from datetime import datetime
from typing import TYPE_CHECKING

from sqlalchemy import (
    DateTime,
    Enum,
    ForeignKey,
    Index,
    Integer,
    String,
    func,
)
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.db.base import Base
from app.models.enums import OrderStatus, TicketStatus

if TYPE_CHECKING:
    from app.models.catalog import Event, TicketType


class Order(Base):
    __tablename__ = "orders"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    user_id: Mapped[int] = mapped_column(ForeignKey("users.id", ondelete="RESTRICT"), index=True)
    event_id: Mapped[int] = mapped_column(ForeignKey("events.id", ondelete="RESTRICT"), index=True)
    status: Mapped[OrderStatus] = mapped_column(Enum(OrderStatus), default=OrderStatus.pending, index=True)
    total_paise: Mapped[int] = mapped_column(Integer)
    currency: Mapped[str] = mapped_column(String(3), default="INR")
    payment_reference: Mapped[str | None] = mapped_column(String(128), nullable=True)
    provider_order_id: Mapped[str | None] = mapped_column(String(64), unique=True, nullable=True, index=True)
    provider_payment_id: Mapped[str | None] = mapped_column(String(64), nullable=True, index=True)
    idempotency_key: Mapped[str | None] = mapped_column(String(64), unique=True, nullable=True, index=True)
    expires_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True, index=True)
    paid_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        server_default=func.now(),
        onupdate=func.now(),
    )

    items: Mapped[list["OrderItem"]] = relationship(
        "OrderItem",
        back_populates="order",
        cascade="all, delete-orphan",
    )
    tickets: Mapped[list["Ticket"]] = relationship(
        "Ticket",
        back_populates="order",
        cascade="all, delete-orphan",
    )
    event: Mapped["Event"] = relationship("Event")


class OrderItem(Base):
    __tablename__ = "order_items"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    order_id: Mapped[int] = mapped_column(ForeignKey("orders.id", ondelete="CASCADE"), index=True)
    ticket_type_id: Mapped[int] = mapped_column(ForeignKey("ticket_types.id", ondelete="RESTRICT"), index=True)
    quantity: Mapped[int] = mapped_column(Integer)
    unit_price_paise: Mapped[int] = mapped_column(Integer)
    line_total_paise: Mapped[int] = mapped_column(Integer)

    order: Mapped["Order"] = relationship("Order", back_populates="items")
    ticket_type: Mapped["TicketType"] = relationship("TicketType")
    tickets: Mapped[list["Ticket"]] = relationship("Ticket", back_populates="order_item")


class Ticket(Base):
    __tablename__ = "tickets"
    __table_args__ = (Index("ix_tickets_user_status", "user_id", "status"),)

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    code: Mapped[str] = mapped_column(String(32), unique=True, index=True)
    order_id: Mapped[int] = mapped_column(ForeignKey("orders.id", ondelete="CASCADE"), index=True)
    order_item_id: Mapped[int] = mapped_column(ForeignKey("order_items.id", ondelete="CASCADE"), index=True)
    ticket_type_id: Mapped[int] = mapped_column(ForeignKey("ticket_types.id", ondelete="RESTRICT"), index=True)
    event_id: Mapped[int] = mapped_column(ForeignKey("events.id", ondelete="RESTRICT"), index=True)
    user_id: Mapped[int] = mapped_column(ForeignKey("users.id", ondelete="RESTRICT"), index=True)
    status: Mapped[TicketStatus] = mapped_column(Enum(TicketStatus), default=TicketStatus.valid, index=True)
    qr_token: Mapped[str] = mapped_column(String(64), unique=True, index=True)
    used_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())

    order: Mapped["Order"] = relationship("Order", back_populates="tickets")
    order_item: Mapped["OrderItem"] = relationship("OrderItem", back_populates="tickets")