'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 ProviderUtils = require('./lib/utils.js');
var ProviderHealth = require('./lib/health.js');
var ProviderRAS = require('./lib/ras.js');
var ProviderUpdate = require('./lib/update.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);


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

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

// 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 dbProtocol = process.env.DB_PROTOCOL;
var dbPrefix = process.env.DB_PREFIX;
var databaseName = dbPrefix + constants.TRIGGER_DB_SUFFIX;
var ddname = '_design/filters';

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

function createDatabase (nanop) {
    logger.info('createDatabase', 'creating the trigger database');
    return new Promise(function(resolve, reject) {
        nanop.db.create(databaseName, function (err, body) {
            if (!err) {
                logger.info('createDatabase', 'created trigger database:', databaseName);
            }
            else {
                logger.info('createDatabase', 'failed to create trigger database:', databaseName, err);
            }
            var db = nanop.db.use(databaseName);
            var only_triggers = {
                map: function (doc) {
                    if (doc.maxTriggers) {
                        emit(doc._id, 1);
                    }
                }.toString()
            };

            db.get(ddname, function (error, body) {
                if (error) {
                    //new design doc
                    db.insert({
                        views: {
                            only_triggers: only_triggers
                        },
                    }, ddname, function (error, body) {
                        if (error) {
                            reject("view could not be created: " + error);
                        }
                        resolve(db);
                    });
                }
                else {
                    resolve(db);
                }
            });
        });
    });
}

function createTriggerDb () {
    logger.info('createTriggerDb', 'database url is ' +  dbProtocol + '://' + dbUsername + ':' + dbPassword + '@' + dbHost);
    var nanop = require('nano')(dbProtocol + '://' + dbUsername + ':' + dbPassword + '@' + dbHost);
    if (nanop !== null) {
        return createDatabase (nanop);
    }
    else {
        Promise.reject('nano provider did not get created.  check db URL: ' + dbHost);
    }
}

// Initialize the Provider Server
function init(server) {

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

    createTriggerDb()
    .then(nanoDb => {
        logger.info('init', 'trigger storage database details:', nanoDb);

        var providerUtils = new ProviderUtils(logger, app, retriesBeforeDelete, nanoDb, routerHost);
        var providerRAS = new ProviderRAS(logger);
        var providerHealth = new ProviderHealth(logger, providerUtils);
        var providerUpdate = new ProviderUpdate(logger, providerUtils);
        var providerDelete = new ProviderDelete(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 Deleting an existing Trigger.
        app.delete(providerDelete.endPoint, providerUtils.authorize, providerDelete.delete);

        providerUtils.initAllTriggers();

    }).catch(err => {
        logger.error('init', 'an error occurred creating database:', err);
    });

}

init(server);