#include "../ComponentManager.h"
#include "../api/Button.h"
#include "../api/EventManager.h"

#include "InputSystem.h"

using namespace crepe;


void InputSystem::update() {
	ComponentManager & mgr = this->component_manager;
	EventManager & event_mgr = EventManager::get_instance();
	std::vector<SDLContext::EventData> event_list = SDLContext::get_instance().get_events();
	RefVector<Button> buttons = mgr.get_components_by_type<Button>();
	RefVector<Camera> cameras = mgr.get_components_by_type<Camera>();

	// Find the active camera
	for (Camera & cam : cameras) {
		if (!cam.active) continue;
		this->curr_cam_ref = cam;
		break;
	}
	if (!curr_cam_ref) return;
	Camera& current_cam = curr_cam_ref;
	RefVector<Transform> transform_vec = mgr.get_components_by_id<Transform>(current_cam.game_object_id);
	Transform& cam_transform = transform_vec.front().get();
	int camera_origin_x = cam_transform.position.x + current_cam.offset.x - (current_cam.viewport_size.x / 2);
	int camera_origin_y = cam_transform.position.y + current_cam.offset.y - (current_cam.viewport_size.y / 2);
	for (const SDLContext::EventData & event : event_list) {
		int world_mouse_x = event.mouse_position.first + camera_origin_x;
		int world_mouse_y = event.mouse_position.second + camera_origin_y;

		switch (event.event_type) {
			case SDLContext::EventType::KEYDOWN:
				event_mgr.queue_event<KeyPressEvent>(KeyPressEvent{
					.repeat = event.key_repeat,
					.key = event.key,
				});
				break;
			case SDLContext::EventType::KEYUP:
				event_mgr.queue_event<KeyReleaseEvent>(KeyReleaseEvent{
					.key = event.key,
				});
				break;
			case SDLContext::EventType::MOUSEDOWN:
				event_mgr.queue_event<MousePressEvent>(MousePressEvent{
					.mouse_x = world_mouse_x,
					.mouse_y = world_mouse_y,
					.button = event.mouse_button,
				});
				last_mouse_down_position = {world_mouse_x, world_mouse_y};
				last_mouse_button = event.mouse_button;
				break;
			case SDLContext::EventType::MOUSEUP: {
				event_mgr.queue_event<MouseReleaseEvent>(MouseReleaseEvent{
					.mouse_x = world_mouse_x,
					.mouse_y = world_mouse_y,
					.button = event.mouse_button,
				});
				//check if its a click by checking the last button down
				int delta_x = world_mouse_x - last_mouse_down_position.first;
				int delta_y = world_mouse_y - last_mouse_down_position.second;

				if (last_mouse_button == event.mouse_button
					&& std::abs(delta_x) <= click_tolerance
					&& std::abs(delta_y) <= click_tolerance) {
					event_mgr.queue_event<MouseClickEvent>(MouseClickEvent{
						.mouse_x = world_mouse_x,
						.mouse_y = world_mouse_y,
						.button = event.mouse_button,
					});

					handle_click(event.mouse_button, world_mouse_x, world_mouse_y);
				}
			} break;
			case SDLContext::EventType::MOUSEMOVE:
				event_mgr.queue_event<MouseMoveEvent>(MouseMoveEvent{
					.mouse_x = world_mouse_x,
					.mouse_y = world_mouse_y,
					.rel_x = event.rel_mouse_move.first,
					.rel_y = event.rel_mouse_move.second,
				});
				handle_move(event, world_mouse_x, world_mouse_y);
				break;
			case SDLContext::EventType::MOUSEWHEEL:
				event_mgr.queue_event<MouseScrollEvent>(MouseScrollEvent{
					.scroll_x = event.wheel_delta,
					.scroll_y = 0,
					.direction = event.wheel_delta,
				});
				break;
			case SDLContext::EventType::SHUTDOWN:
				event_mgr.queue_event<ShutDownEvent>(ShutDownEvent{});
				break;
			default:
				break;
		}
	}
}

void InputSystem::handle_move(const SDLContext::EventData & event_data, const int& world_mouse_x, const int& world_mouse_y) {
	ComponentManager & mgr = this->component_manager;

	RefVector<Button> buttons = mgr.get_components_by_type<Button>();

	for (Button & button : buttons) {
		RefVector<Transform> transform_vec
			= mgr.get_components_by_id<Transform>(button.game_object_id);
		OptionalRef<Transform> transform(transform_vec.front().get());
		if (!transform) continue;

		bool was_hovering = button.hover;
		if (button.active && is_mouse_inside_button(world_mouse_x, world_mouse_y, button, transform)) {
			button.hover = true;
			if (!was_hovering && button.on_enter) {
				button.on_enter();
			}
		} else {
			button.hover = false;
			// Trigger the on_exit callback if the hover state just changed to false
			if (was_hovering && button.on_exit) {
				button.on_exit();
			}
		}
	}
}

void InputSystem::handle_click(const MouseButton& mouse_button, const int& world_mouse_x, const int& world_mouse_y) {
	ComponentManager & mgr = this->component_manager;

	RefVector<Button> buttons = mgr.get_components_by_type<Button>();

	for (Button & button : buttons) {
		RefVector<Transform> transform_vec
			= mgr.get_components_by_id<Transform>(button.game_object_id);
		OptionalRef<Transform> transform(transform_vec.front().get());

		if (button.active && is_mouse_inside_button(world_mouse_x, world_mouse_y, button, transform)) {
			handle_button_press(button);
		}
	}
}

bool InputSystem::is_mouse_inside_button(const int& mouse_x, const int& mouse_y, const Button & button, const Transform & transform) {
	return mouse_x >= transform.position.x
		   && mouse_x <= transform.position.x + button.width
		   && mouse_y >= transform.position.y
		   && mouse_y <= transform.position.y + button.height;
}

void InputSystem::handle_button_press(Button & button) {
	if (button.is_toggle) {
		if (!button.is_pressed && button.on_click) {
			button.on_click();
		}
		button.is_pressed = !button.is_pressed;
	} else if (button.on_click) {
		button.on_click();
	}
}