#include "TeamManager.h"

#include <algorithm>
#include <numeric>
#include <random>
#include <utility>

#include <entt/entity/registry.hpp>

#include <kurator/engine/Context.h>
#include <kurator/sim/components.h>
#include <kurator/sim/events.h>
#include <kurator/universe/ShipType.h>


namespace kurator
{
namespace sim
{


TeamManager::TeamManager() :
	teams {},
	generator {std::random_device{}()}
{
}


void
TeamManager::extend(entt::registry& registry)
{
	auto ships = registry.view<universe::ShipType, sim::Team>();
	for (const auto& [entity, type, team] : ships.each())
		add(team.id, entity);
}


void
TeamManager::add(int team, entt::entity entity)
{
	for (int i = teams.size(); i < team + 1; ++i)
		teams.emplace_back();
	teams.at(team).push_back(std::move(entity));
}


entt::entity
TeamManager::random(const int exclude)
{
	std::vector<int> open;
	open.resize(teams.size());
	std::iota(open.begin(), open.end(), 0);
	auto is_closed = [&](const int team){ return team == exclude || teams.at(team).empty(); };
	open.erase(std::remove_if(open.begin(), open.end(), is_closed), open.end());
	if (open.empty())
		return entt::null;
	std::uniform_int_distribution<Team::size_type> team{0, open.size() - 1};
	const auto& members = teams.at(open.at(team(generator)));
	std::uniform_int_distribution<Team::size_type> member{0, members.size() - 1};
	return members.at(member(generator));
}


void
TeamManager::update(engine::Context& ctx)
{
	for (auto& members : teams) {
		auto is_valid = [&](entt::entity entity){ return !ctx.registry.valid(entity); };
		members.erase(std::remove_if(members.begin(), members.end(), is_valid), members.end());
	}
	const auto left = std::count_if(teams.begin(), teams.end(), [](const Team& team){ return team.size() > 0; });
	if (left < 2)
		ctx.dispatcher.trigger(End{});
}


}  // namespace sim
}  // namespace kurator