types.py

# -*- coding: utf-8 -*-
import json
import struct
import time
from calendar import timegm
from binascii import hexlify, unhexlify
from .objecttypes import object_type
from .utils import unicodify

timeformat = "%Y-%m-%dT%H:%M:%S%Z"


def varint(n):
    """Varint encoding"""
    data = b""
    while n >= 0x80:
        data += bytes([(n & 0x7F) | 0x80])
        n >>= 7
    data += bytes([n])
    return data


def varintdecode(data):  # pragma: no cover
    """Varint decoding"""
    shift = 0
    result = 0
    for b in bytes(data):
        result |= (b & 0x7F) << shift
        if not (b & 0x80):
            break
        shift += 7
    return result


def variable_buffer(s):
    """Encode variable length buffer"""
    return varint(len(s)) + s


def JsonObj(data):
    """Return json object from data

    If data has a __json__() method, use that, else assume it follows the
    convention that its string representation is interprettable as valid json.
    (The latter can be problematic if str(data) returns, e.g., "1234". Was
    this supposed to be the string "1234" or the number 1234? If this
    ambiguity exists, the data type must implement __json__().)

    """
    try:
        return data.__json__()
    except Exception:
        return json.loads(str(data))


class Uint8:
    def __init__(self, d):
        self.data = int(d)

    def __bytes__(self):
        return struct.pack("<B", self.data)

    def __str__(self):
        return "%d" % self.data


class Int16:
    def __init__(self, d):
        self.data = int(d)

    def __bytes__(self):
        return struct.pack("<h", int(self.data))

    def __str__(self):
        return "%d" % self.data


class Uint16:
    def __init__(self, d):
        self.data = int(d)

    def __bytes__(self):
        return struct.pack("<H", self.data)

    def __str__(self):
        return "%d" % self.data


class Uint32:
    def __init__(self, d):
        self.data = int(d)

    def __bytes__(self):
        return struct.pack("<I", self.data)

    def __str__(self):
        return "%d" % self.data


class Uint64:
    def __init__(self, d):
        self.data = int(d)

    def __bytes__(self):
        return struct.pack("<Q", self.data)

    def __str__(self):
        return "%d" % self.data


class Varint32:
    def __init__(self, d):
        self.data = int(d)

    def __bytes__(self):
        return varint(self.data)

    def __str__(self):
        return "%d" % self.data


class Int64:
    def __init__(self, d):
        self.data = int(d)

    def __bytes__(self):
        return struct.pack("<q", self.data)

    def __str__(self):
        return "%d" % self.data


class String:
    def __init__(self, d):
        self.data = d

    def __bytes__(self):
        if self.data:
            d = unicodify(self.data)
        else:
            d = b""
        return varint(len(d)) + d

    def __str__(self):
        return "%s" % str(self.data)


class Bytes:
    """Bytes

    Initializes from and stores internally as a string of hex digits.
    Byte-serializes as a length-prefixed series of bytes represented
    by those hex digits.

    Ex: len(str(Bytes("deadbeef")) == 8   # Eight hex chars
        len(bytes(Bytes("deadbeef")) == 5 # Four data bytes plus varint length

    Implements __json__() method to disambiguate between string and numeric in
    event where hex digits include only numeric digits and no alpha digits.

    """

    def __init__(self, d):
        self.data = d

    def __bytes__(self):
        d = unhexlify(bytes(self.data, "utf-8"))
        return varint(len(d)) + d

    def __json__(self):
        return str(self.data)

    def __str__(self):
        return str(self.data)


class Hash(Bytes):
    def json(self):
        return str(self.data)

    def __bytes__(self):
        return unhexlify(bytes(self.data, "utf-8"))


class Ripemd160(Hash):
    def __init__(self, a):
        assert len(a) == 40, "Require 40 char long hex"
        super().__init__(a)


class Sha1(Hash):
    def __init__(self, a):
        assert len(a) == 40, "Require 40 char long hex"
        super().__init__(a)


class Sha256(Hash):
    def __init__(self, a):
        assert len(a) == 64, "Require 64 char long hex"
        super().__init__(a)


class Hash160(Hash):
    def __init__(self, a):
        assert len(a) == 40, "Require 40 char long hex"
        super().__init__(a)


class Void:
    def __init__(self):
        pass

    def __bytes__(self):
        return b""

    def __str__(self):
        return ""


class Array:
    def __init__(self, d):
        self.data = d or []
        self.length = Varint32(len(self.data))

    def __bytes__(self):
        return bytes(self.length) + b"".join([bytes(a) for a in self.data])

    def __str__(self):
        r = []
        for a in self.data:
            try:
                r.append(JsonObj(a))
            except Exception:
                r.append(str(a))
        return json.dumps(r)


class PointInTime:
    def __init__(self, d):
        self.data = d

    def __bytes__(self):
        return struct.pack("<I", timegm(time.strptime((self.data + "UTC"), timeformat)))

    def __str__(self):
        return self.data


class Signature:
    def __init__(self, d):
        self.data = d

    def __bytes__(self):
        return self.data

    def __str__(self):
        return json.dumps(hexlify(self.data).decode("ascii"))


class Bool(Uint8):  # Bool = Uint8
    def __init__(self, d):
        super().__init__(d)

    def __str__(self):
        return json.dumps(True) if self.data else json.dumps(False)


class Set(Array):  # Set = Array
    def __init__(self, d):
        super().__init__(d)


class Fixed_array:
    pass


class Optional:
    def __init__(self, d):
        self.data = d

    def __bytes__(self):
        if not bool(self.data):
            return bytes(Bool(0))
        else:
            return (
                bytes(Bool(1)) + bytes(self.data)
                if bytes(self.data)
                else bytes(Bool(0))
            )

    def __str__(self):
        return str(self.data)

    def isempty(self):
        if self.data is None:
            return True
        if not bool(str(self.data)):  # pragma: no cover
            return True
        return not bool(bytes(self.data))


class Static_variant:
    def __init__(self, d, type_id):
        self.data = d
        self.type_id = type_id

    def __bytes__(self):
        return varint(self.type_id) + bytes(self.data)

    def __str__(self):
        return json.dumps([self.type_id, self.data.json()])


class Map:
    def __init__(self, data):
        self.data = data

    def __bytes__(self):
        b = b""
        b += varint(len(self.data))
        for e in self.data:
            b += bytes(e[0]) + bytes(e[1])
        return b

    def __str__(self):
        r = []
        for e in self.data:
            r.append([str(e[0]), JsonObj(str(e[1]))])
        return json.dumps(r)


class Id:
    def __init__(self, d):
        self.data = Varint32(d)

    def __bytes__(self):
        return bytes(self.data)

    def __str__(self):
        return str(self.data)


class VoteId:
    def __init__(self, vote):
        parts = vote.split(":")
        assert len(parts) == 2
        self.type = int(parts[0])
        self.instance = int(parts[1])

    def __bytes__(self):
        binary = (self.type & 0xFF) | (self.instance << 8)
        return struct.pack("<I", binary)

    def __str__(self):
        return "%d:%d" % (self.type, self.instance)


class ObjectId:
    """Encodes protocol ids - serializes to the *instance* only!"""

    object_types = object_type

    def __init__(self, object_str, type_verify=None):
        if len(object_str.split(".")) == 3:
            space, type, id = object_str.split(".")
            self.space = int(space)
            self.type = int(type)
            self.instance = Id(int(id))
            self.Id = object_str
            if type_verify:
                assert (
                    type_verify in self.object_types
                ), "Type {} is not defined!".format(type_verify)
                assert self.object_types[type_verify] == int(type), (
                    "Object id does not match object type! "
                    + "Excpected %d, got %d"
                    % (self.object_types[type_verify], int(type))
                )
        else:
            raise Exception("Object id is invalid")

    def __bytes__(self):
        return bytes(self.instance)  # only yield instance

    def __str__(self):
        return self.Id


class FullObjectId:
    """Encodes object ids - serializes to a full object id"""

    def __init__(self, object_str):
        if len(object_str.split(".")) == 3:
            space, type, id = object_str.split(".")
            self.space = int(space)
            self.type = int(type)
            self.id = int(id)
            self.instance = Id(int(id))
            self.Id = object_str
        else:
            raise ValueError("Object id is invalid")

    def __bytes__(self):
        return (self.space << 56 | self.type << 48 | self.id).to_bytes(
            8, byteorder="little", signed=False
        )

    def __str__(self):
        return self.Id


class Enum8(Uint8):
    # List needs to be provided by super class
    options = []

    def __init__(self, selection):
        if selection not in self.options or (
            isinstance(selection, int) and len(self.options) < selection
        ):
            raise ValueError(
                "Options are {}. Given '{}'".format(str(self.options), selection)
            )

        super(Enum8, self).__init__(self.options.index(selection))

    def __str__(self):
        return str(self.options[self.data])