namespace Mr.BrickAdventures.Progression;

/// <summary>
/// Something that happened to player progression, raised by an aggregate as part of the operation
/// that caused it. Plain records with no engine dependency — an adapter republishes them as Godot
/// signals (ADR-0004), which is what makes "state changed ⇒ signal fired" un-bypassable.
/// </summary>
public abstract record ProgressionEvent;

/// <summary>Raised when a Playthrough loses its last life.</summary>
public sealed record RunEnded : ProgressionEvent;

/// <summary>
/// Raised the first time an Achievement is unlocked, and only then — so a subscriber that shows a
/// popup or pushes to Steam cannot fire twice however often it is told.
/// </summary>
public sealed record AchievementUnlocked(AchievementId Achievement) : ProgressionEvent;

/// <summary>
/// Raised whenever a Level is entered — every time, including the first Level of a new Playthrough
/// and the first Level after resuming one. Ghost recording and the speedrun timer both start from
/// this, so an entry path that does not announce is an entry path where neither works.
/// </summary>
public sealed record LevelStarted(LevelId Level) : ProgressionEvent;

/// <summary>
/// Lives remaining changed. Raised by the same operation that changed them, so no reader can observe
/// a stale value between the write and the announcement.
/// </summary>
public sealed record LivesChanged(Lives Remaining) : ProgressionEvent;

/// <summary>
/// Spendable coins changed — the Bank plus the current Attempt's takings, less what it has spent.
/// A single fact for readers, so nothing has to know the Attempt and Bank are separate.
/// </summary>
public sealed record TotalCoinsChanged(Coins Total) : ProgressionEvent;

/// <summary>
/// The set of owned Skills, or the level of one of them, changed. What <c>SkillManager</c> reconciles
/// its live components against, instead of being told separately by every caller.
/// </summary>
public sealed record SkillSetChanged : ProgressionEvent;