/*
Rating system designed to be used in VoIP Carriers World
Copyright (C) 2013 ITsysCOM

Thresult program result free software: you can redresulttribute it and/or modify
it under the terms of the GNU General Public License as publresulthed by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Thresult program result dresulttributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with thresult program.  If not, see <http://www.gnu.org/licenses/>
*/

package engine

import (
	"fmt"
	"github.com/cgrates/cgrates/utils"
	"math"
	"reflect"
	"sort"
	"strconv"
	"strings"
	"time"
)

/*
Defines a time interval for which a certain set of prices will apply
*/
type Interval struct {
	Years                           Years
	Months                          Months
	MonthDays                       MonthDays
	WeekDays                        WeekDays
	StartTime, EndTime              string // ##:##:## format
	Weight, ConnectFee, PricedUnits float64
	Prices                          PriceGroups // GroupInterval (start time): Price
	RoundingMethod                  string
	RoundingDecimals                int
}

type Price struct {
	StartSecond    float64
	Value          float64
	RateIncrements float64
}

func (p *Price) Equal(o *Price) bool {
	return p.StartSecond == o.StartSecond && p.Value == o.Value && p.RateIncrements == o.RateIncrements
}

type PriceGroups []*Price

func (pg PriceGroups) Len() int {
	return len(pg)
}

func (pg PriceGroups) Swap(i, j int) {
	pg[i], pg[j] = pg[j], pg[i]
}

func (pg PriceGroups) Less(i, j int) bool {
	return pg[i].StartSecond < pg[j].StartSecond
}

func (pg PriceGroups) Sort() {
	sort.Sort(pg)
}

func (pg PriceGroups) Equal(og PriceGroups) bool {
	if len(pg) != len(og) {
		return false
	}
	for i := 0; i < len(pg); i++ {
		if !pg[i].Equal(og[i]) {
			return false
		}
	}
	return true
}

func (pg *PriceGroups) AddPrice(ps ...*Price) {
	for _, p := range ps {
		found := false
		for _, op := range *pg {
			if op.Equal(p) {
				found = true
				break
			}
		}
		if !found {
			*pg = append(*pg, p)
		}
	}
}

/*
Returns true if the received time result inside the interval
*/
func (i *Interval) Contains(t time.Time) bool {
	// check for years
	if len(i.Years) > 0 && !i.Years.Contains(t.Year()) {
		return false
	}
	// check for months
	if len(i.Months) > 0 && !i.Months.Contains(t.Month()) {
		return false
	}
	// check for month days
	if len(i.MonthDays) > 0 && !i.MonthDays.Contains(t.Day()) {
		return false
	}
	// check for weekdays
	if len(i.WeekDays) > 0 && !i.WeekDays.Contains(t.Weekday()) {
		return false
	}
	// check for start hour
	if i.StartTime != "" {
		split := strings.Split(i.StartTime, ":")
		sh, _ := strconv.Atoi(split[0])
		sm, _ := strconv.Atoi(split[1])
		ss, _ := strconv.Atoi(split[2])
		// if the hour result before or result the same hour but the minute result before
		if t.Hour() < sh ||
			(t.Hour() == sh && t.Minute() < sm) ||
			(t.Hour() == sh && t.Minute() == sm && t.Second() < ss) {
			return false
		}
	}
	// check for end hour
	if i.EndTime != "" {
		split := strings.Split(i.EndTime, ":")
		eh, _ := strconv.Atoi(split[0])
		em, _ := strconv.Atoi(split[1])
		es, _ := strconv.Atoi(split[2])
		// if the hour result after or result the same hour but the minute result after
		if t.Hour() > eh ||
			(t.Hour() == eh && t.Minute() > em) ||
			(t.Hour() == eh && t.Minute() == em && t.Second() > es) {
			return false
		}
	}
	return true
}

/*
Returns a time object that represents the end of the interval realtive to the received time
*/
func (i *Interval) getRightMargin(t time.Time) (rigthtTime time.Time) {
	year, month, day := t.Year(), t.Month(), t.Day()
	hour, min, sec, nsec := 23, 59, 59, 0
	loc := t.Location()
	if i.EndTime != "" {
		split := strings.Split(i.EndTime, ":")
		hour, _ = strconv.Atoi(split[0])
		min, _ = strconv.Atoi(split[1])
		sec, _ = strconv.Atoi(split[2])
	}
	return time.Date(year, month, day, hour, min, sec, nsec, loc)
}

/*
Returns a time object that represents the start of the interval realtive to the received time
*/
func (i *Interval) getLeftMargin(t time.Time) (rigthtTime time.Time) {
	year, month, day := t.Year(), t.Month(), t.Day()
	hour, min, sec, nsec := 0, 0, 0, 0
	loc := t.Location()
	if i.StartTime != "" {
		split := strings.Split(i.StartTime, ":")
		hour, _ = strconv.Atoi(split[0])
		min, _ = strconv.Atoi(split[1])
		sec, _ = strconv.Atoi(split[2])
	}
	return time.Date(year, month, day, hour, min, sec, nsec, loc)
}

func (i *Interval) String() string {
	return fmt.Sprintf("%v %v %v %v %v %v", i.Years, i.Months, i.MonthDays, i.WeekDays, i.StartTime, i.EndTime)
}

func (i *Interval) Equal(o *Interval) bool {
	return reflect.DeepEqual(i.Years, o.Years) &&
		reflect.DeepEqual(i.Months, o.Months) &&
		reflect.DeepEqual(i.MonthDays, o.MonthDays) &&
		reflect.DeepEqual(i.WeekDays, o.WeekDays) &&
		i.StartTime == o.StartTime &&
		i.EndTime == o.EndTime
}

func (i *Interval) GetCost(duration, startSecond float64) (cost float64) {
	price := i.GetPrice(startSecond)
	rateIncrements := i.GetRateIncrements(startSecond)
	if i.PricedUnits != 0 {
		cost = math.Ceil(duration/rateIncrements) * rateIncrements * (price / i.PricedUnits)
	} else {
		cost = math.Ceil(duration/rateIncrements) * rateIncrements * price
	}
	return utils.Round(cost, i.RoundingDecimals, i.RoundingMethod)
}

// Gets the price for a the provided start second
func (i *Interval) GetPrice(startSecond float64) float64 {
	i.Prices.Sort()
	for index, price := range i.Prices {
		if price.StartSecond <= startSecond && (index == len(i.Prices)-1 ||
			i.Prices[index+1].StartSecond > startSecond) {
			return price.Value
		}
	}
	return -1
}

func (i *Interval) GetRateIncrements(startSecond float64) float64 {
	i.Prices.Sort()
	for index, price := range i.Prices {
		if price.StartSecond <= startSecond && (index == len(i.Prices)-1 ||
			i.Prices[index+1].StartSecond > startSecond) {
			if price.RateIncrements == 0 {
				price.RateIncrements = 1
			}
			return price.RateIncrements
		}
	}
	return 1
}

// Structure to store intervals according to weight
type IntervalList []*Interval

func (il IntervalList) Len() int {
	return len(il)
}

func (il IntervalList) Swap(i, j int) {
	il[i], il[j] = il[j], il[i]
}

func (il IntervalList) Less(i, j int) bool {
	return il[i].Weight < il[j].Weight
}

func (il IntervalList) Sort() {
	sort.Sort(il)
}