"""Exchange rate CSV formatter."""

from decimal import Decimal, InvalidOperation

from abacus_common_data.currency import Currency

from royalties.constants.constants import EXCHANGE_RATE_BULK_COLUMNS
from royalties.constants.error import (
    ERROR_CSV_EMPTY_FIELDS,
    ERROR_CSV_MISSING_FIELDS,
    ERROR_CSV_RATE_INVALID,
    ERROR_CSV_UNKNOWN_CURRENCY,
)
from royalties.utils.csv_parser import CSVInputError


class ExchangeRateCSVRowParser:
    """Formatter for exchange rate CSV data."""

    def __init__(self, statement_period_id):
        """Set initial validation values."""
        self.statement_period_id = statement_period_id
        self.headers = EXCHANGE_RATE_BULK_COLUMNS

    def format(self, row, line_number, **kwargs):  #
        """Format data."""
        row_data = dict((el, None) for el in self.headers)
        if len(row) != len(row_data):
            raise CSVInputError(ERROR_CSV_MISSING_FIELDS, line_number)
        for field in row:
            if field is None:
                raise CSVInputError(ERROR_CSV_EMPTY_FIELDS, line_number)
        row_data[self.headers[0]] = self.statement_period_id
        row_data[self.headers[1]] = self.set_currency_code(row[1], line_number)
        row_data[self.headers[2]] = self.set_currency_code(row[2], line_number)
        row_data[self.headers[3]] = self.set_rate(row, line_number)
        return row_data

    def set_currency_code(self, value, line_number):
        """Set from_currency_code."""
        try:
            Currency(value)
        except KeyError:
            raise CSVInputError(
                ERROR_CSV_UNKNOWN_CURRENCY.format(code=value), line_number
            )
        return value

    def set_rate(self, row, line_number):
        """Set rate."""
        try:
            value = Decimal(row[3])
        except InvalidOperation:
            raise CSVInputError(ERROR_CSV_RATE_INVALID, line_number)
        if value <= 0:
            raise CSVInputError(ERROR_CSV_RATE_INVALID, line_number)
        return value


class ExchangeRateStandardFXParser(ExchangeRateCSVRowParser):
    """Formatter for standard FX rates sheet."""

    def format(self, row, line_number, header_values):  #
        """Format data."""
        if len(row) != len(header_values):
            raise CSVInputError(ERROR_CSV_MISSING_FIELDS, line_number)
        result = []
        for index, cell_value in enumerate(row):
            if index in (0, 1):
                # skip first two columns
                continue
            row_data = dict((el, None) for el in self.headers)
            if cell_value is None:
                raise CSVInputError(ERROR_CSV_EMPTY_FIELDS, line_number)
            row_data[self.headers[0]] = self.statement_period_id
            row_data[self.headers[1]] = self.set_currency_code(row[1], line_number)
            row_data[self.headers[2]] = self.set_currency_code(
                header_values[index], line_number
            )
            row_data[self.headers[3]] = self.set_rate(
                cell_value.replace(',', '.'), line_number
            )
            result.append(row_data)
        return result

    def set_rate(self, rate, line_number):
        """Set rate."""
        try:
            value = Decimal(rate)
        except InvalidOperation:
            raise CSVInputError(ERROR_CSV_RATE_INVALID, line_number)
        if value <= 0:
            raise CSVInputError(ERROR_CSV_RATE_INVALID, line_number)
        return value