-- LegacyWorlds Beta 6
-- PostgreSQL database scripts
--
-- Resource providers functions
--
-- Copyright(C) 2004-2012, DeepClone Development
-- --------------------------------------------------------


/*
 * Compute resource provider regeneration
 * 
 * This function computes the quantity in a resource provider after it has
 * been regenerated.
 * 
 * Parameters:
 *		_quantity		The current quantity of resources in the provider
 *		_max			The maximal amount of resources supported by the
 *							provider
 *		_recovery_rate	The provider's recovery rate
 *
 * Returns:
 *		?				The new quantity of resources.
 */
CREATE OR REPLACE FUNCTION verse.compute_provider_regeneration(
				_quantity		DOUBLE PRECISION ,
				_max			DOUBLE PRECISION ,
				_recovery_rate	DOUBLE PRECISION )
		RETURNS DOUBLE PRECISION
		STRICT IMMUTABLE
		SECURITY INVOKER
	AS $compute_provider_regeneration$

DECLARE
	_uc_recovery	DOUBLE PRECISION;
	_uc_dampening	DOUBLE PRECISION;
	_uc_ticks		DOUBLE PRECISION;
	_result			DOUBLE PRECISION;

BEGIN
	_uc_recovery := sys.get_constant( 'game.resources.recovery' );
	_uc_dampening := sys.get_constant( 'game.resources.recoveryDampening' );
	_uc_ticks := 1440; -- FIXME: this should be a constant
	
	_result := ( 1 - _quantity / _max ) ^ _uc_dampening;
	_result := _quantity + _result * _recovery_rate * _uc_recovery / _uc_ticks;

	IF _result > _max THEN
		_result := _max;
	END IF;

	RETURN _result;
END;
$compute_provider_regeneration$ LANGUAGE PLPGSQL;


REVOKE EXECUTE
	ON FUNCTION verse.compute_provider_regeneration(
		DOUBLE PRECISION , DOUBLE PRECISION ,
		DOUBLE PRECISION )
	FROM PUBLIC;