const path = require('path');
const mysql = require('mysql2/promise');

require('dotenv').config({
  path: path.join(__dirname, '..', 'backend', '.env')
});

function toDateTimeExpr(columnExpr) {
  return `CASE
    WHEN ${columnExpr} IS NULL OR ${columnExpr} = 0 THEN NULL
    WHEN ${columnExpr} > 100000000000 THEN FROM_UNIXTIME(${columnExpr} / 1000)
    ELSE FROM_UNIXTIME(${columnExpr})
  END`;
}

async function main() {
  if (!process.env.DB_PASSWORD) {
    throw new Error('DB_PASSWORD is required');
  }

  const conn = await mysql.createConnection({
    host: process.env.DB_HOST || '127.0.0.1',
    port: parseInt(process.env.DB_PORT, 10) || 3306,
    user: process.env.DB_USER || 'tilbudgivern_service',
    password: process.env.DB_PASSWORD,
    database: process.env.DB_NAME || 'tilbudgivern',
    multipleStatements: true
  });

  try {
    await conn.execute(
      `
        CREATE TABLE IF NOT EXISTS ordrestyring_case_latest (
          case_number VARCHAR(64) NOT NULL PRIMARY KEY,
          customer_number VARCHAR(255) NULL,
          offer_number INT NULL,
          description TEXT NULL,
          remarks TEXT NULL,
          work_done TEXT NULL,
          status INT NULL,
          created_at_ordrestyring DATETIME NULL,
          updated_at_ordrestyring DATETIME NULL,
          source_case_id INT NULL,
          synced_at TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
          INDEX idx_case_latest_customer_number (customer_number),
          INDEX idx_case_latest_offer_number (offer_number),
          INDEX idx_case_latest_updated_at (updated_at_ordrestyring)
        )
      `
    );

    const createdExpr = toDateTimeExpr('c.created_at');
    const updatedExpr = toDateTimeExpr('COALESCE(NULLIF(c.updated_at, 0), NULLIF(c.creation_date, 0), NULLIF(c.created_at, 0))');

    await conn.execute('TRUNCATE TABLE ordrestyring_case_latest');
    await conn.execute(
      `
        INSERT INTO ordrestyring_case_latest (
          case_number,
          customer_number,
          offer_number,
          description,
          remarks,
          work_done,
          status,
          created_at_ordrestyring,
          updated_at_ordrestyring,
          source_case_id
        )
        SELECT
          ranked.case_number,
          ranked.customer_number,
          ranked.offer_number,
          ranked.description,
          ranked.remarks,
          ranked.work_done,
          ranked.status,
          ranked.created_at_ordrestyring,
          ranked.updated_at_ordrestyring,
          ranked.source_case_id
        FROM (
          SELECT
            c.case_number,
            c.customer_number,
            c.offer_number,
            c.description,
            c.remarks,
            c.work_done,
            c.status,
            ${createdExpr} AS created_at_ordrestyring,
            ${updatedExpr} AS updated_at_ordrestyring,
            c.id AS source_case_id,
            ROW_NUMBER() OVER (
              PARTITION BY c.case_number
              ORDER BY COALESCE(NULLIF(c.updated_at, 0), NULLIF(c.creation_date, 0), NULLIF(c.created_at, 0), 0) DESC, c.id DESC
            ) AS rn
          FROM ordrestyring_local.cases c
          WHERE c.case_number IS NOT NULL
            AND c.case_number <> ''
        ) ranked
        WHERE ranked.rn = 1
      `
    );

    const [[stats]] = await conn.execute(
      `
        SELECT
          COUNT(*) AS rows_inserted,
          COUNT(DISTINCT case_number) AS distinct_case_numbers
        FROM ordrestyring_case_latest
      `
    );

    console.log(JSON.stringify({
      table: 'ordrestyring_case_latest',
      rowsInserted: Number(stats.rows_inserted || 0),
      distinctCaseNumbers: Number(stats.distinct_case_numbers || 0)
    }, null, 2));
  } finally {
    await conn.end();
  }
}

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