#include "common.hpp"
#include <sstream>

namespace world {

sector_index_t sector_index_at(v2f_t x)
{
	return sector_index_t((x / SECTOR_SIZE).floor());
}

tile_index_t tile_index_at(v2f_t x)
{
	return sector_index_t(x.floor());
}

world_t::world_t(void)
{
	prng.seed(125);
	perlin.generate(&prng, 32);
}

void world_t::generate_tile(tile_t *tile, tile_index_t x)
{
	float waterlevel, height;

	waterlevel = perlin.get(x, 1000.0f) * 0.3f +
	             perlin.get(x, 500.0f) * 0.1f;

	height = perlin.get(x, 40.0f) * 0.6f +
	         perlin.get(x, 20.0f) * 0.25f +
	         perlin.get(x, 10.0f) * 0.2f +
	         perlin.get(x, 4.0f) * 0.1f +
	         perlin.get(x, 1.0f) * 0.05f;

	if (height < waterlevel)
		tile->type = TILE_NONE;
	else if (height < waterlevel + 0.1)
		tile->type = TILE_DIRT;
	else if (perlin.get(x, 3.0f) > 0.0f)
		tile->type = TILE_WALL;
	else
		tile->type = TILE_DIRT;
}

void world_t::generate(sector_t *sector, sector_index_t index, bool partial)
{
	sector->index = index;

	sector->bounds.v[0] = (v2f_t)index * SECTOR_SIZE;
	sector->bounds.v[1] = sector->bounds.v[0] + v2f_t(SECTOR_SIZE, SECTOR_SIZE);

	for (coord_t ly = 0; ly < SECTOR_SIZE; ly++)
	for (coord_t lx = 0; lx < SECTOR_SIZE; lx++)
		generate_tile(sector->tiles + ly * SECTOR_SIZE + lx,
		              tile_index_t(index[0] * SECTOR_SIZE + lx,
		                           index[1] * SECTOR_SIZE + ly));

	sector->empty = false;

	if (partial)
		return;

	for (coord_t ly = 0; ly < SECTOR_SIZE; ly++)
	for (coord_t lx = 0; lx < SECTOR_SIZE; lx++) {
		tile_t *tile;

		tile = sector->tiles + ly * SECTOR_SIZE + lx;
		tile->neighbors = 0;

		for (size_t i = 0; i < 8; i++) {
			tile_index_t neighbor_index;
			tile_t *neighbor;

			neighbor_index = index * SECTOR_SIZE + tile_index_t(lx, ly) + neighbor_offsets[i];
			neighbor = get_tile(neighbor_index, true);

			if (neighbor->type == tile->type)
				tile->neighbors |= (1 << i);
		}
	}
}

bool world_t::find_path(v2f_t src, v2f_t dst, cmodel_t *cmodel, entity_t *ignore,
                        std::list<v2f_t> *path)
{
	path_finder_t finder;
	rectf_t bounds;
	v2f_t cmodel_dims;

	finder.setup_nodes(src, dst, cmodel->cflags);

	cmodel_dims = cmodel->bounds.dims();

	for (size_t y = 0; y < finder.height; y++)
	for (size_t x = 0; x < finder.width; x++) {
		tile_index_t index;
		rectf_t combined;

		index = finder.base + tile_index_t(x, y);

		if (get_tile(index)->type == TILE_DIRT)
			continue;

		combined[0] = v2f_t(index)  - cmodel_dims / 2;
		combined[1] = v2f_t(index) + v2f_t(1.0f, 1.0f) + cmodel_dims / 2;

		finder.eliminate_nodes(combined);
	}

	bounds = rectf_t(src, dst).norm();

	for (entity_t *ent : get_entities(bounds, cmodel->cflags))
		if (ent != ignore)
			finder.eliminate_nodes(ent->cmodel.bounds);

	if (!finder.find())
		return false;

	finder.export_path(path);
	return true;
}

sector_t *world_t::get_sector(sector_index_t index, bool partial)
{
	sector_t *sector;

	sector = &sectors[index];

	if (sector->empty)
		generate(sector, index, partial);

	return sector;
}

tile_t *world_t::get_tile(tile_index_t index, bool partial)
{
	sector_index_t sector_index;
	sector_t *sector;
	int64_t tx, ty;

	sector_index[0] = divide_rmi(index[0], (int64_t)SECTOR_SIZE, &tx);
	sector_index[1] = divide_rmi(index[1], (int64_t)SECTOR_SIZE, &ty);
	sector = get_sector(sector_index, partial);

	return sector->tiles + ty * SECTOR_SIZE + tx;
}

std::list<sector_t*> world_t::get_sectors(rectf_t rect)
{
	sector_index_t base, upper;
	std::list<sector_t*> list;

	base = sector_index_at(rect.v[0]);
	upper = sector_index_at(rect.v[1]);

	for (int64_t y = base[1]; y <= upper[1]; y++)
	for (int64_t x = base[0]; x <= upper[0]; x++) {
		sector_index_t index(x, y);
		list.push_back(get_sector(index));
	}

	return list;
}

std::list<entity_t*> world_t::get_entities(rectf_t rect, cflags_t cflags)
{
	static size_t cookie = 0;
	std::list<entity_t*> list;

	cookie++;

	for (sector_t *sector : get_sectors(rect))
	for (entity_t *ent : sector->ents) {
		if (ent->cookie == cookie)
			continue;

		ent->cookie = cookie;

		if (!(ent->cmodel.cflags & cflags))
			continue;

		if (!(rect && ent->cmodel.bounds))
			continue;

		list.push_back(ent);
	}

	return list;
}

std::list<entity_t*> world_t::get_render_entities(rectf_t rect)
{
	static size_t cookie = 0;
	std::list<entity_t*> list;

	cookie++;

	for (sector_t *sector : get_sectors(rect))
	for (entity_t *ent : sector->ents) {
		if (ent->cookie == cookie)
			continue;

		if (!(rect && ent->render_bounds))
			continue;

		ent->cookie = cookie;

		list.push_back(ent);
	}

	return list;
}

bool world_t::test_rect(const cmodel_t *cmodel, const entity_t *ignore)
{
	static size_t cookie = 0;

	cookie++;

	for (sector_t *sector : get_sectors(cmodel->bounds)) {
		rect_t<coord_t, 2> bounds;
		tile_index_t index;

		bounds[0] = (cmodel->bounds[0] - sector->bounds[0]).floor();
		bounds[1] = (cmodel->bounds[1] - sector->bounds[0]).floor();

		if (bounds[0][0] < 0)
			bounds[0][0] = 0;
		if (bounds[0][1] < 0)
			bounds[0][1] = 0;
		if (bounds[1][0] >= (coord_t)SECTOR_SIZE)
			bounds[1][0] = SECTOR_SIZE - 1;
		if (bounds[1][1] >= (coord_t)SECTOR_SIZE)
			bounds[1][1] = SECTOR_SIZE - 1;

		for (index[1] = bounds[0][1]; index[1] <= bounds[1][1]; index[1]++)
		for (index[0] = bounds[0][0]; index[0] <= bounds[1][0]; index[0]++) {
			tile_t *tile;

			tile = sector->tiles + index[1] * SECTOR_SIZE + index[0];
			if (tile->type != TILE_DIRT)
				return true;
		}

		for (entity_t *ent : sector->ents) {
			if (ent == ignore)
				continue;

			if (ent->cookie == cookie)
				continue;

			ent->cookie = cookie;

			if (!(ent->cmodel.cflags & cmodel->cflags))
				continue;

			if (!(cmodel->bounds && ent->cmodel.bounds))
				continue;

			return true;
		}
	}

	return false;
}

void world_t::debug_point(sf::Vector2f point)
{
	sector_index_t index = sector_index_at(point);
	printf("sector (%zd, %zd)\n", index[0], index[1]);
}

entity_t::entity_t(int type_)
{
	type = type_;
}

void entity_t::link_to_sector(sector_t *sector)
{
	parents.push_back(sector);
	sector->ents.insert(this);
}

void entity_t::link(world_t *world)
{
	rectf_t total_bounds;
	float fx, fy;
	sector_index_t base;
	float xlip, ylip;
	size_t xsecs, ysecs;

	total_bounds = cmodel.bounds | render_bounds;

	fx = floor(total_bounds[0][0]);
	fy = floor(total_bounds[0][1]);

	base = sector_index_at(v2f_t(fx, fy));
	xlip = total_bounds[1][0] - (base[0] + 1) * SECTOR_SIZE;
	ylip = total_bounds[1][1] - (base[1] + 1) * SECTOR_SIZE;

	if (xlip > 0.0f)
		xsecs = ceil(xlip / SECTOR_SIZE) + 1;
	else
		xsecs = 1;

	if (ylip > 0.0f)
		ysecs = ceil(ylip / SECTOR_SIZE) + 1;
	else
		ysecs = 1;

	for (int64_t y = 0; y < (int64_t)ysecs; y++)
	for (int64_t x = 0; x < (int64_t)xsecs; x++) {
		sector_index_t index = base + sector_index_t(x, y);
		sector_t *sector;

		sector = world->get_sector(index);
		link_to_sector(sector);
	}
}

void entity_t::unlink(void)
{
	for (sector_t *sector : parents) {
		if (sector->ents.find(this) == sector->ents.end()) {
			printf("entity_t::unlink: %p should belong to %p (%" PRIi64", %" PRIi64") but it doesn't\n",
			       this, sector, sector->index[0], sector->index[1]);
			continue;
		}

		sector->ents.erase(sector->ents.find(this));
	}

	parents.clear();
	parent_world = nullptr;
}

} // namespace world