned = new();
    public Observable<ITarget> TargetSpawned => _targetSpawned.AsObservable();
}