#include "ai.h"

#include <algorithm>

#include <entt/entt.hpp>

#include <kurator/sim/components.h>
#include <kurator/sim/State.h>
#include <kurator/sim/weapons.h>

#include "TeamManager.h"


namespace kurator
{
namespace sim
{


static double find_worst_range(State& ctx, entt::entity ship);


void
setup_ai_components(State&)
{
	// e.g., remove other actions if new one is inserted.
}


void
pick_random_targets(State& ctx, TeamManager& manager)
{
	auto view = ctx.registry.view<Team, AIShip>();
	for (auto&& [entity, team, ai] : view.each()) {
		if (!ctx.registry.valid(ai.target)) {
			ai.target = manager.random(team.id);
			ctx.registry.emplace_or_replace<KeepAtRange>(entity, find_worst_range(ctx, entity), ai.target);
		}
	}
}


void
keep_at_range(State& ctx)
{
	auto view = ctx.registry.view<AIShip, KeepAtRange>();
	for (auto&& [entity, ai, action] : view.each()) {
		if (!ctx.registry.valid(action.target))
			continue;
		const auto here = ctx.registry.get<Transform>(entity).position;
		const auto there = ctx.registry.get<Transform>(action.target).position;
		const auto offset = there - here;
		ai.destination = there - offset.normalized().scale(action.distance);
	}
}


void
shoot_at_targets(State& ctx)
{
	auto view = ctx.registry.view<Turret>();
	for (auto&& [entity, turret] : view.each()) {
		if (!ctx.registry.all_of<AIShip, Transform>(turret.owner))
			continue;
		const auto& [state, transform] = ctx.registry.get<AIShip, Transform>(turret.owner);
		if (!ctx.registry.valid(state.target))
			continue;
		const auto& target = ctx.registry.get<Transform>(state.target);
		const auto distance = transform.position.distance(target.position);
		if (distance <= turret.type.effective_range())
			turret.shoot_at(ctx, state.target, distance);  // passing distance here is wrong
	}
}


double
find_worst_range(State& ctx, entt::entity ship)
{
	double range = 20000.0;
	auto turrets = ctx.registry.view<Turret>();
	for (const auto& [_, turret] : turrets.each()) {
		if (turret.owner == ship)
			range = std::min(range, turret.type.optimal_range);
	}
	return range;
}


}  // namespace sim
}  // namespace kurator