/*
 * 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 <https://www.gnu.org/licenses/old-licenses/gpl-2.0>.
 */

/** @file newgrf_house.cpp Implementation of NewGRF houses. */

#include "stdafx.h"
#include "debug.h"
#include "landscape.h"
#include "newgrf_badge.h"
#include "newgrf_house.h"
#include "newgrf_spritegroup.h"
#include "newgrf_town.h"
#include "newgrf_sound.h"
#include "company_func.h"
#include "company_base.h"
#include "town.h"
#include "genworld.h"
#include "newgrf_animation_base.h"
#include "newgrf_cargo.h"
#include "station_base.h"

#include "safeguards.h"

static BuildingCounts<uint32_t> _building_counts{};
static std::vector<HouseClassMapping> _class_mapping{};

HouseOverrideManager _house_mngr(NEW_HOUSE_OFFSET, NUM_HOUSES, INVALID_HOUSE_ID);

/**
 * Retrieve the grf file associated with a house.
 * @param house_id House to query.
 * @return The associated GRF file (may be \c nullptr).
 */
static const GRFFile *GetHouseSpecGrf(HouseID house_id)
{
	const HouseSpec *hs  = HouseSpec::Get(house_id);
	return (hs != nullptr) ? hs->grf_prop.grffile : nullptr;
}

extern const HouseSpec _original_house_specs[NEW_HOUSE_OFFSET];
std::vector<HouseSpec> _house_specs;

/**
 * Get a reference to all HouseSpecs.
 * @return Reference to vector of all HouseSpecs.
 */
std::vector<HouseSpec> &HouseSpec::Specs()
{
	return _house_specs;
}

/**
 * Gets the index of this spec.
 * @return The index.
 */
HouseID HouseSpec::Index() const
{
	return static_cast<HouseID>(this - _house_specs.data());
}

/**
 * Get the spec for a house ID.
 * @param house_id The ID of the house.
 * @return The HouseSpec associated with the ID.
 */
HouseSpec *HouseSpec::Get(size_t house_id)
{
	/* Empty house if index is out of range -- this might happen if NewGRFs are changed. */
	static HouseSpec empty = {};

	assert(house_id < NUM_HOUSES);
	if (house_id >= _house_specs.size()) return &empty;
	return &_house_specs[house_id];
}

/** Reset and initialise house specs. */
void ResetHouses()
{
	_house_specs.clear();
	_house_specs.reserve(std::size(_original_house_specs));

	ResetHouseClassIDs();

	/* Copy default houses. */
	_house_specs.insert(std::end(_house_specs), std::begin(_original_house_specs), std::end(_original_house_specs));

	/* Reset any overrides that have been set. */
	_house_mngr.ResetOverride();
}

/**
 * Construct a resolver for a house.
 * @param house_id House to query.
 * @param tile %Tile containing the house.
 * @param town %Town containing the house.
 * @param callback Callback ID.
 * @param param1 First parameter (var 10) of the callback.
 * @param param2 Second parameter (var 18) of the callback.
 * @param not_yet_constructed House is still under construction.
 * @param initial_random_bits Random bits during construction checks.
 * @param watched_cargo_triggers Cargo types that triggered the watched cargo callback.
 * @param view The house's 'view'.
 */
HouseResolverObject::HouseResolverObject(HouseID house_id, TileIndex tile, Town *town,
		CallbackID callback, uint32_t param1, uint32_t param2,
		bool not_yet_constructed, uint8_t initial_random_bits, CargoTypes watched_cargo_triggers, int view)
	: SpecializedResolverObject<HouseRandomTriggers>(GetHouseSpecGrf(house_id), callback, param1, param2),
	house_scope(*this, house_id, tile, town, not_yet_constructed, initial_random_bits, watched_cargo_triggers, view),
	town_scope(*this, town, not_yet_constructed) // Don't access StorePSA if house is not yet constructed.
{
	/* Tile must be valid and a house tile, unless not yet constructed in which case it may also be INVALID_TILE. */
	assert((IsValidTile(tile) && (not_yet_constructed || IsTileType(tile, TileType::House))) || (not_yet_constructed && tile == INVALID_TILE));

	this->root_spritegroup = HouseSpec::Get(house_id)->grf_prop.GetSpriteGroup(!not_yet_constructed);
}

GrfSpecFeature HouseResolverObject::GetFeature() const
{
	return GrfSpecFeature::Houses;
}

uint32_t HouseResolverObject::GetDebugID() const
{
	return HouseSpec::Get(this->house_scope.house_id)->grf_prop.local_id;
}

void ResetHouseClassIDs()
{
	_class_mapping.clear();

	/* Add initial entry for HOUSE_NO_CLASS. */
	_class_mapping.emplace_back();
}

HouseClassID AllocateHouseClassID(uint8_t grf_class_id, uint32_t grfid)
{
	/* Start from 1 because 0 means that no class has been assigned. */
	auto it = std::find_if(std::next(std::begin(_class_mapping)), std::end(_class_mapping), [grf_class_id, grfid](const HouseClassMapping &map) { return map.class_id == grf_class_id && map.grfid == grfid; });

	/* HouseClass not found, allocate a new one. */
	if (it == std::end(_class_mapping)) it = _class_mapping.insert(it, {.grfid = grfid, .class_id = grf_class_id});

	return static_cast<HouseClassID>(std::distance(std::begin(_class_mapping), it));
}

/**
 * Initialise building counts for a town.
 * @param t Town cache to initialise.
 */
void InitializeBuildingCounts(Town *t)
{
	t->cache.building_counts.id_count.clear();
	t->cache.building_counts.class_count.clear();
	t->cache.building_counts.id_count.resize(HouseSpec::Specs().size());
	t->cache.building_counts.class_count.resize(_class_mapping.size());
}

/**
 * Initialise global building counts and all town building counts.
 */
void InitializeBuildingCounts()
{
	_building_counts.id_count.clear();
	_building_counts.class_count.clear();
	_building_counts.id_count.resize(HouseSpec::Specs().size());
	_building_counts.class_count.resize(_class_mapping.size());

	for (Town *t : Town::Iterate()) {
		InitializeBuildingCounts(t);
	}
}

/**
 * Get read-only span of total HouseID building counts.
 * @return span of HouseID building counts.
 */
std::span<const uint> GetBuildingHouseIDCounts()
{
	return _building_counts.id_count;
}

/**
 * IncreaseBuildingCount()
 * Increase the count of a building when it has been added by a town.
 * @param t The town that the building is being built in
 * @param house_id The id of the house being added
 */
void IncreaseBuildingCount(Town *t, HouseID house_id)
{
	HouseClassID class_id = HouseSpec::Get(house_id)->class_id;

	t->cache.building_counts.id_count[house_id]++;
	_building_counts.id_count[house_id]++;

	if (class_id == HOUSE_NO_CLASS) return;

	t->cache.building_counts.class_count[class_id]++;
	_building_counts.class_count[class_id]++;
}

/**
 * DecreaseBuildingCount()
 * Decrease the number of a building when it is deleted.
 * @param t The town that the building was built in
 * @param house_id The id of the house being removed
 */
void DecreaseBuildingCount(Town *t, HouseID house_id)
{
	HouseClassID class_id = HouseSpec::Get(house_id)->class_id;

	if (t->cache.building_counts.id_count[house_id] > 0) t->cache.building_counts.id_count[house_id]--;
	if (_building_counts.id_count[house_id] > 0) _building_counts.id_count[house_id]--;

	if (class_id == HOUSE_NO_CLASS) return;

	if (t->cache.building_counts.class_count[class_id] > 0) t->cache.building_counts.class_count[class_id]--;
	if (_building_counts.class_count[class_id] > 0) _building_counts.class_count[class_id]--;
}

/* virtual */ uint32_t HouseScopeResolver::GetRandomBits() const
{
	/* Note: Towns build houses over houses. So during construction checks 'tile' may be a valid but unrelated house. */
	return this->not_yet_constructed ? this->initial_random_bits : GetHouseRandomBits(this->tile);
}

/* virtual */ uint32_t HouseScopeResolver::GetRandomTriggers() const
{
	/* Note: Towns build houses over houses. So during construction checks 'tile' may be a valid but unrelated house. */
	return this->not_yet_constructed ? 0 : GetHouseRandomTriggers(this->tile).base();
}

static uint32_t GetNumHouses(HouseID house_id, const Town *town)
{
	HouseClassID class_id = HouseSpec::Get(house_id)->class_id;

	uint8_t map_id_count     = ClampTo<uint8_t>(_building_counts.id_count[house_id]);
	uint8_t map_class_count  = ClampTo<uint8_t>(_building_counts.class_count[class_id]);
	uint8_t town_id_count    = ClampTo<uint8_t>(town->cache.building_counts.id_count[house_id]);
	uint8_t town_class_count = ClampTo<uint8_t>(town->cache.building_counts.class_count[class_id]);

	return map_class_count << 24 | town_class_count << 16 | map_id_count << 8 | town_id_count;
}

/**
 * Get information about a nearby tile.
 * @param parameter from callback. It's in fact a pair of coordinates
 * @param tile TileIndex from which the callback was initiated
 * @param grf_version8 True, if we are dealing with a new NewGRF which uses GRF version >= 8.
 * @return a construction of bits obeying the newgrf format
 */
static uint32_t GetNearbyTileInformation(uint8_t parameter, TileIndex tile, bool grf_version8)
{
	tile = GetNearbyTile(parameter, tile);
	return GetNearbyTileInformation(tile, grf_version8);
}

/**
 * This function will activate a search around a central tile, looking for some houses
 * that fit the requested characteristics
 * @param parameter that is given by the callback.
 *                  bits 0..6 radius of the search
 *                  bits 7..8 search type i.e.: 0 = houseID/ 1 = classID/ 2 = grfID
 * @param start_tile TileIndex from which to start the search
 * @param start_house the HouseID that is associated to the house, the callback is called for
 * @return the Manhattan distance from the center tile, if any, and 0 if failure
 */
static uint32_t GetDistanceFromNearbyHouse(uint8_t parameter, TileIndex start_tile, HouseID start_house)
{
	uint8_t searchtype = GB(parameter, 6, 2);
	uint8_t searchradius = GB(parameter, 0, 6);
	if (searchradius < 1) return 0; // do not use a too low radius

	const auto *start_hs = HouseSpec::Get(start_house);
	const auto start_north_tile = start_tile + GetHouseNorthPart(start_house); // modifies 'start_house'!

	for (auto tile : SpiralTileSequence(start_tile, 2 * searchradius + 1)) {
		if (!IsTileType(tile, TileType::House)) continue;
		HouseID house = GetHouseType(tile);
		const HouseSpec *hs = HouseSpec::Get(house);
		if (!hs->grf_prop.HasGrfFile()) continue; // must be one from a grf file
		if (start_north_tile == tile + GetHouseNorthPart(house)) continue; // Always ignore origin house

		bool match;
		switch (searchtype) {
			case 0:
				match = hs->grf_prop.local_id == start_hs->grf_prop.local_id &&  // same local id as the one requested
						hs->grf_prop.grfid == start_hs->grf_prop.grfid;  // from the same grf
				break;
			case 1:
				match = hs->class_id == start_hs->class_id &&  // same classid as the one requested
						hs->grf_prop.grfid == start_hs->grf_prop.grfid;  // from the same grf
				break;
			case 2:
				match = hs->grf_prop.grfid == start_hs->grf_prop.grfid;  // from the same grf
				break;
			default:
				return 0;
		}
		if (match) return DistanceManhattan(tile, start_tile);
	}
	return 0;
}

/* virtual */ uint32_t HouseScopeResolver::GetVariable(uint8_t variable, [[maybe_unused]] uint32_t parameter, bool &available) const
{
	if (this->tile == INVALID_TILE) {
		/* House does not yet exist, nor is it being planned to exist. Provide some default values instead. */
		switch (variable) {
			case 0x40: return TOWN_HOUSE_COMPLETED | this->view << 2; /* Construction stage. */
			case 0x41: return 0;
			case 0x42: return 0;
			case 0x43: return 0;
			case 0x44: return 0;
			case 0x45: return _generating_world ? 1 : 0;
			case 0x46: return 0;
			case 0x47: return 0;
			case 0x60: return 0;
			case 0x61: return 0;
			case 0x62: return 0;
			case 0x63: return 0;
			case 0x64: return 0;
			case 0x65: return 0;
			case 0x66: return 0xFFFFFFFF; /* Class and ID of nearby house. */
			case 0x67: return 0;

			case 0x7A: return GetBadgeVariableResult(*this->ro.grffile, HouseSpec::Get(this->house_id)->badges, parameter);
		}

		Debug(grf, 1, "Unhandled house variable 0x{:X}", variable);
		available = false;
		return UINT_MAX;
	}

	switch (variable) {
		/* Construction stage. */
		case 0x40: return (IsTileType(this->tile, TileType::House) ? GetHouseBuildingStage(this->tile) : 0) | TileHash2Bit(TileX(this->tile), TileY(this->tile)) << 2;

		/* Building age. */
		case 0x41: return IsTileType(this->tile, TileType::House) ? GetHouseAge(this->tile).base() : 0;

		/* Town zone */
		case 0x42: return to_underlying(GetTownRadiusGroup(this->town, this->tile));

		/* Terrain type */
		case 0x43: return GetTerrainType(this->tile);

		/* Number of this type of building on the map. */
		case 0x44: return GetNumHouses(this->house_id, this->town);

		/* Whether the town is being created or just expanded. */
		case 0x45: return _generating_world ? 1 : 0;

		/* Current animation frame. */
		case 0x46: return IsTileType(this->tile, TileType::House) ? GetAnimationFrame(this->tile) : 0;

		/* Position of the house */
		case 0x47: return TileY(this->tile) << 16 | TileX(this->tile);

		/* Building counts for old houses with id = parameter. */
		case 0x60: return parameter < NEW_HOUSE_OFFSET ? GetNumHouses(parameter, this->town) : 0;

		/* Building counts for new houses with id = parameter. */
		case 0x61: {
			const HouseSpec *hs = HouseSpec::Get(this->house_id);
			if (!hs->grf_prop.HasGrfFile()) return 0;

			HouseID new_house = _house_mngr.GetID(parameter, hs->grf_prop.grfid);
			return new_house == INVALID_HOUSE_ID ? 0 : GetNumHouses(new_house, this->town);
		}

		/* Land info for nearby tiles. */
		case 0x62: return GetNearbyTileInformation(parameter, this->tile, this->ro.grffile->grf_version >= 8);

		/* Current animation frame of nearby house tiles */
		case 0x63: {
			TileIndex testtile = GetNearbyTile(parameter, this->tile);
			return IsTileType(testtile, TileType::House) ? GetAnimationFrame(testtile) : 0;
		}

		/* Cargo acceptance history of nearby stations */
		case 0x64: {
			CargoType cargo_type = GetCargoTranslation(parameter, this->ro.grffile);
			if (!IsValidCargoType(cargo_type)) return 0;

			/* Extract tile offset. */
			int8_t x_offs = GB(this->ro.GetRegister(0x100), 0, 8);
			int8_t y_offs = GB(this->ro.GetRegister(0x100), 8, 8);
			TileIndex testtile = Map::WrapToMap(this->tile + TileDiffXY(x_offs, y_offs));

			StationFinder stations(TileArea(testtile, 1, 1));

			/* Collect acceptance stats. */
			uint32_t res = 0;
			for (Station *st : stations.GetStations()) {
				res |= st->goods[cargo_type].ConvertState();
			}

			/* Cargo triggered CB 148? */
			if (this->watched_cargo_triggers.Test(cargo_type)) SetBit(res, 4);

			return res;
		}

		/* Distance test for some house types */
		case 0x65: return GetDistanceFromNearbyHouse(parameter, this->tile, this->house_id);

		/* Class and ID of nearby house tile */
		case 0x66: {
			TileIndex testtile = GetNearbyTile(parameter, this->tile);
			if (!IsTileType(testtile, TileType::House)) return 0xFFFFFFFF;
			HouseID nearby_house_id = GetHouseType(testtile);
			HouseSpec *hs = HouseSpec::Get(nearby_house_id);
			/* Information about the grf local classid if the house has a class */
			uint houseclass = 0;
			if (hs->class_id != HOUSE_NO_CLASS) {
				houseclass = (hs->grf_prop.grffile == this->ro.grffile ? 1 : 2) << 8;
				houseclass |= _class_mapping[hs->class_id].class_id;
			}
			/* old house type or grf-local houseid */
			uint local_houseid = 0;
			if (nearby_house_id < NEW_HOUSE_OFFSET) {
				local_houseid = nearby_house_id;
			} else {
				local_houseid = (hs->grf_prop.grffile == this->ro.grffile ? 1 : 2) << 8;
				local_houseid |= ClampTo<uint8_t>(hs->grf_prop.local_id); // Spec only allows 8 bits, so all local-ids above 254 are clamped.
			}
			return houseclass << 16 | local_houseid;
		}

		/* GRFID of nearby house tile */
		case 0x67: {
			TileIndex testtile = GetNearbyTile(parameter, this->tile);
			if (!IsTileType(testtile, TileType::House)) return 0xFFFFFFFF;
			HouseID house_id = GetHouseType(testtile);
			if (house_id < NEW_HOUSE_OFFSET) return 0;
			/* Checking the grffile information via HouseSpec doesn't work
			 * in case the newgrf was removed. */
			return _house_mngr.GetGRFID(house_id);
		}

		case 0x7A: return GetBadgeVariableResult(*this->ro.grffile, HouseSpec::Get(this->house_id)->badges, parameter);
	}

	Debug(grf, 1, "Unhandled house variable 0x{:X}", variable);

	available = false;
	return UINT_MAX;
}

/**
 * Get the result of a house callback.
 * @param callback Callback ID.
 * @param param1 First parameter (var 10) of the callback.
 * @param param2 Second parameter (var 18) of the callback.
 * @param house_id House to query.
 * @param town %Town containing the house.
 * @param tile %Tile containing the house.
 * @param[out] regs100 Additional result values from registers 100+.
 * @param not_yet_constructed House is still under construction.
 * @param initial_random_bits Random bits during construction checks.
 * @param watched_cargo_triggers Cargo types that triggered the watched cargo callback.
 * @param view The house's 'view'.
 * @return The NewGRF result of the callback.
 */
uint16_t GetHouseCallback(CallbackID callback, uint32_t param1, uint32_t param2, HouseID house_id, Town *town, TileIndex tile, std::span<int32_t> regs100,
		bool not_yet_constructed, uint8_t initial_random_bits, CargoTypes watched_cargo_triggers, int view)
{
	HouseResolverObject object(house_id, tile, town, callback, param1, param2,
			not_yet_constructed, initial_random_bits, watched_cargo_triggers, view);
	return object.ResolveCallback(regs100);
}

static void DrawTileLayout(const TileInfo *ti, const DrawTileSpriteSpan &dts, uint8_t stage, HouseID house_id)
{
	const HouseSpec *hs = HouseSpec::Get(house_id);
	PaletteID palette = GetColourPalette(hs->random_colour[TileHash2Bit(ti->x, ti->y)]);
	if (hs->callback_mask.Test(HouseCallbackMask::Colour)) {
		uint16_t callback = GetHouseCallback(CBID_HOUSE_COLOUR, 0, 0, house_id, Town::GetByTile(ti->tile), ti->tile);
		if (callback != CALLBACK_FAILED) {
			/* If bit 14 is set, we should use a 2cc colour map, else use the callback value. */
			palette = HasBit(callback, 14) ? GB(callback, 0, 8) + SPR_2CCMAP_BASE : callback;
		}
	}

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

	if (HasBit(image, SPRITE_MODIFIER_CUSTOM_SPRITE)) image += stage;
	if (HasBit(pal, SPRITE_MODIFIER_CUSTOM_SPRITE)) pal += stage;

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

	DrawNewGRFTileSeq(ti, &dts, TransparencyOption::Houses, stage, palette);
}

void DrawNewHouseTile(TileInfo *ti, HouseID house_id)
{
	const HouseSpec *hs = HouseSpec::Get(house_id);

	if (ti->tileh != SLOPE_FLAT) {
		bool draw_old_one = true;
		if (hs->callback_mask.Test(HouseCallbackMask::DrawFoundations)) {
			/* Called to determine the type (if any) of foundation to draw for the house tile */
			uint32_t callback_res = GetHouseCallback(CBID_HOUSE_DRAW_FOUNDATIONS, 0, 0, house_id, Town::GetByTile(ti->tile), ti->tile);
			if (callback_res != CALLBACK_FAILED) draw_old_one = ConvertBooleanCallback(hs->grf_prop.grffile, CBID_HOUSE_DRAW_FOUNDATIONS, callback_res);
		}

		if (draw_old_one) DrawFoundation(ti, Foundation::Leveled);
	}

	HouseResolverObject object(house_id, ti->tile, Town::GetByTile(ti->tile));

	const auto *group = object.Resolve<TileLayoutSpriteGroup>();
	if (group != nullptr) {
		/* Limit the building stage to the number of stages supplied. */
		uint8_t stage = GetHouseBuildingStage(ti->tile);
		auto processor = group->ProcessRegisters(object, &stage);
		auto dts = processor.GetLayout();
		DrawTileLayout(ti, dts, stage, house_id);
	}
}

/**
 * Draw representation of a house tile for GUI purposes.
 * @param x Position x of image.
 * @param y Position y of image.
 * @param spec House spec to draw.
 * @param house_id House ID to draw.
 * @param view The house's 'view'.
 */
void DrawNewHouseTileInGUI(int x, int y, const HouseSpec *spec, HouseID house_id, int view)
{
	HouseResolverObject object(house_id, INVALID_TILE, nullptr, CBID_NO_CALLBACK, 0, 0, true, view);
	const auto *group = object.Resolve<TileLayoutSpriteGroup>();
	if (group == nullptr) return;

	uint8_t stage = TOWN_HOUSE_COMPLETED;
	auto processor = group->ProcessRegisters(object, &stage);
	auto dts = processor.GetLayout();

	PaletteID palette = GetColourPalette(spec->random_colour[0]);
	if (spec->callback_mask.Test(HouseCallbackMask::Colour)) {
		uint16_t callback = GetHouseCallback(CBID_HOUSE_COLOUR, 0, 0, house_id, nullptr, INVALID_TILE, {}, true, view);
		if (callback != CALLBACK_FAILED) {
			/* If bit 14 is set, we should use a 2cc colour map, else use the callback value. */
			palette = HasBit(callback, 14) ? GB(callback, 0, 8) + SPR_2CCMAP_BASE : callback;
		}
	}

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

	if (HasBit(image, SPRITE_MODIFIER_CUSTOM_SPRITE)) image += stage;
	if (HasBit(pal, SPRITE_MODIFIER_CUSTOM_SPRITE)) pal += stage;

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

	DrawNewGRFTileSeqInGUI(x, y, &dts, stage, palette);
}

/* Simple wrapper for GetHouseCallback to keep the animation unified. */
static uint16_t GetSimpleHouseCallback(CallbackID callback, uint32_t param1, uint32_t param2, const HouseSpec *spec, Town *town, TileIndex tile, CargoTypes extra_data)
{
	return GetHouseCallback(callback, param1, param2, spec - HouseSpec::Get(0), town, tile, {}, false, 0, extra_data);
}

/** Helper class for animation control. */
struct HouseAnimationBase : public AnimationBase<HouseAnimationBase, HouseSpec, Town, CargoTypes, GetSimpleHouseCallback, TileAnimationFrameAnimationHelper<Town> > {
	static constexpr CallbackID cb_animation_speed      = CBID_HOUSE_ANIMATION_SPEED;
	static constexpr CallbackID cb_animation_next_frame = CBID_HOUSE_ANIMATION_NEXT_FRAME;

	static constexpr HouseCallbackMask cbm_animation_speed      = HouseCallbackMask::AnimationSpeed;
	static constexpr HouseCallbackMask cbm_animation_next_frame = HouseCallbackMask::AnimationNextFrame;
};

void AnimateNewHouseTile(TileIndex tile)
{
	const HouseSpec *hs = HouseSpec::Get(GetHouseType(tile));
	if (hs == nullptr) return;

	HouseAnimationBase::AnimateTile(hs, Town::GetByTile(tile), tile, hs->extra_flags.Test(HouseExtraFlag::Callback1ARandomBits));
}

void TriggerHouseAnimation_ConstructionStageChanged(TileIndex tile, bool first_call)
{
	const HouseSpec *hs = HouseSpec::Get(GetHouseType(tile));

	if (hs->callback_mask.Test(HouseCallbackMask::AnimationTriggerConstructionStageChanged)) {
		HouseAnimationBase::ChangeAnimationFrame(CBID_HOUSE_ANIMATION_TRIGGER_CONSTRUCTION_STAGE_CHANGED, hs, Town::GetByTile(tile), tile, Random(), first_call ? 1 : 0);
	}
}

bool CanDeleteHouse(TileIndex tile)
{
	const HouseSpec *hs = HouseSpec::Get(GetHouseType(tile));

	/* Humans are always allowed to remove buildings, as is water and disasters and
	 * anyone using the scenario editor. */
	if (Company::IsValidHumanID(_current_company) || _current_company == OWNER_WATER || _current_company == OWNER_NONE || _game_mode == GameMode::Editor || _generating_world) {
		return true;
	}

	if (hs->callback_mask.Test(HouseCallbackMask::DenyDestruction)) {
		uint16_t callback_res = GetHouseCallback(CBID_HOUSE_DENY_DESTRUCTION, 0, 0, GetHouseType(tile), Town::GetByTile(tile), tile);
		return (callback_res == CALLBACK_FAILED || !ConvertBooleanCallback(hs->grf_prop.grffile, CBID_HOUSE_DENY_DESTRUCTION, callback_res));
	} else {
		return !IsHouseProtected(tile);
	}
}

/**
 * Call the tile loop animation trigger for houses, if enabled.
 * @param tile House tile
 * @param sync Whether to call the synchronized or the unsynchronized trigger.
 * @param random_bits Shared random bits for the synchronized trigger.
 */
static void TriggerHouseAnimation_TileLoop(TileIndex tile, bool sync, uint16_t random_bits)
{
	const HouseSpec *hs = HouseSpec::Get(GetHouseType(tile));

	/* Check whether the matching trigger is enabled */
	if (hs->callback_mask.Test(HouseCallbackMask::AnimationTriggerTileLoop) &&
			hs->extra_flags.Test(HouseExtraFlag::SynchronisedCallback1B) == sync) {
		uint32_t param = sync ? (GB(Random(), 0, 16) | random_bits << 16) : Random();
		HouseAnimationBase::ChangeAnimationFrame(CBID_HOUSE_ANIMATION_TRIGGER_TILE_LOOP, hs, Town::GetByTile(tile), tile, param, 0);
	}
}

bool NewHouseTileLoop(TileIndex tile)
{
	const HouseSpec *hs = HouseSpec::Get(GetHouseType(tile));

	if (GetHouseProcessingTime(tile) > 0) {
		DecHouseProcessingTime(tile);
		return true;
	}

	TriggerHouseRandomisation(tile, HouseRandomTrigger::TileLoop);
	if (hs->building_flags.Any(BUILDING_HAS_1_TILE)) TriggerHouseRandomisation(tile, HouseRandomTrigger::TileLoopNorth);

	/* Call the unsynchronized tile loop trigger */
	TriggerHouseAnimation_TileLoop(tile, false, 0);

	/* Call the synchronized tile loop trigger, if this is the north tile */
	if (hs->building_flags.Any(BUILDING_HAS_1_TILE)) {
		uint16_t random = GB(Random(), 0, 16);
		TriggerHouseAnimation_TileLoop(tile, true, random);
		if (hs->building_flags.Any(BUILDING_2_TILES_Y)) TriggerHouseAnimation_TileLoop(TileAddXY(tile, 0, 1), true, random);
		if (hs->building_flags.Any(BUILDING_2_TILES_X)) TriggerHouseAnimation_TileLoop(TileAddXY(tile, 1, 0), true, random);
		if (hs->building_flags.Any(BUILDING_HAS_4_TILES)) TriggerHouseAnimation_TileLoop(TileAddXY(tile, 1, 1), true, random);
	}

	/* Check callback 21, which determines if a house should be destroyed. */
	if (hs->callback_mask.Test(HouseCallbackMask::Destruction)) {
		uint16_t callback_res = GetHouseCallback(CBID_HOUSE_DESTRUCTION, 0, 0, GetHouseType(tile), Town::GetByTile(tile), tile);
		if (callback_res != CALLBACK_FAILED && Convert8bitBooleanCallback(hs->grf_prop.grffile, CBID_HOUSE_DESTRUCTION, callback_res)) {
			ClearTownHouse(Town::GetByTile(tile), tile);
			return false;
		}
	}

	SetHouseProcessingTime(tile, hs->processing_time);
	MarkTileDirtyByTile(tile);
	return true;
}

static void DoTriggerHouseRandomisation(TileIndex tile, HouseRandomTrigger trigger, uint8_t base_random, bool first)
{
	/* We can't trigger a non-existent building... */
	assert(IsTileType(tile, TileType::House));

	HouseID hid = GetHouseType(tile);
	HouseSpec *hs = HouseSpec::Get(hid);

	if (!hs->grf_prop.HasSpriteGroups()) return;

	HouseResolverObject object(hid, tile, Town::GetByTile(tile), CBID_RANDOM_TRIGGER);
	auto waiting_random_triggers = GetHouseRandomTriggers(tile);
	waiting_random_triggers.Set(trigger);
	SetHouseRandomTriggers(tile, waiting_random_triggers); // store now for var 5F
	object.SetWaitingRandomTriggers(waiting_random_triggers);

	object.ResolveRerandomisation();

	/* Store remaining triggers. */
	waiting_random_triggers.Reset(object.GetUsedRandomTriggers());
	SetHouseRandomTriggers(tile, waiting_random_triggers);

	/* Rerandomise bits. Scopes other than SELF are invalid for houses. For bug-to-bug-compatibility with TTDP we ignore the scope. */
	uint8_t new_random_bits = Random();
	uint8_t random_bits = GetHouseRandomBits(tile);
	uint32_t reseed = object.GetReseedSum();
	random_bits &= ~reseed;
	random_bits |= (first ? new_random_bits : base_random) & reseed;
	SetHouseRandomBits(tile, random_bits);

	switch (trigger) {
		case HouseRandomTrigger::TileLoop:
			/* Random value already set. */
			break;

		case HouseRandomTrigger::TileLoopNorth:
			if (!first) {
				/* The top tile is marked dirty by the usual TileLoop */
				MarkTileDirtyByTile(tile);
				break;
			}
			/* Random value of first tile already set. */
			if (hs->building_flags.Any(BUILDING_2_TILES_Y))   DoTriggerHouseRandomisation(TileAddXY(tile, 0, 1), trigger, random_bits, false);
			if (hs->building_flags.Any(BUILDING_2_TILES_X))   DoTriggerHouseRandomisation(TileAddXY(tile, 1, 0), trigger, random_bits, false);
			if (hs->building_flags.Any(BUILDING_HAS_4_TILES)) DoTriggerHouseRandomisation(TileAddXY(tile, 1, 1), trigger, random_bits, false);
			break;
	}
}

void TriggerHouseRandomisation(TileIndex t, HouseRandomTrigger trigger)
{
	DoTriggerHouseRandomisation(t, trigger, 0, true);
}

/**
 * Run the watched cargo accepted callback for a single house tile.
 * @param tile The house tile.
 * @param origin The triggering tile.
 * @param trigger_cargoes Cargo types that triggered the callback.
 * @param random Random bits.
 */
static void DoTriggerHouseAnimation_WatchedCargoAccepted(TileIndex tile, TileIndex origin, CargoTypes trigger_cargoes, uint16_t random)
{
	TileIndexDiffC diff = TileIndexToTileIndexDiffC(origin, tile);
	uint32_t cb_info = random << 16 | (uint8_t)diff.y << 8 | (uint8_t)diff.x;
	HouseAnimationBase::ChangeAnimationFrame(CBID_HOUSE_ANIMATION_TRIGGER_WATCHED_CARGO_ACCEPTED, HouseSpec::Get(GetHouseType(tile)), Town::GetByTile(tile), tile, 0, cb_info, trigger_cargoes);
}

/**
 * Run watched cargo accepted callback for a house.
 * @param tile House tile.
 * @param trigger_cargoes Triggering cargo types.
 * @pre IsTileType(t, TileType::House)
 */
void TriggerHouseAnimation_WatchedCargoAccepted(TileIndex tile, CargoTypes trigger_cargoes)
{
	assert(IsTileType(tile, TileType::House));
	HouseID id = GetHouseType(tile);
	const HouseSpec *hs = HouseSpec::Get(id);

	trigger_cargoes = trigger_cargoes & hs->watched_cargoes;
	/* None of the trigger cargoes is watched? */
	if (trigger_cargoes.None()) return;

	/* Same random value for all tiles of a multi-tile house. */
	uint16_t r = Random();

	/* Do the callback, start at northern tile. */
	TileIndex north = tile + GetHouseNorthPart(id);
	hs = HouseSpec::Get(id);

	DoTriggerHouseAnimation_WatchedCargoAccepted(north, tile, trigger_cargoes, r);
	if (hs->building_flags.Any(BUILDING_2_TILES_Y))   DoTriggerHouseAnimation_WatchedCargoAccepted(TileAddXY(north, 0, 1), tile, trigger_cargoes, r);
	if (hs->building_flags.Any(BUILDING_2_TILES_X))   DoTriggerHouseAnimation_WatchedCargoAccepted(TileAddXY(north, 1, 0), tile, trigger_cargoes, r);
	if (hs->building_flags.Any(BUILDING_HAS_4_TILES)) DoTriggerHouseAnimation_WatchedCargoAccepted(TileAddXY(north, 1, 1), tile, trigger_cargoes, r);
}

