UUID.c

// This file is part of the CircuitPython project: https://circuitpython.org
//
// SPDX-FileCopyrightText: Copyright (c) 2019 Dan Halbert for Adafruit Industries
// SPDX-FileCopyrightText: Copyright (c) 2018 Artur Pacholec
// SPDX-FileCopyrightText: Copyright (c) 2017 Glenn Ruben Bakke
//
// SPDX-License-Identifier: MIT

#include <string.h>

#include "py/objproperty.h"
#include "py/objstr.h"
#include "py/runtime.h"
#include "shared-bindings/_bleio/UUID.h"

//| class UUID:
//|     """A 16-bit or 128-bit UUID. Can be used for services, characteristics, descriptors and more."""
//|
//|     def __init__(self, value: Union[int, ReadableBuffer, str]) -> None:
//|         """Create a new UUID or UUID object encapsulating the uuid value.
//|         The value can be one of:
//|
//|         - an `int` value in range 0 to 0xFFFF (Bluetooth SIG 16-bit UUID)
//|         - a buffer object (bytearray, bytes) of 16 bytes in little-endian order (128-bit UUID)
//|         - a string of hex digits of the form 'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx'
//|
//|         Creating a 128-bit UUID registers the UUID with the onboard BLE software, and provides a
//|         temporary 16-bit UUID that can be used in place of the full 128-bit UUID.
//|
//|         :param value: The uuid value to encapsulate
//|         :type value: int, ~circuitpython_typing.ReadableBuffer or str"""
//|         ...
//|
static mp_obj_t bleio_uuid_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
    mp_arg_check_num(n_args, n_kw, 1, 1, false);

    bleio_uuid_obj_t *self = mp_obj_malloc(bleio_uuid_obj_t, &bleio_uuid_type);

    const mp_obj_t value = all_args[0];
    uint8_t uuid128[16];

    if (mp_obj_is_int(value)) {
        mp_int_t uuid16 = mp_obj_get_int(value);
        if (uuid16 < 0 || uuid16 > 0xffff) {
            mp_raise_ValueError(MP_ERROR_TEXT("UUID integer value must be 0-0xffff"));
        }

        // NULL means no 128-bit value.
        common_hal_bleio_uuid_construct(self, uuid16, NULL);

    } else {
        if (mp_obj_is_str(value)) {
            // 'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx'
            GET_STR_DATA_LEN(value, chars, len);
            char hex[32];
            // Validate length, hyphens, and hex digits.
            bool good_uuid =
                len == 36 && chars[8] == '-' && chars[13] == '-' && chars[18] == '-' && chars[23] == '-';
            if (good_uuid) {
                size_t hex_idx = 0;
                for (size_t i = 0; i < len; i++) {
                    if (unichar_isxdigit(chars[i])) {
                        hex[hex_idx] = chars[i];
                        hex_idx++;
                    }
                }
                good_uuid = hex_idx == 32;
            }
            if (!good_uuid) {
                mp_raise_ValueError(MP_ERROR_TEXT("UUID string not 'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx'"));
            }

            size_t hex_idx = 0;
            for (int i = 15; i >= 0; i--) {
                uuid128[i] = (unichar_xdigit_value(hex[hex_idx]) << 4) | unichar_xdigit_value(hex[hex_idx + 1]);
                hex_idx += 2;
            }
        } else {
            // Last possibility is that it's a buf.
            mp_buffer_info_t bufinfo;
            if (!mp_get_buffer(value, &bufinfo, MP_BUFFER_READ)) {
                mp_raise_ValueError(MP_ERROR_TEXT("UUID value is not str, int or byte buffer"));
            }

            if (bufinfo.len != 16) {
                mp_raise_ValueError(MP_ERROR_TEXT("Byte buffer must be 16 bytes."));
            }

            memcpy(uuid128, bufinfo.buf, 16);
        }

        // Str and bytes both get constructed the same way here.
        uint32_t uuid16 = (uuid128[13] << 8) | uuid128[12];
        uuid128[12] = 0;
        uuid128[13] = 0;
        common_hal_bleio_uuid_construct(self, uuid16, uuid128);
    }

    return MP_OBJ_FROM_PTR(self);
}

//|     uuid16: int
//|     """The 16-bit part of the UUID. (read-only)
//|
//|     :type: int"""
static mp_obj_t bleio_uuid_get_uuid16(mp_obj_t self_in) {
    bleio_uuid_obj_t *self = MP_OBJ_TO_PTR(self_in);
    return MP_OBJ_NEW_SMALL_INT(common_hal_bleio_uuid_get_uuid16(self));
}

MP_DEFINE_CONST_FUN_OBJ_1(bleio_uuid_get_uuid16_obj, bleio_uuid_get_uuid16);

MP_PROPERTY_GETTER(bleio_uuid_uuid16_obj,
    (mp_obj_t)&bleio_uuid_get_uuid16_obj);

//|     uuid128: bytes
//|     """The 128-bit value of the UUID
//|     Raises AttributeError if this is a 16-bit UUID. (read-only)
//|
//|     :type: bytes"""
static mp_obj_t bleio_uuid_get_uuid128(mp_obj_t self_in) {
    bleio_uuid_obj_t *self = MP_OBJ_TO_PTR(self_in);

    uint8_t uuid128[16];
    if (common_hal_bleio_uuid_get_size(self) != 128) {
        mp_raise_AttributeError(MP_ERROR_TEXT("not a 128-bit UUID"));
    }
    common_hal_bleio_uuid_get_uuid128(self, uuid128);
    return mp_obj_new_bytes(uuid128, 16);
}

MP_DEFINE_CONST_FUN_OBJ_1(bleio_uuid_get_uuid128_obj, bleio_uuid_get_uuid128);

MP_PROPERTY_GETTER(bleio_uuid_uuid128_obj,
    (mp_obj_t)&bleio_uuid_get_uuid128_obj);

//|     size: int
//|     """128 if this UUID represents a 128-bit vendor-specific UUID. 16 if this UUID represents a
//|     16-bit Bluetooth SIG assigned UUID. (read-only) 32-bit UUIDs are not currently supported.
//|
//|     :type: int"""
//|
static mp_obj_t bleio_uuid_get_size(mp_obj_t self_in) {
    bleio_uuid_obj_t *self = MP_OBJ_TO_PTR(self_in);
    return MP_OBJ_NEW_SMALL_INT(common_hal_bleio_uuid_get_size(self));
}

MP_DEFINE_CONST_FUN_OBJ_1(bleio_uuid_get_size_obj, bleio_uuid_get_size);

MP_PROPERTY_GETTER(bleio_uuid_size_obj,
    (mp_obj_t)&bleio_uuid_get_size_obj);


//|     def pack_into(self, buffer: WriteableBuffer, offset: int = 0) -> None:
//|         """Packs the UUID into the given buffer at the given offset."""
//|         ...
//|
static mp_obj_t bleio_uuid_pack_into(mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
    bleio_uuid_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);

    enum { ARG_buffer, ARG_offset };
    static const mp_arg_t allowed_args[] = {
        { MP_QSTR_buffer, MP_ARG_OBJ | MP_ARG_REQUIRED },
        { MP_QSTR_offset, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
    };

    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
    mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);


    mp_buffer_info_t bufinfo;
    mp_get_buffer_raise(args[ARG_buffer].u_obj, &bufinfo, MP_BUFFER_WRITE);

    size_t offset = args[ARG_offset].u_int;
    if (offset + common_hal_bleio_uuid_get_size(self) / 8 > bufinfo.len) {
        mp_raise_ValueError(MP_ERROR_TEXT("Buffer + offset too small %d %d %d"));
    }

    common_hal_bleio_uuid_pack_into(self, bufinfo.buf + offset);
    return mp_const_none;
}
static MP_DEFINE_CONST_FUN_OBJ_KW(bleio_uuid_pack_into_obj, 1, bleio_uuid_pack_into);

static const mp_rom_map_elem_t bleio_uuid_locals_dict_table[] = {
    { MP_ROM_QSTR(MP_QSTR_uuid16), MP_ROM_PTR(&bleio_uuid_uuid16_obj) },
    { MP_ROM_QSTR(MP_QSTR_uuid128), MP_ROM_PTR(&bleio_uuid_uuid128_obj) },
    { MP_ROM_QSTR(MP_QSTR_size), MP_ROM_PTR(&bleio_uuid_size_obj) },
    { MP_ROM_QSTR(MP_QSTR_pack_into), MP_ROM_PTR(&bleio_uuid_pack_into_obj) },
};

static MP_DEFINE_CONST_DICT(bleio_uuid_locals_dict, bleio_uuid_locals_dict_table);

static mp_obj_t bleio_uuid_unary_op(mp_unary_op_t op, mp_obj_t self_in) {
    bleio_uuid_obj_t *self = MP_OBJ_TO_PTR(self_in);
    switch (op) {
        case MP_UNARY_OP_HASH:
            if (common_hal_bleio_uuid_get_size(self) == 16) {
                return MP_OBJ_NEW_SMALL_INT(common_hal_bleio_uuid_get_uuid16(self));
            } else {
                union {
                    uint8_t uuid128_bytes[16];
                    uint16_t uuid128_uint16[8];
                } uuid128;
                common_hal_bleio_uuid_get_uuid128(self, uuid128.uuid128_bytes);
                int hash = 0;
                for (size_t i = 0; i < MP_ARRAY_SIZE(uuid128.uuid128_uint16); i++) {
                    hash += uuid128.uuid128_uint16[i];
                }
                return MP_OBJ_NEW_SMALL_INT(hash);
            }
        default:
            return MP_OBJ_NULL; // op not supported
    }
}

//|     def __eq__(self, other: object) -> bool:
//|         """Two UUID objects are equal if their values match and they are both 128-bit or both 16-bit."""
//|         ...
//|
//|
static mp_obj_t bleio_uuid_binary_op(mp_binary_op_t op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
    switch (op) {
        // Two UUID's are equal if their uuid16 values match or their uuid128 values match.
        case MP_BINARY_OP_EQUAL:
            if (mp_obj_is_type(rhs_in, &bleio_uuid_type)) {
                if (common_hal_bleio_uuid_get_size(lhs_in) == 16 &&
                    common_hal_bleio_uuid_get_size(rhs_in) == 16) {
                    return mp_obj_new_bool(common_hal_bleio_uuid_get_uuid16(lhs_in) ==
                        common_hal_bleio_uuid_get_uuid16(rhs_in));
                }
                uint8_t lhs[16];
                uint8_t rhs[16];
                common_hal_bleio_uuid_get_uuid128(lhs_in, lhs);
                common_hal_bleio_uuid_get_uuid128(rhs_in, rhs);
                return mp_obj_new_bool(memcmp(lhs, rhs, sizeof(lhs)) == 0);
            } else {
                return mp_const_false;
            }

        default:
            return MP_OBJ_NULL; // op not supported
    }
}

void bleio_uuid_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
    bleio_uuid_obj_t *self = MP_OBJ_TO_PTR(self_in);
    uint32_t size = common_hal_bleio_uuid_get_size(self);
    if (size == 16) {
        mp_printf(print, "UUID(0x%04x)", common_hal_bleio_uuid_get_uuid16(self));
    } else {
        uint8_t uuid128[16];
        common_hal_bleio_uuid_get_uuid128(self, uuid128);
        mp_printf(print, "UUID('"
            "%02x%02x%02x%02x-"
            "%02x%02x-"
            "%02x%02x-"
            "%02x%02x-"
            "%02x%02x%02x%02x%02x%02x')",
            uuid128[15], uuid128[14], uuid128[13], uuid128[12],
            uuid128[11], uuid128[10],
            uuid128[9], uuid128[8],
            uuid128[7], uuid128[6],
            uuid128[5], uuid128[4], uuid128[3], uuid128[2], uuid128[1], uuid128[0]);
    }
}

MP_DEFINE_CONST_OBJ_TYPE(
    bleio_uuid_type,
    MP_QSTR_UUID,
    MP_TYPE_FLAG_HAS_SPECIAL_ACCESSORS,
    print, bleio_uuid_print,
    make_new, bleio_uuid_make_new,
    locals_dict, &bleio_uuid_locals_dict,
    unary_op, bleio_uuid_unary_op,
    binary_op, bleio_uuid_binary_op
    );