from datetime import datetime, timezone
from app.extensions import db
from sqlalchemy.exc import IntegrityError
from sqlalchemy import and_, or_, not_

class Transaction(db.Model):
    __tablename__ = 'transactions'
    id = db.Column(
        db.Integer,
        primary_key=True,
        autoincrement=True,
    )
    transaction_id = db.Column(db.String(50), nullable=False)
    account_id = db.Column(db.String(50), nullable=True)
    customer_id = db.Column(db.String(50), nullable=True)
    type = db.Column(db.String(50), nullable=False)
    channel = db.Column(db.String(50), nullable=False)
    created_at = db.Column(db.DateTime, default=datetime.now(timezone.utc))
    updated_at = db.Column(db.DateTime, default=datetime.now(timezone.utc), onupdate=datetime.now(timezone.utc))

    def __repr__(self):
        return f'<Transaction {self.id}>'

    @classmethod
    def create_transaction(cls, transaction_id, account_id, customer_id, type, channel):

        # if cls.query.filter_by(transaction_id=transaction_id).first():
        #     raise ValueError("Duplicate Transaction")

        if cls.query.filter( and_( cls.transaction_id ==transaction_id, cls.type==type) ).first():
            raise ValueError("Duplicate Transaction")

        transaction = cls(
            transaction_id = transaction_id,
            customer_id = customer_id,
            account_id = account_id,
            type = type,
            channel = channel
        )

        try:
            db.session.add(transaction)
        except IntegrityError as err:
            raise ValueError(f"Database integrity error: {err}")

        return transaction

    @classmethod
    def get_transaction_by_id(cls, transaction_id):
        return cls.query.get(transaction_id)

    @classmethod
    def get_all_transactions(cls, account_id=None, transaction_id=None, transaction_type=None, channel=None, start_date=None, end_date=None, page=1, limit=20):
        """
        Get all transactions with optional filtering

        Args:
            account_id (str, optional): Filter by account ID
            transaction_id (str, optional): Filter by transaction ID
            transaction_type (str, optional): Filter by transaction type
            channel (str, optional): Filter by channel
            start_date (datetime, optional): Filter by start date
            end_date (datetime, optional): Filter by end date

        Returns:
            list: List of Transaction objects
        """
        query = cls.query

        # Apply filters if provided
        if account_id:
            query = query.filter(cls.account_id == account_id)

        if transaction_id:
            query = query.filter(cls.transaction_id == transaction_id)

        if transaction_type:
            query = query.filter(cls.type == transaction_type)

        if channel:
            query = query.filter(cls.channel == channel)

        if start_date:
            query = query.filter(cls.created_at >= start_date)

        if end_date:
            query = query.filter(cls.created_at <= end_date)

        # Order by created_at descending (newest first)
        query = query.order_by(cls.created_at.desc())

        # Get total count before pagination
        total_count = query.count()

        # Apply pagination
        offset = (page - 1) * limit
        query = query.limit(limit).offset(offset)

        return query.all(), total_count