/** @file demands.h Declaration of demand calculating link graph handler. */

#ifndef DEMANDS_H
#define DEMANDS_H

#include "linkgraphjob_base.h"

/**
 * Calculate the demands. This class has a state, but is recreated for each
 * call to of DemandHandler::Run.
 */
class DemandCalculator {
public:
	DemandCalculator(LinkGraphJob &job);

private:
	int32 max_distance; ///< Maximum distance possible on the map.
	int32 mod_dist;     ///< Distance modifier, determines how much demands decrease with distance.
	int32 accuracy;     ///< Accuracy of the calculation.

	template<class Tscaler>
	void CalcDemand(LinkGraphJob &job, Tscaler scaler);
};

/**
 * Stateless, thread safe demand handler. Doesn't do anything but call DemandCalculator.
 */
class DemandHandler : public ComponentHandler {
public:

	/**
	 * Call the demand calculator on the given component.
	 * @param job Component to calculate the demands for.
	 */
	virtual void Run(LinkGraphJob &job) const { DemandCalculator c(job); }

	/**
	 * Virtual destructor has to be defined because of virtual Run().
	 */
	virtual ~DemandHandler() {}
};

#endif /* DEMANDS_H */
