from sqlalchemy import Column, Integer, String, Numeric, DateTime, ForeignKey, Boolean, JSON, Enum as SQLEnum
from sqlalchemy.orm import relationship
from app.db.base_class import Base
from app.models.enums import SplitTypeEnum, ExpenseOverallStatusEnum, ExpenseSplitStatusEnum

class RecurrencePattern(Base):
    __tablename__ = "recurrence_patterns"

    id = Column(Integer, primary_key=True, index=True)
    type = Column(String, nullable=False)  # 'daily', 'weekly', 'monthly', 'yearly'
    interval = Column(Integer, nullable=False)
    days_of_week = Column(JSON, nullable=True)  # For weekly recurrence
    end_date = Column(DateTime, nullable=True)
    max_occurrences = Column(Integer, nullable=True)
    created_at = Column(DateTime, nullable=False)
    updated_at = Column(DateTime, nullable=False)

    # Relationship
    expense = relationship("Expense", back_populates="recurrence_pattern", uselist=False)

class Expense(Base):
    __tablename__ = "expenses"

    # ... existing columns ...

    # New columns for recurring expenses
    is_recurring = Column(Boolean, default=False, nullable=False)
    next_occurrence = Column(DateTime, nullable=True)
    last_occurrence = Column(DateTime, nullable=True)
    recurrence_pattern_id = Column(Integer, ForeignKey("recurrence_patterns.id"), nullable=True)
    
    # New relationship
    recurrence_pattern = relationship("RecurrencePattern", back_populates="expense", uselist=False)
    generated_expenses = relationship("Expense", 
                                    backref=relationship("parent_expense", remote_side=[id]),
                                    foreign_keys="Expense.parent_expense_id")
    parent_expense_id = Column(Integer, ForeignKey("expenses.id"), nullable=True)

    # ... rest of existing code ...