"""AI usage tracking for quota enforcement and cost visibility.

Every AI API call is recorded here. Only rows with counts_toward_quota=True
and succeeded=True are counted against the user's monthly quota.
"""
import uuid
from datetime import datetime, timezone
from typing import Optional, Any

from sqlalchemy import String, DateTime, ForeignKey, Integer, Boolean, Numeric
from sqlalchemy.orm import Mapped, mapped_column
from sqlalchemy.dialects.postgresql import UUID, JSONB

from app.core.database import Base


class AIUsage(Base):
    __tablename__ = "ai_usage"

    id: Mapped[uuid.UUID] = mapped_column(
        UUID(as_uuid=True), primary_key=True, default=uuid.uuid4
    )
    user_id: Mapped[uuid.UUID] = mapped_column(
        UUID(as_uuid=True),
        ForeignKey("users.id", ondelete="CASCADE"),
        nullable=False,
        index=True,
    )
    account_id: Mapped[uuid.UUID] = mapped_column(
        UUID(as_uuid=True),
        ForeignKey("accounts.id", ondelete="CASCADE"),
        nullable=False,
        index=True,
    )
    conversation_id: Mapped[Optional[uuid.UUID]] = mapped_column(
        UUID(as_uuid=True),
        ForeignKey("ai_conversations.id", ondelete="SET NULL"),
        nullable=True,
    )
    generation_type: Mapped[str] = mapped_column(
        String(20),
        nullable=False,
        comment="scaffold | branch_detail | branch_suggest",
    )
    tier_at_time: Mapped[str] = mapped_column(
        String(20),
        nullable=False,
        comment="free | pro | team | enterprise",
    )
    input_tokens: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    output_tokens: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    estimated_cost_usd: Mapped[float] = mapped_column(
        Numeric(10, 6), nullable=False, default=0
    )
    succeeded: Mapped[bool] = mapped_column(Boolean, nullable=False, default=True)
    counts_toward_quota: Mapped[bool] = mapped_column(
        Boolean, nullable=False, default=False
    )
    error_code: Mapped[Optional[str]] = mapped_column(
        String(100), nullable=True
    )
    extra_data: Mapped[dict[str, Any]] = mapped_column(
        "metadata", JSONB, nullable=False, default=dict
    )
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        default=lambda: datetime.now(timezone.utc),
        index=True,
    )