/**
 * Severity constants, risk scoring, and verdict logic for config-audit scanners.
 * Zero external dependencies.
 */

export const SEVERITY = Object.freeze({
  critical: 'critical',
  high: 'high',
  medium: 'medium',
  low: 'low',
  info: 'info',
});

const WEIGHTS = { critical: 25, high: 10, medium: 4, low: 1, info: 0 };

/**
 * Calculate a 0-100 risk score from severity counts.
 * @param {{ critical?: number, high?: number, medium?: number, low?: number, info?: number }} counts
 * @returns {number}
 */
export function riskScore(counts) {
  let score = 0;
  for (const [sev, weight] of Object.entries(WEIGHTS)) {
    score += (counts[sev] || 0) * weight;
  }
  return Math.min(score, 100);
}

/**
 * Determine overall verdict from severity counts.
 * @param {{ critical?: number, high?: number, medium?: number, low?: number, info?: number }} counts
 * @returns {'FAIL' | 'WARNING' | 'PASS'}
 */
export function verdict(counts) {
  const score = riskScore(counts);
  if ((counts.critical || 0) >= 1 || score >= 61) return 'FAIL';
  if ((counts.high || 0) >= 1 || score >= 21) return 'WARNING';
  return 'PASS';
}

/**
 * Map a risk score to a human-readable band.
 * @param {number} score
 * @returns {'Low' | 'Medium' | 'High' | 'Critical' | 'Extreme'}
 */
export function riskBand(score) {
  if (score <= 10) return 'Low';
  if (score <= 30) return 'Medium';
  if (score <= 60) return 'High';
  if (score <= 80) return 'Critical';
  return 'Extreme';
}

/**
 * Grade from a quality pass rate (0-100%).
 * @param {number} passRate - 0-100
 * @returns {'A' | 'B' | 'C' | 'D' | 'F'}
 */
export function gradeFromPassRate(passRate) {
  if (passRate >= 90) return 'A';
  if (passRate >= 75) return 'B';
  if (passRate >= 60) return 'C';
  if (passRate >= 40) return 'D';
  return 'F';
}

/** Config audit quality categories */
export const QUALITY_CATEGORIES = Object.freeze({
  STRUCTURE: 'Structure & Format',
  CONTENT: 'Content Quality',
  HIERARCHY: 'Hierarchy & Scope',
  SECURITY: 'Security',
  FEATURES: 'Feature Utilization',
  COHERENCE: 'Cross-file Coherence',
});