"""Monthly per-user usage tracking model.

One row per user per calendar month. Tracks granular counts for each
billable metric so the usage endpoint and admin dashboard can report
accurate numbers.
"""
from __future__ import annotations

from datetime import datetime

from sqlalchemy import DateTime, Float, Integer, String, UniqueConstraint, func
from sqlalchemy.orm import Mapped, mapped_column

from app.core.database import Base
from app.utils.ids import prefixed_id


class UserUsageMonthly(Base):
    __tablename__ = "user_usage_monthly"
    __table_args__ = (
        UniqueConstraint("user_id", "month", name="uq_user_usage_monthly_user_month"),
    )

    id: Mapped[str] = mapped_column(
        String(40),
        primary_key=True,
        default=lambda: prefixed_id("usg"),
    )
    user_id: Mapped[str] = mapped_column(
        String(40),
        index=True,
        nullable=False,
    )
    month: Mapped[str] = mapped_column(
        String(7),  # YYYY-MM
        nullable=False,
    )

    documents_uploaded_count: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    generations_count: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    quizzes_generated_count: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    flashcards_generated_count: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    videos_generated_count: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    audio_minutes_generated: Mapped[float] = mapped_column(Float, default=0.0, nullable=False)
    storage_bytes_used: Mapped[int] = mapped_column(Integer, default=0, nullable=False)

    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        server_default=func.now(),
        nullable=False,
    )
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        server_default=func.now(),
        onupdate=func.now(),
        nullable=False,
    )