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>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,
    };
}