1 files changed, 106 insertions, 0 deletions
diff --git a/src/gym_leader_rematch.c b/src/gym_leader_rematch.c
new file mode 100644
index 000000000..355ae5534
--- /dev/null
+++ b/src/gym_leader_rematch.c
@@ -0,0 +1,106 @@
+#include "global.h"
+#include "constants/flags.h"
+#include "random.h"
+#include "event_data.h"
+#include "battle_setup.h"
+#include "gym_leader_rematch.h"
+
+static void UpdateGymLeaderRematchFromArray(const u16 *data, size_t size, u32 maxRematch);
+static s32 GetRematchIndex(u32 trainerIdx);
+
+static const u16 GymLeaderRematches_AfterNewMauville[] = {
+    REMATCH_ROXANNE,
+    REMATCH_BRAWLY,
+    REMATCH_WATTSON,
+    REMATCH_FLANNERY,
+    REMATCH_NORMAN,
+    REMATCH_WINONA,
+    REMATCH_TATE_AND_LIZA,
+    REMATCH_JUAN
+};
+
+static const u16 GymLeaderRematches_BeforeNewMauville[] = {
+    REMATCH_ROXANNE,
+    REMATCH_BRAWLY,
+    // Wattson isn't available at this time
+    REMATCH_FLANNERY,
+    REMATCH_NORMAN,
+    REMATCH_WINONA,
+    REMATCH_TATE_AND_LIZA,
+    REMATCH_JUAN
+};
+
+void UpdateGymLeaderRematch(void)
+{
+    if (FlagGet(FLAG_SYS_GAME_CLEAR) && (Random() % 100) <= 30)
+    {
+        if (FlagGet(FLAG_WATTSON_REMATCH_AVAILABLE))
+            UpdateGymLeaderRematchFromArray(GymLeaderRematches_AfterNewMauville, ARRAY_COUNT(GymLeaderRematches_AfterNewMauville), 5);
+        else
+            UpdateGymLeaderRematchFromArray(GymLeaderRematches_BeforeNewMauville, ARRAY_COUNT(GymLeaderRematches_BeforeNewMauville), 1);
+    }
+}
+
+static void UpdateGymLeaderRematchFromArray(const u16 *data, size_t size, u32 maxRematch)
+{
+    s32 whichLeader = 0;
+    s32 lowestRematchIndex = 5;
+    u32 i;
+    s32 rematchIndex;
+    for (i = 0; i < size; i++)
+    {
+        if (!gSaveBlock1Ptr->trainerRematches[data[i]])
+        {
+            rematchIndex = GetRematchIndex(data[i]);
+            if (lowestRematchIndex > rematchIndex)
+                lowestRematchIndex = rematchIndex;
+            whichLeader++;
+        }
+    }
+    if (whichLeader != 0 && lowestRematchIndex <= maxRematch)
+    {
+        whichLeader = 0;
+        for (i = 0; i < size; i++)
+        {
+            if (!gSaveBlock1Ptr->trainerRematches[data[i]])
+            {
+                rematchIndex = GetRematchIndex(data[i]);
+                if (rematchIndex == lowestRematchIndex)
+                    whichLeader++;
+            }
+        }
+        if (whichLeader != 0)
+        {
+            whichLeader = Random() % whichLeader;
+            for (i = 0; i < size; i++)
+            {
+                if (!gSaveBlock1Ptr->trainerRematches[data[i]])
+                {
+                    rematchIndex = GetRematchIndex(data[i]);
+                    if (rematchIndex == lowestRematchIndex)
+                    {
+                        if (whichLeader == 0)
+                        {
+                            gSaveBlock1Ptr->trainerRematches[data[i]] = lowestRematchIndex;
+                            break;
+                        }
+                        whichLeader--;
+                    }
+                }
+            }
+        }
+    }
+}
+
+static s32 GetRematchIndex(u32 trainerIdx)
+{
+    s32 i;
+    for (i = 0; i < 5; i++)
+    {
+        if (!HasTrainerBeenFought(gRematchTable[trainerIdx].trainerIds[i]))
+        {
+            return i;
+        }
+    }
+    return 5;
+}