/*
 * Copyright (c) 2012-2024 Daniele Bartolini et al.
 * SPDX-License-Identifier: MIT
 */

#include "core/error/error.h"
#include "core/math/constants.h"
#include "core/math/math.h"
#include "core/math/vector3.inl"
#include "core/memory/allocator.h"
#include "core/memory/memory.inl"
#include "core/strings/string.inl"
#include "core/strings/string_id.inl"
#include "device/input_device.h"
#include <string.h> // strcpy, memset

#define CE_BUTTON_STATE_MASK  0x01
#define CE_BUTTON_STATE_SHIFT 0
#define CE_BUTTON_MASK        0xc0
#define CE_BUTTON_SHIFT       6
#define CE_BUTTON_PRESSED     0x40
#define CE_BUTTON_RELEASED    0x80

namespace crown
{
const char *InputDevice::name() const
{
	return _name;
}

bool InputDevice::connected() const
{
	return _connected;
}

u8 InputDevice::num_buttons() const
{
	return _num_buttons;
}

u8 InputDevice::num_axes() const
{
	return _num_axes;
}

bool InputDevice::pressed(u8 id) const
{
	return id < _num_buttons
		? (_state[id] & CE_BUTTON_PRESSED) != 0
		: false
		;
}

bool InputDevice::released(u8 id) const
{
	return id < _num_buttons
		? (_state[id] & CE_BUTTON_RELEASED) != 0
		: false
		;
}

u8 InputDevice::any_pressed() const
{
	return pressed(_first_button[1]) ? _first_button[1] : UINT8_MAX;
}

u8 InputDevice::any_released() const
{
	return released(_first_button[0]) ? _first_button[0] : UINT8_MAX;
}

f32 InputDevice::button(u8 id) const
{
	return id < _num_buttons
		? f32((_state[id] & CE_BUTTON_STATE_MASK) >> CE_BUTTON_STATE_SHIFT)
		: 0.0f
		;
}

Vector3 InputDevice::axis(u8 id) const
{
	if (id >= _num_axes)
		return VECTOR3_ZERO;

	return _axis[id];
}

const char *InputDevice::button_name(u8 id) const
{
	return id < _num_buttons
		? _button_name[id]
		: NULL
		;
}

const char *InputDevice::axis_name(u8 id) const
{
	return id < _num_axes
		? _axis_name[id]
		: NULL
		;
}

u8 InputDevice::button_id(StringId32 name) const
{
	for (u32 i = 0; i < _num_buttons; ++i) {
		if (_button_hash[i] == name)
			return i;
	}

	return UINT8_MAX;
}

u8 InputDevice::axis_id(StringId32 name) const
{
	for (u32 i = 0; i < _num_axes; ++i) {
		if (_axis_hash[i] == name)
			return i;
	}

	return UINT8_MAX;
}

f32 InputDevice::deadzone(u8 id, DeadzoneMode::Enum *deadzone_mode) const
{
	if (id < _num_axes) {
		*deadzone_mode = (DeadzoneMode::Enum)_deadzone_mode[id];
		return _deadzone_size[id];
	} else {
		*deadzone_mode = DeadzoneMode::COUNT;
		return 0.0f;
	}
}

void InputDevice::set_deadzone(u8 id, DeadzoneMode::Enum deadzone_mode, f32 deadzone_size)
{
	if (id < _num_axes) {
		_deadzone_mode[id] = deadzone_mode;
		_deadzone_size[id] = deadzone_size;
	}
}

void InputDevice::set_button(u8 id, u8 state)
{
	CE_ASSERT(id < _num_buttons, "Index out of bounds");

	bool pressed = (_state[id] & CE_BUTTON_STATE_MASK) >> CE_BUTTON_STATE_SHIFT == 1;

	if (pressed && state == 0)
		_state[id] |= CE_BUTTON_RELEASED;
	if (!pressed && state == 1)
		_state[id] |= CE_BUTTON_PRESSED;

	_state[id] = (_state[id] & ~(1 << CE_BUTTON_STATE_SHIFT))
		| (state << CE_BUTTON_STATE_SHIFT);

	if (_first_button[state % countof(_first_button)] == UINT8_MAX)
		_first_button[state % countof(_first_button)] = id;
}

void InputDevice::set_axis(u8 id, f32 x, f32 y, f32 z)
{
	CE_ASSERT(id < _num_axes, "Index out of bounds");
	_axis[id].x = x;
	_axis[id].y = y;
	_axis[id].z = z;
}

void InputDevice::update()
{
	for (u32 ii = 0; ii < _num_buttons; ++ii)
		_state[ii] &= ~CE_BUTTON_MASK;

	_first_button[0] = UINT8_MAX;
	_first_button[1] = UINT8_MAX;
}

namespace input_device
{
	InputDevice *create(Allocator &a, const char *name, u8 num_buttons, u8 num_axes, const char **button_names, const char **axis_names)
	{
		const u32 size = 0
			+ sizeof(InputDevice) + alignof(InputDevice)
			+ sizeof(u8)*num_buttons*2 + alignof(u8)
			+ sizeof(Vector3)*num_axes + alignof(Vector3)
			+ sizeof(u32)*num_axes + alignof(u32)
			+ sizeof(f32)*num_axes + alignof(f32)
			+ sizeof(StringId32)*num_buttons + alignof(StringId32)
			+ sizeof(StringId32)*num_axes + alignof(StringId32)
			+ strlen32(name) + 1 + alignof(char)
			;

		InputDevice *id = (InputDevice *)a.allocate(size);

		id->_connected       = false;
		id->_num_buttons     = num_buttons;
		id->_num_axes        = num_axes;
		id->_first_button[0] = UINT8_MAX;
		id->_first_button[1] = UINT8_MAX;
		id->_button_name     = button_names;
		id->_axis_name       = axis_names;

		id->_state         = (u8 *        )&id[1];
		id->_axis          = (Vector3 *   )memory::align_top(id->_state + num_buttons,       alignof(Vector3));
		id->_deadzone_mode = (u32 *       )memory::align_top(id->_axis + num_axes,           alignof(u32));
		id->_deadzone_size = (f32 *       )memory::align_top(id->_deadzone_mode + num_axes,  alignof(f32));
		id->_button_hash   = (StringId32 *)memory::align_top(id->_deadzone_size + num_axes,  alignof(StringId32));
		id->_axis_hash     = (StringId32 *)memory::align_top(id->_button_hash + num_buttons, alignof(StringId32));
		id->_name          = (char *      )memory::align_top(id->_axis_hash + num_axes,      alignof(char));
		id->_lua_object    = 0;

		memset(id->_state, 0, sizeof(u8)*num_buttons);
		memset(id->_axis, 0, sizeof(Vector3)*num_axes);
		memset(id->_deadzone_mode, 0, sizeof(*id->_deadzone_mode)*num_axes);
		memset(id->_deadzone_size, 0, sizeof(*id->_deadzone_size)*num_axes);

		for (u32 i = 0; i < num_buttons; ++i)
			id->_button_hash[i] = StringId32(button_names[i]);

		for (u32 i = 0; i < num_axes; ++i)
			id->_axis_hash[i] = StringId32(axis_names[i]);

		strcpy(id->_name, name);

		return id;
	}

	void destroy(Allocator &a, InputDevice &id)
	{
		a.deallocate(&id);
	}

} // namespace input_device

} // namespace crown