const mysql = require('mysql2/promise');
const fs = require('fs');
require('dotenv').config();

function getCleanMapKey(path) {
  let clean = path.replace('img/location_photo/', '').replace('.png', '');
  clean = clean.replace('서관', 'W').replace('동관', 'E');
  clean = clean.replace('한맥빌딩/MDF실/MDF_', 'HAN-MDF-');
  clean = clean.replace('기술개발센터/서버실/서버실_', 'DEV-SVR-');
  clean = clean.replace(/\//g, '-');
  return clean;
}

function getLocationName(path) {
  if (path.includes('IDC')) return 'IDC';
  if (path.includes('한맥빌딩')) return '한맥빌딩';
  if (path.includes('기술개발센터')) return '기술개발센터';
  return '기타';
}

function getLocationDetail(path, idx) {
  let clean = path.replace('img/location_photo/', '').replace('.png', '');
  let parts = clean.split('/');
  let lastPart = parts[parts.length - 1]; // e.g. "서관205", "MDF_1", "서버실_1"
  return `${lastPart} 구역 자리 #${idx + 1}`;
}

async function main() {
  console.log('🏁 Starting DB migration...');

  const pool = mysql.createPool({
    host: process.env.DB_HOST,
    user: process.env.DB_USER,
    password: process.env.DB_PASS,
    database: process.env.DB_NAME,
    port: process.env.DB_PORT
  });

  const connection = await pool.getConnection();

  try {
    // 1. Create physical_locations table
    console.log('⏳ Creating physical_locations table...');
    await connection.query(`
      CREATE TABLE IF NOT EXISTS physical_locations (
          location_code VARCHAR(50) NOT NULL COMMENT '위치 식별 코드 (예: LOC-IDC-W205-001)',
          location_name VARCHAR(100) NOT NULL COMMENT '물리 위치 대분류 (예: IDC 서관)',
          location_detail VARCHAR(100) NOT NULL COMMENT '상세 위치/랙 번호 (예: 205호 1번 랙)',
          map_image VARCHAR(150) NOT NULL COMMENT '해당 도면 파일 경로 (예: img/location_photo/IDC/서관205.png)',
          map_x DECIMAL(5,2) NOT NULL COMMENT '도면 내 X 백분율 좌표',
          map_y DECIMAL(5,2) NOT NULL COMMENT '도면 내 Y 백분율 좌표',
          map_w DECIMAL(5,2) NOT NULL DEFAULT 4.00 COMMENT '도면 내 박스 너비(%)',
          map_h DECIMAL(5,2) NOT NULL DEFAULT 4.00 COMMENT '도면 내 박스 높이(%)',
          created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
          PRIMARY KEY (location_code)
      ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
    `);
    console.log('✅ physical_locations table ready.');

    // 2. Create asset_audit_pending table
    console.log('⏳ Creating asset_audit_pending table...');
    await connection.query(`
      CREATE TABLE IF NOT EXISTS asset_audit_pending (
          id INT AUTO_INCREMENT PRIMARY KEY,
          asset_code VARCHAR(50) NOT NULL COMMENT '스캔된 자산 고유번호 (예: server_1779761946023_14)',
          physical_location_code VARCHAR(50) NOT NULL COMMENT '스캔된 위치 마스터 코드 (예: LOC-IDC-W205-001)',
          status VARCHAR(20) NOT NULL DEFAULT 'PENDING' COMMENT '상태: PENDING(대기), APPROVED(승인), REJECTED(반려)',
          scanned_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
          processed_at TIMESTAMP NULL COMMENT '승인/반려 처리 일시',
          processed_by VARCHAR(50) NULL COMMENT '처리한 관리자',
          CONSTRAINT fk_audit_physical FOREIGN KEY (physical_location_code) REFERENCES physical_locations(location_code)
      ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
    `);
    console.log('✅ asset_audit_pending table ready.');

    // 3. Add physical_location_code to asset_location
    console.log('⏳ Checking physical_location_code column in asset_location...');
    const [cols] = await connection.query('DESCRIBE asset_location');
    const hasCol = cols.some(c => c.Field === 'physical_location_code');
    if (!hasCol) {
      await connection.query(`
        ALTER TABLE asset_location 
          ADD COLUMN physical_location_code VARCHAR(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL COMMENT 'physical_locations의 location_code FK'
      `);
      console.log('✅ physical_location_code column added with utf8mb4_unicode_ci collation.');
    } else {
      console.log('ℹ️ physical_location_code column already exists. Enforcing collation...');
      await connection.query(`
        ALTER TABLE asset_location 
          MODIFY COLUMN physical_location_code VARCHAR(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL COMMENT 'physical_locations의 location_code FK'
      `);
      console.log('✅ physical_location_code column collation enforced.');
    }

    // Add constraint if not exists
    console.log('⏳ Checking foreign key constraint fk_asset_loc_physical...');
    const [constraints] = await connection.query(`
      SELECT CONSTRAINT_NAME 
      FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE 
      WHERE TABLE_NAME = 'asset_location' 
        AND CONSTRAINT_NAME = 'fk_asset_loc_physical'
        AND TABLE_SCHEMA = DATABASE()
    `);

    if (constraints.length === 0) {
      console.log('⏳ Adding foreign key constraint...');
      await connection.query(`
        ALTER TABLE asset_location
          ADD CONSTRAINT fk_asset_loc_physical 
          FOREIGN KEY (physical_location_code) REFERENCES physical_locations(location_code)
      `);
      console.log('✅ Foreign key constraint added.');
    } else {
      console.log('ℹ️ Foreign key constraint already exists.');
    }

    // 4. Load map_config.json and migrate
    console.log('⏳ Migrating map_config.json data to physical_locations...');
    if (fs.existsSync('map_config.json')) {
      const mapConfig = JSON.parse(fs.readFileSync('map_config.json', 'utf8') || '{}');
      let insertCount = 0;
      let syncCount = 0;

      for (const [mapPath, boxes] of Object.entries(mapConfig)) {
        const cleanKey = getCleanMapKey(mapPath);
        const locName = getLocationName(mapPath);

        for (let i = 0; i < boxes.length; i++) {
          const box = boxes[i];
          const padIdx = String(i + 1).padStart(3, '0');
          const locCode = `LOC-${cleanKey}-${padIdx}`;
          const locDetail = getLocationDetail(mapPath, i);

          const bx = parseFloat(box.x);
          const by = parseFloat(box.y);
          const bw = parseFloat(box.w || 4.00);
          const bh = parseFloat(box.h || 4.00);

          // Insert into physical_locations (ignore if duplicate)
          await connection.query(`
            INSERT INTO physical_locations 
              (location_code, location_name, location_detail, map_image, map_x, map_y, map_w, map_h)
            VALUES (?, ?, ?, ?, ?, ?, ?, ?)
            ON DUPLICATE KEY UPDATE 
              location_name = VALUES(location_name),
              location_detail = VALUES(location_detail),
              map_image = VALUES(map_image),
              map_x = VALUES(map_x),
              map_y = VALUES(map_y),
              map_w = VALUES(map_w),
              map_h = VALUES(map_h)
          `, [locCode, locName, locDetail, mapPath, bx, by, bw, bh]);
          
          insertCount++;

          // Sync database asset if box.asset_id exists
          if (box.asset_id) {
            const [rows] = await connection.query(
              'SELECT id FROM asset_location WHERE asset_id = ? AND is_active = 1',
              [box.asset_id]
            );
            if (rows.length > 0) {
              await connection.query(
                'UPDATE asset_location SET physical_location_code = ? WHERE asset_id = ? AND is_active = 1',
                [locCode, box.asset_id]
              );
              syncCount++;
            }
          }
        }
      }
      console.log(`✅ Migrated ${insertCount} physical locations and synced ${syncCount} existing assets.`);
    } else {
      console.log('⚠️ map_config.json not found, skipping initial migration.');
    }

    console.log('🎉 DB Migration successfully completed!');
  } catch (err) {
    console.error('❌ Migration failed:', err);
    throw err;
  } finally {
    connection.release();
    await pool.end();
  }
}

main().catch(err => {
  process.exit(1);
});