# String encodings and numeric representations
import json
import re

from eth_abi.encoding import (
 BaseArrayEncoder,
)
from eth_utils import (
 add_0x_prefix,
 big_endian_to_int,
 decode_hex,
 encode_hex,
 int_to_big_endian,
 is_boolean,
 is_bytes,
 is_hex,
 is_integer,
 is_list_like,
 remove_0x_prefix,
 to_hex,
)
from eth_utils.toolz import (
 curry,
)
from hexbytes import (
 HexBytes,
)

from utils.abi import (
 is_address_type,
 is_array_type,
 is_bool_type,
 is_bytes_type,
 is_int_type,
 is_string_type,
 is_uint_type,
 size_of_type,
 sub_type_of_array_type,
)
from utils.validation import (
 assert_one_val,
 validate_abi_type,
 validate_abi_value,
)
from utils.datastructures import (
 AttributeDict,
)


def hex_encode_abi_type(abi_type, value, force_size=None):
 """
 Encodes value into a hex string in format of abi_type
 """
 validate_abi_type(abi_type)
 validate_abi_value(abi_type, value)

 data_size = force_size or size_of_type(abi_type)
 if is_array_type(abi_type):
 sub_type = sub_type_of_array_type(abi_type)
 return "".join([remove_0x_prefix(hex_encode_abi_type(sub_type, v, 256)) for v in value])
 elif is_bool_type(abi_type):
 return to_hex_with_size(value, data_size)
 elif is_uint_type(abi_type):
 return to_hex_with_size(value, data_size)
 elif is_int_type(abi_type):
 return to_hex_twos_compliment(value, data_size)
 elif is_address_type(abi_type):
 return pad_hex(value, data_size)
 elif is_bytes_type(abi_type):
 if is_bytes(value):
 return encode_hex(value)
 else:
 return value
 elif is_string_type(abi_type):
 return to_hex(text=value)
 else:
 raise ValueError(
 "Unsupported ABI type: {0}".format(abi_type)
 )


def to_hex_twos_compliment(value, bit_size):
 """
 Converts integer value to twos compliment hex representation with given bit_size
 """
 if value >= 0:
 return to_hex_with_size(value, bit_size)

 value = (1 << bit_size) + value
 hex_value = hex(value)
 hex_value = hex_value.rstrip("L")
 return hex_value


def to_hex_with_size(value, bit_size):
 """
 Converts a value to hex with given bit_size:
 """
 return pad_hex(to_hex(value), bit_size)


def pad_hex(value, bit_size):
 """
 Pads a hex string up to the given bit_size
 """
 value = remove_0x_prefix(value)
 return add_0x_prefix(value.zfill(int(bit_size / 4)))


def trim_hex(hexstr):
 if hexstr.startswith('0x0'):
 hexstr = re.sub('^0x0+', '0x', hexstr)
 if hexstr == '0x':
 hexstr = '0x0'
 return hexstr


def to_int(value=None, hexstr=None, text=None):
 """
 Converts value to it's integer representation.

 Values are converted this way:

 * value:
 * bytes: big-endian integer
 * bool: True => 1, False => 0
 * hexstr: interpret hex as integer
 * text: interpret as string of digits, like '12' => 12
 """
 assert_one_val(value, hexstr=hexstr, text=text)

 if hexstr is not None:
 return int(hexstr, 16)
 elif text is not None:
 return int(text)
 elif isinstance(value, bytes):
 return big_endian_to_int(value)
 elif isinstance(value, str):
 raise TypeError("Pass in strings with keyword hexstr or text")
 else:
 return int(value)


@curry
def pad_bytes(fill_with, num_bytes, unpadded):
 return unpadded.rjust(num_bytes, fill_with)


zpad_bytes = pad_bytes(b'0円')


def to_bytes(primitive=None, hexstr=None, text=None):
 assert_one_val(primitive, hexstr=hexstr, text=text)

 if is_boolean(primitive):
 return b'\x01' if primitive else b'\x00'
 elif isinstance(primitive, bytes):
 return primitive
 elif is_integer(primitive):
 return to_bytes(hexstr=to_hex(primitive))
 elif hexstr is not None:
 if len(hexstr) % 2:
 hexstr = '0x0' + remove_0x_prefix(hexstr)
 return decode_hex(hexstr)
 elif text is not None:
 return text.encode('utf-8')
 raise TypeError("expected an int in first arg, or keyword of hexstr or text")


def to_text(primitive=None, hexstr=None, text=None):
 assert_one_val(primitive, hexstr=hexstr, text=text)

 if hexstr is not None:
 return to_bytes(hexstr=hexstr).decode('utf-8')
 elif text is not None:
 return text
 elif isinstance(primitive, str):
 return to_text(hexstr=primitive)
 elif isinstance(primitive, bytes):
 return primitive.decode('utf-8')
 elif is_integer(primitive):
 byte_encoding = int_to_big_endian(primitive)
 return to_text(byte_encoding)
 raise TypeError("Expected an int, bytes or hexstr.")


@curry
def text_if_str(to_type, text_or_primitive):
 """
 Convert to a type, assuming that strings can be only unicode text (not a hexstr)

 @param to_type is a function that takes the arguments (primitive, hexstr=hexstr, text=text),
 eg~ to_bytes, to_text, to_hex, to_int, etc
 @param hexstr_or_primitive in bytes, str, or int.
 """
 if isinstance(text_or_primitive, str):
 (primitive, text) = (None, text_or_primitive)
 else:
 (primitive, text) = (text_or_primitive, None)
 return to_type(primitive, text=text)


@curry
def hexstr_if_str(to_type, hexstr_or_primitive):
 """
 Convert to a type, assuming that strings can be only hexstr (not unicode text)

 @param to_type is a function that takes the arguments (primitive, hexstr=hexstr, text=text),
 eg~ to_bytes, to_text, to_hex, to_int, etc
 @param text_or_primitive in bytes, str, or int.
 """
 if isinstance(hexstr_or_primitive, str):
 (primitive, hexstr) = (None, hexstr_or_primitive)
 if remove_0x_prefix(hexstr) and not is_hex(hexstr):
 raise ValueError(
 "when sending a str, it must be a hex string. Got: {0!r}".format(
 hexstr_or_primitive,
 )
 )
 else:
 (primitive, hexstr) = (hexstr_or_primitive, None)
 return to_type(primitive, hexstr=hexstr)


class FriendlyJsonSerde:
 """
 Friendly JSON serializer & deserializer

 When encoding or decoding fails, this class collects
 information on which fields failed, to show more
 helpful information in the raised error messages.
 """

 def _json_mapping_errors(self, mapping):
 for key, val in mapping.items():
 try:
 self._friendly_json_encode(val)
 except TypeError as exc:
 yield "%r: because (%s)" % (key, exc)

 def _json_list_errors(self, iterable):
 for index, element in enumerate(iterable):
 try:
 self._friendly_json_encode(element)
 except TypeError as exc:
 yield "%d: because (%s)" % (index, exc)

 def _friendly_json_encode(self, obj, cls=None):
 try:
 encoded = json.dumps(obj, cls=cls)
 return encoded
 except TypeError as full_exception:
 if hasattr(obj, 'items'):
 item_errors = '; '.join(self._json_mapping_errors(obj))
 raise TypeError("dict had unencodable value at keys: {{{}}}".format(item_errors))
 elif is_list_like(obj):
 element_errors = '; '.join(self._json_list_errors(obj))
 raise TypeError("list had unencodable value at index: [{}]".format(element_errors))
 else:
 raise full_exception

 def json_decode(self, json_str):
 try:
 decoded = json.loads(json_str)
 return decoded
 except json.decoder.JSONDecodeError as exc:
 err_msg = 'Could not decode {} because of {}.'.format(repr(json_str), exc)
 # Calling code may rely on catching JSONDecodeError to recognize bad json
 # so we have to re-raise the same type.
 raise json.decoder.JSONDecodeError(err_msg, exc.doc, exc.pos)

 def json_encode(self, obj, cls=None):
 try:
 return self._friendly_json_encode(obj, cls=cls)
 except TypeError as exc:
 raise TypeError("Could not encode to JSON: {}".format(exc))


def to_4byte_hex(hex_or_str_or_bytes):
 size_of_4bytes = 4 * 8
 byte_str = hexstr_if_str(to_bytes, hex_or_str_or_bytes)
 if len(byte_str) > 4:
 raise ValueError(
 'expected value of size 4 bytes. Got: %d bytes' % len(byte_str)
 )
 hex_str = encode_hex(byte_str)
 return pad_hex(hex_str, size_of_4bytes)


class DynamicArrayPackedEncoder(BaseArrayEncoder):
 is_dynamic = True

 def encode(self, value):
 encoded_elements = self.encode_elements(value)
 encoded_value = encoded_elements

 return encoded_value


# TODO: Replace with eth-abi packed encoder once web3 requires eth-abi>=2
def encode_single_packed(_type, value):
 import codecs
 from eth_abi import (
 grammar as abi_type_parser,
 )
 from eth_abi.registry import has_arrlist, registry
 abi_type = abi_type_parser.parse(_type)
 if has_arrlist(_type):
 item_encoder = registry.get_encoder(abi_type.item_type.to_type_str())
 if abi_type.arrlist[-1] != 1:
 return DynamicArrayPackedEncoder(item_encoder=item_encoder).encode(value)
 else:
 raise NotImplementedError(
 "Fixed arrays are not implemented in this packed encoder prototype")
 elif abi_type.base == "string":
 return codecs.encode(value, 'utf8')
 elif abi_type.base == "bytes":
 return value


class Web3JsonEncoder(json.JSONEncoder):
 def default(self, obj):
 if isinstance(obj, AttributeDict):
 return {k: v for k, v in obj.items()}
 if isinstance(obj, HexBytes):
 return obj.hex()
 return json.JSONEncoder.default(self, obj)


def to_json(obj):
 '''
 Convert a complex object (like a transaction object) to a JSON string
 '''
 return FriendlyJsonSerde().json_encode(obj, cls=Web3JsonEncoder)