package domain

import (
	"fmt"
	"math"
)

// ComputeTrendFromAvgs is a pure version of the trend computation for testing.
func ComputeTrendFromAvgs(recentAvg, olderAvg float64) (pts int, direction string) {
	if olderAvg < 1 {
		if recentAvg > 0 {
			return 15, "new"
		}
		return 5, "stable"
	}
	changePct := math.Round((recentAvg - olderAvg) / olderAvg * 100)
	if recentAvg > olderAvg*1.2 {
		return 15, fmt.Sprintf("+%.0f%%", changePct)
	}
	if olderAvg > recentAvg*1.2 {
		return 0, fmt.Sprintf("%.0f%%", changePct)
	}
	return 5, "stable"
}