1 files changed, 169 insertions, 0 deletions
diff --git a/src/game-server/trade.cpp b/src/game-server/trade.cpp
new file mode 100644
index 00000000..c6cd8425
--- /dev/null
+++ b/src/game-server/trade.cpp
@@ -0,0 +1,169 @@
+/*
+ *  The Mana World Server
+ *  Copyright 2007 The Mana World Development Team
+ *
+ *  This file is part of The Mana World.
+ *
+ *  The Mana World is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  any later version.
+ *
+ *  The Mana World is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with The Mana World; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ *  $Id$
+ */
+
+#include <algorithm>
+#include <cassert>
+
+#include "game-server/trade.hpp"
+
+#include "defines.h"
+#include "game-server/character.hpp"
+#include "game-server/gamehandler.hpp"
+#include "game-server/inventory.hpp"
+#include "net/messageout.hpp"
+
+Trade::Trade(Character *c1, Character *c2):
+    mChar1(c1), mChar2(c2), mState(TRADE_INIT)
+{
+    MessageOut msg(GPMSG_TRADE_REQUEST);
+    msg.writeShort(c1->getPublicID());
+    c2->getClient()->send(msg);
+    c1->setTrading(this);
+    c2->setTrading(this);
+}
+
+Trade::~Trade()
+{
+    mChar1->setTrading(NULL);
+    mChar2->setTrading(NULL);
+}
+
+void Trade::cancel(Character *c)
+{
+    MessageOut msg(GPMSG_TRADE_CANCEL);
+    if (c != mChar1) mChar1->getClient()->send(msg);
+    if (c != mChar2) mChar2->getClient()->send(msg);
+    delete this;
+}
+
+bool Trade::request(Character *c, int id)
+{
+    if (mState != TRADE_INIT || c != mChar2 || mChar1->getPublicID() != id)
+    {
+        /* This is not an ack for the current transaction. So assume
+           a new one is about to start and cancel the current one. */
+        cancel(c);
+        return false;
+    }
+
+    // Starts trading.
+    mState = TRADE_RUN;
+    MessageOut msg(GPMSG_TRADE_START);
+    mChar1->getClient()->send(msg);
+    mChar2->getClient()->send(msg);
+    return true;
+}
+
+static bool performTrade(TradedItems items, Inventory &inv1, Inventory &inv2)
+{
+    for (TradedItems::const_iterator i = items.begin(),
+         i_end = items.end(); i != i_end; ++i)
+    {
+        if (i->id != inv1.getItem(i->slot) ||
+            inv1.removeFromSlot(i->slot, i->amount) != 0 ||
+            inv2.insert(i->id, i->amount) != 0)
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void Trade::accept(Character *c)
+{
+    if (mState == TRADE_RUN)
+    {
+        if (c == mChar2)
+        {
+            std::swap(mChar1, mChar2);
+            std::swap(mItems1, mItems2);
+        }
+        assert(c == mChar1);
+        // First player agrees.
+        mState = TRADE_EXIT;
+        MessageOut msg(GPMSG_TRADE_ACCEPT);
+        mChar2->getClient()->send(msg);
+        return;
+    }
+
+    if (mState != TRADE_EXIT || c != mChar2)
+    {
+        // First player has already agreed. We only care about the second one.
+        return;
+    }
+
+    Inventory v1(mChar1, true), v2(mChar2, true);
+    if (!performTrade(mItems1, v1, v2) || !performTrade(mItems2, v2, v1))
+    {
+        v1.cancel();
+        v2.cancel();
+        cancel(NULL);
+        return;
+    }
+
+    MessageOut msg(GPMSG_TRADE_COMPLETE);
+    mChar1->getClient()->send(msg);
+    mChar2->getClient()->send(msg);
+    delete this;
+}
+
+void Trade::addItem(Character *c, int slot, int amount)
+{
+    if (mState == TRADE_INIT) return;
+
+    Character *other;
+    TradedItems *items;
+    if (c == mChar1)
+    {
+        other = mChar2;
+        items = &mItems1;
+    }
+    else
+    {
+        assert(c == mChar2);
+        other = mChar1;
+        items = &mItems2;
+    }
+
+    // Arbitrary limit to prevent a client from DOSing the server.
+    if (items->size() >= 50) return;
+
+    Inventory inv(c, true);
+    int id = inv.getItem(slot);
+    if (id == 0) return;
+
+    /* Checking now if there is enough items is useless as it can change
+       later on. At worst, the transaction will be cancelled at the end if
+       the client lied. */
+
+    TradedItem ti = { id, slot, amount };
+    items->push_back(ti);
+
+    MessageOut msg(GPMSG_TRADE_ADD_ITEM);
+    msg.writeShort(id);
+    msg.writeByte(amount);
+    other->getClient()->send(msg);
+
+    // Go back to normal run.
+    mState = TRADE_RUN;
+}