package curl2info

import (
	"errors"
	"fmt"
	"log"
	"regexp"
	"strconv"
	"strings"
	"time"

	"github.com/davecgh/go-spew/spew"
)

type timePointer struct {
	left, right           int
	leftlimit, rightlimit int
	per                   int
	isAll                 bool
}

func (tp *timePointer) String() string {
	return fmt.Sprintf("left: %d, right: %d, leftlimit: %d, rightlimit: %d, per: %d", tp.left, tp.right, tp.leftlimit, tp.rightlimit, tp.per)
}

// Crontab 的string解析
type Crontab struct {
	Min   []timePointer
	Hour  []timePointer
	Day   []timePointer
	Month []timePointer
	Week  []timePointer

	WillPlans []time.Time
	SkipPlans []time.Time

	YearPlan *TrieYear
}

// NewCrontab create 一个crontab
func NewCrontab(crontab string) *Crontab {
	cron := &Crontab{}
	cron.FromString(crontab)
	return cron
}

func (cron *Crontab) String() string {
	return fmt.Sprintf("min:%s\nhour:%s\nday:%s\nmonth:%s\nweek:%s\n", spew.Sdump(cron.Min), spew.Sdump(cron.Hour), spew.Sdump(cron.Day), spew.Sdump(cron.Month), spew.Sdump(cron.Week))
}

// FromString 解析crontab 的 表达式
func (cron *Crontab) FromString(crontab string) error {
	crontab = strings.TrimSpace(crontab)

	matches := regexp.MustCompile("[^ ]+").FindAllString(crontab, -1)
	mlen := len(matches)
	switch mlen {
	case 5:
		cron.Min = createTimePointer(matches[0], 0, 59, true)
		cron.Hour = createTimePointer(matches[1], 0, 23, true)
		cron.Day = createTimePointer(matches[2], 1, 31, false)
		cron.Month = createTimePointer(matches[3], 1, 12, true)
		cron.Week = createTimePointer(matches[4], 0, 6, true)

		cron.CreateYearPlan()
	default:
		return errors.New("mathches len != want, check crontab string")
	}

	return nil
}

// CreateYearPlan 创建年度计划
func (cron *Crontab) CreateYearPlan() {
	cron.YearPlan = newTrieYear(time.Now().Year())
	cron.YearPlan.FromCrontab(cron)
}

// TimeUp 是否时间快到
func (cron *Crontab) TimeUp(now time.Time) bool {

	maxlen := 1000
	createlen := 500

	plen := len(cron.WillPlans)
	if plen <= createlen {
		var lastplan time.Time
		if plen == 0 {
			lastplan = now
		} else {
			lastplan = cron.WillPlans[plen-1].Add(time.Minute)
		}
		if !cron.YearPlan.CheckYear() {
			cron.CreateYearPlan()
		}

		timeplans := cron.YearPlan.GetPlanTime(cron, lastplan, uint(maxlen-plen))
		cron.WillPlans = append(cron.WillPlans, timeplans...)
	}

	if len(cron.WillPlans) > 0 {
		istimeup := false
		for i := 0; i < maxlen; i++ {
			if now.Unix() >= cron.WillPlans[i].Unix() {
				istimeup = true
			} else {
				if istimeup {
					if i > 0 {
						cron.SkipPlans = append(cron.SkipPlans, cron.WillPlans[0:i]...)
						if len(cron.SkipPlans) >= maxlen+200 {
							cron.SkipPlans = cron.SkipPlans[200:]
						}
					}
					cron.WillPlans = cron.WillPlans[i+1:]
					return istimeup
				}

				return istimeup
			}
		}
		cron.SkipPlans = cron.WillPlans
		cron.WillPlans = nil
		return istimeup
	}

	log.Panicln("error willplans range")
	return false
}

func createTimePointer(min string, llimit, rlimit int, fixedLeftRight bool) []timePointer {

	var result []timePointer

	exelist := strings.Split(min, ",")
	for _, exe := range exelist {
		tp := timePointer{}

		takeper := strings.Split(exe, "/") // per
		var rangevalue, per string
		if len(takeper) == 1 {
			rangevalue = exe
			per = "1"
		} else {
			rangevalue = takeper[0]
			per = takeper[1]
		}
		// takeRange
		be := strings.Split(rangevalue, "-")
		var left, rigth string
		switch len(be) {
		case 1:
			left = be[0]
			rigth = be[0]
		case 2:
			left = be[0]
			rigth = be[1]
		default:
			panic(errors.New("range value is > 2"))
		}

		if left == "*" {
			tp.left = llimit
		} else {
			ileft, err := strconv.Atoi(strings.Replace(left, "^", "-", -1))
			if err != nil {
				panic(err)
			}
			tp.left = ileft
		}

		if rigth == "*" {
			tp.right = rlimit
		} else {
			iright, err := strconv.Atoi(strings.Replace(rigth, "^", "-", -1))
			if err != nil {
				panic(err)
			}
			tp.right = iright
		}

		iper, err := strconv.Atoi(per)
		if err != nil {
			panic(err)
		}

		tp.per = iper
		tp.leftlimit = llimit
		tp.rightlimit = rlimit

		// 修正左值
		leftfixed := tp.left
		if leftfixed < 0 {
			leftfixed += tp.rightlimit + 1
			if fixedLeftRight {
				tp.left = leftfixed
			}
		}

		rightfixed := tp.right
		if rightfixed < 0 {
			rightfixed += tp.rightlimit + 1
			if fixedLeftRight {
				tp.right = rightfixed
			}
		}

		// 全部符合 当左等于左 且 右等于右最大 并且 per == 1 TODO: 如果加入时间间隔 就需要 加多一个 附加值
		if leftfixed == tp.leftlimit && rightfixed == tp.rightlimit && tp.per == 1 {
			tp.isAll = true
		}

		result = append(result, tp)
	}

	return result
}