Fixed bug with spending more gold than in treasury

3 files changed, 58 insertions, 27 deletions

diff --git a/ai_trade.c b/ai_trade.c
index 00b9ea3..bf6aaf8 100644
--- a/ai_trade.c
+++ b/ai_trade.c
@@ -13,46 +13,74 @@ int* trade_gettradables(int player, int direction);
 int data_gettotvps(int p);
 int data_getdir(int dir, int p);
 
+static int bestCost[3];
+
 void ai_cleartrade(int trade[3][GOLD])
 {
  int i, j;
- for(i = 0; i < 3; i++)
+ for(i = 0; i < 3; i++) {
+  bestCost[i] = 0;
   for(j = 0; j < GOLD; j++)
    trade[i][j] = 0;
+ }
+}
+
+int saveCost(int trade[3][GOLD], int player)
+{
+ int buffer[3] = {0};
+ int i, j;
+ for(i = 0; i < 2; i++) {
+  for(j = 0; j < GOLD; j++) {
+   buffer[i] += get_trade(player, j, i) * trade[i][j];
+  }
+  buffer[2] += buffer[i];
+ }
+ if(buffer[2] < bestCost[2] || bestCost[2] == 0) {
+  for(i = 0; i < 3; i++)
+  bestCost[i] = buffer[i];
+ }
+ return buffer[2];
 }
 
-int recurse(int ret[], int cost, int trade[3][GOLD], int player, int era, int card)
+void restoreCost(int ret[3])
+{
+ int i;
+ for(i = 0; i < 3; i++)
+  ret[i] = bestCost[i];
+}
+
+int bestNeighbor(int player, int res)
+{
+ int best = 0;
+ if(get_trade(player, res, 0) != get_trade(player, res, 1)) {
+  best = (get_trade(player, res, 0) < get_trade(player, res, 1))? 0 : 1;
+ } else if(data_gettotvps(data_getdir(0, player)) > data_gettotvps(data_getdir(1, player)))
+  best = 0;
+ else best = 1;
+ return best;
+}
+
+void recurse(int ret[], int cost, int trade[3][GOLD], int player, int era, int card)
 {
  int i, j, k;
  if(data_canafford(player, era, card)) {
-  if(cost < ret[2] || ret[2] == 0) {
-   ret[2] = cost;
-   ret[0] = ret[1] = 0;
-   for(i = 0; i < 2; i++) {
-    for(j = 0; j < GOLD; j++) {
-     ret[i] += get_trade(player, j, i) * trade[i][j];
-    }
-   }
-  }
-  return 1; //if we can afford it, don't bother recursing further.
+  saveCost(trade, player);
+  return; //if we can afford it, don't bother recursing further.
  }
- for(k = 0; k < 2; k++) {
-  if(data_gettotvps(data_getdir(0, player)) > data_gettotvps(data_getdir(1, player)))
-   i = 0;
-  else i = 1;
-  if(k) i = (i-1)*-1; //The preceeding block selects the weaker neighbor for trade preference.
-  for(j = 0; j < GOLD; j++) {
-   if(data_getgold(player) - cost - get_trade(player, j, i) >= 0 && trade_gettradables(player, i)[j] - trade[i][j] >= trade[i][j]+1) {
+ for(j = 0; j < GOLD; j++) {
+  for(k = 0; k < 1; k++) {
+   i = bestNeighbor(player, j);
+   if(k) i = (i-1)*-1;
+   if(data_getgold(player) - cost - get_trade(player, j, i) >= 0 && trade_gettradables(player, i)[j] >= 1) {
     trade[i][j]++;
     trade[2][j]++;
     trade_set(player, trade);
-    if(recurse(ret, cost+get_trade(player, j, i), trade, player, era, card)) return 1;
+    recurse(ret, cost+get_trade(player, j, i), trade, player, era, card);
     trade[i][j]--;
     trade[2][j]--;
    }
   }
  }
- return 0;
 }
 
 int* ai_trade(int player, int era, int card)
@@ -65,6 +93,7 @@ int* ai_trade(int player, int era, int card)
  ai_cleartrade(trade);
  int gold = data_getgold(player);
  recurse(ret, 0, trade, player, era, card);
+ restoreCost(ret);
  ai_cleartrade(trade);
  trade_set(player, trade);
  return ret;
diff --git a/data.c b/data.c
index f631e3e..f9a8ba6 100644
--- a/data.c
+++ b/data.c
@@ -570,15 +570,14 @@ int data_iscouponed(int p, int era, int card)
 
 int data_canafford(int p, int era, int card)
 {
- int ret;
  if(data_iscouponed(p, era, card)) return 1;
  int *cost = cards_getcost(era, card);
+ if(cost[GOLD] > data_getgold(p) && p != hasfreebuild) return 0;
  int i, j, k;
  data_removedefinites(p, cost);
  data_removetraded(p, cost);
  if(data_iszerocost(cost)) return 1;
- ret = recurse(cost, data_getindefinites(p), 0) && (cost[GOLD] <= data_getgold(p));
- if(ret) return 1;
+ if(recurse(cost, data_getindefinites(p), 0)) return 1;
  if(p == hasfreebuild) return 2;
  return 0;
 }
diff --git a/trade.c b/trade.c
index 1a187b1..d916395 100644
--- a/trade.c
+++ b/trade.c
@@ -54,12 +54,15 @@ void trade_clear(int player)
 void trade_set(int player, int trade[3][GOLD])
 {
  int i, j;
- for(i = 0; i < 3; i++) {
+ for(i = 0; i < 3; i++)
+  tradebuffer[i][GOLD] = 0; //we deal with gold in the method that calls this
+ for(i = 0; i < 2; i++) {
   for(j = 0; j < GOLD; j++) {
-   tradebuffer[i][j] = trade[i][j];
+   tradebuffer[i][j] = trade[i][j] * -1;
   }
-  tradebuffer[i][GOLD] = 0; //we deal with gold in the method that calls this
  }
+ for(j = 0; j < GOLD; j++)
+  tradebuffer[2][j] = trade[2][j];
 }
 
 //gold amounts relative to player