from src.application.abstractions import IUnitOfWork
from src.application.contracts import IHashService, ILogger, ICache
from src.application.domain.exceptions import ApplicationException
from src.infrastructure.database.decorators import transactional


class ChangeEmailCompleteCommand:
    def __init__(
        self,
        unit_of_work: IUnitOfWork,
        hash_service: IHashService,
        cache: ICache,
        logger: ILogger,
    ):
        self._unit_of_work = unit_of_work
        self._hash_service = hash_service
        self._cache = cache
        self._logger = logger

    @transactional
    async def __call__(self, *, user_id: str, code: str) -> bool:
        code = (code or '').strip()

        NEW_USER_PREFIX = 'change_email:new_user:'
        NEW_CODE_PREFIX = 'change_email:new_code:'

        new_user_key = f'{NEW_USER_PREFIX}{user_id}'
        new_code_key = f'{NEW_CODE_PREFIX}{code}'

        cached_user_id = await self._cache.get(new_code_key)
        if not cached_user_id:
            self._logger.info(f'Change email complete failed: code not found (user_id={user_id})')
            raise ApplicationException(400, 'Invalid or expired code')

        if cached_user_id != user_id:
            self._logger.info(f'Change email complete failed: code-user mismatch (user_id={user_id})')
            raise ApplicationException(400, 'Invalid or expired code')

        raw_value = await self._cache.get(new_user_key)
        if not raw_value:
            self._logger.info(f'Change email complete failed: user key missing (user_id={user_id})')
            raise ApplicationException(400, 'Invalid or expired code')

        separator_idx = raw_value.index(':')
        code_hash = raw_value[:separator_idx]
        new_email = raw_value[separator_idx + 1:]

        ok = await self._hash_service.verify(hashed_value=code_hash, plain_value=code)
        if not ok:
            self._logger.info(f'Change email complete failed: code hash mismatch (user_id={user_id})')
            raise ApplicationException(400, 'Invalid or expired code')

        user = await self._unit_of_work.user_repository.set_email(user_id=user_id, email=new_email)
        await self._cache.set_user(user_id, user)

        try:
            await self._cache.delete(new_code_key)
            await self._cache.delete(new_user_key)
        except Exception as e:
            self._logger.warning(f'Change email complete cleanup failed (user_id={user_id}): {e}')

        self._logger.info(f'Email changed for user_id={user_id}')
        return True