/* $Id$ */

/*
 * 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 newgrf_object.cpp Handling of object NewGRFs. */

#include "stdafx.h"
#include "company_base.h"
#include "company_func.h"
#include "core/mem_func.hpp"
#include "date_func.h"
#include "debug.h"
#include "landscape.h"
#include "newgrf.h"
#include "newgrf_class_func.h"
#include "newgrf_object.h"
#include "newgrf_spritegroup.h"
#include "newgrf_town.h"
#include "object_base.h"
#include "object_map.h"
#include "sprite.h"
#include "town.h"
#include "viewport_func.h"
#include "water.h"

/** The override manager for our objects. */
ObjectOverrideManager _object_mngr(NEW_OBJECT_OFFSET, NUM_OBJECTS, INVALID_OBJECT_TYPE);

extern const ObjectSpec _original_objects[NEW_OBJECT_OFFSET];
/** All the object specifications. */
ObjectSpec _object_specs[NUM_OBJECTS];

/* static */ const ObjectSpec *ObjectSpec::Get(ObjectType index)
{
	assert(index < NUM_OBJECTS);
	return &_object_specs[index];
}

/* static */ const ObjectSpec *ObjectSpec::GetByTile(TileIndex tile)
{
	return ObjectSpec::Get(GetObjectType(tile));
}

bool ObjectSpec::IsAvailable() const
{
	return
			this->enabled &&
			_date > this->introduction_date &&
			(_date < this->end_of_life_date || this->end_of_life_date < this->introduction_date + 365) &&
			HasBit(this->climate, _settings_game.game_creation.landscape) &&
			(flags & (_game_mode != GM_EDITOR ? OBJECT_FLAG_ONLY_IN_SCENEDIT : OBJECT_FLAG_ONLY_IN_GAME)) == 0;
}

uint ObjectSpec::Index() const
{
	return this - _object_specs;
}

/** This function initialize the spec arrays of objects. */
void ResetObjects()
{
	/* Clean the pool. */
	MemSetT(_object_specs, 0, lengthof(_object_specs));

	/* And add our originals. */
	MemCpyT(_object_specs, _original_objects, lengthof(_original_objects));
}

template <typename Tspec, typename Tid, Tid Tmax>
/* static */ void NewGRFClass<Tspec, Tid, Tmax>::InsertDefaults()
{
	/* We only add the transmitters in the scenario editor. */
	if (_game_mode != GM_EDITOR) return;

	ObjectClassID cls = ObjectClass::Allocate('LTHS');
	ObjectClass::SetName(cls, STR_OBJECT_CLASS_LTHS);
	_object_specs[OBJECT_LIGHTHOUSE].cls_id = cls;
	ObjectClass::Assign(&_object_specs[OBJECT_LIGHTHOUSE]);

	cls = ObjectClass::Allocate('TRNS');
	ObjectClass::SetName(cls, STR_OBJECT_CLASS_TRNS);
	_object_specs[OBJECT_TRANSMITTER].cls_id = cls;
	ObjectClass::Assign(&_object_specs[OBJECT_TRANSMITTER]);
}

INSTANTIATE_NEWGRF_CLASS_METHODS(ObjectClass, ObjectSpec, ObjectClassID, OBJECT_CLASS_MAX)


static uint32 ObjectGetRandomBits(const ResolverObject *object)
{
	return IsTileType(object->u.object.tile, MP_OBJECT) ? GetObjectRandomBits(object->u.object.tile) : 0;
}

static uint32 ObjectGetTriggers(const ResolverObject *object)
{
	return 0;
}

static void ObjectSetTriggers(const ResolverObject *object, int triggers)
{
}


/**
 * Make an analysis of a tile and check for its belonging to the same
 * object, and/or the same grf file
 * @param tile TileIndex of the tile to query
 * @param index Object to which to compare the tile to
 * @param cur_grfid GRFID of the current callback chain
 * @return value encoded as per NFO specs
 */
static uint32 GetObjectIDAtOffset(TileIndex tile, ObjectID oid, uint32 cur_grfid)
{
	if (!IsTileType(tile, MP_OBJECT) || GetObjectIndex(tile) != oid) {
		/* No object and/or the tile does not have the same object as the one we match it with */
		return 0xFFFF;
	}

	const ObjectSpec *spec = ObjectSpec::GetByTile(tile);

	if (spec->grf_prop.grffile->grfid == cur_grfid) { // same object, same grf ?
		return spec->grf_prop.local_id;
	}

	return 0xFFFE; // Defined in another grf file
}

/**
 * Based on newhouses equivalent, but adapted for newobjects
 * @param parameter from callback.  It's in fact a pair of coordinates
 * @param tile TileIndex from which the callback was initiated
 * @param index of the object been queried for
 * @return a construction of bits obeying the newgrf format
 */
static uint32 GetNearbyObjectTileInformation(byte parameter, TileIndex tile, ObjectID index)
{
	if (parameter != 0) tile = GetNearbyTile(parameter, tile); // only perform if it is required
	bool is_same_object = (IsTileType(tile, MP_OBJECT) && GetObjectIndex(tile) == index);

	return GetNearbyTileInformation(tile) | (is_same_object ? 1 : 0) << 8;
}

/**
 * Get the object's animation counter data.
 * @param tile The tile to query.
 * @return The object's data.
 */
static uint32 GetObjectAnimationCounter(TileIndex tile)
{
	return Object::GetByTile(tile)->colour << 8 | GetAnimationFrame(tile);
}

/**
 * Get the closest object of a given type.
 * @param tile    The tile to start searching from.
 * @param type    The type of the object to search for.
 * @param current The current object (to ignore).
 * @return The distance to the closest object.
 */
static uint32 GetClosestObject(TileIndex tile, ObjectType type, const Object *current)
{
	uint32 best_dist = UINT32_MAX;
	const Object *o;
	FOR_ALL_OBJECTS(o) {
		if (GetObjectType(o->location.tile) != type || o == current) continue;

		best_dist = min(best_dist, DistanceManhattan(tile, o->location.tile));
	}

	return best_dist;
}

/**
 * Implementation of var 65
 * @param local_id Parameter given to the callback, which is the set id, or the local id, in our terminology.
 * @param grfid    The object's GRFID.
 * @param tile     The tile to look from.
 * @param current  Object for which the inquiry is made
 * @return The formatted answer to the callback : rr(reserved) cc(count) dddd(manhattan distance of closest sister)
 */
static uint32 GetCountAndDistanceOfClosestInstance(byte local_id, uint32 grfid, TileIndex tile, const Object *current)
{
	uint32 grf_id = GetRegister(0x100);  // Get the GRFID of the definition to look for in register 100h
	uint32 idx;

	/* Determine what will be the object type to look for */
	switch (grf_id) {
		case 0:  // this is a default object type
			idx = local_id;
			break;

		case 0xFFFFFFFF: // current grf
			grf_id = grfid;
			/* FALL THROUGH */

		default: // use the grfid specified in register 100h
			idx = _object_mngr.GetID(local_id, grf_id);
			break;
	}

	/* If the object type is invalid, there is none and the closest is far away. */
	if (idx >= NUM_OBJECTS) return 0 | 0xFFFF;

	return Object::GetTypeCount(idx) << 16 | min(GetClosestObject(tile, idx, current), 0xFFFF);
}

/** Used by the resolver to get values for feature 0F deterministic spritegroups. */
static uint32 ObjectGetVariable(const ResolverObject *object, byte variable, byte parameter, bool *available)
{
	const Object *o = object->u.object.o;
	TileIndex tile = object->u.object.tile;

	if (object->scope == VSG_SCOPE_PARENT) {
		/* Pass the request on to the town of the object */
		return TownGetVariable(variable, parameter, available, (o == NULL) ? ClosestTownFromTile(tile, UINT_MAX) : o->town);
	}

	/* We get the town from the object, or we calculate the closest
	 * town if we need to when there's no object. */
	const Town *t = NULL;

	if (o == NULL) {
		switch (variable) {
			/* Allow these when there's no object. */
			case 0x41:
			case 0x60:
			case 0x61:
			case 0x62:
			case 0x64:
			case 0x65:
				break;

			/* Allow these, but find the closest town. */
			case 0x45:
			case 0x46:
				t = ClosestTownFromTile(tile, UINT_MAX);
				break;

			/* Construction date */
			case 0x42: return _date;

			/* Object founder information */
			case 0x44: return _current_company;

			/*
			 * Disallow the rest:
			 * 0x40: Relative position is passed as parameter during construction.
			 * 0x43: Animation counter is only for actual tiles.
			 * 0x63: Animation counter of nearby tile, see above.
			 */
			default:
				DEBUG(grf, 1, "Unhandled object property 0x%X", variable);

				*available = false;
				return UINT_MAX;
		}
	} else {
		t = o->town;
	}

	switch (variable) {
		/* Relative position. */
		case 0x40: {
			uint offset = tile - o->location.tile;
			uint offset_x = TileX(offset);
			uint offset_y = TileY(offset);
			return offset_y << 20 | offset_x << 16 | offset_y << 8 | offset_x;
		}

		/* Tile information. */
		case 0x41: return GetTileSlope(tile, NULL) << 8 | GetTerrainType(tile);

		/* Construction date */
		case 0x42: return o->build_date;

		/* Animation counter */
		case 0x43: return GetObjectAnimationCounter(tile);

		/* Object founder information */
		case 0x44: return GetTileOwner(tile);

		/* Get town zone and Manhattan distance of closest town */
		case 0x45: return GetTownRadiusGroup(t, tile) << 16 | min(DistanceManhattan(tile, t->xy), 0xFFFF);

		/* Get square of Euclidian distance of closes town */
		case 0x46: return GetTownRadiusGroup(t, tile) << 16 | min(DistanceSquare(tile, t->xy), 0xFFFF);

		/* Get object ID at offset param */
		case 0x60: return GetObjectIDAtOffset(GetNearbyTile(parameter, tile), o == NULL ? INVALID_OBJECT : o->index, object->grffile->grfid);

		/* Get random tile bits at offset param */
		case 0x61:
			tile = GetNearbyTile(parameter, tile);
			return (IsTileType(tile, MP_OBJECT) && Object::GetByTile(tile) == o) ? GetObjectRandomBits(tile) : 0;

		/* Land info of nearby tiles */
		case 0x62: return GetNearbyObjectTileInformation(parameter, tile, o == NULL ? INVALID_OBJECT : o->index);

		/* Animation counter of nearby tile */
		case 0x63:
			tile = GetNearbyTile(parameter, tile);
			return (IsTileType(tile, MP_OBJECT) && Object::GetByTile(tile) == o) ? GetObjectAnimationCounter(tile) : 0;

		/* Distance of nearest object of given type */
		case 0x64: return GetClosestObject(tile, GetObjectType(tile), o);

		/* Count of object, distance of closest instance */
		case 0x65: return GetCountAndDistanceOfClosestInstance(parameter, object->grffile->grfid, tile, o);
	}

	DEBUG(grf, 1, "Unhandled object property 0x%X", variable);

	*available = false;
	return UINT_MAX;
}

static const SpriteGroup *ObjectResolveReal(const ResolverObject *object, const RealSpriteGroup *group)
{
	/* Objects do not have 'real' groups */
	return NULL;
}

/**
 * Get the object's sprite group.
 * @param spec The specification to get the sprite group from.
 * @param o    The object to get he sprite group for.
 * @return The resolved sprite group.
 */
static const SpriteGroup *GetObjectSpriteGroup(const ObjectSpec *spec, const Object *o)
{
	const SpriteGroup *group = NULL;

	if (o == NULL) group = spec->grf_prop.spritegroup[CT_PURCHASE_OBJECT];
	if (group != NULL) return group;

	/* Fall back to the default set if the selected cargo type is not defined */
	return spec->grf_prop.spritegroup[0];

}

/**
 * Returns a resolver object to be used with feature 0F spritegroups.
 */
static void NewObjectResolver(ResolverObject *res, const ObjectSpec *spec, const Object *o, TileIndex tile)
{
	res->GetRandomBits = ObjectGetRandomBits;
	res->GetTriggers   = ObjectGetTriggers;
	res->SetTriggers   = ObjectSetTriggers;
	res->GetVariable   = ObjectGetVariable;
	res->ResolveReal   = ObjectResolveReal;

	res->u.object.o    = o;
	res->u.object.tile = tile;

	res->callback        = CBID_NO_CALLBACK;
	res->callback_param1 = 0;
	res->callback_param2 = 0;
	res->last_value      = 0;
	res->trigger         = 0;
	res->reseed          = 0;
	res->count           = 0;

	res->grffile = spec->grf_prop.grffile;
}

/**
 * Perform a callback for an object.
 * @param callback The callback to perform.
 * @param param1   The first parameter to pass to the NewGRF.
 * @param param2   The second parameter to pass to the NewGRF.
 * @param spec     The specification of the object / the entry point.
 * @param o        The object to call the callback for.
 * @param tile     The tile the callback is called for.
 * @return The result of the callback.
 */
uint16 GetObjectCallback(CallbackID callback, uint32 param1, uint32 param2, const ObjectSpec *spec, const Object *o, TileIndex tile)
{
	ResolverObject object;
	NewObjectResolver(&object, spec, o, tile);
	object.callback = callback;
	object.callback_param1 = param1;
	object.callback_param2 = param2;

	const SpriteGroup *group = SpriteGroup::Resolve(GetObjectSpriteGroup(spec, o), &object);
	if (group == NULL) return CALLBACK_FAILED;

	return group->GetCallbackResult();
}

/**
 * Draw an group of sprites on the map.
 * @param ti    Information about the tile to draw on.
 * @param group The group of sprites to draw.
 * @param spec  Object spec to draw.
 */
static void DrawTileLayout(const TileInfo *ti, const TileLayoutSpriteGroup *group, const ObjectSpec *spec)
{
	const DrawTileSprites *dts = group->dts;
	PaletteID palette = ((spec->flags & OBJECT_FLAG_2CC_COLOUR) ? SPR_2CCMAP_BASE : PALETTE_RECOLOUR_START) + Object::GetByTile(ti->tile)->colour;

	SpriteID image = dts->ground.sprite;
	PaletteID pal  = dts->ground.pal;

	if (GB(image, 0, SPRITE_WIDTH) != 0) {
		/* If the ground sprite is the default flat water sprite, draw also canal/river borders
		 * Do not do this if the tile's WaterClass is 'land'. */
		if ((image == SPR_FLAT_WATER_TILE || spec->flags & OBJECT_FLAG_DRAW_WATER) && IsTileOnWater(ti->tile)) {
			DrawWaterClassGround(ti);
		} else {
			DrawGroundSprite(image, GroundSpritePaletteTransform(image, pal, palette));
		}
	}

	DrawNewGRFTileSeq(ti, dts, TO_STRUCTURES, 0, palette);
}

/**
 * Draw an object on the map.
 * @param ti   Information about the tile to draw on.
 * @param spec Object spec to draw.
 */
void DrawNewObjectTile(TileInfo *ti, const ObjectSpec *spec)
{
	ResolverObject object;
	const Object *o = Object::GetByTile(ti->tile);
	NewObjectResolver(&object, spec, o, ti->tile);

	const SpriteGroup *group = SpriteGroup::Resolve(GetObjectSpriteGroup(spec, o), &object);
	if (group == NULL || group->type != SGT_TILELAYOUT) return;

	DrawTileLayout(ti, (const TileLayoutSpriteGroup *)group, spec);
}

/**
 * Draw representation of an object (tile) for GUI purposes.
 * @param x    Position x of image.
 * @param y    Position y of image.
 * @param spec Object spec to draw.
 */
void DrawNewObjectTileInGUI(int x, int y, const ObjectSpec *spec)
{
	ResolverObject object;
	NewObjectResolver(&object, spec, NULL, INVALID_TILE);

	const SpriteGroup *group = SpriteGroup::Resolve(GetObjectSpriteGroup(spec, NULL), &object);
	if (group == NULL || group->type != SGT_TILELAYOUT) return;

	const DrawTileSprites *dts = ((const TileLayoutSpriteGroup *)group)->dts;

	PaletteID palette;
	if (Company::IsValidID(_local_company)) {
		/* Get the colours of our company! */
		if (spec->flags & OBJECT_FLAG_2CC_COLOUR) {
			const Livery *l = Company::Get(_local_company)->livery;
			palette = SPR_2CCMAP_BASE + l->colour1 + l->colour2 * 16;
		} else {
			palette = COMPANY_SPRITE_COLOUR(_local_company);
		}
	} else {
		/* There's no company, so just take the base palette. */
		palette = (spec->flags & OBJECT_FLAG_2CC_COLOUR) ? SPR_2CCMAP_BASE : PALETTE_RECOLOUR_START;
	}

	SpriteID image = dts->ground.sprite;
	PaletteID pal  = dts->ground.pal;

	if (GB(image, 0, SPRITE_WIDTH) != 0) {
		DrawSprite(image, GroundSpritePaletteTransform(image, pal, palette), x, y);
	}

	DrawNewGRFTileSeqInGUI(x, y, dts, 0, palette);
}