from __future__ import annotations

from datetime import datetime

from sqlalchemy import DateTime, ForeignKey, Index, Integer, String
from sqlalchemy.orm import Mapped, mapped_column

from app.enums.llm_billing import LlmCallAttemptStatus
from app.models.base import Base, TimestampMixin


class LlmCallAttempt(Base, TimestampMixin):
    __tablename__ = "llm_call_attempts"
    __table_args__ = (
        Index("uq_llm_call_attempts_sequence", "billing_execution_id", "call_sequence", unique=True),
        Index("ix_llm_call_attempts_execution_time", "billing_execution_id", "created_at"),
        Index("ix_llm_call_attempts_provider_request", "provider_request_id"),
    )

    id: Mapped[str] = mapped_column(String(32), primary_key=True)
    billing_execution_id: Mapped[str] = mapped_column(
        String(32), ForeignKey("llm_billing_executions.id", ondelete="CASCADE"), nullable=False
    )
    call_sequence: Mapped[int] = mapped_column(nullable=False)
    retry_sequence: Mapped[int] = mapped_column(nullable=False, default=0, server_default="0")
    model_config_id: Mapped[str | None] = mapped_column(
        String(32), ForeignKey("model_configs.id", ondelete="SET NULL"), nullable=True
    )
    model_name_snapshot: Mapped[str | None] = mapped_column(String(128), nullable=True)
    provider_snapshot: Mapped[str | None] = mapped_column(String(64), nullable=True)
    provider_request_id: Mapped[str | None] = mapped_column(String(160), nullable=True)
    request_started_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
    response_received_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    duration_ms: Mapped[int | None] = mapped_column(Integer, nullable=True)
    status: Mapped[str] = mapped_column(
        String(24), nullable=False, default=LlmCallAttemptStatus.STARTED.value,
        server_default=LlmCallAttemptStatus.STARTED.value,
    )
    input_tokens: Mapped[int | None] = mapped_column(Integer, nullable=True)
    output_tokens: Mapped[int | None] = mapped_column(Integer, nullable=True)
    total_tokens: Mapped[int | None] = mapped_column(Integer, nullable=True)
    token_usage_id: Mapped[str | None] = mapped_column(
        String(32), ForeignKey("token_usage.id", ondelete="SET NULL"), nullable=True
    )
    http_status: Mapped[int | None] = mapped_column(Integer, nullable=True)
    provider_error_code: Mapped[str | None] = mapped_column(String(128), nullable=True)
    error_message: Mapped[str | None] = mapped_column(String(1000), nullable=True)
    token_unavailable_reason: Mapped[str | None] = mapped_column(String(256), nullable=True)
    postprocess_status: Mapped[str | None] = mapped_column(String(32), nullable=True)
    postprocess_error: Mapped[str | None] = mapped_column(String(1000), nullable=True)