import re
from abc import ABC
from abc import abstractmethod
from datetime import datetime
from decimal import Decimal
from email.message import EmailMessage
from email.message import Message
from uuid import UUID

from model import Transaction


class TransactionParser(ABC):
    @abstractmethod
    def match(self, msg: Message) -> bool:
        pass

    @abstractmethod
    def extract(self, msg: EmailMessage) -> Transaction:
        pass


class TransactionParsingFailed(Exception):
    pass


class RogersBankParser(TransactionParser):
    EXTRACT_RE = re.compile(
        r"Attempt of \$(\d+\.\d{2}) was made on ([A-z]{3} \d{1,2}, \d{4})[^<]*at ([^<]+) in"
    )

    def __init__(self, account_id: UUID):
        self.account_id = account_id

    def match(self, msg: Message) -> bool:
        return (
            msg["From"] == "Rogers Bank <onlineservices@RogersBank.com>"
            and msg["Subject"] == "Purchase amount alert"
        )

    def extract(self, msg: EmailMessage) -> Transaction:
        body = msg.get_body()
        if body is None:
            raise TransactionParsingFailed("No body of message found")
        matches = self.EXTRACT_RE.search(body.as_string())
        if matches is None:
            raise TransactionParsingFailed("No matches for extraction RE")
        amount = Decimal(matches[1])
        date_raw = matches[2]
        payee = matches[3]
        date = datetime.strptime(date_raw, "%b %d, %Y").date()
        return Transaction(
            account=self.account_id,
            date=date,
            amount=amount,
            payee=payee,
            notes="via email",
            imported_id=msg["Message-ID"],
        )


class MBNAParser(TransactionParser):
    EXTRACT_RE = re.compile(
        r"A purchase of \$(\d+\.\d{2}) from ([^<]+) was made at (\d{1,2}:\d{2} (AM|PM)) UTC on (\d{4}-\d{2}-\d{2})"  # noqa: E501
    )

    def __init__(self, account_id: UUID):
        self.account_id = account_id

    def match(self, msg: Message):
        return (
            msg["From"] == "MBNA Notifications <noreply@mbna.ca>"
            and msg["Subject"] == "MBNA - Transaction Alert"
        )

    def extract(self, msg: EmailMessage) -> Transaction:
        body = msg.get_body()
        if body is None:
            raise TransactionParsingFailed("No body of message found")
        matches = self.EXTRACT_RE.search(body.as_string())
        if matches is None:
            raise TransactionParsingFailed("No matches for extraction RE")
        amount = Decimal(matches[1])
        payee = matches[2]
        date = matches[5]
        return Transaction(
            account=self.account_id,
            date=date,
            amount=amount,
            payee=payee,
            notes="via email",
            imported_id=msg["Message-ID"],
        )