'use strict';

// Runner
// -------
module.exports = function(client) {

var Promise  = require('../../promise');

// Require the SQLite3 Runner.
require('../sqlite3/runner')(client);
var Runner_SQLite3 = client.Runner;

var inherits = require('inherits');
var _        = require('lodash');

// Inherit from the `Runner` constructor's prototype,
// so we can add the correct `then` method.
function Runner_WebSQL() {
  Runner_SQLite3.apply(this, arguments);
}
inherits(Runner_WebSQL, Runner_SQLite3);

// Runs the query on the specified connection, providing the bindings and any other necessary prep work.
Runner_WebSQL.prototype._query = Promise.method(function(obj) {
  if (this.isDebugging()) this.debug(obj);
  var connection = this.connection;
  return new Promise(function(resolver, rejecter) {
    if (!connection) {
      return rejecter(new Error('No connection provided.'));
    }
    connection.executeSql(obj.sql, obj.bindings, function(trx, response) {
      obj.response = response;
      return resolver(obj);
    }, function(trx, err) {
      console.error(err);
      rejecter(err);
    });
  });
});

// Null out the transaction statements so they aren't run.
Runner_WebSQL.prototype._beginTransaction    = null;
Runner_WebSQL.prototype._commitTransaction   = null;
Runner_WebSQL.prototype._rollbackTransaction = null;

// Ensures the response is returned in the same format as other clients.
Runner_WebSQL.prototype.processResponse = function(obj) {
  var resp = obj.response;
  if (obj.output) return obj.output.call(this, resp);
  switch (obj.method) {
    case 'pluck':
    case 'first':
    case 'select':
      var results = [];
      for (var i = 0, l = resp.rows.length; i < l; i++) {
        results[i] = _.clone(resp.rows.item(i));
      }
      if (obj.method === 'pluck') results = _.pluck(results, obj.pluck);
      return obj.method === 'first' ? results[0] : results;
    case 'insert':
      return [resp.insertId];
    case 'delete':
    case 'update':
    case 'counter':
      return resp.rowsAffected;
    default:
      return resp;
  }
};

// Assign the newly extended `Runner` constructor to the client object.
client.Runner = Runner_WebSQL;

};