backend/db/models.py

from sqlalchemy import Column, Integer, String, Float, DateTime, Text
from sqlalchemy.sql import func
from .database import Base

class LoanApplication(Base):
    __tablename__ = "loan_applications"

    id = Column(Integer, primary_key=True, index=True)
    applicant_name = Column(String, default="Applicant")
    
    # Financial Inputs (Stored as stringified JSON or separate columns, but columns are safer for SQLite)
    gender = Column(String)
    married = Column(String)
    dependents = Column(String)
    education = Column(String)
    self_employed = Column(String)
    applicant_income = Column(Float)
    coapplicant_income = Column(Float)
    loan_amount = Column(Float)
    loan_amount_term = Column(Float)
    credit_history = Column(Float)
    property_area = Column(String)
    
    # Processed Results
    prediction = Column(String) # "Y" or "N"
    confidence = Column(Float)
    dti_ratio = Column(Float)
    
    # AI & Explanation Outputs
    explanation_text = Column(Text, nullable=True)
    optimized_suggestion = Column(Text, nullable=True)
    feature_importance_json = Column(Text, nullable=True) # stringified JSON
    benchmarks_json = Column(Text, nullable=True) # stringified JSON
    
    created_at = Column(DateTime(timezone=True), server_default=func.now())