interface DriftOptions {
	maxDrift?: number;
}

interface DriftResult {
	driftScore: number;
	overThreshold: boolean;
}

export const checkDrift = (
	original: string,
	current: string,
	options: DriftOptions = {},
): DriftResult => {
	const maxDrift = options.maxDrift ?? 0.6;

	if (original === current) return { driftScore: 0, overThreshold: false };

	// Simple character-level diff ratio
	const maxLen = Math.max(original.length, current.length);
	if (maxLen === 0) return { driftScore: 0, overThreshold: false };

	let changes = 0;
	for (let i = 0; i < maxLen; i++) {
		if (original[i] !== current[i]) changes++;
	}

	const driftScore = Math.round((changes / maxLen) * 100) / 100;
	return { driftScore, overThreshold: driftScore > maxDrift };
};