from __future__ import annotations

from datetime import UTC, datetime
from enum import StrEnum
from typing import Any

from sqlalchemy import (
    JSON,
    DateTime,
    Float,
    ForeignKey,
    Integer,
    String,
)
from sqlalchemy import (
    Enum as SAEnum,
)
from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column, relationship


def utcnow() -> datetime:
    return datetime.now(UTC)


class Base(DeclarativeBase):
    pass


class PositionSide(StrEnum):
    LONG = "long"
    SHORT = "short"


class PositionStatus(StrEnum):
    OPEN = "open"
    CLOSED = "closed"


class OrderSide(StrEnum):
    BUY = "buy"
    SELL = "sell"


class StrategyConfig(Base):
    __tablename__ = "strategy_configs"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    name: Mapped[str] = mapped_column(String(80), default="")
    strategy_key: Mapped[str] = mapped_column(String(64), index=True)
    symbol: Mapped[str] = mapped_column(String(32))
    timeframe: Mapped[str] = mapped_column(String(16))
    params: Mapped[dict[str, Any]] = mapped_column(JSON, default=dict)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)


class Position(Base):
    __tablename__ = "positions"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    strategy_key: Mapped[str] = mapped_column(String(64), index=True)
    symbol: Mapped[str] = mapped_column(String(32), index=True)
    side: Mapped[PositionSide] = mapped_column(SAEnum(PositionSide))
    qty: Mapped[float] = mapped_column(Float)
    entry_price: Mapped[float] = mapped_column(Float)
    status: Mapped[PositionStatus] = mapped_column(
        SAEnum(PositionStatus), default=PositionStatus.OPEN, index=True
    )
    stop_loss: Mapped[float | None] = mapped_column(Float, nullable=True)
    take_profit: Mapped[float | None] = mapped_column(Float, nullable=True)
    trailing_stop_pct: Mapped[float] = mapped_column(Float, default=0.0)
    entry_fee: Mapped[float] = mapped_column(Float, default=0.0)
    exit_price: Mapped[float | None] = mapped_column(Float, nullable=True)
    exit_fee: Mapped[float] = mapped_column(Float, default=0.0)
    realized_pnl: Mapped[float | None] = mapped_column(Float, nullable=True)
    opened_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)
    closed_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)

    orders: Mapped[list[Order]] = relationship(back_populates="position")


class Order(Base):
    __tablename__ = "orders"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    position_id: Mapped[int | None] = mapped_column(
        ForeignKey("positions.id"), nullable=True, index=True
    )
    strategy_key: Mapped[str] = mapped_column(String(64), index=True)
    symbol: Mapped[str] = mapped_column(String(32))
    side: Mapped[OrderSide] = mapped_column(SAEnum(OrderSide))
    qty: Mapped[float] = mapped_column(Float)
    price: Mapped[float] = mapped_column(Float)
    fee: Mapped[float] = mapped_column(Float, default=0.0)
    reason: Mapped[str] = mapped_column(String(255), default="")
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=utcnow, index=True
    )

    position: Mapped[Position | None] = relationship(back_populates="orders")


class EquitySnapshot(Base):
    __tablename__ = "equity_snapshots"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    equity: Mapped[float] = mapped_column(Float)
    cash: Mapped[float] = mapped_column(Float)
    price: Mapped[float] = mapped_column(Float)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=utcnow, index=True
    )


class Event(Base):
    __tablename__ = "events"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    level: Mapped[str] = mapped_column(String(16), default="info")
    message: Mapped[str] = mapped_column(String(512))
    strategy_key: Mapped[str | None] = mapped_column(String(64), nullable=True, index=True)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=utcnow, index=True
    )