SVSimServer/SVSim.BattleNode/Sessions/Dispatch/KnownListBuilder.cs

using SVSim.BattleNode.Protocol.Bodies;

namespace SVSim.BattleNode.Sessions.Dispatch;

/// <summary>Pure transforms from the active player's RawBody sub-structures to the opponent-facing
/// shapes. No session state, no wire I/O — unit-testable in isolation. RawBody nested values arrive
/// as <c>Dictionary&lt;string,object?&gt;</c> / <c>List&lt;object?&gt;</c> with numeric leaves boxed
/// as long/int/double (see MsgEnvelope.FromJson).</summary>
internal static class KnownListBuilder
{
    /// <summary>The played card's knownList entry, or null when its identity can't be synthesized
    /// (token idx not in the deck map, or no matching move op). spellboost/attachTarget default to
    /// 0/"" for the vanilla slice; cost/clan/tribe are deferred (receiver re-derives from cardId).</summary>
    public static KnownCardEntry? BuildPlayedCard(
        IReadOnlyDictionary<int, long> deckMap, int playIdx, object? orderList)
    {
        if (!deckMap.TryGetValue(playIdx, out var cardId)) return null;
        var to = ExtractMoveTo(orderList, playIdx);
        if (to is null) return null;
        return new KnownCardEntry(Idx: playIdx, CardId: cardId, To: to.Value, Spellboost: 0, AttachTarget: "");
    }

    /// <summary>The <c>to</c> place-state of the FIRST <c>move</c> op whose <c>idx</c> list contains
    /// <paramref name="playIdx"/> (the played card's own move; later add/alter ops are the deferred
    /// token slice), or null if absent. NOTE: the sender-side <c>to</c> is passed through verbatim —
    /// for the vanilla slice we assume send-side and recv-side place-state codes match, pending
    /// recv-capture confirmation.</summary>
    public static int? ExtractMoveTo(object? orderList, int playIdx)
    {
        if (orderList is not IEnumerable<object?> ops) return null;
        foreach (var op in ops)
        {
            if (op is not IDictionary<string, object?> opDict) continue;
            if (!opDict.TryGetValue("move", out var moveRaw) || moveRaw is not IDictionary<string, object?> move) continue;
            if (move.TryGetValue("idx", out var idxRaw) && idxRaw is IEnumerable<object?> idxList)
            {
                foreach (var i in idxList)
                    if (AsLong(i) == playIdx && move.TryGetValue("to", out var toRaw))
                        return (int)AsLong(toRaw);
            }
        }
        return null;
    }

    /// <summary>Mine generated-token identities from a sender's <c>add</c> ops: yields
    /// <c>(idx, cardId, isSelf)</c> for every idx in each <c>{add:{idx:[...], isSelf, card:{cardId}}}</c>
    /// op. <c>isSelf</c> is surfaced verbatim (the sender's perspective tag on <c>CardObj.IsPlayer</c>,
    /// <c>RegisterToken.cs:22</c>) so the caller can route the identity into the correct side's map —
    /// <c>isSelf:1</c> = the sender's own token, <c>isSelf:0</c> = a cross-side gift living at this idx
    /// in the OPPONENT's index space (<see cref="BattleSessionState.RecordTokensFrom"/>). Skips any add
    /// whose <c>card</c> has no concrete <c>cardId</c> — choice tokens (<c>card:{candidates}</c>,
    /// <c>RegisterChoiceAdd</c>), copy tokens (<c>card:{baseIdx}</c>, <c>RegisterCopyToken</c>), and
    /// private-group adds (string <c>idx</c>) — all deferred and all caught by the <c>cardId</c>-key /
    /// <c>idx</c>-is-list guards. This is the only place a freshly-generated card's identity exists on
    /// the wire (bullet-3 audit F1; producing code <c>RegisterToken</c>/<c>RegisterActionBase</c>) —
    /// the played-card op itself never carries a <c>cardId</c>.</summary>
    public static IEnumerable<(int Idx, long CardId, int IsSelf)> MineAddOps(object? orderList)
    {
        if (orderList is not IEnumerable<object?> ops) yield break;
        foreach (var op in ops)
        {
            if (op is not IDictionary<string, object?> opDict) continue;
            if (!opDict.TryGetValue("add", out var addRaw) || addRaw is not IDictionary<string, object?> add) continue;

            add.TryGetValue("isSelf", out var isSelfRaw);
            var isSelf = (int)AsLong(isSelfRaw);

            if (!add.TryGetValue("card", out var cardRaw) || cardRaw is not IDictionary<string, object?> card) continue;
            if (!card.TryGetValue("cardId", out var cardIdRaw)) continue; // candidates/isChoice → no identity yet
            var cardId = AsLong(cardIdRaw);

            if (!add.TryGetValue("idx", out var idxRaw) || idxRaw is not IEnumerable<object?> idxList) continue;
            foreach (var i in idxList)
                yield return ((int)AsLong(i), cardId, isSelf);
        }
    }

    /// <summary>Mine choice/Discover-token identities: for each <c>isChoice</c> add op (idx, isSelf,
    /// candidates), resolve its cardId from the keyAction <c>selectCard</c> pick whose cardId is in that
    /// op's candidate pool. Yields <c>(idx, cardId, isSelf)</c> — same shape as <see cref="MineAddOps"/>,
    /// routed by the same <see cref="BattleSessionState.RecordTokensFrom"/> rule. The pick is on
    /// keyAction.selectCard, NOT the add op (RegisterChoiceAdd strips the concrete cardId,
    /// <c>NetworkBattleSetupCardEvent.cs:531-543</c>); the candidate-membership join handles the single
    /// case unambiguously (multi-choice: each chosen cardId matches the one choiceAdd whose candidates
    /// contain it). <c>type</c>/<c>cardId</c>/<c>open</c> on the keyAction are ignored here — <c>open</c>
    /// only gates the strip (<see cref="StripKeyActionForOpponent"/>), not the recording. An add whose
    /// candidates contain none of the picks is skipped (defensive — no record, no desync); Echo (no
    /// keyAction) yields nothing, leaving it mining-only via <see cref="MineAddOps"/>.</summary>
    public static IEnumerable<(int Idx, long CardId, int IsSelf)> MineChoicePicks(object? orderList, object? keyAction)
    {
        if (orderList is not IEnumerable<object?> ops) yield break;

        // Flatten every selectCard.cardId pick across all keyAction entries into a membership set.
        var picks = new HashSet<long>();
        if (keyAction is IEnumerable<object?> kaEntries)
        {
            foreach (var ka in kaEntries)
            {
                if (ka is not IDictionary<string, object?> kaDict) continue;
                if (!kaDict.TryGetValue("selectCard", out var scRaw) || scRaw is not IDictionary<string, object?> sc) continue;
                if (!sc.TryGetValue("cardId", out var idsRaw) || idsRaw is not IEnumerable<object?> ids) continue;
                foreach (var id in ids) picks.Add(AsLong(id));
            }
        }
        if (picks.Count == 0) yield break;

        foreach (var op in ops)
        {
            if (op is not IDictionary<string, object?> opDict) continue;
            if (!opDict.TryGetValue("add", out var addRaw) || addRaw is not IDictionary<string, object?> add) continue;
            if (!add.ContainsKey("isChoice")) continue;
            if (!add.TryGetValue("card", out var cardRaw) || cardRaw is not IDictionary<string, object?> card) continue;
            if (!card.TryGetValue("candidates", out var candRaw) || candRaw is not IEnumerable<object?> candidates) continue;

            // The chosen cardId is the candidate that the active player picked (∈ picks). One per op.
            long? chosen = null;
            foreach (var c in candidates)
            {
                var cid = AsLong(c);
                if (picks.Contains(cid)) { chosen = cid; break; }
            }
            if (chosen is null) continue; // no pick in this op's pool — skip (no desync, just no record)

            add.TryGetValue("isSelf", out var isSelfRaw);
            var isSelf = (int)AsLong(isSelfRaw);

            if (!add.TryGetValue("idx", out var idxRaw) || idxRaw is not IEnumerable<object?> idxList) continue;
            foreach (var i in idxList)
                yield return ((int)AsLong(i), chosen.Value, isSelf);
        }
    }

    /// <summary>Map an inbound keyAction (the active player's send) to the opponent-facing list:
    /// for each Choice(1)/HaveBeforeSkillChoice(5) entry, keep <c>{type,cardId}</c> and drop
    /// <c>selectCard</c> when its <c>open==0</c> (hidden draw-to-hand pick stays secret), pass it
    /// through when <c>open==1</c> (visible board choice — provisional reveal-immediately, §6).
    /// Non-choice KeyActionTypes are dropped (current behavior) until their own specs. Returns null
    /// for absent/empty keyAction or when every entry was dropped (vanilla play unchanged).</summary>
    public static IReadOnlyList<KeyActionEntry>? StripKeyActionForOpponent(object? keyAction)
    {
        if (keyAction is not IEnumerable<object?> entries) return null;
        var result = new List<KeyActionEntry>();
        foreach (var e in entries)
        {
            if (e is not IDictionary<string, object?> d) continue;
            d.TryGetValue("type", out var typeRaw);
            var type = (int)AsLong(typeRaw);
            if (type is not (1 or 5)) continue; // only Choice / HaveBeforeSkillChoice handled

            d.TryGetValue("cardId", out var cardIdRaw);
            var cardId = AsLong(cardIdRaw);

            SelectCardEntry? selectCard = null;
            if (d.TryGetValue("selectCard", out var scRaw) && scRaw is IDictionary<string, object?> sc)
            {
                sc.TryGetValue("open", out var openRaw);
                var open = (int)AsLong(openRaw);
                if (open != 0 && sc.TryGetValue("cardId", out var idsRaw) && idsRaw is IEnumerable<object?> ids)
                    selectCard = new SelectCardEntry(ids.Select(AsLong).ToList(), open);
            }
            result.Add(new KeyActionEntry(type, cardId, selectCard));
        }
        return result.Count == 0 ? null : result;
    }

    /// <summary>Rename <c>targetList</c> -> <c>oppoTargetList</c>; <c>isSelf</c> is actor-relative
    /// and passes through unchanged (F2). Null for a missing/empty list.</summary>
    public static IReadOnlyList<OppoTargetEntry>? RenameTargets(object? targetList)
    {
        if (targetList is not IEnumerable<object?> entries) return null;
        var result = new List<OppoTargetEntry>();
        foreach (var e in entries)
        {
            if (e is not IDictionary<string, object?> d) continue;
            d.TryGetValue("targetIdx", out var targetIdxRaw);
            d.TryGetValue("isSelf", out var isSelfRaw);
            result.Add(new OppoTargetEntry(
                TargetIdx: (int)AsLong(targetIdxRaw),
                IsSelf: (int)AsLong(isSelfRaw)));
        }
        return result.Count == 0 ? null : result;
    }

    /// <summary>Coerce a boxed RawBody numeric leaf (long/int/double/decimal/string) to long; 0 for
    /// null/unparseable.</summary>
    public static long AsLong(object? value) => value switch
    {
        long l => l,
        int i => i,
        double d => (long)d,
        decimal m => (long)m,
        string s when long.TryParse(s, out var p) => p,
        _ => 0,
    };
}