rbtree.hpp

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#pragma once
 
#include "../parser/toml_parser.hpp"
#include "songmap.hpp"
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <dirent.h>
#include <sys/stat.h>
#include <unordered_map>
#include <vector>
 
using namespace std;
 
#define RED   'R'
#define BLACK 'B'
 
string DIRECTORY_FIELD = string(parseTOMLField(
  PARENT_LIB, PARENT_LIB_FIELD_DIR)); // fetches the directory from the example config.toml for now
string DEBUG_LOG_PARSE = string(parseTOMLField(PARENT_DBG, PARENT_DBG_FIELD_TAGLIB_PARSER_LOG));
 
// Node structure for the Red-Black Tree
struct Node
{
  ino_t data; // Using inode type (ino_t) for directory entries
  char  color;
  Node *left, *right, *parent;
 
  Node(ino_t data) : data(data), color(RED), left(nullptr), right(nullptr), parent(nullptr) {}
};
 
// Red-Black Tree class
class RedBlackTree
{
private:
  Node*    root;
  Node*    NIL;
  SongTree songTree;
 
  void leftRotate(Node* x)
  {
    Node* y  = x->right;
    x->right = y->left;
    if (y->left != NIL)
    {
      y->left->parent = x;
    }
    y->parent = x->parent;
    if (x->parent == nullptr)
    {
      root = y;
    }
    else if (x == x->parent->left)
    {
      x->parent->left = y;
    }
    else
    {
      x->parent->right = y;
    }
    y->left   = x;
    x->parent = y;
  }
 
  void rightRotate(Node* x)
  {
    Node* y = x->left;
    x->left = y->right;
    if (y->right != NIL)
    {
      y->right->parent = x;
    }
    y->parent = x->parent;
    if (x->parent == nullptr)
    {
      root = y;
    }
    else if (x == x->parent->right)
    {
      x->parent->right = y;
    }
    else
    {
      x->parent->left = y;
    }
    y->right  = x;
    x->parent = y;
  }
 
  void fixInsert(Node* k)
  {
    while (k != root && k->parent->color == RED)
    {
      if (k->parent == k->parent->parent->left)
      {
        Node* u = k->parent->parent->right; // uncle
        if (u->color == RED)
        {
          k->parent->color         = BLACK;
          u->color                 = BLACK;
          k->parent->parent->color = RED;
          k                        = k->parent->parent;
        }
        else
        {
          if (k == k->parent->right)
          {
            k = k->parent;
            leftRotate(k);
          }
          k->parent->color         = BLACK;
          k->parent->parent->color = RED;
          rightRotate(k->parent->parent);
        }
      }
      else
      {
        Node* u = k->parent->parent->left; // uncle
        if (u->color == RED)
        {
          k->parent->color         = BLACK;
          u->color                 = BLACK;
          k->parent->parent->color = RED;
          k                        = k->parent->parent;
        }
        else
        {
          if (k == k->parent->left)
          {
            k = k->parent;
            rightRotate(k);
          }
          k->parent->color         = BLACK;
          k->parent->parent->color = RED;
          leftRotate(k->parent->parent);
        }
      }
    }
    root->color = BLACK;
  }
 
  void inorderHelper(Node* node)
  {
    TagLibParser parser(DEBUG_LOG_PARSE);
 
    if (node != NIL)
    {
      inorderHelper(node->left);
      auto metadataMap = parser.parseFromInode(node->data, DIRECTORY_FIELD);
      if (metadataMap.empty())
      {
        sendErrMsg(DEBUG_LOG_PARSE,
                   "Error: No files found matching the inode or no metadata extracted.");
      }
 
      for (const auto& pair : metadataMap)
      {
        /*std::cout << "File: " << pair.first << std::endl; */
        songTree.addSong(Song(node->data, pair.second));
      };
      inorderHelper(node->right);
    }
  }
 
public:
  RedBlackTree()
  {
    NIL        = new Node(0);
    NIL->color = BLACK;
    NIL->left = NIL->right = NIL;
    root                   = NIL;
  }
 
  void insert(ino_t data)
  {
    Node* new_node  = new Node(data);
    new_node->left  = NIL;
    new_node->right = NIL;
 
    Node* parent  = nullptr;
    Node* current = root;
 
    while (current != NIL)
    {
      parent = current;
      if (new_node->data < current->data)
      {
        current = current->left;
      }
      else
      {
        current = current->right;
      }
    }
 
    new_node->parent = parent;
 
    if (parent == nullptr)
    {
      root = new_node;
    }
    else if (new_node->data < parent->data)
    {
      parent->left = new_node;
    }
    else
    {
      parent->right = new_node;
    }
 
    if (new_node->parent == nullptr)
    {
      new_node->color = BLACK;
      return;
    }
 
    if (new_node->parent->parent == nullptr)
    {
      return;
    }
 
    fixInsert(new_node);
  }
 
  void inorderStoreMetadata() { inorderHelper(root); }
  void printSongTree() { songTree.display(); }
  auto returnSongTree() -> SongTree { return songTree; }
};