/**************************************************************************/
/*  joypad_sdl.cpp                                                        */
/**************************************************************************/
/*                         This file is part of:                          */
/*                             GODOT ENGINE                               */
/*                        https://godotengine.org                         */
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/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
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#include "joypad_sdl.h"

#ifdef SDL_ENABLED

#include "core/input/default_controller_mappings.h"
#include "core/os/time.h"
#include "core/variant/dictionary.h"

#include <iterator>

#include <SDL3/SDL.h>
#include <SDL3/SDL_error.h>
#include <SDL3/SDL_events.h>
#include <SDL3/SDL_gamepad.h>
#include <SDL3/SDL_iostream.h>
#include <SDL3/SDL_joystick.h>

JoypadSDL *JoypadSDL::singleton = nullptr;

// Macro to skip the SDL joystick event handling if the device is an SDL gamepad, because
// there are separate events for SDL gamepads
#define SKIP_EVENT_FOR_GAMEPAD                    \
	if (SDL_IsGamepad(sdl_event.jdevice.which)) { \
		continue;                                 \
	}

JoypadSDL::JoypadSDL() {
	singleton = this;
}

JoypadSDL::~JoypadSDL() {
	// Process any remaining input events
	process_events();
	for (int i = 0; i < Input::JOYPADS_MAX; i++) {
		if (joypads[i].attached) {
			close_joypad(i);
		}
	}
	SDL_Quit();
	singleton = nullptr;
}

JoypadSDL *JoypadSDL::get_singleton() {
	return singleton;
}

Error JoypadSDL::initialize() {
	SDL_SetHint(SDL_HINT_JOYSTICK_THREAD, "1");
	SDL_SetHint(SDL_HINT_NO_SIGNAL_HANDLERS, "1");
	ERR_FAIL_COND_V_MSG(!SDL_Init(SDL_INIT_JOYSTICK | SDL_INIT_GAMEPAD), FAILED, SDL_GetError());

	// Add Godot's mapping database from memory
	int i = 0;
	while (DefaultControllerMappings::mappings[i]) {
		String mapping_string = DefaultControllerMappings::mappings[i++];
		CharString data = mapping_string.utf8();
		SDL_IOStream *rw = SDL_IOFromMem((void *)data.ptr(), data.size());
		SDL_AddGamepadMappingsFromIO(rw, 1);
	}

	// Make sure that we handle already connected joypads when the driver is initialized.
	process_events();

	print_verbose("SDL: Init OK!");
	return OK;
}

void JoypadSDL::process_events() {
	// Update rumble first for it to be applied when we handle SDL events
	for (int i = 0; i < Input::JOYPADS_MAX; i++) {
		Joypad &joy = joypads[i];
		if (joy.attached && joy.supports_force_feedback) {
			uint64_t timestamp = Input::get_singleton()->get_joy_vibration_timestamp(i);

			// Update the joypad rumble only if there was a new vibration request
			if (timestamp > joy.ff_effect_timestamp) {
				joy.ff_effect_timestamp = timestamp;

				SDL_Joystick *sdl_joy = SDL_GetJoystickFromID(joypads[i].sdl_instance_idx);
				Vector2 strength = Input::get_singleton()->get_joy_vibration_strength(i);

				// If the vibration was requested to start, SDL_RumbleJoystick will start it.
				// If the vibration was requested to stop, strength and duration will be 0, so SDL will stop the rumble.
				SDL_RumbleJoystick(
						sdl_joy,
						// Rumble strength goes from 0 to 0xFFFF
						strength.x * UINT16_MAX,
						strength.y * UINT16_MAX,
						Input::get_singleton()->get_joy_vibration_duration(i) * 1000);
			}
		}
	}

	SDL_Event sdl_event;
	while (SDL_PollEvent(&sdl_event)) {
		// A new joypad was attached
		if (sdl_event.type == SDL_EVENT_JOYSTICK_ADDED) {
			int joy_id = Input::get_singleton()->get_unused_joy_id();
			if (joy_id == -1) {
				// There is no space for more joypads...
				print_error("A new joypad was attached but couldn't allocate a new id for it because joypad limit was reached.");
			} else {
				SDL_Joystick *joy = nullptr;
				String device_name;

				// Gamepads must be opened with SDL_OpenGamepad to get their special remapped events
				if (SDL_IsGamepad(sdl_event.jdevice.which)) {
					SDL_Gamepad *gamepad = SDL_OpenGamepad(sdl_event.jdevice.which);

					ERR_CONTINUE_MSG(!gamepad,
							vformat("Error opening gamepad at index %d: %s", sdl_event.jdevice.which, SDL_GetError()));

					device_name = SDL_GetGamepadName(gamepad);
					joy = SDL_GetGamepadJoystick(gamepad);

					print_verbose(vformat("SDL: Gamepad %s connected", SDL_GetGamepadName(gamepad)));
				} else {
					joy = SDL_OpenJoystick(sdl_event.jdevice.which);
					ERR_CONTINUE_MSG(!joy,
							vformat("Error opening joystick at index %d: %s", sdl_event.jdevice.which, SDL_GetError()));

					device_name = SDL_GetJoystickName(joy);

					print_verbose(vformat("SDL: Joystick %s connected", SDL_GetJoystickName(joy)));
				}

				const int MAX_GUID_SIZE = 64;
				char guid[MAX_GUID_SIZE] = {};

				SDL_GUIDToString(SDL_GetJoystickGUID(joy), guid, MAX_GUID_SIZE);
				SDL_PropertiesID propertiesID = SDL_GetJoystickProperties(joy);

				joypads[joy_id].attached = true;
				joypads[joy_id].sdl_instance_idx = sdl_event.jdevice.which;
				joypads[joy_id].supports_force_feedback = SDL_GetBooleanProperty(propertiesID, SDL_PROP_JOYSTICK_CAP_RUMBLE_BOOLEAN, false);
				joypads[joy_id].guid = StringName(String(guid));

				sdl_instance_id_to_joypad_id.insert(sdl_event.jdevice.which, joy_id);

				// Skip Godot's mapping system because SDL already handles the joypad's mapping
				Dictionary joypad_info;
				joypad_info["mapping_handled"] = true;

				Input::get_singleton()->joy_connection_changed(
						joy_id,
						true,
						device_name,
						joypads[joy_id].guid,
						joypad_info);
			}
			// An event for an attached joypad
		} else if (sdl_event.type >= SDL_EVENT_JOYSTICK_AXIS_MOTION && sdl_event.type < SDL_EVENT_FINGER_DOWN && sdl_instance_id_to_joypad_id.has(sdl_event.jdevice.which)) {
			int joy_id = sdl_instance_id_to_joypad_id.get(sdl_event.jdevice.which);

			switch (sdl_event.type) {
				case SDL_EVENT_JOYSTICK_REMOVED:
					Input::get_singleton()->joy_connection_changed(joy_id, false, "");
					close_joypad(joy_id);
					break;

				case SDL_EVENT_JOYSTICK_AXIS_MOTION:
					SKIP_EVENT_FOR_GAMEPAD;

					Input::get_singleton()->joy_axis(
							joy_id,
							static_cast<JoyAxis>(sdl_event.jaxis.axis), // Godot joy axis constants are already intentionally the same as SDL's
							((sdl_event.jaxis.value - SDL_JOYSTICK_AXIS_MIN) / (float)(SDL_JOYSTICK_AXIS_MAX - SDL_JOYSTICK_AXIS_MIN) - 0.5f) * 2.0f);
					break;

				case SDL_EVENT_JOYSTICK_BUTTON_UP:
				case SDL_EVENT_JOYSTICK_BUTTON_DOWN:
					SKIP_EVENT_FOR_GAMEPAD;

					Input::get_singleton()->joy_button(
							joy_id,
							static_cast<JoyButton>(sdl_event.jbutton.button), // Godot button constants are intentionally the same as SDL's, so we can just straight up use them
							sdl_event.jbutton.down);
					break;

				case SDL_EVENT_JOYSTICK_HAT_MOTION:
					SKIP_EVENT_FOR_GAMEPAD;

					Input::get_singleton()->joy_hat(
							joy_id,
							(HatMask)sdl_event.jhat.value // Godot hat masks are identical to SDL hat masks, so we can just use them as-is.
					);
					break;

				case SDL_EVENT_GAMEPAD_AXIS_MOTION: {
					float axis_value;

					if (sdl_event.gaxis.axis == SDL_GAMEPAD_AXIS_LEFT_TRIGGER || sdl_event.gaxis.axis == SDL_GAMEPAD_AXIS_RIGHT_TRIGGER) {
						// Gamepad triggers go from 0 to SDL_JOYSTICK_AXIS_MAX
						axis_value = sdl_event.gaxis.value / (float)SDL_JOYSTICK_AXIS_MAX;
					} else {
						// Other axis go from SDL_JOYSTICK_AXIS_MIN to SDL_JOYSTICK_AXIS_MAX
						axis_value =
								((sdl_event.gaxis.value - SDL_JOYSTICK_AXIS_MIN) / (float)(SDL_JOYSTICK_AXIS_MAX - SDL_JOYSTICK_AXIS_MIN) - 0.5f) * 2.0f;
					}

					Input::get_singleton()->joy_axis(
							joy_id,
							static_cast<JoyAxis>(sdl_event.gaxis.axis), // Godot joy axis constants are already intentionally the same as SDL's
							axis_value);
				} break;

				// Do note SDL gamepads do not have separate events for the dpad
				case SDL_EVENT_GAMEPAD_BUTTON_UP:
				case SDL_EVENT_GAMEPAD_BUTTON_DOWN:
					Input::get_singleton()->joy_button(
							joy_id,
							static_cast<JoyButton>(sdl_event.gbutton.button), // Godot button constants are intentionally the same as SDL's, so we can just straight up use them
							sdl_event.gbutton.down);
					break;
			}
		}
	}
}

#ifdef WINDOWS_ENABLED
extern "C" {
HWND SDL_HelperWindow;
}

// Required for DInput joypads to work
void JoypadSDL::setup_sdl_helper_window(HWND p_hwnd) {
	SDL_HelperWindow = p_hwnd;
}
#endif

void JoypadSDL::close_joypad(int p_pad_idx) {
	int sdl_instance_idx = joypads[p_pad_idx].sdl_instance_idx;

	joypads[p_pad_idx].attached = false;
	sdl_instance_id_to_joypad_id.erase(sdl_instance_idx);

	if (SDL_IsGamepad(sdl_instance_idx)) {
		SDL_Gamepad *gamepad = SDL_GetGamepadFromID(sdl_instance_idx);
		SDL_CloseGamepad(gamepad);
	} else {
		SDL_Joystick *joy = SDL_GetJoystickFromID(sdl_instance_idx);
		SDL_CloseJoystick(joy);
	}
}

#endif // SDL_ENABLED