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OpenTTD-patches/src/ai/api/ai_subsidy.hpp

110 lines
3.4 KiB
C++

/* $Id$ */
/** @file ai_subsidy.hpp Everything to query subsidies. */
#ifndef AI_SUBSIDY_HPP
#define AI_SUBSIDY_HPP
#include "ai_object.hpp"
#include "ai_company.hpp"
/**
* Class that handles all subsidy related functions.
*/
class AISubsidy : public AIObject {
public:
static const char *GetClassName() { return "AISubsidy"; }
/**
* Enumeration for source and destination of a subsidy.
* @note The list of values may grow in future.
*/
enum SubsidyParticipantType {
SPT_INDUSTRY = 0, //!< Subsidy participant is an industry
SPT_TOWN = 1, //!< Subsidy participant is a town
SPT_INVALID = 0xFF, //!< Invalid/unknown participant type
};
/**
* Check whether this is a valid SubsidyID.
* @param subsidy_id The SubsidyID to check.
* @return True if and only if this subsidy is still valid.
*/
static bool IsValidSubsidy(SubsidyID subsidy_id);
/**
* Checks whether this subsidy is already awarded to some company.
* @param subsidy_id The SubsidyID to check.
* @pre IsValidSubsidy(subsidy).
* @return True if and only if this subsidy is already awarded.
*/
static bool IsAwarded(SubsidyID subsidy_id);
/**
* Get the company index of the company this subsidy is awarded to.
* @param subsidy_id The SubsidyID to check.
* @pre IsAwarded(subsidy_id).
* @return The companyindex of the company this subsidy is awarded to.
*/
static AICompany::CompanyID GetAwardedTo(SubsidyID subsidy_id);
/**
* Get the date this subsidy expires. In case the subsidy is already
* awarded, return the date the subsidy expires, else, return the date the
* offer expires.
* @param subsidy_id The SubsidyID to check.
* @pre IsValidSubsidy(subsidy_id).
* @return The last valid date of this subsidy.
* @note The return value of this function will change if the subsidy is
* awarded.
*/
static int32 GetExpireDate(SubsidyID subsidy_id);
/**
* Get the cargo type that has to be transported in order to be awarded this
* subsidy.
* @param subsidy_id The SubsidyID to check.
* @pre IsValidSubsidy(subsidy_id).
* @return The cargo type to transport.
*/
static CargoID GetCargoType(SubsidyID subsidy_id);
/**
* Returns the type of source of subsidy.
* @param subsidy_id The SubsidyID to check.
* @pre IsValidSubsidy(subsidy_id).
* @return Type of source of subsidy.
*/
static SubsidyParticipantType GetSourceType(SubsidyID subsidy_id);
/**
* Return the source IndustryID/TownID the subsidy is for.
* \li GetSourceType(subsidy_id) == SPT_INDUSTRY -> return the IndustryID.
* \li GetSourceType(subsidy_id) == SPT_TOWN -> return the TownID.
* @param subsidy_id The SubsidyID to check.
* @pre IsValidSubsidy(subsidy_id).
* @return One of TownID/IndustryID.
*/
static int32 GetSourceIndex(SubsidyID subsidy_id);
/**
* Returns the type of destination of subsidy.
* @param subsidy_id The SubsidyID to check.
* @pre IsValidSubsidy(subsidy_id).
* @return Type of destination of subsidy.
*/
static SubsidyParticipantType GetDestinationType(SubsidyID subsidy_id);
/**
* Return the destination IndustryID/TownID the subsidy is for.
* \li GetDestinationType(subsidy_id) == SPT_INDUSTRY -> return the IndustryID.
* \li GetDestinationType(subsidy_id) == SPT_TOWN -> return the TownID.
* @param subsidy_id the SubsidyID to check.
* @pre IsValidSubsidy(subsidy_id).
* @return One of TownID/IndustryID.
*/
static int32 GetDestinationIndex(SubsidyID subsidy_id);
};
#endif /* AI_SUBSIDY_HPP */