"""SQLAlchemy models: User, Service, ServiceComponent, Transaction."""

from datetime import datetime, timezone

from sqlalchemy import (
    Column,
    Integer,
    String,
    Float,
    Boolean,
    DateTime,
    ForeignKey,
)
from sqlalchemy.orm import relationship

from database import Base


class User(Base):
    __tablename__ = "users"

    id = Column(Integer, primary_key=True, index=True)
    username = Column(String, unique=True, index=True, nullable=False)
    password_hash = Column(String, nullable=False)
    display_name = Column(String, nullable=False)
    role = Column(String, nullable=False, default="viewer")  # admin | viewer

    transactions = relationship("Transaction", back_populates="creator")


class Service(Base):
    __tablename__ = "services"

    id = Column(Integer, primary_key=True, index=True)
    name = Column(String, unique=True, nullable=False)
    description = Column(String, default="")
    sell_price = Column(Float, nullable=False)  # MAD/month — auto-computed from components
    cost_price = Column(Float, nullable=False)  # MAD/month — auto-computed from components
    active = Column(Boolean, default=True)

    transactions = relationship("Transaction", back_populates="service")
    components = relationship(
        "ServiceComponent",
        back_populates="service",
        cascade="all, delete-orphan",
        order_by="ServiceComponent.id",
    )

    def recompute_prices(self):
        """Update sell_price and cost_price from component totals."""
        self.sell_price = sum(
            (c.unit_sell * c.quantity) for c in self.components
        ) if self.components else 0.0
        self.cost_price = sum(
            (c.unit_cost * c.quantity) for c in self.components
        ) if self.components else 0.0


class ServiceComponent(Base):
    """A cost/sell component of a service offer (e.g. RAM, HDD, Transport)."""
    __tablename__ = "service_components"

    id = Column(Integer, primary_key=True, index=True)
    service_id = Column(Integer, ForeignKey("services.id"), nullable=False)
    name = Column(String, nullable=False)
    unit_cost = Column(Float, nullable=False, default=0.0)  # what we pay / unit
    unit_sell = Column(Float, nullable=False, default=0.0)  # what we charge / unit
    quantity = Column(Integer, nullable=False, default=1)
    notes = Column(String, default="")

    service = relationship("Service", back_populates="components")


class Transaction(Base):
    __tablename__ = "transactions"

    id = Column(Integer, primary_key=True, index=True)
    service_id = Column(Integer, ForeignKey("services.id"), nullable=False)
    quantity = Column(Integer, nullable=False, default=1)
    month = Column(String, nullable=False)  # YYYY-MM format
    notes = Column(String, default="")
    created_by = Column(Integer, ForeignKey("users.id"), nullable=False)
    created_at = Column(DateTime, default=lambda: datetime.now(timezone.utc))

    service = relationship("Service", back_populates="transactions")
    creator = relationship("User", back_populates="transactions")

    @property
    def revenue(self) -> float:
        """Calculated: quantity * service.sell_price"""
        return self.quantity * self.service.sell_price

    @property
    def cost(self) -> float:
        """Calculated: quantity * service.cost_price"""
        return self.quantity * self.service.cost_price