package logic

import (
	"github.com/oylshe1314/framework/util"
)

const GameDailyResetHour int64 = 0
const GameDailyResetTime int64 = 3600 * GameDailyResetHour

type GameTime struct {
	Timestamp int64

	Days   int64
	Weeks  int64
	Months int64
	Years  int64
}

func NewGameTime(timestamp int64) *GameTime {
	if timestamp < 0 {
		timestamp = util.Unix()
	}

	var gt = &GameTime{
		Timestamp: timestamp,
	}

	if gt.Timestamp == 0 {
		return gt
	}

	util.Unix()

	gt.Days, gt.Weeks, gt.Months, gt.Years = absDate(gt.Timestamp)
	return gt
}

func leapYear(years int64) bool {
	return years%4 == 0 && (years%100 != 0 || years%400 == 0)
}

const (
	endJanuary   int64 = 31
	endFebruary        = endJanuary + 28
	endMarch           = endFebruary + 31
	endApril           = endMarch + 30
	endMay             = endApril + 31
	endJune            = endMay + 30
	endJuly            = endJune + 31
	endAugust          = endJuly + 31
	endSeptember       = endAugust + 30
	endOctober         = endSeptember + 31
	endNovember        = endOctober + 30
	endDecember        = endNovember + 31
)

var monthlyBefore = [...]int64{
	0,
	endJanuary,
	endFebruary,
	endMarch,
	endApril,
	endMay,
	endJune,
	endJuly,
	endAugust,
	endSeptember,
	endOctober,
	endNovember,
	endDecember,
}

func absDate(timestamp int64) (days int64, weeks int64, months int64, years int64) {
	timestamp -= GameDailyResetTime
	days = (timestamp - (timestamp+util.UTC8TimezoneOffset)%util.DayTotalSeconds + util.UTC8TimezoneOffset) / util.DayTotalSeconds
	weeks = (days + 3) / 7

	var leapYears = (days + 730) / 1461

	years = (days - leapYears) / 365

	var yearDays = days - (365*years + leapYears)

	months = years * 12

	if yearDays < endJanuary {
		months += 1
		return
	}

	if leapYear(years) {
		yearDays--
	}

	var month = yearDays / 31
	var end = monthlyBefore[month+1]
	if yearDays >= end {
		month++
	}

	months += month
	return
}