/**
 * Content Governance Checker Service
 * Unified framework checker for all external communications
 *
 * Used by:
 * - Blog posts (before publication)
 * - Media inquiry responses (before sending)
 * - Response templates (on create/update)
 * - Newsletter content (future)
 *
 * Enforces:
 * - inst_016: No fabricated statistics without citation
 * - inst_017: No absolute guarantees
 * - inst_018: No unverified production claims
 * - inst_079: No dark patterns or manipulative urgency
 */

// Pattern definitions from governance rules
const contentPatterns = {
  inst_016_fabricated_stats: {
    patterns: [
      /\b\d+%\s+(?:faster|better|improvement|increase|decrease|reduction|more|less)\b(?!\s*\[NEEDS VERIFICATION\]|\s*\(source:|\s*\[source:)/gi,
      /\b(?:faster|better|improvement)\s+of\s+\d+%\b(?!\s*\[NEEDS VERIFICATION\]|\s*\(source:|\s*\[source:)/gi,
      /\b\d+x\s+(?:faster|better|more|increase)\b(?!\s*\[NEEDS VERIFICATION\]|\s*\(source:|\s*\[source:)/gi
    ],
    severity: 'HIGH',
    message: 'Statistics require citation or [NEEDS VERIFICATION] marker (inst_016)',
    instruction: 'inst_016'
  },
  inst_017_absolute_guarantees: {
    patterns: [
      /\bguarantee(?:s|d|ing)?\b/gi,
      /\b100%\s+(?:secure|safe|reliable|effective)\b/gi,
      /\bcompletely\s+prevents?\b/gi,
      /\bnever\s+fails?\b/gi,
      /\balways\s+works?\b/gi,
      /\beliminates?\s+all\b/gi,
      /\bperfect(?:ly)?\s+(?:secure|safe|reliable)\b/gi
    ],
    severity: 'HIGH',
    message: 'Absolute guarantees prohibited - use evidence-based language (inst_017)',
    instruction: 'inst_017'
  },
  inst_018_unverified_claims: {
    patterns: [
      /\bproduction-ready\b(?!\s+development\s+tool|\s+proof-of-concept)/gi,
      /\bbattle-tested\b/gi,
      /\benterprise-proven\b/gi,
      /\bwidespread\s+adoption\b/gi,
      /\bindustry-standard\b/gi
    ],
    severity: 'MEDIUM',
    message: 'Production claims require evidence (this is proof-of-concept) (inst_018)',
    instruction: 'inst_018'
  },
  inst_079_dark_patterns: {
    patterns: [
      /\bclick\s+here\s+now\b/gi,
      /\blimited\s+time\s+offer\b/gi,
      /\bonly\s+\d+\s+spots?\s+left\b/gi,
      /\bact\s+fast\b/gi,
      /\bhurry\b.*\b(?:before|while)\b/gi,
      /\bdon't\s+miss\s+out\b/gi
    ],
    severity: 'MEDIUM',
    message: 'Possible manipulative urgency/dark pattern detected (inst_079)',
    instruction: 'inst_079'
  }
};

/**
 * Scan content for governance violations
 * @param {string} text - Content to scan
 * @param {object} options - Scanning options
 * @returns {Promise<object>} - Scan results with violations array
 */
async function scanContent(text, options = {}) {
  const {
    type = 'general', // blog, media_response, template, newsletter
    context = {}
  } = options;

  if (!text || typeof text !== 'string') {
    return {
      success: true,
      violations: [],
      scannedAt: new Date(),
      type,
      context
    };
  }

  const violations = [];

  // Scan for each pattern
  for (const [ruleId, config] of Object.entries(contentPatterns)) {
    for (const pattern of config.patterns) {
      const matches = text.match(pattern);
      if (matches) {
        // Get unique matches only
        const uniqueMatches = [...new Set(matches)];

        uniqueMatches.forEach(match => {
          violations.push({
            rule: ruleId,
            instruction: config.instruction,
            severity: config.severity,
            match,
            message: config.message,
            position: text.indexOf(match),
            context: getMatchContext(text, text.indexOf(match))
          });
        });
      }
    }
  }

  return {
    success: violations.length === 0,
    violations,
    scannedAt: new Date(),
    type,
    context,
    summary: {
      total: violations.length,
      high: violations.filter(v => v.severity === 'HIGH').length,
      medium: violations.filter(v => v.severity === 'MEDIUM').length,
      byRule: violations.reduce((acc, v) => {
        acc[v.instruction] = (acc[v.instruction] || 0) + 1;
        return acc;
      }, {})
    }
  };
}

/**
 * Get context around a match (50 chars before and after)
 */
function getMatchContext(text, position, contextLength = 50) {
  const start = Math.max(0, position - contextLength);
  const end = Math.min(text.length, position + contextLength);

  let context = text.substring(start, end);

  // Add ellipsis if truncated
  if (start > 0) context = '...' + context;
  if (end < text.length) context = context + '...';

  return context;
}

/**
 * Format violations for display
 */
function formatViolations(violations) {
  if (!violations || violations.length === 0) {
    return 'No violations found';
  }

  return violations.map((v, idx) =>
    `${idx + 1}. [${v.severity}] ${v.rule}\n` +
    `   Match: "${v.match}"\n` +
    `   ${v.message}\n` +
    `   Context: ${v.context}`
  ).join('\n\n');
}

/**
 * Check if content is safe for publication
 * Convenience method that returns boolean
 */
async function isSafeForPublication(text, options = {}) {
  const result = await scanContent(text, options);
  return result.success;
}

module.exports = {
  scanContent,
  formatViolations,
  isSafeForPublication,
  contentPatterns
};