from sqlalchemy import and_, select, func
from sqlalchemy.orm import aliased

from transaction.models import Split, Transaction

class LedgerResource:
    @classmethod
    def get_ledger(cls, account_id, filters):
        split_account = aliased(Split)
        split_balance = aliased(Split)
        transaction_balance = aliased(Transaction)

        balance_stmt = select(func.sum(split_balance.amount)) \
            .join(transaction_balance) \
            .where(and_(
                split_balance.account_id == split_account.account_id,
                transaction_balance.sequence <= Transaction.sequence)
            ).scalar_subquery()

        stmt = select(Transaction,split_account,balance_stmt.label('balance')) \
            .join(
                split_account,
                and_(Transaction.id == split_account.transaction_id, split_account.account_id == account_id)
            )

        return filters.filter(stmt)