using Microsoft.Extensions.Logging;

namespace NewMoon.Samples.NPC;

/// <summary>
/// The custom NPC: a <c>npc_bot_newmoon</c> classname that is a factory alias of <c>base_boss</c>. Spawning it yields a real
/// <c>base_boss</c> that carries the new classname, and the registry calls the lifecycle overrides below.
/// </summary>
/// <remarks>
/// The class only logs. Reading keyvalues, inputs and outputs from a custom entity is not part of the landed API yet, so the
/// spawner supplies <c>health</c> and <c>model</c>, for example <c>ent_create npc_bot_newmoon health 500 model models/bots/headless_hatman.mdl</c>. The registry needs an accessible parameterless constructor.
/// </remarks>
[CustomEntity("npc_bot_newmoon", "base_boss", PrecacheModels = ["models/bots/headless_hatman.mdl"])]
internal sealed class NPCBotNewMoon : FCustomEntity
{
    /// <summary>
    /// The logger the callbacks write to; set by <see cref="CustomNpcSample"/> at start-up, because the registry creates this
    /// object through its parameterless constructor.
    /// </summary>
    internal static ILogger? Log { get; set; }

    // Captured at spawn so the remove log never depends on the view still resolving while the instance is torn down.
    private int _index = -1;

    /// <inheritdoc/>
    protected override void OnSpawn()
    {
        _index = Entity.Index;
        Log?.LogNPCSpawn(_index);
    }

    /// <inheritdoc/>
    protected override void OnActivate() => Log?.LogNPCActivate(_index);

    /// <inheritdoc/>
    protected override void OnRemoved() => Log?.LogNPCRemoved(_index);
}