package danmaku

import (
	"git.noahlan.cn/northlan/ntools-go/stringn/ac"
	"strings"
)

type (
	CMD struct {
		IsCMD bool     // 是否CMD
		Arr   []string // 具体CMD  []string
	}
	Parser struct {
		trie       *ac.Trie
		allKeyArr  []string
		keywordMap map[string]struct{}
	}
	ParserBuilder struct {
	}
)

func NewCMDParser(keys []string) *Parser {
	p := &Parser{
		keywordMap: make(map[string]struct{}),
		allKeyArr:  make([]string, len(keys)),
	}
	for _, keyword := range keys {
		p.keywordMap[keyword] = struct{}{}
		p.allKeyArr = append(p.allKeyArr, keyword)
	}
	p.trie = ac.NewTrieBuilder().AddStrings(p.allKeyArr).Build()
	return p
}

func (p *Parser) ParseTest(content string) {
	p.trie.MatchString(content)
}

func (p *Parser) Parse(content string) *CMD {
	// 移除多余空格,小写
	tmpContent := strings.ToLower(strings.TrimSpace(content))
	matches := p.trie.MatchString(tmpContent)

	allKeyLen := 0
	matchedKeyMap := make(map[string]struct{})
	for _, match := range matches {
		tmp := p.allKeyArr[match.Pattern()]
		matchedKeyMap[tmp] = struct{}{}
		allKeyLen += len(tmp)
	}
	isCMD := len(tmpContent) <= allKeyLen

	// 避免同类型指令重复
	arrMap := make(map[rune]struct{})
	var matchedCmdArr []string
	if isCMD {
		matchedCmdArr = make([]string, 0, len(matchedKeyMap))
		for s := range matchedKeyMap {
			sRune := []rune(s)
			if _, ok := arrMap[sRune[0]]; !ok {
				arrMap[sRune[0]] = struct{}{}
				matchedCmdArr = append(matchedCmdArr, s)
			}
		}
	}
	return &CMD{
		IsCMD: len(tmpContent) <= allKeyLen,
		Arr:   matchedCmdArr,
	}
}