/* eslint camelcase: "off" */
'use strict';

const async = require('async');

exports.up = function (db, callback) {
    const populateNewData = (cb) => {
        db.all('select name, parameters_template from strategies', (err, results) => {
            const updateSQL = results
              .map(({ name, parameters_template }) => {
                  const parameters = [];
                  Object.keys(parameters_template || {}).forEach(p => {
                      parameters.push({ name: p, type: parameters_template[p], description: '' });
                  });
                  return { name, parameters };
              })
              .map(strategy => `
                UPDATE strategies 
                SET parameters='${JSON.stringify(strategy.parameters)}'
                WHERE name='${strategy.name}';`)
              .join('\n');

            db.runSql(updateSQL, cb);
        });
    };

    async.series([
        db.addColumn.bind(db, 'strategies', 'parameters', { type: 'json' }),
        populateNewData.bind(db),
        db.removeColumn.bind(db, 'strategies', 'parameters_template'),
    ], callback);
};

exports.down = function (db, callback) {
    const populateOldData = (cb) => {
        db.all('select name, parameters from strategies', (err, results) => {
            const updateSQL = results
              .map(({ name, parameters }) => {
                  const parameters_template = {};
                  parameters.forEach(p => {
                      parameters_template[p.name] = p.type;
                  });

                  return { name, parameters_template };
              })
              .map(strategy => `
                UPDATE strategies 
                SET parameters_template='${JSON.stringify(strategy.parameters_template)}'
                WHERE name='${strategy.name}';`)
              .join('\n');

            db.runSql(updateSQL, cb);
        });
    };

    async.series([
        db.addColumn.bind(db, 'strategies', 'parameters_template', { type: 'json' }),
        populateOldData.bind(db),
        db.removeColumn.bind(db, 'strategies', 'parameters'),
    ], callback);
};