var di = require('di');
var _ = require('lodash');
var DillerConfig = require('./DillerConfig');
var DillerDao = require('./DillerDao');
var Diller = require('./Diller');

var pgpConstructor = require('pg-promise');

var pgp;

/**
 * @param config DillerConfig
 * @returns {Function}
 * @constructor
 */
function DillerTx(config) {
  var log = config.log();

  function queryLogger(e) {
    log.info("Query:", e.query);
    if (e.ctx) {
      // this query is executing inside a task or transaction,
      if (e.ctx.isTX) {
        // this query is inside a transaction;
      } else {
        // this query is inside a task;
      }

    }
  }

  function connectLogger(client) {
    log.info('PGP: connect');
  }

  function disconnectLogger(client) {
    log.info('PGP: disconnect');
  }

  if (!pgp) {
    var pgpOptions = {};

    pgpOptions.query = (config.logQueries && queryLogger) || undefined;
    //pgpOptions.connect = (config.logQueries && connectLogger) || undefined;
    //pgpOptions.disconnect = (config.logQueries && disconnectLogger) || undefined;

    pgp = pgpConstructor(pgpOptions);
  }

  return function (action) {
    var con = pgp(config.postgresqlConfig);

    return con.tx(function (pg) {
      var dao = new DillerDao(con);
      var diller = new Diller(config, con, dao);
      return action(pg, dao, diller)
    });
  };
}

di.annotate(DillerTx, new di.Inject(DillerConfig));

module.exports = DillerTx;