@mapbox/cloudfriend/lib/shortcuts/glue-presto-view.js

Helper functions for assembling CloudFormation templates in JavaScript

'use strict';

const GlueTable = require('./glue-table');

/**
 * Create a Glue Presto View.
 *
 * @param {Object} options - Accepts the same options as [`GlueTable`](#gluetable), though the following additional attributes are either required or hard-wired:
 * @param {String} options.OriginalSql - The SQL query that defines the view.
 * @param {String} [options.TableType='VIRTUAL_VIEW'] - Hard-wired by this shortcut.
 */
class GluePrestoView extends GlueTable {
  constructor(options) {
    if (!options) throw new Error('Options required');
    let { Parameters, SqlVariables = {} } = options;
    const {
      Columns,
      DatabaseName,
      OriginalSql: originalSql
    } = options;

    const required = [DatabaseName, Columns, originalSql];
    if (required.some((variable) => !variable))
      throw new Error(
        'You must provide a DatabaseName, Columns, and OriginalSql'
      );

    const TableType = 'VIRTUAL_VIEW';
    const StoredAsSubDirectories = false;
    const ViewExpandedText = '/* Presto View */';
    Parameters = Object.assign(
      { comment: 'Presto View', presto_view: 'true' },
      Parameters
    );
    SqlVariables = Object.assign({ DatabaseName }, SqlVariables);

    const columns = Columns.map((c) => ({
      name: c.Name,
      type: c.Type
        .replace(/:string/g, ':varchar')
        .replace(/^string/g, 'varchar')
        .replace(/<string/g, '(varchar')
        .replace(/, ?string/g, ',varchar')
        .replace(/:int/g, ':integer')
        .replace(/^int/g, 'integer')
        .replace(/<int/g, '(integer')
        .replace(/, ?int/g, ',integer')
        .replace(/:float/g, ':real')
        .replace(/^float/g, 'real')
        .replace(/<float/g, '(real')
        .replace(/, ?float/g, ',real')
        .replace(/struct/g, 'row')
        .replace(/</g, '(')
        .replace(/>/g, ')')
        .replace(/:/g, ' ')
    }));

    const view = {
      'Fn::Base64': {
        'Fn::Sub': [
          JSON.stringify({
            catalog: 'awsdatacatalog',
            schema: '${DatabaseName}',
            originalSql,
            columns
          }),
          SqlVariables
        ]
      }
    };

    const ViewOriginalText = {
      'Fn::Sub': ['/* Presto View: ${view} */', { view }]
    };

    super(
      Object.assign(
        {
          TableType,
          Parameters,
          StoredAsSubDirectories,
          ViewOriginalText,
          ViewExpandedText
        },
        options
      )
    );
  }
}

module.exports = GluePrestoView;