package cost

import (
	"crypto/sha256"
	"encoding/hex"
	"strings"
)

// KeyFingerprint returns a stable short hash for grouping usage by API key.
func KeyFingerprint(providerID, apiKey string) string {
	providerID = strings.TrimSpace(providerID)
	apiKey = strings.TrimSpace(apiKey)
	if apiKey == "" {
		return providerID + ":none"
	}
	sum := sha256.Sum256([]byte(providerID + ":" + apiKey))
	return hex.EncodeToString(sum[:8])
}