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# Source code for schwifty.iban

    from __future__ import annotations

    import re
    import string
    from typing import Any
    from typing import TYPE_CHECKING

    from pycountry import countries  # type: ignore
    from pycountry.db import Data  # type: ignore

    from schwifty import common
    from schwifty import exceptions
    from schwifty import registry
    from schwifty.bic import BIC
    from schwifty.checksum import algorithms
    from schwifty.checksum import InputType

    if TYPE_CHECKING:
        from pydantic import GetCoreSchemaHandler
        from pydantic_core import CoreSchema

    _spec_to_re: dict[str, str] = {"n": r"\d", "a": r"[A-Z]", "c": r"[A-Za-z0-9]", "e": r" "}

    _alphabet: str = string.digits + string.ascii_uppercase

    def _get_iban_spec(country_code: str) -> dict:
        try:
            spec = registry.get("iban")
            assert isinstance(spec, dict)
            return spec[country_code]
        except KeyError as e:
            raise exceptions.InvalidCountryCode(f"Unknown country-code '{country_code}'") from e

    def numerify(value: str) -> int:
        return int("".join(str(_alphabet.index(c)) for c in value))

    def calc_checksum(value: str) -> str:
        return f"{98 - (numerify(value) * 100) % 97:02d}"

    def code_length(spec: dict[str, Any], code_type: str) -> int:
        start, end = spec["positions"][code_type]
        return end - start

    def add_bban_checksum(country_code: str, bban: str) -> str:
        if country_code in ["IT", "SM"]:
            # The IBAN of San Marino is covered by the Italian IBAN and uses the same checksum
            checksum = algorithms["IT:default"].compute(bban[1:])
            bban = checksum + bban[1:]
        elif country_code == "BE":
            # The Belgian BBAN format is XXXYYYYYYYZZ where:
            # - XXX: bank code
            # - YYYYYYY: account number
            # - ZZ: mod 97 remainder of XXYYYYYYY
            # The bban passed to this function has this format XXX00YYYYY
            bban = bban[:3] + bban[5:]
            checksum = algorithms["BE:default"].compute(bban)
            bban = bban + checksum
        elif country_code == "FR":
            checksum = algorithms["FR:default"].compute(bban)
            bban = bban[0:21] + checksum
        return bban

    class IBAN(common.Base):
        """The IBAN object.

        Examples:

            You create a new IBAN object by supplying an IBAN code in text form. The IBAN
            is validated behind the scenes and you can then access all relevant components
            as properties::

                >>> iban = IBAN('DE89 3704 0044 0532 0130 00')
                >>> iban.account_code
                '0532013000'
                >>> iban.bank_code
                '37040044'
                >>> iban.country_code
                'DE'
                >>> iban.checksum_digits
                '89'

        Args:
            iban (str): The IBAN code.
            allow_invalid (bool): If set to `True` IBAN validation is skipped on instantiation.
            validate_bban (bool): If set to `True` also check the country specific checksum of the BBAN.

        Raises:
            InvalidStructure: If the IBAN contains invalid characters or the BBAN does not match the
                              country specific format.
            InvalidChecksumDigits: If the IBAN's checksum is invalid.
            InvalidLength: If the length does not match the country specific specification.

        .. versionchanged:: 2021.05.1
            Added the `validate_bban` parameter that controls if the country specific checksum within
            the BBAN is also validated.
        .. versionchanged:: 2023.10.0
            The :class:`.IBAN` is now a subclass of :class:`str` and supports all its methods.

        """

        def __init__(self, iban: str, allow_invalid: bool = False, validate_bban: bool = False) -> None:
            super().__init__()
            if not allow_invalid:
                self.validate(validate_bban)

        @classmethod
        def generate(
            cls, country_code: str, bank_code: str, account_code: str, branch_code: str = ""
        ) -> IBAN:
            """Generate an IBAN from it's components.

            If the bank-code and/or account-number have less digits than required by their
            country specific representation, the respective component is padded with zeros.

            Examples:

                To generate an IBAN do the following::

                    >>> bank_code = '37040044'
                    >>> account_code = '532013000'
                    >>> iban = IBAN.generate('DE', bank_code, account_code)
                    >>> iban.formatted
                    'DE89 3704 0044 0532 0130 00'

            Args:
                country_code (str): The ISO 3166 alpha-2 country code.
                bank_code (str): The country specific bank-code.
                account_code (str): The customer specific account-code.

            .. versionchanged:: 2020.08.3
                Added the `branch_code` parameter to allow the branch code (or sort code) to be
                specified independently.

            .. versionchanged:: 2021.05.2
                Added support for generating the country specific checksum of the BBAN for Belgian
                banks.
            """
            spec: dict[str, Any] = _get_iban_spec(country_code)
            bank_code_length: int = code_length(spec, "bank_code")
            branch_code_length: int = code_length(spec, "branch_code")
            account_code_length: int = code_length(spec, "account_code")

            country_code = common.clean(country_code)
            bank_code = common.clean(bank_code)
            account_code = common.clean(account_code)
            branch_code = common.clean(branch_code)

            if len(bank_code) == bank_code_length + branch_code_length:
                bank_code, branch_code = bank_code[:bank_code_length], bank_code[bank_code_length:]

            if len(bank_code) > bank_code_length:
                raise exceptions.InvalidBankCode(f"Bank code exceeds maximum size {bank_code_length}")

            if len(branch_code) > branch_code_length:
                raise exceptions.InvalidBranchCode(
                    f"Branch code exceeds maximum size {branch_code_length}"
                )

            if len(account_code) > account_code_length:
                raise exceptions.InvalidAccountCode(
                    f"Account code exceeds maximum size {account_code_length}"
                )

            bban = "0" * spec["bban_length"]
            positions = spec["positions"]
            components = {
                "bank_code": bank_code,
                "branch_code": branch_code,
                "account_code": account_code,
            }
            for key, value in components.items():
                end = positions[key][1]
                start = end - len(value)
                bban = bban[:start] + value + bban[end:]

            bban = add_bban_checksum(country_code, bban)
            return cls(country_code + calc_checksum(bban + country_code) + bban)

        def validate(self, validate_bban: bool = False) -> bool:
            """Validate the structural integrity of this IBAN.

            This function will verify the country specific format as well as the Luhn checksum in the
            3rd and 4th position of the IBAN. For some countries (currently Belgium, Germany and Italy)
            it will also verify the correctness of the country specific checksum within the BBAN if the
            `validate_bban` parameter is set to `True`. For German banks it will pick the appropriate
            algorithm based on the bank code and verify that the account code has the correct checksum.

            Note:
                You have to use the `allow_invalid` paramter when constructing the :class:`IBAN`-object
                to circumvent the implicit validation.

            Raises:
                InvalidStructure: If the IBAN contains invalid characters or the BBAN does not match the
                                  country specific format.
                InvalidChecksumDigits: If the IBAN's checksum is invalid.
                InvalidLength: If the length does not match the country specific specification.

            .. versionchanged:: 2021.05.1
                Added the `validate_bban` parameter that controls if the country specific checksum
                within the BBAN is also validated.
            """
            self._validate_characters()
            self._validate_length()
            self._validate_format()
            self._validate_iban_checksum()
            if validate_bban:
                self._validate_bban_checksum()
            return True

        def _validate_characters(self) -> None:
            if not re.match(r"[A-Z]{2}\d{2}[A-Z]*", self):
                raise exceptions.InvalidStructure(f"Invalid characters in IBAN {self!s}")

        def _validate_length(self) -> None:
            if self.spec["iban_length"] != len(self):
                raise exceptions.InvalidLength("Invalid IBAN length")

        def _validate_format(self) -> None:
            if not self.spec["regex"].match(self.bban):
                raise exceptions.InvalidStructure(
                    f"Invalid BBAN structure: '{self.bban}' doesn't match '{self.spec['bban_spec']}'"
                )

        def _validate_iban_checksum(self) -> None:
            if (
                self.numeric % 97 != 1
                or calc_checksum(self.bban + self.country_code) != self.checksum_digits
            ):
                raise exceptions.InvalidChecksumDigits("Invalid checksum digits")

        def _validate_bban_checksum(self) -> None:
            bank = self.bank or {}
            algo_name = bank.get("checksum_algo", "default")
            algo = algorithms.get(f"{self.country_code}:{algo_name}")
            if algo is None:
                return
            if algo.accepts == InputType.ACCOUNT_CODE:
                value = self.account_code
            elif algo.accepts == InputType.BBAN:
                value = self.bban
            else:
                raise exceptions.SchwiftyException("Unsupported checksum algorithm input type")
            if not algo.validate(value):
                raise exceptions.InvalidBBANChecksum("Invalid BBAN checksum")

        @property
        def is_valid(self) -> bool:
            """bool: Indicate if this is a valid IBAN.

            Note:
                You have to use the `allow_invalid` paramter when constructing the :class:`IBAN`-object
                to circumvent the implicit validation.

            Examples:
                >>> IBAN('AB1234567890', allow_invalid=True).is_valid
                False

            .. versionadded:: 2020.08.1
            """
            try:
                return self.validate()
            except exceptions.SchwiftyException:
                return False

        @property
        def numeric(self) -> int:
            """int: A numeric represenation of the IBAN."""
            return numerify(self.bban + self[:4])

        @property
        def formatted(self) -> str:
            """str: The IBAN formatted in blocks of 4 digits."""
            return " ".join(self[i : i + 4] for i in range(0, len(self), 4))

        @property
        def spec(self) -> dict[str, Any]:
            """dict: The country specific IBAN specification."""
            return _get_iban_spec(self.country_code)

        @property
        def bic(self) -> BIC | None:
            """BIC or None: The BIC associated to the IBAN's bank-code.

            If the bank code is not available in Schwifty's registry ``None`` is returned.

            .. versionchanged:: 2020.08.1
                Returns ``None`` if no appropriate :class:`BIC` can be constructed.
            """
            try:
                return BIC.from_bank_code(self.country_code, self.bank_code or self.branch_code)
            except exceptions.SchwiftyException:
                return None

        @property
        def country(self) -> Data | None:
            """Country: The country this IBAN is registered in."""
            return countries.get(alpha_2=self.country_code)

        def _get_code(self, code_type: str) -> str:
            start, end = self.spec["positions"][code_type]
            return self.bban[start:end]

        @property
        def bban(self) -> str:
            """str: The BBAN part of the IBAN."""
            return self._get_component(start=4)

        @property
        def country_code(self) -> str:
            """str: ISO 3166 alpha-2 country code."""
            return self._get_component(start=0, end=2)

        @property
        def checksum_digits(self) -> str:
            """str: Two digit checksum of the IBAN."""
            return self._get_component(start=2, end=4)

        @property
        def bank_code(self) -> str:
            """str: The country specific bank-code."""
            return self._get_code(code_type="bank_code")

        @property
        def branch_code(self) -> str:
            """str or None: The branch-code of the bank if available."""
            return self._get_code(code_type="branch_code")

        @property
        def account_code(self) -> str:
            """str: The customer specific account-code"""
            return self._get_code(code_type="account_code")

        @property
        def bank(self) -> dict | None:
            bank_registry = registry.get("bank_code")
            assert isinstance(bank_registry, dict)
            bank_entry = bank_registry.get((self.country_code, self.bank_code or self.branch_code))
            if not bank_entry:
                return None
            return bank_entry and bank_entry[0]

        @property
        def bank_name(self) -> str | None:
            """str or None: The name of the bank associated with the IBAN bank code.

            Examples:
                >>> IBAN('DE89370400440532013000').bank_name
                'Commerzbank'

            .. versionadded:: 2022.04.2
            """

            return None if self.bank is None else self.bank["name"]

        @property
        def bank_short_name(self) -> str | None:
            """str or None: The name of the bank associated with the IBAN bank code.

            Examples:
                >>> IBAN('DE89370400440532013000').bank_short_name
                'Commerzbank Köln'

            .. versionadded:: 2022.04.2
            """

            return None if self.bank is None else self.bank["short_name"]

        @classmethod
        def __get_pydantic_core_schema__(cls, source: Any, handler: GetCoreSchemaHandler) -> CoreSchema:
            from pydantic_core import core_schema

            return core_schema.union_schema(
                [
                    core_schema.is_instance_schema(IBAN),
                    core_schema.no_info_plain_validator_function(IBAN),
                ]
            )

    def add_bban_regex(country: str, spec: dict) -> dict:
        bban_spec = spec["bban_spec"]
        spec_re = r"(\d+)(!)?([{}])".format("".join(_spec_to_re.keys()))

        def convert(match: re.Match) -> str:
            quantifier = ("{%s}" if match.group(2) else "{1,%s}") % match.group(1)
            return _spec_to_re[match.group(3)] + quantifier

        spec["regex"] = re.compile(rf"^{re.sub(spec_re, convert, bban_spec)}$")
        return spec

    registry.manipulate("iban", add_bban_regex)