// CartoDB SQL API
//
// all requests expect the following URL args:
// - `sql` {String} SQL to execute
//
// for private (read/write) queries:
// - OAuth. Must have proper OAuth 1.1 headers. For OAuth 1.1 spec see Google
//
// eg. /api/v1/?sql=SELECT 1 as one (with a load of OAuth headers or URL arguments)
//
// for public (read only) queries:
// - sql only, provided the subdomain exists in CartoDB and the table's sharing options are public
//
// eg. vizzuality.cartodb.com/api/v1/?sql=SELECT * from my_table
//

var express = require('express');
var os = require('os');
var Profiler = require('step-profiler');
var StatsD = require('node-statsd').StatsD;
var _ = require('underscore');
var LRU = require('lru-cache');

var GenericController = require('./controllers/generic_controller');
var QueryController = require('./controllers/query_controller');
var JobController = require('./controllers/job_controller');
var CacheStatusController = require('./controllers/cache_status_controller');
var HealthCheckController = require('./controllers/health_check_controller');
var VersionController = require('./controllers/version_controller');

var Batch = require('../batch/batch');

process.env.PGAPPNAME = process.env.PGAPPNAME || 'cartodb_sqlapi';

// override Date.toJSON
require('./utils/date_to_json');

// jshint maxcomplexity:21
function App() {

    var app = express.createServer();

    var metadataBackend = require('cartodb-redis')({
        host: global.settings.redis_host,
        port: global.settings.redis_port,
        max: global.settings.redisPool,
        idleTimeoutMillis: global.settings.redisIdleTimeoutMillis,
        reapIntervalMillis: global.settings.redisReapIntervalMillis
    });

    // Set default configuration
    global.settings.db_pubuser = global.settings.db_pubuser || "publicuser";
    global.settings.bufferedRows = global.settings.bufferedRows || 1000;

    var tableCache = LRU({
      // store no more than these many items in the cache
      max: global.settings.tableCacheMax || 8192,
      // consider entries expired after these many milliseconds (10 minutes by default)
      maxAge: global.settings.tableCacheMaxAge || 1000*60*10
    });

    // Size based on https://github.com/CartoDB/cartodb.js/blob/3.15.2/src/geo/layer_definition.js#L72
    var SQL_QUERY_BODY_LOG_MAX_LENGTH = 2000;
    app.getSqlQueryFromRequestBody = function(req) {
        var sqlQuery = req.body && req.body.q;
        if (!sqlQuery) {
            return '';
        }

        if (sqlQuery.length > SQL_QUERY_BODY_LOG_MAX_LENGTH) {
            sqlQuery = sqlQuery.substring(0, SQL_QUERY_BODY_LOG_MAX_LENGTH) + ' [...]';
        }
        return JSON.stringify({q: sqlQuery});
    };

    if ( global.log4js ) {
        var loggerOpts = {
            buffer: true,
            // log4js provides a tokens solution as expess but in does not provide the request/response in the callback.
            // Thus it is not possible to extract relevant information from them.
            // This is a workaround to be able to access request/response.
            format: function(req, res, format) {
                var logFormat = global.settings.log_format ||
                    ':remote-addr :method :req[Host]:url :status :response-time ms -> :res[Content-Type]';

                logFormat = logFormat.replace(/:sql/, app.getSqlQueryFromRequestBody(req));
                return format(logFormat);
            }
        };
        app.use(global.log4js.connectLogger(global.log4js.getLogger(), _.defaults(loggerOpts, {level:'info'})));
    } else {
        // Express logger uses tokens as described here: http://www.senchalabs.org/connect/logger.html
        express.logger.token('sql', function(req) {
            return app.getSqlQueryFromRequestBody(req);
        });
        app.use(express.logger({
            buffer: true,
            format: global.settings.log_format ||
                ':remote-addr :method :req[Host]:url :status :response-time ms -> :res[Content-Type]'
        }));
    }

    // Initialize statsD client if requested
    var statsd_client;
    if ( global.settings.statsd ) {

      // Perform keyword substitution in statsd
      if ( global.settings.statsd.prefix ) {
        var host_token = os.hostname().split('.').reverse().join('.');
        global.settings.statsd.prefix = global.settings.statsd.prefix.replace(/:host/, host_token);
      }

      statsd_client = new StatsD(global.settings.statsd);
      statsd_client.last_error = { msg:'', count:0 };
      statsd_client.socket.on('error', function(err) {
        var last_err = statsd_client.last_error;
        var last_msg = last_err.msg;
        var this_msg = ''+err;
        if ( this_msg !== last_msg ) {
          console.error("statsd client socket error: " + err);
          statsd_client.last_error.count = 1;
          statsd_client.last_error.msg = this_msg;
        } else {
            ++last_err.count;
            if ( ! last_err.interval ) {
              //console.log("Installing interval");
              statsd_client.last_error.interval = setInterval(function() {
                var count = statsd_client.last_error.count;
                if ( count > 1 ) {
                  console.error("last statsd client socket error repeated " + count + " times");
                  statsd_client.last_error.count = 1;
                  //console.log("Clearing interval");
                  clearInterval(statsd_client.last_error.interval);
                  statsd_client.last_error.interval = null;
                }
              }, 1000);
            }
        }
      });
    }

    // Use step-profiler
    if ( global.settings.useProfiler ) {
      app.use(function(req, res, next) {
        req.profiler = new Profiler({statsd_client:statsd_client});
        next();
      });
    }

    // Set connection timeout
    if ( global.settings.hasOwnProperty('node_socket_timeout') ) {
      var timeout = parseInt(global.settings.node_socket_timeout);
      app.use(function(req, res, next) {
        req.connection.setTimeout(timeout);
        next();
      });
    }

    app.use(express.bodyParser());
    app.enable('jsonp callback');
    app.set("trust proxy", true);

    // basic routing

    var genericController = new GenericController();
    genericController.route(app);

    var queryController = new QueryController(metadataBackend, tableCache, statsd_client);
    queryController.route(app);

    var jobController = new JobController(metadataBackend, tableCache, statsd_client);
    jobController.route(app);

    var cacheStatusController = new CacheStatusController(tableCache);
    cacheStatusController.route(app);

    var healthCheckController = new HealthCheckController();
    healthCheckController.route(app);

    var versionController = new VersionController();
    versionController.route(app);

    if (global.settings.environment !== 'test') {
        var batch = new Batch(metadataBackend);
        batch.start();
    }

    return app;
}

module.exports = App;