/*
This file is part of Minitrem.

Minitrem 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, either version 2 of the License, or
(at your option) any later version.

Minitrem 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 Minitrem.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "game.hpp"

namespace game {

bool load_assets(void)
{
	assets::load();
	return true;
}

size_t selection_cookie = 1;

entity_t::entity_t(game::state_t *game_, int type_) : world::entity_t(type_)
{
	game = game_;
}

entity_t::~entity_t(void)
{
	sleep();
	unlink();
}

void entity_t::place(world::world_t *world_)
{
	bool do_spawn = false;

	if (!world)
		do_spawn = true;

	link(world_);

	if (do_spawn)
		on_spawn();
}

void entity_t::place(world::world_t *world, v2f_t x_)
{
	x = x_;
	cmodel.bounds = size + x;
	render_bounds = render_size + x;

	place(world);
}

void entity_t::wake(void)
{
	awake = true;
	wake_time = game->now;
	game->awake_entities.insert(this);

	if (!ignore_waking)
		on_wake();
}

void entity_t::sleep(void)
{
	awake = false;
	game->awake_entities.erase(this);
}

void state_t::start(void)
{
	unit_soldier_t *soldier;
	unit_repl_t *repl;

	world.generator = worldgen;
	world.generator_data = (void*)this;

	soldier = new unit_soldier_t(this);
	soldier->place(&world, v2f_t(0.5, 0.5));
	repl = new unit_repl_t(this);
	repl->place(&world, v2f_t(1.5, 0.5));

	resume();
}

void state_t::stop(void)
{
}

bool state_t::select_unit(unit_t *unit, int type)
{
	switch (type) {
	case SELECT_NEW:
	case SELECT_OR:
		if (unit->selected == selection_cookie)
			return false;
		else
			goto do_select;

	case SELECT_XOR:
		if (unit->selected == selection_cookie)
			goto do_deselect;
		else
			goto do_select;
	}

do_select:
	unit->selected = selection_cookie;
	selected_units.insert(unit);
	return true;

do_deselect:
	unit->selected = selection_cookie - 1;
	selected_units.erase(unit);
	return false;
}

void state_t::select(rectf_t rect, int type)
{
	bool select_one;
	std::list<world::entity_t*> ents;

	if (type == SELECT_NEW) {
		selection_cookie++;
		selected_units.clear();
	}

	select_one = rect.area() < 0.2f;

	ents = world.get_render_entities(rect);
	if (select_one)
		ents.sort(render::visibility_order);

	for (world::entity_t *ent : ents) {
		unit_t *unit;

		if (ent->type != ET_UNIT)
			continue;

		unit = (unit_t*)ent;

		if (!unit->controllable)
			continue;

		if (select_unit(unit, type)) {
			if (unit->type == unit_t::UNIT_SOLDIER)
				unit->say(text::get(text::SAY_READY));
		}

		if (select_one)
			break;
	}
}

enum {
	COMMAND_MOVE,
	COMMAND_FIRE,
	COMMAND_FIRE_ROCKET,
	COMMAND_STOP,

	COMMAND_REPL,
};

bool state_t::populate_pie_menu(std::vector<interface::pie_item_t> &items)
{
	bool soldiers = false, repls = false, rockets = false;

	items.clear();

	if (selected_units.size() == 0)
		return false;

	for (unit_t *unit : selected_units) {
		if (unit->dead || !unit->controllable)
			continue;

		switch (unit->type) {
		case unit_t::UNIT_SOLDIER:
			soldiers = true;
			if (!dynamic_cast<unit_soldier_t*>(unit)->rocket_fired)
				rockets = true;
			break;
		case unit_t::UNIT_REPL:
			repls = true;
			break;

		default:;
		}
	}

	if (soldiers) {
		items.push_back((interface::pie_item_t){"Move", COMMAND_MOVE});
		items.push_back((interface::pie_item_t){"Fire", COMMAND_FIRE});
		if (rockets)
			items.push_back((interface::pie_item_t){"Fire a rocket", COMMAND_FIRE_ROCKET});
		items.push_back((interface::pie_item_t){"Stop", COMMAND_STOP});
	}

	if (repls) {
		items.push_back((interface::pie_item_t){"Replicate", COMMAND_REPL});
	}

	return true;
}

static void command_soldier(unit_soldier_t *soldier, v2f_t x, int number)
{
	switch (number) {
	case COMMAND_MOVE:
		if (!soldier->start_moving(x))
			soldier->say(text::get(text::SAY_NO_PATH));
		else {
			soldier->move_marker = std::make_unique<fx_move_marker_t>(soldier->game, soldier->move.path.back());
			soldier->say(text::get(text::SAY_MOVING));
		}
		break;

	case COMMAND_STOP:
		soldier->stop_moving();
		soldier->manual_firing = false;
		soldier->say(text::get(text::SAY_STOPPING));
		soldier->aim_marker.reset();
		break;

	case COMMAND_FIRE:
		soldier->manual_firing = true;
		soldier->manual_firing_target = x;
		soldier->say(text::get(text::SAY_FIRING));
		break;

	case COMMAND_FIRE_ROCKET:
		{
			v2f_t from, v;
			rocket_t *rocket;

			if (soldier->rocket_fired) {
				soldier->say(text::get(text::SAY_NO_ROCKETS));
				break;
			}

			soldier->rocket_fired = true;

			from = soldier->x + v2f_t(0, -0.5);
			v = x - from;
			v *= 1.0f / v.len() * 10.0f;

			rocket = new rocket_t(soldier->game, from, v, soldier);
			rocket->place(&soldier->game->world, from);
		}
	}
}

static void command_repl(unit_repl_t *repl, v2f_t x, int number)
{
	switch (number) {
	case COMMAND_REPL:
		repl->activate();
		break;
	}
}

void state_t::command(v2f_t x, int number)
{
	bool unlink;

	if (!selected_units.size())
		return;

	unlink = (number == COMMAND_MOVE);
	if (unlink)
		for (unit_t *unit : selected_units)
			unit->cmodel.ignore = true;

	for (unit_t *unit : selected_units) {
		if (unit->dead || !unit->controllable)
			continue;

		switch (unit->type) {
		case unit_t::UNIT_SOLDIER:
			command_soldier(dynamic_cast<unit_soldier_t*>(unit),
			                x, number);
			break;

		case unit_t::UNIT_REPL:
			command_repl(dynamic_cast<unit_repl_t*>(unit),
			             x, number);
			break;

		default:;
		}
	}

	if (unlink)
		for (unit_t *unit : selected_units)
			unit->cmodel.ignore = false;
}

void state_t::pause(void)
{
	paused = true;
}

void state_t::resume(void)
{
	t0 = nclock();
	frames_since_t0 = 0;

	paused = false;
}

#define TIME_DELTA ((ntime_t)1000000000 / 100)
#define TIME_LIMIT ((ntime_t)1000000000 / 20)

void state_t::tick(ntime_t time_)
{
	size_t target;

	if (paused)
		return;

	target = (time_ - t0) / TIME_DELTA;

	while (frames_since_t0 < target) {
		// FIXME: Is this non-deterministic enough?
		prng.seed(prng.next() ^ time);

		// setting up old variables (refactor them out eventually)
		now = time * 1.0e-9;
		dt = TIME_DELTA * 1.0e-9;

		for (entity_t *ent : deletion_list)
			delete ent;
		deletion_list.clear();

		// on_think can insert/erase elements of awake_entities so iterate
		// over a copy of it.
		auto copy = awake_entities;
		for (entity_t *ent : copy)
			if (awake_entities.find(ent) != awake_entities.end())
				ent->on_think();

		frames++;
		frames_since_t0++;
		time += TIME_DELTA;

		fc_game.tick();

		if (nclock() - time_ > TIME_LIMIT) {
			size_t left;

			left = target - frames_since_t0;
			t0 = nclock();
			frames_since_t0 = 0;
			frames_behind++;

			interface->print("(Lag: " + std::to_string(left) + ")");

			break;
		}
	}
}

#define XRES 9
#define YRES 9

void state_t::compute_ambience(render::state_t *render)
{
	const size_t samples = XRES * YRES;
	rectf_t area;
	v2f_t origins[AMBIENT_COUNT];
	size_t hits[AMBIENT_COUNT];

	area = render->window_in_world_space();

	for (size_t i = 0; i < AMBIENT_COUNT; i++) {
		origins[i] = v2f_t(0, 0);
		hits[i] = 0;
	}

	// resolution chosen arbitrarily
	for (size_t y = 0; y < YRES; y++)
	for (size_t x = 0; x < XRES; x++) {
		v2f_t point;
		world::tile_t *tile;
		int type;

		point[0] = lerp(area[0][0], area[1][0], y / (YRES - 1.0f));
		point[1] = lerp(area[0][1], area[1][1], x / (XRES - 1.0f));

		tile = world.get_tile(world::tile_index_t(point), world::SECTOR_FULL);

		switch (tile->type) {
		case TILE_DIRT:
			type = AMBIENT_WIND;
			break;

		case TILE_GRAVEL:
		case TILE_STONE:
			type = AMBIENT_CHASM;
			break;

		case TILE_WATER:
			type = AMBIENT_WATER;
			break;

		case TILE_DIRT_RED:
		case TILE_STONE_RED:
			type = AMBIENT_NEXUS;
			break;

		default:
			continue;
		}

		origins[type] += point;
		hits[type]++;
	}

	for (size_t i = 0; i < AMBIENT_COUNT; i++) {
		assets::ambients[i].origin = origins[i] / hits[i];
		assets::ambients[i].weight = (float)hits[i] / samples;
	}
}

void state_t::explosion(v2f_t x)
{
	fx_explosion_t *explosion;

	explosion = new fx_explosion_t(this, x);
	explosion->place(&world);

	for (size_t i = 0; i < 60; i++) {
		v2f_t end;
		world::trace_t trace;
		fx_tracer_t *tracer;
		entity_t *ent;
		int damage;

		end = x + prng.unit_vec2() * 6.0f;
		trace = world.ray_v_all(x, end, CF_SOLID|CF_BODY|CF_BODY_SMALL|CF_DECOS, nullptr);

		tracer = new fx_tracer_t(this, x, trace.end);
		tracer->place(&world);

		if (!trace.hit)
			continue;

		if (!trace.ent)
			continue;

		ent = dynamic_cast<entity_t*>(trace.ent);
		damage = pow(1 - trace.frac, 2.0f) * 20.0f;
		ent->damage(damage, nullptr);
	}
}

} //namespace game