using System.Collections.Generic;
using Godot;
using Mr.BrickAdventures.Progression;
using Mr.BrickAdventures.scripts.Resources;

namespace Mr.BrickAdventures.Autoloads;

/// <summary>
/// Translates domain events into Godot signals on the <see cref="EventBus"/>.
/// </summary>
/// <remarks>
/// <para>
/// The adapter half of ADR-0004. Aggregates raise plain records with no engine dependency; this is the
/// single place that turns them into signals, which is what makes "state changed ⇒ signal fired"
/// un-bypassable. Existing subscribers and scene wiring keep working unchanged.
/// </para>
/// <para>
/// Not a Node — it has no lifecycle of its own. The composition root owns one and hands it every
/// batch of drained events.
/// </para>
/// </remarks>
public sealed class ProgressionEventRepublisher
{
    private readonly LevelCatalogue _catalogue;
    private readonly SceneTree _tree;

    public ProgressionEventRepublisher(LevelCatalogue catalogue, SceneTree tree)
    {
        _catalogue = catalogue;
        _tree = tree;
    }

    public void Publish(IReadOnlyList<ProgressionEvent> events)
    {
        foreach (var @event in events)
            Publish(@event);
    }

    private void Publish(ProgressionEvent @event)
    {
        switch (@event)
        {
            case LevelStarted started:
                // The existing signal is keyed by array index because GhostManager names its replay
                // files ghost_level_{index}.json. Transitional: once ghosts key on LevelId this
                // becomes a straight pass-through and the index lookup goes away.
                EventBus.EmitLevelStarted(IndexOf(started.Level), _tree.CurrentScene);
                break;

            case RunEnded:
                EventBus.EmitRunEnded();
                break;

            case AchievementUnlocked unlocked:
                EventBus.EmitAchievementUnlocked(unlocked.Achievement.Value);
                break;

            default:
                GD.PushWarning($"No signal is published for domain event {@event.GetType().Name}.");
                break;
        }
    }

    private int IndexOf(LevelId level)
    {
        for (var i = 0; i < _catalogue.Levels.Count; i++)
            if (_catalogue.Levels[i]?.Id == level.Value)
                return i;

        return -1;
    }
}