package match

import (
	"context"
	"fmt"
	"github.com/gogf/gf/v2/frame/g"
)

// 定义前缀树节点
type TrieNode struct {
	Children map[rune]*TrieNode // 子节点
	IsEnd    bool               // 是否为单词结尾
}

// 插入单词到前缀树中
func (tn *TrieNode) Insert(words ...string) {
	for _, word := range words {
		current := tn
		for _, char := range word {
			if current.Children == nil {
				current.Children = make(map[rune]*TrieNode)
			}
			node, exists := current.Children[char]
			if !exists {
				node = &TrieNode{}
				current.Children[char] = node
			}
			current = node
		}
		current.IsEnd = true
	}
}

// Remove 删除单词
func (tn *TrieNode) Remove(words ...string) {
	if tn == nil {
		g.Log().Infof(context.Background(), "TrieNode Remove is nil")
	}
	for _, word := range words {
		current := tn
		parent := tn
		if tn == nil {
			return
		}
		var lastChar int32
		for _, char := range word {
			if current == nil || current.Children == nil {
				return
			}
			node, _ := current.Children[char]
			parent = current
			current = node
			lastChar = char
		}

		if current != nil && current.IsEnd {
			current.IsEnd = false
		}
		if current != nil && current.Children != nil && len(current.Children) == 0 {
			delete(parent.Children, lastChar)
		}

	}
}

//func (trie *TrieNode) Print() {
//	g.Dump(trie)
//}

// 加载数据到前缀树中
func (trie *TrieNode) LoadDataToTrie(data map[string]int) {
	for key, value := range data {
		runes := []rune(key)
		current := trie
		for i, char := range runes {
			isEnd := 0
			if i == len(runes)-1 {
				isEnd = value
			}
			if current.Children == nil {
				current.Children = make(map[rune]*TrieNode)
			}
			node, exists := current.Children[char]
			if !exists {
				node = &TrieNode{}
				current.Children[char] = node
			}
			current = node
			current.IsEnd = isEnd == 1
		}
	}
}

// 在前缀树中查找单词
func (trie *TrieNode) FindWordInTrie(word string) bool {
	current := trie
	for _, char := range word {
		node, exists := current.Children[char]
		if !exists {
			return false
		}
		current = node
	}
	return current.IsEnd
}

// 在文本中查找单词
func (trie *TrieNode) FindWords(text string) []string {
	words := map[string]struct{}{}
	var rData []string

	runes := []rune(text)
	for i := 0; i < len(runes); i++ {
		current := trie
		for j := i; j < len(runes); j++ {
			char := runes[j]
			node, exists := current.Children[char]
			if !exists {
				break
			}
			current = node
			if current.IsEnd {
				words[string(runes[i:j+1])] = struct{}{}
			}
		}
	}
	for word, _ := range words {
		rData = append(rData, word)
	}
	return rData
}

func (trie *TrieNode) FindOneMaxStr(text string) string {
	stringArr := trie.FindWords(text)
	if len(stringArr) == 0 {
		return "" // 处理空数组的情况
	}

	longest := stringArr[0]
	for _, s := range stringArr {
		if len(s) > len(longest) {
			longest = s
		}
	}
	return longest
}

// 在文本中查找单词
func (trie *TrieNode) FindWordsInText(title, detail string) map[string]string {
	words := map[string]string{}
	var nomatchDetail string
	runes := []rune(fmt.Sprintf("%s %s", detail, title))
	detailArr := []rune(detail)
	detailLen := len(detailArr)
	for i := 0; i < len(runes); i++ {
		current := trie
		for j := i; j < len(runes); j++ {
			char := runes[j]
			node, exists := current.Children[char]
			if !exists {
				break
			}
			current = node
			if current.IsEnd {
				if _, ok := words[string(runes[i:j+1])]; !ok {
					if j < detailLen { //匹配正文
						//fmt.Println(string(runes[i : j+1]))
						words[string(runes[i:j+1])] = getDetailMatchStr(detailArr, i, j)
					} else { //匹配到标题
						if nomatchDetail == "" && detailLen > 0 { //匹配到标题后，正文取开头
							nomatchDetail = getDetailMatchStr(detailArr, detailLen-1, detailLen)
						}
						words[string(runes[i:j+1])] = nomatchDetail
					}
				}
			}
		}
	}

	return words
}

// 取关键词前40后40个字
var splitRune = map[int32]bool{}

func init() {
	splitRune = map[int32]bool{}
	for _, s := range []string{" ", ",", ".", "，", "。", " ", ":", "：", "、", "-"} {
		splitRune[[]rune(s)[0]] = true
	}
}

// getDetailMatchStr 获取正文中匹配到的短句
func getDetailMatchStr(desc []rune, left, right int) string {
	s, e, l := 0, 0, len(desc)

	sT := left - 40
	if sT < 0 {
		sT = 0
	}

	eT := sT + 80
	if eT > l {
		eT = l
	}

	for i := 1; i < 20; i++ {
		if s != 0 && e != 0 {
			return string(desc[s:e])
		}

		if s == 0 {
			//fmt.Printf("[sT]%s-%d   %s-%d\n", string(desc[sT-i]), desc[sT-i], string(desc[sT+i]), desc[sT+i])
			if sT+i < left && splitRune[desc[sT+i]] {
				s = sT + i + 1
			}
			if sT-i > 0 && splitRune[desc[sT-i]] {
				s = sT - i + 1
			}
		}

		if e == 0 {
			//fmt.Printf("[eT]%s-%d   %s-%d\n", string(desc[eT-i]), desc[eT-i], string(desc[eT+i]), desc[eT+i])
			if eT+i < l && splitRune[desc[eT+i]] {
				e = eT + i
			}
			if eT-i > right && splitRune[desc[eT-i]] {
				e = eT - i
			}
		}
	}

	if s == 0 {
		s = sT
	}
	if e == 0 {
		e = eT
	}

	return string(desc[s:e])
}