webapi-eca/js-coffee/engine.js

// Generated by CoffeeScript 1.6.3
/*

Engine
==================
> The heart of the WebAPI ECA System. The engine loads action invoker modules
> corresponding to active rules actions and invokes them if an appropriate event
> is retrieved.
*/


(function() {
  var db, dynmod, exports, isRunning, listUserRules, pollQueue, processEvent, updateActionModules, validConditions,
    _this = this,
    __indexOf = [].indexOf || function(item) { for (var i = 0, l = this.length; i < l; i++) { if (i in this && this[i] === item) return i; } return -1; };

  db = require('./persistence');

  dynmod = require('./dynamic-modules');

  listUserRules = {};

  isRunning = false;

  /*
  Module call
  -----------
  Initializes the Engine and starts polling the event queue for new events.
  
  @param {Object} args
  */


  exports = module.exports = function(args) {
    if (!isRunning) {
      isRunning = true;
      _this.log = args.logger;
      db(args);
      dynmod(args);
      pollQueue();
      return module.exports;
    }
  };

  /*
  Add an event handler (eh) that listens for rules.
  
  @public addRuleListener ( *eh* )
  @param {function} eh
  */


  exports.internalEvent = function(evt) {
    var oRule, oUser;
    if (!listUserRules[evt.user]) {
      listUserRules[evt.user] = {
        rules: {},
        actions: {}
      };
    }
    oUser = listUserRules[evt.user];
    oRule = evt.rule;
    if (evt.event === 'new' || (evt.event === 'init' && !oUser.rules[oRule.id])) {
      oUser.rules[oRule.id] = oRule;
      return updateActionModules(oRule);
    }
  };

  updateActionModules = function(oNewRule) {
    var fAddRequired, fRemoveNotRequired, name, oUser, userName, _results;
    fRemoveNotRequired = function(oUser) {
      var action, fRequired, _results;
      fRequired = function(actionName) {
        var nmRl, oRl, _ref;
        _ref = oUser.rules;
        for (nmRl in _ref) {
          oRl = _ref[nmRl];
          if (__indexOf.call(oRl.actions, actionName) >= 0) {
            return true;
          }
        }
        return false;
      };
      _results = [];
      for (action in oUser.actions) {
        if (!fRequired(action)) {
          _results.push(delete oUser.actions[action]);
        }
      }
      return _results;
    };
    for (name in listUserRules) {
      oUser = listUserRules[name];
      fRemoveNotRequired(oUser);
    }
    fAddRequired = function(userName, oUser) {
      var fCheckRules, nmRl, oRl, _ref, _results;
      fCheckRules = function(oRule) {
        var action, fAddIfNewOrNotExisting, _i, _len, _ref, _results;
        fAddIfNewOrNotExisting = function(actionName) {
          var moduleName;
          moduleName = (actionName.split(' -> '))[0];
          if (!oUser.actions[moduleName] || oRule.id === oNewRule.id) {
            return db.actionInvokers.getModule(moduleName, function(err, obj) {
              var params, res;
              params = {};
              res = dynmod.compileString(obj.data, userName, moduleName, params, obj.lang);
              return oUser.actions[moduleName] = res.module;
            });
          }
        };
        _ref = oRule.actions;
        _results = [];
        for (_i = 0, _len = _ref.length; _i < _len; _i++) {
          action = _ref[_i];
          _results.push(fAddIfNewOrNotExisting(action));
        }
        return _results;
      };
      _ref = oUser.rules;
      _results = [];
      for (nmRl in _ref) {
        oRl = _ref[nmRl];
        _results.push(fCheckRules(oRl));
      }
      return _results;
    };
    _results = [];
    for (userName in listUserRules) {
      oUser = listUserRules[userName];
      _results.push(fAddRequired(userName, oUser));
    }
    return _results;
  };

  pollQueue = function() {
    if (isRunning) {
      return db.popEvent(function(err, obj) {
        if (!err && obj) {
          processEvent(obj);
        }
        return setTimeout(pollQueue, 50);
      });
    }
  };

  /*
  Checks whether all conditions of the rule are met by the event.
  
  @private validConditions ( *evt, rule* )
  @param {Object} evt
  @param {Object} rule
  */


  validConditions = function(evt, rule) {
    var conds, prop;
    conds = rule.conditions;
    for (prop in conds) {
      if (!evt[prop] || evt[prop] !== conds[prop]) {
        return false;
      }
    }
    return true;
  };

  /*
  Handles retrieved events.
  
  @private processEvent ( *evt* )
  @param {Object} evt
  */


  processEvent = function(evt) {
    return this.log.info('EN | processing event: ' + evt.event + '(' + evt.eventid + ')');
  };

  exports.shutDown = function() {
    return isRunning = false;
  };

}).call(this);