'use strict';
/**
 * Service which can be configured to listen for triggers from a provider.
 * The Provider will store, invoke, and POST whisk events appropriately.
 */
var http = require('http');
var express = require('express');
var request = require('request');
var bodyParser = require('body-parser');
var logger = require('./Logger');
var RequestAgent = require('agentkeepalive');

var ProviderUtils = require('./lib/utils.js');
var ProviderHealth = require('./lib/health.js');
var ProviderRAS = require('./lib/ras.js');
var ProviderUpdate = require('./lib/update.js');
var ProviderCreate = require('./lib/create.js');
var ProviderDelete = require('./lib/delete.js');
var constants = require('./lib/constants.js');

// Initialize the Express Application
var app = express();
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.set('port', process.env.PORT || 8080);

// TODO: Setup a proper Transaction ID
var tid = "??";

// Whisk API Router Host
var routerHost = process.env.ROUTER_HOST || 'localhost';

// This is the maximum times a single trigger is allow to fire.
// Trigger should not be allow to be created with a value higher than this value
// Trigger can be created with a value lower than this between 1 and this value
var triggerFireLimit = 10000;

// Maximum number of times to retry the invocation of an action
// before deleting the associated trigger
var retriesBeforeDelete = 5;

// The maxSockets determines how many concurrent sockets the agent can have open per
// host, is present in an agent by default with value ??.
var maximumDbConnections = 50;

// Allow invoking servers with self-signed certificates.
process.env.NODE_TLS_REJECT_UNAUTHORIZED = "0";

// If it does not already exist, create the triggers database.  This is the database that will
// store the managed triggers.
//
var dbUsername = process.env.DB_USERNAME;
var dbPassword = process.env.DB_PASSWORD;
var dbHost = process.env.DB_HOST;
var dbPort = process.env.DB_PORT;
var dbProtocol = process.env.DB_PROTOCOL;
var dbPrefix = process.env.DB_PREFIX;
var databaseName = dbPrefix + constants.TRIGGER_DB_SUFFIX;

// Create the Provider Server
var server = http.createServer(app);
server.listen(app.get('port'), function(){
    logger.info(tid, 'server.listen', 'Express server listening on port ' + app.get('port'));
});

function createDatabase (nanop) {

  if (nanop !== null) {
    nanop.db.create(databaseName, function(err, body, header) {
        if (!err) {
          logger.info(tid, databaseName, ' database for triggers was created.');
        } else {
          logger.info(tid, databaseName, err);
        }
    });
    var chDb = nanop.db.use(databaseName);
    return chDb;
  } else {
    return null;
  }

}

function createTriggerDb () {

  var nanop = null;

  var connectionAgent = new RequestAgent({
    maxSockets: maximumDbConnections
  });

  // no need for a promise here, but leaving code inplace until we prove out the question of cookie usage
  var promise = new Promise(function(resolve, reject) {

    logger.info('url is ' +  dbProtocol + '://' + dbUsername + ':' + dbPassword + '@' + dbHost);
    nanop = require('nano')(dbProtocol + '://' + dbUsername + ':' + dbPassword + '@' + dbHost);
    resolve(createDatabase (nanop));

  });

  return promise;

}

// Initialize the Provider Server
function init(server) {
    if (server !== null) {
        var address = server.address();
        if (address === null) {
            logger.error(tid, 'init', 'Error initializing server. Perhaps port is already in use.');
            process.exit(-1);
        }
    }

    ///
    var triggerDBPromise = createTriggerDb();
    triggerDBPromise.then(function (nanoDb) {

      logger.info(tid, 'init', 'trigger storage database details: ', nanoDb);

      var providerUtils = new ProviderUtils (tid, logger, app, retriesBeforeDelete, nanoDb, triggerFireLimit, routerHost);
      var providerRAS = new ProviderRAS (tid, logger, providerUtils);
      var providerHealth = new ProviderHealth (tid, logger, providerUtils);
      var providerUpdate = new ProviderUpdate (tid, logger, providerUtils);
      var providerCreate = new ProviderCreate (tid, logger, providerUtils);
      var providerDelete = new ProviderDelete (tid, logger, providerUtils);

      // RAS Endpoint
      app.get(providerRAS.endPoint, providerRAS.ras);

      // Health Endpoint
      app.get(providerHealth.endPoint, providerHealth.health);

      // Endpoint for Update OR Create a Trigger
      app.put(providerUpdate.endPoint, providerUtils.authorize, providerUpdate.update);

      // Endpoint for Creating a new Trigger
      app.post(providerCreate.endPoint, providerUtils.authorize, providerCreate.create);

      // Endpoint for Deleting an existing Trigger.
      app.delete(providerDelete.endPoint, providerUtils.authorize, providerDelete.delete);

      providerUtils.initAllTriggers();
    }, function(err) {
      logger.info(tid, 'init', 'found an error creating database: ', err);
    });

}

init(server);