package billing

import (
	"errors"
	"math"
	"strings"
)

const Seedream50ProModel = "doubao-seedream-5-0-pro-260628"

// CalculateSeedreamAmountFen applies Seedream's additive input-image price
// before the platform markup: the first reference image is free and every
// additional reference image costs 2 fen.
func CalculateSeedreamAmountFen(outputPriceFen int64, referenceImageCount int, markupMultiplier float64) (int64, error) {
	if outputPriceFen <= 0 {
		return 0, errors.New("seedream output price must be positive")
	}
	if referenceImageCount < 0 || referenceImageCount > 10 {
		return 0, errors.New("seedream reference image count must be between 0 and 10")
	}
	if math.IsNaN(markupMultiplier) || math.IsInf(markupMultiplier, 0) || markupMultiplier < 1 {
		return 0, errors.New("seedream markup multiplier must be at least 1")
	}
	extraInputPriceFen := int64(max(0, referenceImageCount-1) * 2)
	return int64(math.Ceil(float64(outputPriceFen+extraInputPriceFen) * markupMultiplier)), nil
}

func IsSeedreamBillingModel(model string) bool {
	return strings.TrimSpace(model) == Seedream50ProModel
}