package service

import (
	"strings"
	"time"
)

const (
	depreciationStartAgeDayCloseHouse = 175
	depreciationStartAgeDayOpenHouse  = 175
)

func NormalizeDepreciationHouseType(raw string) string {
	return strings.TrimSpace(strings.ToLower(raw))
}

func DepreciationStartAgeDay(houseType string) int {
	switch NormalizeDepreciationHouseType(houseType) {
	case "close_house":
		return depreciationStartAgeDayCloseHouse
	case "open_house":
		return depreciationStartAgeDayOpenHouse
	default:
		return 0
	}
}

func FlockAgeDay(originDate time.Time, periodDate time.Time) int {
	origin := time.Date(originDate.Year(), originDate.Month(), originDate.Day(), 0, 0, 0, 0, time.UTC)
	period := time.Date(periodDate.Year(), periodDate.Month(), periodDate.Day(), 0, 0, 0, 0, time.UTC)
	if period.Before(origin) {
		return 0
	}
	return int(period.Sub(origin).Hours() / 24)
}

func DepreciationScheduleDay(originDate time.Time, periodDate time.Time, houseType string) int {
	ageDay := FlockAgeDay(originDate, periodDate)
	startAgeDay := DepreciationStartAgeDay(houseType)
	if ageDay <= 0 || startAgeDay <= 0 || ageDay < startAgeDay {
		return 0
	}
	return ageDay - startAgeDay + 1
}

func CalculateDepreciationAtDayN(
	initialPulletCost float64,
	dayN int,
	houseType string,
	multiplicationByHouseType map[string]map[int]float64,
) (float64, float64, float64) {
	return CalculateDepreciationFromDayRange(initialPulletCost, 1, dayN, houseType, multiplicationByHouseType)
}

func CalculateDepreciationFromDayRange(
	initialPulletCost float64,
	startDay int,
	endDay int,
	houseType string,
	multiplicationByHouseType map[string]map[int]float64,
) (pulletCostDayN, depreciationValue, multiplicationPercentage float64) {
	if initialPulletCost <= 0 || endDay <= 0 {
		return 0, 0, 0
	}
	if startDay <= 0 {
		startDay = 1
	}
	if endDay < startDay {
		return 0, 0, 0
	}

	normalizedHouseType := NormalizeDepreciationHouseType(houseType)
	houseMult, exists := multiplicationByHouseType[normalizedHouseType]
	if !exists {
		return 0, 0, 0
	}

	current := initialPulletCost
	for day := startDay; day <= endDay; day++ {
		mult, ok := houseMult[day]
		if !ok {
			// No standard for this day → assume no depreciation (mult=1).
			mult = 1.0
		}
		if day == endDay {
			pulletCostDayN = current
			multiplicationPercentage = mult
			depreciationValue = current * (1.0 - mult)
		}
		current = current * mult
		if current < 0 {
			current = 0
		}
	}

	return pulletCostDayN, depreciationValue, multiplicationPercentage
}

func CalculateEffectiveDepreciationPercent(totalDepreciationValue, totalPulletCostDayN float64) float64 {
	if totalPulletCostDayN <= 0 {
		return 0
	}
	return (totalDepreciationValue / totalPulletCostDayN) * 100
}