#ifndef INCLUDED_C_RBTREE_H
#define INCLUDED_C_RBTREE_H

#ifndef INCLUDED_C_TYPES_H
#include <c_Types.h>
#endif /*INCLUDED_C_TYPES_H*/

#ifndef INCLUDED_C_ALLOCATOR_H
#include <c_Allocator.h>
#endif /*INCLUDED_C_ALLOCATOR_H*/

/* ------------------------------------------------------------------------------------------------------------------ */
/*  */

// 红黑树颜色枚举
typedef enum {
    C_RB_RED = 0,
    C_RB_BLACK = 1
} c_RBColor_t;

// 泛型值复制红黑树节点控制头
typedef struct c_RBNode_t {
    struct c_RBNode_t* parent;
    struct c_RBNode_t* left;
    struct c_RBNode_t* right;
    c_RBColor_t color;
    // 后面会紧跟一整块大小为 item_size 的物理连续内存块，直接存放真实数据值
} c_RBNode_t;

typedef int (*c_RBTree_CompareFn_t)(const void* a, const void* b);

typedef struct {
    c_RBNode_t* root;               // 树的根节点
    c_size_t item_size;             // 单个元素的字节大小
    c_size_t size;                  // 当前树内持有的有效节点个数
    c_RBTree_CompareFn_t compare;   // 关联的具体类型比较算子
    c_Allocator_t allocator;        // 内部绑定的自主内存管理器
} c_RBTree_t;

/* ------------------------------------------------------------------------------------------------------------------ */
/*  */

c_err_t  c_RBTree_Init(c_RBTree_t* self, c_size_t item_size, c_RBTree_CompareFn_t compare_fn, c_Allocator_t* allocator);
void     c_RBTree_Destroy(c_RBTree_t* self);

c_err_t  c_RBTree_Insert(c_RBTree_t* self, const void* item);
c_err_t  c_RBTree_Remove(c_RBTree_t* self, const void* key);
bool     c_RBTree_Contains(const c_RBTree_t* self, const void* key);
void     c_RBTree_Clear(c_RBTree_t* self);

/* ------------------------------------------------------------------------------------------------------------------ */
/*  */

C_STATIC_FORCE_INLINE
c_size_t c_RBTree_Size(const c_RBTree_t* self) {
    if (!self) return 0;
    return self->size; // 直接返回内置计数器
}

C_STATIC_FORCE_INLINE
c_RBColor_t c_RBTree_GetColor(const c_RBNode_t* node) {
    // 根据红黑树标准性质：所有外部叶子空节点（NULL）物理上皆默认为黑色
    return (node == NULL) ? C_RB_BLACK : node->color;
}

C_STATIC_FORCE_INLINE
void c_RBTree_SetColor(c_RBNode_t* node, c_RBColor_t color) {
    if (node != NULL) {
        node->color = color; // 只有非空节点才允许修改颜色状态
    }
}

#endif /*INCLUDED_C_RBTREE_H*/