using SVSim.BattleNode.Sessions;

namespace SVSim.BattleNode.Sessions.Dispatch;

/// <summary>Mutable per-session state shared across frame handlers. The mulligan barrier's
/// post-swap hands, plus (PvP-equivalency, vanilla slice) the per-side idx->cardId map used to
/// synthesize the opponent-facing <c>knownList</c>. Generated tokens (cardIds mined from
/// orderList <c>add</c> ops) are recorded into the SAME
/// <see cref="IdxToCardId"/> map via <see cref="RecordToken"/>; a reveal-gate set is still future.</summary>
internal sealed class BattleSessionState
{
    public BattleSessionPhase SessionPhase { get; set; } = BattleSessionPhase.AwaitingInitNetwork;
    public Dictionary<IBattleParticipant, long[]> PostSwapHands { get; } = new();

    /// <summary>Per-side idx->cardId, seeded lazily from <see cref="MatchContext.SelfDeckCardIds"/>.
    /// Holds deck cards (idx 1..deckCount, seeded) and generated tokens (idx>deckCount, recorded
    /// from add ops via <see cref="RecordToken"/>).</summary>
    public Dictionary<IBattleParticipant, Dictionary<int, long>> IdxToCardId { get; } = new();

    /// <summary>The sender's idx->cardId map, seeding it from its <see cref="MatchContext"/> on first
    /// use. <c>BuildPlayerDeck</c> assigns deck idx = position+1, so entry (i+1) -> cardIds[i].</summary>
    public IReadOnlyDictionary<int, long> GetOrSeedDeckMap(IBattleParticipant side)
    {
        if (!IdxToCardId.TryGetValue(side, out var map))
        {
            map = new Dictionary<int, long>();
            var deck = side.Context.SelfDeckCardIds;
            for (var i = 0; i < deck.Count; i++) map[i + 1] = deck[i];
            IdxToCardId[side] = map;
        }
        return map;
    }

    /// <summary>Record a generated token's identity into the side's idx->cardId map (the same map
    /// that holds deck cards). Mined from the sender's <c>orderList</c> <c>add</c> ops by
    /// <see cref="KnownListBuilder.MineAddOps"/>; surfaced later by <c>BuildPlayedCard</c> when the
    /// token is the played card. Deck idxs (1..deckCount) and token idxs (&gt;deckCount) don't
    /// collide — the client allocates token idxs after the deck.</summary>
    public void RecordToken(IBattleParticipant side, int idx, long cardId)
    {
        GetOrSeedDeckMap(side);            // ensure the per-side map exists (deck-seeded)
        IdxToCardId[side][idx] = cardId;   // overwrite-on-conflict: latest identity wins
    }
}