From f05b3c0b017e4e61333ab6df889b437289de6627 Mon Sep 17 00:00:00 2001
From: Henrique Gemignani Passos Lima <henrique@gemignani.org>
Date: Fri, 28 Oct 2022 11:43:51 +0300
Subject: [PATCH] Progress for rbtree_rebalance_for_erase

---
 src/Kyoto/rstl/rstl_map.cpp | 112 +++++++++++++++++++++++++++++++++++-
 1 file changed, 110 insertions(+), 2 deletions(-)

diff --git a/src/Kyoto/rstl/rstl_map.cpp b/src/Kyoto/rstl/rstl_map.cpp
index fe6181d6..33dd87bd 100644
--- a/src/Kyoto/rstl/rstl_map.cpp
+++ b/src/Kyoto/rstl/rstl_map.cpp
@@ -97,7 +97,7 @@ void rbtree_rebalance(void* header_void, void* node_void) {
       p->mColor = kNC_Red;
       node->mParent->mParent->mColor = kNC_Black;
       node = node->mParent->mParent;
-      
+
     } else {
       if (node == node->mParent->mLeft) {
         node = node->mParent;
@@ -115,7 +115,115 @@ void* rbtree_rebalance_for_erase(void* header_void, void* node_void) {
   _header* header = static_cast< _header* >(header_void);
   _node* node = static_cast< _node* >(node_void);
 
-  return nullptr;
+  _node* next;
+  _node* result = node;
+
+  if (node->mLeft == nullptr) {
+    next = node->mRight;
+  } else {
+    _node* tmp = node->mRight;
+    if (tmp == nullptr) {
+      next = tmp;
+    } else {
+      do {
+        result = tmp;
+        tmp = result->mLeft;
+      } while (result->mLeft != nullptr);
+      next = result->mRight;
+    }
+  }
+
+  if (result != node) {
+    node->mLeft->mParent = result;
+    result->mLeft = node->mLeft;
+
+    _node* tmp = result;
+    if (result != node->mRight) {
+      tmp = result->mParent;
+      if (next != nullptr) {
+        next->mParent = result->mParent;
+      }
+      result->mParent->mLeft = next;
+      result->mRight = node->mRight;
+      node->mRight->mParent = result;
+    }
+
+    if (header->mRootNode == node) {
+      header->mRootNode = result;
+    } else {
+      if (node->mParent->mLeft == node) {
+        node->mParent->mLeft = result;
+      } else {
+        node->mParent->mRight = result;
+      }
+    }
+
+    result->mParent = node->mParent;
+    node_color c = result->mColor;
+    result->mColor = node->mColor;
+    node->mColor = c;
+    result = node;
+
+  } else {
+    _node* a1 = result->mParent;
+    if (next != nullptr) {
+      next->mParent = a1;
+    }
+    if (header->mRootNode == node) {
+      header->mRootNode = next;
+    } else {
+      if (node->mParent->mLeft == node) {
+        node->mParent->mLeft = next;
+      } else {
+        node->mParent->mRight = next;
+      }
+    }
+
+    if (header->mLeftmost == node) {
+      if (node->mRight == nullptr) {
+        header->mLeftmost = node->mParent;
+      } else {
+        // prVar1 = next;
+        _node* prVar1 = next;
+        if (next == nullptr) {
+          header->mLeftmost = nullptr;
+        } else {
+          _node* newLeftmost;
+          do {
+            newLeftmost = prVar1;
+            prVar1 = newLeftmost->mLeft;
+          } while (newLeftmost->mLeft != nullptr);
+          header->mLeftmost = newLeftmost;
+        }
+      }
+    }
+
+    if (header->mRightmost == node) {
+      if (node->mLeft == nullptr) {
+        header->mRightmost = node->mParent;
+      } else {
+        // prVar1 = next;
+        _node* prVar1 = next;
+        if (next == nullptr) {
+          header->mRightmost = nullptr;
+        } else {
+          _node* newRightmost;
+          do {
+            newRightmost = prVar1;
+            prVar1 = newRightmost->mRight;
+          } while (newRightmost->mRight != nullptr);
+          header->mRightmost = newRightmost;
+        }
+      }
+    }
+  }
+
+  if (result->mColor != kNC_Black) {
+    while (true) {
+    }
+  }
+
+  return result;
 }
 
 void* rbtree_traverse_forward(const void* header_void, void* node_void) {