TradeSession

Remarks

Doc 28 is emphatic and it is right: the confirm-lock is not UI polish. It is the mechanism that makes the classic swap-at-the-last-moment scam impossible — the one where somebody replaces a legendary with a grey the instant before you click accept.

⚠ A confirmation quotes the revision it saw, and that is the part the document does not say. "Any change re-opens both confirmations" is necessary and not sufficient: it loses the race where a change and a confirmation cross in flight, because the confirmation arrives after the change has already cleared the flags and simply sets one again — against goods its sender never saw. Making the client quote a revision turns that race into a Stale, and it is the only form of the rule that holds without assuming an ordering the network does not give.

⚠ Nothing here moves anything. Settle produces one EconomyIntent and the ledger decides; a trade that half-applied is the duplication bug the whole design exists to prevent, and one intent is the only arrangement in which it cannot happen.

Fields and properties (8)

• public PlayerId Left

  One party.

• public PlayerId Right

  The other.

• public string Id

  What names it.

• public TradeStatus Status

  Where it is.

• public int Revision

  How many times what is on the table has changed. What a confirmation quotes.

• public TradeOffer LeftOffer

  What the left is offering.

• public TradeOffer RightOffer

  What the right is offering.

• public bool IsLocked

  Whether both have confirmed the current revision.

Events (1)

• public Action<TradeSession>? Changed

  Raised whenever what is on the table changes, so both clients redraw.

Methods (9)

• public TradeSession(PlayerId left, PlayerId right, string id)

  Opens a trade between two players.

• public bool HasConfirmed(PlayerId player)

  Whether somebody has confirmed the current revision.

• public TradeOffer? OfferOf(PlayerId player)

  What a player is offering.

• public TradeRefusal Offer(PlayerId player, DefId asset, long amount)

  Puts something on the table, or takes it off with a zero.

• public TradeRefusal Confirm(PlayerId player, int revision)

  Says yes to what is on the table right now.

• public TradeRefusal Unconfirm(PlayerId player)

  Takes a confirmation back.

• public TradeRefusal Cancel(PlayerId player)

  Calls it off.

• public EconomyIntent? Compose()

  What the swap would be, as one intent.

• public TradeRefusal Settle(IEconomyLedger ledger, out EconomyResult result)

  Does the swap.

Used by (1)

• TradeTestsVixen.Gameplay.Economy.Tests