package identify

import (
	"encoding/json"
)

type MultiItem struct {
	nvs map[ItemName]ItemValue // 当前值
	ovs map[ItemName]ItemValue // 上一次的值

	rules map[EventName]MultiRule
}

func (m *MultiItem) Check(ovs, nvs map[ItemName]ItemValue) EventName {
	m.ovs = ovs
	m.nvs = nvs
	defer func() {
		m.ovs = nil
		m.nvs = nil
	}()

	for eventName, multiRule := range m.rules {
		if m.check(multiRule) {
			return eventName
		}
	}

	return ""
}

func (m *MultiItem) check(rules MultiRule) bool {
	s := newSingleCheckForMultiItem()
	s.SetVars(m.nvs)
	// 判断指定的点位名, 是否通过了检测, 有一项不为true, 提前返回false
	for itemName, rule := range rules {
		if s.checkForMulti(m.ovs[itemName], m.nvs[itemName], rule) == false {
			return false
		}
	}

	return true
}

func NewMultiCheck(rules map[EventName]MultiRule) *MultiItem {
	return &MultiItem{
		rules: rules,
	}
}

func MultiTest(ovs, nvs map[ItemName]ItemValue, ruleString string) string {
	rules := make(map[EventName]MultiRule)
	err := json.Unmarshal([]byte(ruleString), &rules)
	if err != nil {
		println(err.Error())
	}

	return NewMultiCheck(rules).Check(ovs, nvs)
}