// main.h: defines the class Sim, used to create one object "sim".
//
// The object sim is declared here for inclusion everywhere, but defined
// and initialized in main.cc. It carries global variables and constants
// used throughout the simulation.

class Sim {
public:
   double simulationTime; // What time is it?
   int simulating; // set to false by end-of-simulation event

   double reportInterval; // How often should we report?
      
   // quantities that determine how we model the real world
   // In a more elaborate program, these might be input data.
   
   // economics: profit per litre of gas, and cost to operate one pump for a day
   double profit;
   double pumpCost;
   
   // demand: minimum and maximum amount of gas needed by a car
   // See Car constructor.
   double litresNeededMin;
   double litresNeededRange;
   
   // service times: constant base time + time per litre + random spread
   // See Pump.serviceTime().
   double serviceTimeBase;
   double serviceTimePerLitre;
   double serviceTimeSpread;
   
   // customer behaviour: probability of balking depends on three
   // ad-hoc constants. See Arrival.doesCarBalk().
   double balkA;
   double balkB;
   double balkC;
   
   // customer arrival rate
   // See Arrival.interarrivalTime().
   double meanInterarrivalTime; // seconds

   // random-number streams used to model the world
   class Random *arrivalStream; // auto arrival times
   class Random *litreStream; // number of litres needed
   class Random *balkingStream; // balking probability
   class Random *serviceStream; // service times
   
   // major data structures
   class EventList *eventList;
   class CarQueue *carQueue;
   class PumpStand *pumpStand;
   class Statistics *stats;
};

extern Sim *sim;