#include "common.h"

#define nullptr 0

#define u64 unsigned long long int
#define u32 unsigned int
#define maxstringsize 10

typedef struct LinkNode
{
	u64 hash_value;
	u32 depth; // 这个 node 所在的深度， 根目录是0
	u32 mNum;
	u32 create_tm;
	bool is_del;
	char str[maxstringsize];
	LinkNode *father;
	LinkNode *sonlist;
	LinkNode *next; // 用于 sonlist 中链接各个子 node
}LinkNode;

#define maxmemsize 1007  //散列表大小, 根据题目要求, 一般设置为原数据大小的 2-4 倍 + 7 （一个质数， 这样取模后更加均匀散列）
static LinkNode g_n_mem[maxmemsize];
static int g_n_mem_cnt = 0;

typedef struct HashNode
{
	u64 hash_value;
	LinkNode *filePtr;
	HashNode *next;
}HashNode;
#define maxhashsize 107
static HashNode *m_hashmap[maxhashsize];
static HashNode g_hn_mem[maxmemsize * 2];
static int g_hn_mem_cnt = 0;

static char filename[20][maxstringsize]
{
	{"root"},
	{"aaaa"},
	{"bbbb"},
	{"april"},
	{"friday"},
	{"monday"},
	{"love"},
	{"kiss"},
	{"autum"},
	{"weather"},
	{"water"},
	{"leak"},
	{"mouth"},
	{"leader"},
	{"gohome"},
	{"shafa"},
	{"season"},
	{"global"},
	{"see"},
	{"sea"},
};

static LinkNode *root = nullptr;
static u32 g_create_tm = 0;
#define m_max_depth 5 // there is 5 level only

u64 my_hash(const char str[]) //因为题目说只有 小写字母,因此做一个 26 进制的进位就可以满足, 如果是小写+数字，则进位改成 26+10, hash 函数可以根据实际需求构造
{
	u64 h = 0;
	while (*str != '\0')
	{
		h = h * 26 + (*str++) - 'a' + 1; // 字符串全是小写的情况, 可根据情况改成 31 / 131
	}
	return h & 0xFFFFFFFFFFFFFFFF;
}

u64 my_hash2(const char str[]) // 这个hash 实现方法，在几个题目上机试了都没有问题，还是挺实用的
{
	u64 h = 0;
	u64 p = 1;
	while (*str != '\0')
	{
		h += p * (*str++);
		p *= 2531011;
	}
	return h & 0xFFFFFFFFFFFFFFFF;
}

void add_to_hash_list(HashNode **phead, HashNode *pNode) //改变一个指针, 必须要传指针的地址进来
{
	pNode->next = *phead;
	*phead = pNode;
}

LinkNode *is_exist_in_hash_list(u64 hash_value) // 检查 hash 表是否已经存在对应的节点
{
	HashNode *p = m_hashmap[hash_value % maxhashsize];
	while (p != nullptr)
	{
		if (p->hash_value == hash_value)
		{
			return p->filePtr;
		}
		p = p->next;
	}
	return nullptr;
}

HashNode *get_hash_node(u64 hash_value) //获取 hash 节点对应的保存的 指针（文件信息）
{
	HashNode *p = m_hashmap[hash_value % maxhashsize];
	while (p != nullptr)
	{
		if (p->hash_value == hash_value)
		{
			return p;
		}
		p = p->next;
	}
	return nullptr;
}

void del_from_hash_list(u64 hash_value) //从 hash 表中移除, 如果给 hash 表增加头节点, 则删除起来代码更简洁
{
	HashNode *p = m_hashmap[hash_value % maxhashsize];
	if (p->hash_value == hash_value)
	{
		m_hashmap[hash_value % maxhashsize] = p->next;
	}
	else
	{
		HashNode *pre = p;
		p = p->next;
		while (p != nullptr)
		{
			if (p->hash_value == hash_value)
			{
				pre->next = p->next;
				break; //must has break
			}
			pre = p;
			p = p->next;
		}
	}
	p->hash_value = 0;
	p->filePtr = nullptr;
	p->next = nullptr;
}

void add_to_father_son_list(LinkNode *father, LinkNode *pNode) //将文件添加到对应的父节点
{
	pNode->next = father->sonlist;
	father->sonlist = pNode;
	pNode->father = father;
}

void init(int mNum)
{
	LOGE("mNum = %d", mNum);
	g_create_tm = 0;

	for (int i = 0; i < maxhashsize; i++)
	{
		m_hashmap[i] = nullptr;
	}
	g_n_mem_cnt = 0;

	for (int i = 0; i < maxhashsize * 2; i++)
	{
		g_hn_mem[i].filePtr = nullptr;
		g_hn_mem[i].hash_value = 0;
		g_hn_mem[i].next = nullptr;
	}
	g_hn_mem_cnt = 0;

	//add root node
	u64 hash_value = my_hash(filename[0]);
	root = &g_n_mem[g_n_mem_cnt++];
	strcpy_s(root->str, filename[0]);
	root->hash_value = hash_value;
	root->sonlist = nullptr;
	root->next = nullptr;
	root->father = nullptr;
	root->depth = 0;
	root->mNum = mNum;
	root->create_tm = g_create_tm++;
	root->is_del = false;

	//add to hash list
	HashNode *pNode = &g_hn_mem[g_hn_mem_cnt++];
	pNode->hash_value = hash_value;
	pNode->filePtr = root;
	pNode->next = nullptr;
	add_to_hash_list(&m_hashmap[pNode->hash_value % maxhashsize], pNode);
}

void add_file(char upper[], char newFile[], int mNum) // 添加新的文件到已经存在的节点下
{
	u64 hash_value = my_hash(upper);
	LinkNode * father = is_exist_in_hash_list(hash_value);
	if (father == nullptr)
	{
		LOGE("there is no upper= %s mNum=%d return %s", upper, mNum, newFile);
		return;
	}
	else if (mNum >= father->mNum)
	{
		LOGE("can not add to upper= %s mNum=%d > %d return %s", upper, mNum, father->mNum, newFile);
		return;
	}

	father->mNum -= mNum;

	LOGE("father = %s %s , son = %s", father->str, upper, newFile);

	//add node
	u64 son_hash_value = my_hash(newFile);
	LinkNode *son = &g_n_mem[g_n_mem_cnt++];
	strcpy_s(son->str, newFile);
	son->hash_value = son_hash_value;
	son->sonlist = nullptr;
	son->next = nullptr;
	son->mNum = mNum;
	son->depth = father->depth + 1;
	son->create_tm = g_create_tm++;
	son->is_del = false;

	//add to hash list
	HashNode *pNode = &g_hn_mem[g_hn_mem_cnt++];
	pNode->hash_value = son_hash_value;
	pNode->filePtr = son;
	pNode->next = nullptr;
	add_to_hash_list(&m_hashmap[pNode->hash_value % maxhashsize], pNode);

	//add to father son list
	add_to_father_son_list(father, son);
}

void update_depth(LinkNode *father, u32 *max_depth) //更新每个文件所在的 层 (深度) , 并返回当前节点所在链的最大深度 （也可以计算当前节点的子节点的深度）
{
	if (father->sonlist == nullptr)
	{
		if (father->depth > *max_depth)
		{
			*max_depth = father->depth;
		}
		return;
	}

	LinkNode *p = father->sonlist;
	while (p != nullptr) {
		p->depth = father->depth + 1;
		update_depth(p, max_depth);
		p = p->next;
	}
}

//如果file 已经存在于 upper 下, 直接返回
//假设深度最大是5, 如果并入 upper 后，总的深度超过5，则直接返回
//合并规则: file 的 mNum 并入 upper 节点, file 的子链表变成 upper 的子链表， 同时需要删除 file 节点 ( node 本身 和 hash 表都要更新)
void merge_file(char upper[], char file[])
{
	u64 hash_value = my_hash(upper);
	LinkNode * father = is_exist_in_hash_list(hash_value);

	u64 son_hash_value = my_hash(file);
	LinkNode * son = is_exist_in_hash_list(son_hash_value);

	if (father == nullptr || son == nullptr)
		return;

	LOGE("father = %s %s , son = %s %s", father->str, upper, son->str, file);

	u32 max_depth = 0;
	update_depth(son, &max_depth);
	if (father->depth + max_depth - son->depth > m_max_depth)
	{
		LOGE("depth is beyond limit, return depth: %s(%d) %s(%d) max_depth(%d)",
			father->str, father->depth, son->str, son->depth, max_depth);
		return;
	}
	LOGE("max_depth of %s = %d", son->str, max_depth);

	//add to father son list
	LinkNode *p = son->sonlist;
	while (p != nullptr) {
		// 这里有 BUG, 因为添加到父节点的子链表会导致 next指向改变, 再指行 p=p->next 会错误
		LinkNode *q = p;
		p = p->next;
		add_to_father_son_list(father, q);
	}

	max_depth = 0;
	update_depth(father, &max_depth);

	//remove from hash list
	del_from_hash_list(son->hash_value);

	//remove node
	son->sonlist = nullptr;
	son->father = nullptr;
	son->next = nullptr;
	son->hash_value = 0;
	son->mNum = 0;
	son->depth = 0;
	son->is_del = true;
}

//给排名前 depthNum 的文件增加 mNum 个文件 (除了 root 之外)
//排名规则: 人数最少,优先级最高, 如果人数一样,创建时间越晚，优先级越高
//这里有一个问题, 当直接对 g_n_mem 数组进行冒泡排序, 将会改下对于数组里面的内容
//但由于这个数组对应的 hash 节点里的 *filePtr 还是指向之前的内存, 因此需要同步改 hash 对应的 *filePtr

void recuit(u32 depthNum, u32 mNum)
{
	LOGE("depthNum = %d mNum = %d", depthNum, mNum);
	int count = 0;
	for (int i = 1; i < g_n_mem_cnt - 1; i++)
	{
		if (g_n_mem[i].is_del == false)
		{
			count++;
			for (int j = i + 1; j < g_n_mem_cnt; j++)
			{
				if (g_n_mem[j].is_del == false
					&& (g_n_mem[i].mNum > g_n_mem[j].mNum
						|| (g_n_mem[i].mNum > g_n_mem[j].mNum && g_n_mem[i].create_tm < g_n_mem[j].create_tm)))
				{
					//因为 hashnode 保存的指针 filePtr 指向 g_n_mem[i], 而内存里面的数据发生交换，需要同步修改 hash list 
					HashNode *pi = get_hash_node(g_n_mem[i].hash_value);
					HashNode *pj = get_hash_node(g_n_mem[j].hash_value);
					pi->filePtr = &g_n_mem[j];
					pj->filePtr = &g_n_mem[i];

					LinkNode tmp = g_n_mem[i];
					g_n_mem[i] = g_n_mem[j];
					g_n_mem[j] = tmp;
				}
			}
		}
		if (count >= depthNum)
		{
			break;
		}
	}

	count = 0;
	for (int i = 1; i < g_n_mem_cnt - 1; i++)
	{
		if (g_n_mem[i].is_del == false)
		{
			g_n_mem[i].mNum += mNum;
			count++;
		}
		if (count >= depthNum)
		{
			break;
		}
	}
}

//root->1->3(april)->5(monday)->6(love)->7(kiss)
//root->1->4(friday)
//root->2(bbb)->8(autum)->9(weather)->10(water)

extern void test_hash()
{
	init(100);
	add_file(filename[0], filename[1], 50);
	add_file(filename[0], filename[2], 40);
	add_file(filename[1], filename[3], 10);
	add_file(filename[1], filename[4], 15);

	add_file(filename[3], filename[5], 5);
	add_file(filename[5], filename[6], 3);
	add_file(filename[6], filename[7], 2);

	add_file(filename[2], filename[8], 7);

	//add fail
	add_file(filename[8], filename[9], 9); //父只有7个,添加失败
	add_file(filename[9], filename[10], 4); //没有父节点，添加失败

	add_file(filename[8], filename[9], 6); //父有7个
	add_file(filename[9], filename[10], 4); // okay

	//recuit(3, 10);
	merge_file(filename[6], filename[8]);
	merge_file(filename[6], filename[9]);

	//检查 hash 链表 filePtr 是否已经被修改
	for (int i = 0; i < g_n_mem_cnt; i++)
	{
		u64 hash_value = my_hash(filename[i]);
		LinkNode * pNode = is_exist_in_hash_list(hash_value);
		if (pNode != nullptr)
			LOGE("filename[%d] = %s, node str = %s", i, filename[i], pNode->str);
	}
}