from datetime import datetime, timezone
from app.extensions import db
from app.models.charge import Charge
from sqlalchemy.orm import relationship
from sqlalchemy.sql import func

class Offer(db.Model):
    __tablename__ = 'offers'

    id = db.Column(db.String, primary_key=True)
    product_id = db.Column(db.String, nullable=False)
    min_amount = db.Column(db.Float, nullable=False)
    max_amount = db.Column(db.Float, nullable=False)
    tenor = db.Column(db.Integer, nullable=False)
    schedule = db.Column(db.Integer, nullable=True)
    interest_rate = db.Column(db.Float, default=3.0)
    management_rate = db.Column(db.Float, default=1.0)
    insurance_rate = db.Column(db.Float, default=1.0)
    vat_rate = db.Column(db.Float, default=7.5)
    list_order = db.Column(db.Integer, nullable=True)
    max_daily_loans = db.Column(db.Integer, nullable=True)
    max_active_loans = db.Column(db.Integer, nullable=True)
    max_life_loans = db.Column(db.Integer, nullable=True)
    created_at = db.Column(db.DateTime(timezone=True), server_default=func.now())
    updated_at = db.Column(db.DateTime(timezone=True), server_default=func.now(), onupdate=func.now())

    charges = relationship(
        "Charge",
        primaryjoin="Offer.id == Charge.offer_id",
        foreign_keys="Charge.offer_id",
        back_populates="offer",
    )

    @classmethod
    def get_all_offers(cls):
        """
        Return all offers in dictionary format.
        """
        offers = cls.query.all()

        if not offers:
            raise ValueError(f"No available offers")        
        return offers
    
    @classmethod
    def is_valid_offer(cls, offer_id):
        offer = cls.query.filter_by(id=str(offer_id)).first()


        if not offer:
            return False
        return offer

    @classmethod
    def get_offer_by_id(cls, offer_id):
        """
        Return an offer by its ID.
        """
        offer = cls.query.filter_by(id=str(offer_id)).first()

        if not offer:
            raise ValueError(f"Offer with ID {offer_id} not found")
        return offer

    @classmethod
    def get_offer_by_product_id(cls, product_id):
        """
        Return an offer by its product ID.
        """
        offer = cls.query.filter_by(product_id=str(product_id)).first()

        if not offer:
            raise ValueError(f"Offer with Product ID {product_id} not found")
        return offer
    
    def to_dict(self):
        return {
            "offerId": self.id,
            "productId": self.product_id,
            "minAmount": self.min_amount,
            "maxAmount": self.max_amount,
            "tenor": self.tenor,
            "interest_rate": self.interest_rate,
            "management_rate": self.management_rate,
            "insurance_rate": self.insurance_rate,
            "vat_rate": self.vat_rate,
            "maxDailyLoans": self.max_daily_loans,
            "maxActiveLoans": self.max_active_loans,
            "maxLifeLoans": self.max_life_loans

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