/* $Id$ */

/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file cargomonitor.cpp Implementation of the cargo transport monitoring. */

#include "stdafx.h"
#include "cargomonitor.h"
#include "station_base.h"

CargoMonitorMap _cargo_pickups;    ///< Map of monitored pick-ups   to the amount since last query/activation.
CargoMonitorMap _cargo_deliveries; ///< Map of monitored deliveries to the amount since last query/activation.

/** Clear all pick-up cargo monitors. */
void ClearCargoPickupMonitoring()
{
	_cargo_pickups.clear();
}

/** Clear all delivery cargo monitors. */
void ClearCargoDeliveryMonitoring()
{
	_cargo_deliveries.clear();
}

/**
 * Get and reset the amount associated with a cargo monitor.
 * @param[in,out] monitor_map Monitoring map to search (and reset for the queried entry).
 * @param monitor Cargo monitor to query/reset.
 * @param keep_monitoring After returning from this call, continue monitoring.
 * @return Amount collected since last query/activation for the monitored combination.
 */
static uint32 GetAmount(CargoMonitorMap &monitor_map, CargoMonitorID monitor, bool keep_monitoring)
{
	CargoMonitorMap::iterator iter = monitor_map.find(monitor);
	if (iter == monitor_map.end()) {
		if (keep_monitoring) {
			std::pair<CargoMonitorID, uint32> p(monitor, 0);
			monitor_map.insert(p);
		}
		return 0;
	} else {
		uint32 result = iter->second;
		iter->second = 0;
		if (!keep_monitoring) monitor_map.erase(iter);
		return result;
	}
}

/**
 * Get the amount of cargo delivered for the given cargo monitor since activation or last query.
 * @param monitor Cargo monitor to query.
 * @param keep_monitoring After returning from this call, continue monitoring.
 * @return Amount of delivered cargo for the monitored combination.
 */
uint32 GetDeliveryAmount(CargoMonitorID monitor, bool keep_monitoring)
{
	return GetAmount(_cargo_deliveries, monitor, keep_monitoring);
}

/**
 * Get the amount of cargo picked up for the given cargo monitor since activation or last query.
 * @param monitor Monitoring number to query.
 * @param keep_monitoring After returning from this call, continue monitoring.
 * @return Amount of picked up cargo for the monitored combination.
 * @note Cargo pick up is counted on final delivery, to prevent users getting credit for picking up cargo without delivering it.
 */
uint32 GetPickupAmount(CargoMonitorID monitor, bool keep_monitoring)
{
	return GetAmount(_cargo_pickups, monitor, keep_monitoring);
}

/**
 * Cargo was delivered to its final destination, update the pickup and delivery maps.
 * @param cargo_type type of cargo.
 * @param company company delivering the cargo.
 * @param amount Amount of cargo delivered.
 * @param src_type type of \a src.
 * @param src index of source.
 * @param st station where the cargo is delivered to.
 */
void AddCargoDelivery(CargoID cargo_type, CompanyID company, uint32 amount, SourceType src_type, SourceID src, const Station *st)
{
	if (amount == 0) return;

	if (src != INVALID_SOURCE) {
		/* Handle pickup update. */
		switch (src_type) {
			case ST_INDUSTRY: {
				CargoMonitorID num = EncodeCargoIndustryMonitor(company, cargo_type, src);
				CargoMonitorMap::iterator iter = _cargo_pickups.find(num);
				if (iter != _cargo_pickups.end()) iter->second += amount;
				break;
			}
			case ST_TOWN: {
				CargoMonitorID num = EncodeCargoTownMonitor(company, cargo_type, src);
				CargoMonitorMap::iterator iter = _cargo_pickups.find(num);
				if (iter != _cargo_pickups.end()) iter->second += amount;
				break;
			}
			default: break;
		}
	}

	/* Handle delivery.
	 * Note that delivery in the right area is sufficient to prevent trouble with neighbouring industries or houses. */

	/* Town delivery. */
	CargoMonitorID num = EncodeCargoTownMonitor(company, cargo_type, st->town->index);
	CargoMonitorMap::iterator iter = _cargo_deliveries.find(num);
	if (iter != _cargo_deliveries.end()) iter->second += amount;

	/* Industry delivery. */
	for (const Industry * const *ip = st->industries_near.Begin(); ip != st->industries_near.End(); ip++) {
		CargoMonitorID num = EncodeCargoIndustryMonitor(company, cargo_type, (*ip)->index);
		CargoMonitorMap::iterator iter = _cargo_deliveries.find(num);
		if (iter != _cargo_deliveries.end()) iter->second += amount;
	}
}