package evio

import "strings"

type null[T any] struct {
	val T
	ok  bool
}

type matcher struct {
	rawPattern  string
	pattern     string
	matchPrefix bool
	matchSuffix bool
}

// TODO 优化，使用缓存，只处理一次
func NewMatcher(pattern string) Matcher {
	m := matcher{
		rawPattern:  pattern,
		pattern:     pattern,
		matchPrefix: strings.HasSuffix(pattern, ".*"), // foo.*
		matchSuffix: strings.HasPrefix(pattern, ".*"), // *.bar
	}
	if m.matchPrefix {
		m.pattern = pattern[:len(pattern)-1]
	}
	if m.matchSuffix {
		m.pattern = pattern[1:]
	}
	return &m
}

func (m *matcher) Match(topic string) bool {
	if m.rawPattern == topic {
		return true
	}
	hasPrefix := strings.HasPrefix(topic, m.pattern)
	hasSuffix := strings.HasSuffix(topic, m.pattern)
	hasMiddle := strings.Contains(topic, m.pattern)
	// *.bar.*
	if !m.matchPrefix && !m.matchSuffix {
		return hasMiddle && !hasPrefix && !hasSuffix
	}
	// foo.*
	if m.matchPrefix {
		return hasPrefix
	}
	// *.bar
	if m.matchSuffix {
		return hasSuffix
	}
	return false
}