from __future__ import annotations

import uuid
from datetime import datetime
from decimal import Decimal
from typing import List

from sqlalchemy import String, Text, Integer, BigInteger, DateTime, Numeric, Enum, ForeignKey, Index, func
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.core.database import Base


class User(Base):
    __tablename__ = "users"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
    email: Mapped[str] = mapped_column(String(255), unique=True, nullable=False, index=True)
    password_hash: Mapped[str] = mapped_column(String(255), nullable=False)
    balance: Mapped[Decimal] = mapped_column(Numeric(16, 6), default=Decimal("0"))
    status: Mapped[str] = mapped_column(String(20), default="active")  # active / disabled
    created_at: Mapped[datetime] = mapped_column(DateTime, server_default=func.now())
    updated_at: Mapped[datetime] = mapped_column(DateTime, server_default=func.now(), onupdate=func.now())

    api_keys: Mapped[List[ApiKey]] = relationship(back_populates="user")
    transactions: Mapped[List[Transaction]] = relationship(back_populates="user")


class ApiKey(Base):
    __tablename__ = "api_keys"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
    user_id: Mapped[str] = mapped_column(String(36), ForeignKey("users.id"), nullable=False, index=True)
    name: Mapped[str] = mapped_column(String(100), default="")
    key_hash: Mapped[str] = mapped_column(String(64), unique=True, nullable=False)  # SHA256
    key_prefix: Mapped[str] = mapped_column(String(10), nullable=False)
    key_suffix: Mapped[str] = mapped_column(String(10), nullable=False)
    status: Mapped[str] = mapped_column(String(20), default="active")  # active / revoked
    created_at: Mapped[datetime] = mapped_column(DateTime, server_default=func.now())

    user: Mapped["User"] = relationship(back_populates="api_keys")


class UsageLog(Base):
    __tablename__ = "usage_logs"
    __table_args__ = (
        Index("ix_usage_user_time", "user_id", "request_time"),
        Index("ix_usage_model", "user_id", "model"),
    )

    id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=True)
    user_id: Mapped[str] = mapped_column(String(36), ForeignKey("users.id"), nullable=False)
    key_id: Mapped[str] = mapped_column(String(36), ForeignKey("api_keys.id"), nullable=False)
    model: Mapped[str] = mapped_column(String(100), nullable=False)
    prompt_tokens: Mapped[int] = mapped_column(Integer, default=0)
    completion_tokens: Mapped[int] = mapped_column(Integer, default=0)
    total_tokens: Mapped[int] = mapped_column(Integer, default=0)
    cost: Mapped[Decimal] = mapped_column(Numeric(16, 6), default=Decimal("0"))
    request_time: Mapped[datetime] = mapped_column(DateTime, nullable=False)
    response_time: Mapped[datetime] = mapped_column(DateTime, nullable=True)
    status: Mapped[str] = mapped_column(String(20), default="success")  # success / error


class Transaction(Base):
    __tablename__ = "transactions"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
    user_id: Mapped[str] = mapped_column(String(36), ForeignKey("users.id"), nullable=False, index=True)
    type: Mapped[str] = mapped_column(String(20), nullable=False)  # topup / consume / refund
    amount: Mapped[Decimal] = mapped_column(Numeric(16, 6), nullable=False)
    balance_after: Mapped[Decimal] = mapped_column(Numeric(16, 6), nullable=False)
    reference_id: Mapped[str] = mapped_column(String(100), default="")
    created_at: Mapped[datetime] = mapped_column(DateTime, server_default=func.now())

    user: Mapped["User"] = relationship(back_populates="transactions")


class ModelPricing(Base):
    __tablename__ = "models_pricing"

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    model_name: Mapped[str] = mapped_column(String(100), unique=True, nullable=False)
    provider: Mapped[str] = mapped_column(String(50), nullable=False)
    input_price_per_1k: Mapped[Decimal] = mapped_column(Numeric(16, 6), nullable=False)
    output_price_per_1k: Mapped[Decimal] = mapped_column(Numeric(16, 6), nullable=False)
    status: Mapped[str] = mapped_column(String(20), default="available")  # available / offline
    updated_at: Mapped[datetime] = mapped_column(DateTime, server_default=func.now(), onupdate=func.now())