const { Client } = require('pg');
const client = new Client('postgres://postgres:csh%402018@localhost:5432/ai_pharmacy');

client.connect().then(async () => {
  try {
    // 1. Update the pack_size of Losar 50 to 10
    await client.query("UPDATE products SET pack_size = 10 WHERE id = 'prd_4410'");
    
    // 2. Fix all old dispensing records that were calculated with pack_size=1
    // For every dispensing record, we recalculate the total amount.
    const res = await client.query(`
      SELECT d.id, 
        SUM((p.mrp / COALESCE(NULLIF(p.pack_size, 0), 1)) * ABS(sm.qty_delta)) as new_total
      FROM dispensing_records d
      JOIN stock_movements sm ON sm.reference_id = d.id
      JOIN batches b ON b.batch_no = sm.batch_no
      JOIN products p ON p.id = b.product_id
      GROUP BY d.id
    `);

    for (const row of res.rows) {
      await client.query("UPDATE dispensing_records SET total_amount = $1 WHERE id = $2", [row.new_total, row.id]);
    }
    
    console.log("Updated pack_size to 10 for prd_4410 and corrected all historical total amounts.");
  } catch (err) {
    console.error('Error fixing history:', err);
  }
  process.exit(0);
}).catch(console.error);