/**
 * Shared sector classification module for TenderRadar scrapers
 * Exports a classifySector function that categorizes tenders into 9 sectors
 */

/**
 * Classify a tender into one of 9 sectors based on title, description, and authority
 * Uses regex patterns in priority order; first match wins
 * 
 * @param {string} title - Tender title
 * @param {string} description - Tender description
 * @param {string} authorityName - Procuring authority name
 * @returns {string} One of: Health, Education, Construction, IT & Technology, 
 *                    Transport, Defence, Energy, Government, Other
 */
export function classifySector(title, description, authorityName) {
  // Combine all text and normalize to lowercase for case-insensitive matching
  const combined = `${title || ''} ${description || ''} ${authorityName || ''}`.toLowerCase();

  // 1. Health
  if (/\bnhs\b|hospital|clinical|pharmac|medical|health\s*(care|service)|maternity|mental\s*health|dental|ambulance|patient|surgery|pathology|\bward\b/.test(combined)) {
    return 'Health';
  }

  // 2. Education
  if (/\bschool|universit|college|educat|academ|learning|pupil|student|teaching/.test(combined)) {
    return 'Education';
  }

  // 3. Construction
  if (/\bconstruct|demoliti|renovati|building\s*(work|maint|repair)|roofing|plumbing|electrical\s*install|painting\s*(and|&)\s*decorat|repair\s*(of|work)|refurbish|scaffolding|paving|groundwork/.test(combined)) {
    return 'Construction';
  }

  // 4. IT & Technology
  if (/\bsoftware|\b(it|ict)\s+(service|system|support|infra)|digital\s*(platform|service|transform)|cyber|cloud\s*(comput|service|hosting)|network\s*infra|data\s*(centre|center|analy|manage)/.test(combined)) {
    return 'IT & Technology';
  }

  // 5. Transport
  if (/\btransport|vehicle|fleet\s*(manage|maint)|highway|railway|bus\s*(service|route)|traffic|parking/.test(combined)) {
    return 'Transport';
  }

  // 6. Defence
  if (/\bdefence|defense|military|\bmod\b|armed\s*force|navy|royal\s*air/.test(combined)) {
    return 'Defence';
  }

  // 7. Energy
  if (/\benergy\s*(supply|effic|manage)|electricity|solar|renewable|power\s*generat|gas\s*supply|wind\s*(farm|turbin)/.test(combined)) {
    return 'Energy';
  }

  // 8. Government - only if nothing else matched
  if (/\bcouncil|government|civic|municipal|parliament|local\s*authorit/.test(combined)) {
    return 'Government';
  }

  // 9. Other - default fallback
  return 'Other';
}

// Self-test when run directly
if (import.meta.url === `file://${process.argv[1]}`) {
  console.log('Running self-tests...\n');

  const testCases = [
    {
      title: 'NHS Hospital Supplies',
      description: 'Medical equipment for clinical use',
      authority: 'NHS England',
      expected: 'Health'
    },
    {
      title: 'School Building Construction',
      description: 'New educational facility',
      authority: 'Local Education Authority',
      expected: 'Education'
    },
    {
      title: 'Roofing and Painting Services',
      description: 'Building renovation and repairs',
      authority: 'City Council',
      expected: 'Construction'
    },
    {
      title: 'Software Development Services',
      description: 'IT system and cloud hosting',
      authority: 'Government IT Department',
      expected: 'IT & Technology'
    },
    {
      title: 'Public Transport Fleet Maintenance',
      description: 'Vehicle servicing and support',
      authority: 'Transport Department',
      expected: 'Transport'
    },
    {
      title: 'Military Equipment Supply',
      description: 'Defence and armed forces supplies',
      authority: 'Ministry of Defence',
      expected: 'Defence'
    },
    {
      title: 'Renewable Energy Installation',
      description: 'Solar power and wind turbine project',
      authority: 'Energy Commission',
      expected: 'Energy'
    },
    {
      title: 'Council Office Supplies',
      description: 'General supplies for local government',
      authority: 'City Council',
      expected: 'Government'
    },
    {
      title: 'Generic Office Supplies',
      description: 'Standard stationery and equipment',
      authority: 'Random Organization',
      expected: 'Other'
    }
  ];

  let passed = 0;
  let failed = 0;

  testCases.forEach((test, index) => {
    const result = classifySector(test.title, test.description, test.authority);
    const status = result === test.expected ? '✓' : '✗';
    
    if (result === test.expected) {
      passed++;
    } else {
      failed++;
    }

    console.log(`${status} Test ${index + 1}: "${test.title}"`);
    console.log(`  Expected: ${test.expected}, Got: ${result}\n`);
  });

  console.log(`\nResults: ${passed} passed, ${failed} failed`);
  process.exit(failed > 0 ? 1 : 0);
}