package identify

import (
	"encoding/json"
	"strconv"
	"strings"
)

// SingleItem Nv和Ov的组合规则:
// 1. Nv是什么 || Nv不是什么
// 2. Ov是什么 || Ov不是什么
//
// 1与2的布尔运行结果交叉后, 得到4种组合 00, 01, 10, 11.
// 一个事件的判断, 就处在[00, 01, 10, 11]的其中, 有一项为nil, 则表示该项直接通过
// 多个事件, 就判断多个[00, 01, 10, 11], 所以得出以下结论:
// 针对设备配置如下规则:
//
//	{
//			"EventName 1": {
//	          "NvIn": [1,2,3,4],
//	          "NvNotIn": [5,6,7,8],
//	          "OvIn": [1,2,3,4],
//			  "OvNotIn": [5,6,7,8],
//			},
//			"EventName 2": {
//	          "NvIn": [1,2,3,4],
//	          "NvNotIn": [5,6,7,8],
//			  "OvNotIn": [5,6,7,8],
//			},
//	     ......
//	}
type SingleItem struct {
	nv ItemValue // 当前值
	ov ItemValue // 上一次的值

	rules map[EventName]Rule
}

func (s *SingleItem) Check(ov, nv ItemValue) EventName {
	defer func() {
		s.nv = ""
		s.ov = ""
	}()
	s.nv = nv
	s.ov = ov
	for event, rule := range s.rules {
		if s.check(rule) {
			return event
		}
	}
	return ""
}

func (s *SingleItem) checkForMulti(ov, nv ItemValue, rule Rule) bool {
	if ov == "" || nv == "" {
		return false
	}

	s.ov = ov
	s.nv = nv
	defer func() {
		s.nv = ""
		s.ov = ""
	}()

	var ovIn, ovNotIn, nvIn, nvNotIn = true, true, true, true
	if rule.OvIn != nil {
		ovIn = s.ovIn(rule.OvIn)
	}

	if rule.OvNotIn != nil {
		ovNotIn = s.ovNotIn(rule.OvNotIn)
	}

	if rule.NvIn != nil {
		nvIn = s.nvIn(rule.NvIn)
	}

	if rule.NvNotIn != nil {
		nvNotIn = s.nvNotIn(rule.NvNotIn)
	}

	return ovIn && ovNotIn && nvIn && nvNotIn
}

func (s *SingleItem) check(rule Rule) bool {
	if s.ov == "" || s.nv == "" {
		return false
	}

	var ovIn, ovNotIn, nvIn, nvNotIn = true, true, true, true
	if rule.OvIn != nil {
		ovIn = s.ovIn(rule.OvIn)
	}

	if rule.OvNotIn != nil {
		ovNotIn = s.ovNotIn(rule.OvNotIn)
	}

	if rule.NvIn != nil {
		nvIn = s.nvIn(rule.NvIn)
	}

	if rule.NvNotIn != nil {
		nvNotIn = s.nvNotIn(rule.NvNotIn)
	}

	return ovIn && ovNotIn && nvIn && nvNotIn
}

func (s *SingleItem) ovIn(slice []ItemValue) bool {
	b := true
	if slice != nil && s.inSlice(slice, s.ov) == false {
		b = false
	}
	return b
}

func (s *SingleItem) ovNotIn(slice []ItemValue) bool {
	b := true
	if slice != nil && s.inSlice(slice, s.ov) == true {
		b = false
	}
	return b
}

func (s *SingleItem) nvIn(slice []ItemValue) bool {
	b := true
	if slice != nil && s.inSlice(slice, s.nv) == false {
		b = false
	}
	return b
}

func (s *SingleItem) nvNotIn(slice []ItemValue) bool {
	b := true
	if slice != nil && s.inSlice(slice, s.nv) == true {
		b = false
	}
	return b
}

func (s *SingleItem) inSlice(slice []ItemValue, v ItemValue) bool {
	for _, s2 := range slice {
		s1 := s.transVar(s2)

		if s1 == v {
			return true
		}
		// 数字比较
		if _, err := strconv.ParseInt(s1, 10, 64); err != nil {
			return s.compare(s1, v)
		}
	}
	return false
}

func (s *SingleItem) transVar(v ItemValue) ItemValue {
	if v == VAR_NV {
		v = s.nv
	}

	if v == VAR_OV {
		v = s.ov
	}
	return v
}

func (s *SingleItem) compare(r string, v string) bool {
	if strings.Index(r, "...") > -1 {
		return s.compareRange(r, v)
	} else if strings.Index(r, " ") > 1 {
		return s.compareLogic(r, v)
	}

	return false
}

func (s *SingleItem) compareRange(r string, v string) bool {
	rl := strings.Split(r, "...")
	if len(rl) != 2 {
		return false
	}

	var min, max, vi int64 = 0, 0, 0
	if tmin, err := strconv.ParseInt(strings.TrimSpace(rl[0]), 10, 64); err == nil {
		min = tmin
	} else {
		return false
	}

	if tmax, err := strconv.ParseInt(strings.TrimSpace(rl[1]), 10, 64); err == nil {
		max = tmax
	} else {
		return false
	}

	if tvi, err := strconv.ParseInt(strings.TrimSpace(v), 10, 64); err == nil {
		vi = tvi
	} else {
		return false
	}

	return min <= vi && vi <= max
}

func (s *SingleItem) compareLogic(r string, v string) bool {
	rl := strings.Split(r, " ")
	if len(rl) != 2 {
		return false
	}

	var ri, vi int64 = 0, 0
	if tri, err := strconv.ParseInt(strings.TrimSpace(rl[1]), 10, 64); err == nil {
		ri = tri
	} else {
		return false
	}

	if tvi, err := strconv.ParseInt(strings.TrimSpace(v), 10, 64); err == nil {
		vi = tvi
	} else {
		return false
	}

	switch rl[0] {
	case "<":
		return vi < ri
	case "<=":
		return vi <= ri
	case ">":
		return vi > ri
	case ">=":
		return vi >= ri
	case "!=":
		return vi != ri
	}

	return false
}

// NewSingleCheck 生成一个检测对象, 之后调用Check来获得事件名称
func NewSingleCheck(rules map[EventName]Rule) *SingleItem {
	return &SingleItem{
		rules: rules,
	}
}

// NewSingleCheck 生成一个检测对象, 之后调用Check来获得事件名称
func newSingleCheckForMultiItem() *SingleItem {
	return &SingleItem{}
}

func StepTest(ov, nv, ruleString string) string {
	rules := make(map[string]Rule)
	err := json.Unmarshal([]byte(ruleString), &rules)
	if err != nil {
		println(err.Error())
	}

	return NewSingleCheck(rules).Check(ov, nv)
}