import { BigQuery } from '@google-cloud/bigquery';
import { Storage } from '@google-cloud/storage';

// Cross-project setup:
// - BigQuery data source: fynd-jio-commerceml-prod
// - GCS destination: fynd-boltic-prod
const bigquery = new BigQuery({
  projectId: process.env.BIGQUERY_PROJECT || 'fynd-jio-commerceml-prod'
});
const storage = new Storage({
  projectId: process.env.STORAGE_PROJECT || 'fynd-jio-commerceml-prod',
  credentials: {}
});

export const exportMergedJson = async (req, res) => {
  try {
    const datasetId = process.env.DATASET || "temp_zenith_data";
    const sourceTable = process.env.SOURCE_TABLE || "pr_training_data";
    const bucketName = 'pr_dataset_storage';
    const objectPath = '261/643e93f5ffc8101656a5629b/GET_ALL_PRODUCTS/catalog-*.json';
    const uri = `gs://${bucketName}/${objectPath}`;

    // Get deletion criteria from request body or environment
    const companyIdToDelete = req.body?.companyId;
    const applicationIdToDelete = req.body?.applicationId;

    // 1️⃣ Direct export from source table to GCS (cross-project)
    const sourceTablePath = `${bigquery.projectId}.${datasetId}.${sourceTable}`;

    const exportSql = `
      EXPORT DATA
        OPTIONS(
          uri='${uri}',
          format='JSON',
          overwrite=true
        ) AS
      SELECT
        ARRAY_CONCAT_AGG(JSON_EXTRACT_ARRAY(data)) AS merged_array
      FROM
        \`${sourceTablePath}\`
    `;
    const [queryJob] = await bigquery.createQueryJob({
      query: exportSql,
      useLegacySql: false,
    });
    const jobResponse = await queryJob.promise();
    console.log(jobResponse);

    // 2️⃣ Delete rows from source table after successful export
    // if (companyIdToDelete && applicationIdToDelete) {
    //   console.log('Starting deletion of processed rows...');
    //   const [deleteJob] = await bigquery.createQueryJob({
    //     query: `
    //       DELETE FROM \`${sourceTablePath}\`
    //       WHERE companyId = @companyId AND applicationId = @applicationId
    //     `,
    //     params: {
    //       companyId: companyIdToDelete,
    //       applicationId: applicationIdToDelete
    //     },
    //     useLegacySql: false,
    //   });

    //   await deleteJob.promise();
    //   console.log(`Successfully deleted rows with companyId: ${companyIdToDelete}, applicationId: ${applicationIdToDelete}`);
    // } else {
    //   console.log('No deletion criteria provided, skipping row cleanup');
    // }

    const options = {
      version: 'v4',
      action: 'read',
      expires: Date.now() + 15 * 60 * 1000,
      extensionHeaders: {},
      queryParams: {},
      method: 'POST'
    };

    const signedUrl = await storage.bucket(bucketName).file(objectPath.replace('*', '000000000000')).getSignedUrl(options);

    return {
      signedUrl,
      success: true,
      message: `Success: exported to ${uri}`,
      companyId: companyIdToDelete,
      applicationId: applicationIdToDelete,
      destination: uri
    };
  } catch (err) {
    console.error('Export or cleanup failed:', err);
    throw new Error(`Export failed: ${err.message}`);
  }
};