import logging
import re
from decimal import Decimal

from .data import (
    CURRENCY_CODES,
    CURRENCY_SYMBOLS,
    Asset,
    AssetAmount,
    FiatCurrency,
)

logger = logging.getLogger(__name__)

RE_PRICE_RAW = r'\b(?:dkk|sek|usd|nok|eur)?\s*([1-9][\d.]*[\d](?:,\d+)?)\s*(?:,-|:-|.-|;-)?\s*(?:(?:kr|kroner|krone|dkk|sek|usd|eur|nok)\b)?\.?'

RE_PRICE = re.compile(RE_PRICE_RAW, flags=re.IGNORECASE)

RE_PRODUCT_PRICE_DK = r'-?[1-9]\d{0,2}(?:\.?\d{3})*(?:,\d\d\.?)?'
RE_PRODUCT_PRICE_EN = r'-?[1-9]\d{0,2}(?:,?\d{3})*(?:\.\d\d)?'
RE_PRODUCT_PRICE_AMOUNT = r'(?P<amount>'  + RE_PRODUCT_PRICE_DK + '|' + RE_PRODUCT_PRICE_EN + ')'


def parse_amount(price: str) -> Decimal:
    if re.fullmatch(RE_PRODUCT_PRICE_DK, price):
        price = price.replace('.', '').replace(',', '.')
    else:
        price = price.replace(',', '')
    return Decimal(price)


RE_CURRENCY_CODES = '(?P<code>' + '|'.join(re.escape(c) for c in CURRENCY_CODES) + ')'

RE_CURRENCY_SYMBOLS = (
    r'(?P<sym>[' + ''.join(re.escape(c) for c in CURRENCY_SYMBOLS.values()) + '])'
)

RE_SYM_AMOUNT_CODE = re.compile(
    RE_CURRENCY_SYMBOLS
    + r'\s*'
    + RE_PRODUCT_PRICE_AMOUNT
    + r'(?:\s*'
    + RE_CURRENCY_CODES
    + r')?',
    flags=re.IGNORECASE,
)

RE_CODE_AMOUNT = re.compile(
    RE_CURRENCY_CODES
    + r'\s*'
    + RE_PRODUCT_PRICE_AMOUNT,
    flags=re.IGNORECASE,
)

RE_AMOUNT_SYM_CODE = re.compile(
    RE_PRODUCT_PRICE_AMOUNT
    + r'\s*'
    + RE_CURRENCY_SYMBOLS
    + r'(?:\s+'
    + RE_CURRENCY_CODES
    + ')?',
    flags=re.IGNORECASE,
)

RE_AMOUNT_CODE = re.compile(
    RE_PRODUCT_PRICE_AMOUNT + r'\s+' + RE_CURRENCY_CODES,
    flags=re.IGNORECASE,
)

RE_KR_AMOUNT = re.compile(
    r'kr\.?\s*(' + RE_PRODUCT_PRICE_AMOUNT + ')',
    flags=re.IGNORECASE,
)

RE_AMOUNT_KR = re.compile(
    '(' + RE_PRODUCT_PRICE_AMOUNT + r')\s*kr\.?',
    flags=re.IGNORECASE,
)

RE_AMOUNT_SUFFIX = re.compile(
    '(' + RE_PRODUCT_PRICE_AMOUNT + r')\s*(?:;-|,-|\.-)?',
    flags=re.IGNORECASE,
)


def parse_price(text: str, default_currency: Asset) -> AssetAmount | None:
    """
    Attempts to parse price from the given text.

    Text does not need to be stripped beforehand.
    """
    if isinstance(text, AssetAmount):
        return text
    text = str(text).lower().strip()

    if text == 'free':
        return AssetAmount(default_currency, Decimal(0))

    code, sym, amount_text = None, None, None

    if m := RE_SYM_AMOUNT_CODE.fullmatch(text):
        code, sym, amount_text = m.group('code'), m.group('sym'), m.group('amount')
    elif m := RE_CODE_AMOUNT.fullmatch(text):
        code, amount_text = m.group('code'), m.group('amount')
    elif m := RE_AMOUNT_SYM_CODE.fullmatch(text):
        code, sym, amount_text = m.group('code'), m.group('sym'), m.group('amount')
    elif m := RE_AMOUNT_CODE.fullmatch(text):
        code, amount_text = m.group('code'), m.group('amount')
    elif m := (RE_KR_AMOUNT.fullmatch(text) or RE_AMOUNT_KR.fullmatch(text) or RE_AMOUNT_SUFFIX.fullmatch(text)):
        code, amount_text = 'DKK', m.group('amount')
    else:
        return None

    currency = (
        CURRENCY_CODES[code.upper()] if code else FiatCurrency.from_currency_symbol(sym)
    )
    assert currency is not None
    return AssetAmount(currency, parse_amount(amount_text))